{"schemaVersion":2,"status":"Partial circulation reconstruction, not 1:1. A/C span floors 2-110; B spans above-ground floors 1-107, with no floor-2 exit. Plaza stair identities and positions corrected against A-A-22 on 2026-09-10; the erroneous concourse C volume is removed. WTC 2 stair B on77\u201385, outer A/C on77\u201381 and upper A/C on83\u201385 use original plans; the82 transition has separate plan/section review. Remaining bands retain earlier derivation. Transfer corridor envelopes are approximate, including unresolved floor-local elevations; the 66/68 jogs remain absent. Interior flights, landings, door clearances, cellar discharge and the separate floor-110 roof stair are not reconstructed. Cross-source sub-foot footprint intersections remain in the audit and must not be interpreted as verified clearances.","coordinateSystem":"Per-tower tower-centered feet: x east, z south (matches core_floor_plan.json). Vertical placement uses floorElevation() from floor-model.js; a band's shaft spans floorElevation(floors[0]) to floorElevation(floors[1] + 1). Transfer corridors span floorElevation(floor) to floorElevation(floor) + heightFt.","description":"Stairwell shaft footprints (enclosure rectangles) and horizontal transfer corridors for Stairwells A, B, C in WTC 1 and WTC 2. On transfer floors, enclosed 2-hour fire-rated transfer corridors connect offsetting vertical shafts. FEMA stair numbering maps 1->A, 2->C, 3->B.","sources":[{"report":"LERA PAC1 TOWER A architectural plans (sources/LERA - PLANS-022102/)","content":"29 sheets digitized: core plans A-A-20/22/38/45/50/59/66/73/81/90/105/113/124/131/A-A139/148/153/158/162/166/170/175 and full-floor plans A-A-48/65/70/72/74/76/78/123/130 (including transfer floor corridors on A-A-50, A-A-65, A-A-81, A-A-124, A-A139); drawing index analysis/stairwell-data/lera-drawing-index.json; per-sheet calibration and residuals in analysis/stairwell-data/wtc1_stair_digitization.json."},{"report":"NIST NCSTAR 1-7 \u2014 Occupant Behavior, Egress, and Emergency Communications","localPdf":"sources/NCSTAR1-7.pdf","url":"https://archive.org/details/occupantbehavior17aver","content":"Sec 2.2.2 stairwell widths/landings/transfer floors (printed pp. 27-31); Table 2-2 floor bands and qualitative layouts (pp. 20-23); Fig 7-1 WTC 2 floors 77-81 stair positions (p. 99) used to validate the WTC 2 rotation. Printed page = PDF page - 38."},{"report":"FEMA 403 Chapter 2 (sources/fema403/fema403_ch2.pdf)","content":"Stairway 1 additional transfer at floor 26 (text pp. 2-13/2-14); Fig 2-12 94th/95th floor egress plan corroborates the 82-110 arrangement."},{"report":"site/data/truss_layout.json core_column_registration","content":"Documents the WTC 2 = WTC 1 90-degree CCW core rotation ((x2,z2) = (z1,-x1)) on 47 registered core columns; basis of all WTC 2 stair positions."}],"stairwellMeta":{"A":{"femaNumber":1,"widthIn":44,"landingIn":[92,78],"servedRange":"floor 2 (plaza/mezzanine) to floor 110","notes":"East side of core in WTC 1; north side in WTC 2. Only stairwell passable in WTC 2 after impact (NCSTAR 1-7)."},"B":{"femaNumber":3,"widthIn":56,"landingIn":[116,78],"servedRange":"subgrade (B6) to floor 107; no exit at floor 2; single horizontal transfer at floor 76","notes":"North-center below floor 76, south-center above in WTC 1; east-center in WTC 2."},"C":{"femaNumber":2,"widthIn":44,"landingIn":[92,78],"servedRange":"floor 2 (plaza/mezzanine) to floor 110","notes":"West side of core in WTC 1; south side in WTC 2."}},"transferFloors":{"A":[26,42,48,66,68,76,82],"B":[76],"C":[42,48,66,68,76,82],"notes":"NCSTAR 1-7 sec 2.2.2 lists A/C transfers at 42, 48, 66, 68, 76, 82 and B only at 76; FEMA 403 ch2 adds Stairway 1 (A) at floor 26 (confirmed by LERA digitization: A jogs ~18 ft west between A-A-45 and A-A-59). The 66/68 jogs are below digitization read precision and not modeled. At 42-47 and 76-81, A and C move OUTSIDE the core envelope (long transfer corridors with smoke doors and right-angle turns)."},"towers":{"wtc1":{"derivation":"measured (LERA PAC1 TOWER A core plans; analysis/stairwell-data/wtc1_stair_digitization.json)","bands":[{"floors":[1,1],"evidenceType":"NCSTAR 1-7 p.27: only main Stair B reaches the concourse; A/C begin at plaza floor 2. A-A-20 central 'STAIR #3' is B, not C. Preserve B's alignment with floors 2-25 per NIST p.28 (B transfers only at 76); cellar exit geometry remains unresolved.","uncertaintyFt":4.0,"stairs":{"B":{"rectFt":[[1.6,-16.1],[12.2,-4.7]]}}},{"floors":[2,2],"evidenceType":"A-A-22 re-registered to column symbols 501/508/1001/1008 and LERA workbook coordinates; main STAIR #1 east = A, STAIR #2 west = C, central STAIR #3 = B. Source pixels and affine fit: analysis/tower-accuracy-review/plan-registration.json. B passes through floor 2 without a mezzanine exit; alignment with band 3-25 preserved (NCSTAR 1-7 pp.27-28).","uncertaintyFt":2.0,"stairs":{"A":{"rectFt":[[49.32,15.05],[62.7,23.15]]},"C":{"rectFt":[[-60.12,15.17],[-51.28,23.18]]},"B":{"rectFt":[[1.6,-16.1],[12.2,-4.7]]}}},{"floors":[3,25],"evidenceType":"LERA PAC1 TOWER A core plan A-A-45 (20th-23rd), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; A and C in south half of core north of PE 1-11, B north-center. Floors 3-8 assumed identical (core plans A-A-24..34 not yet digitized); 9-10 corroborated for B by A-A-38","uncertaintyFt":4.0,"stairs":{"A":{"rectFt":[[52.7,14.8],[60.9,23.5]]},"C":{"rectFt":[[-60.3,14.8],[-52.5,23.5]]},"B":{"rectFt":[[1.6,-16.1],[12.2,-4.7]]}}},{"floors":[26,41],"evidenceType":"LERA PAC1 TOWER A core plan A-A-59 (35th-39th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; Stairwell A jogged ~19 ft west at the floor-26 transfer documented by FEMA 403 ch2 (Stairway 1 transfer at 26); both A and C in south half","uncertaintyFt":3.0,"stairs":{"A":{"rectFt":[[33.9,14.5],[41.1,23.5]]},"C":{"rectFt":[[-60.4,14.5],[-53.2,23.5]]},"B":{"rectFt":[[-0.3,-13.8],[9.1,-1.8]]}}},{"floors":[42,47],"evidenceType":"LERA PAC1 TOWER A full-floor plans A-A-65/70/72/74/76/78 (42nd-47th) and core plan A-A-66 (Stair 3): Stairwells A and C transfer OUTSIDE the core envelope at the SOUTH end of the building (A southeast, C southwest; NCSTAR 1-7 sec 2.2.2 '>100 ft transfer corridors with right-angle turns'); six sheets agree within 2-5 ft, values from A-A-72 (44th skylobby, labeled); B in place north-center","uncertaintyFt":4.0,"stairs":{"A":{"rectFt":[[77.4,30.7],[85.8,39.3]]},"C":{"rectFt":[[-80.0,31.4],[-71.7,39.5]]},"B":{"rectFt":[[0.6,-16.4],[11.7,-3.6]]}}},{"floors":[48,48],"evidenceType":"LERA PAC1 TOWER A core plan A-A-81 (48th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; A and C transfer back inside the core in the south half (z +16.6..+25.6, NCSTAR 1-7); continuous shaft alignment clears local bank Z2C and south restaurant cars PE 7 / CE 6","uncertaintyFt":4.0,"stairs":{"A":{"rectFt":[[15.2,16.6],[22.5,25.6]]},"C":{"rectFt":[[-31.9,16.6],[-24.3,25.6]]},"B":{"rectFt":[[3.2,-16.1],[11.7,-6.1]]}}},{"floors":[49,75],"evidenceType":"LERA PAC1 TOWER A core plan A-A-90 (57th-58th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; corroborated by A-A-105 (66th) and A-A-113 (70th-71st); Stairs A and C run continuous in south half north of Row 900 (z +16.6..+25.6), B north-center in place; NCSTAR 1-7 Table 2-2 corroborates south half placement; 66-68 jog below read precision","uncertaintyFt":3.0,"stairs":{"A":{"rectFt":[[15.2,16.6],[22.5,25.6]]},"C":{"rectFt":[[-31.9,16.6],[-24.3,25.6]]},"B":{"rectFt":[[-0.9,-16.5],[9.2,-4.7]]}}},{"floors":[76,81],"evidenceType":"LERA PAC1 TOWER A full-floor plans A-A-123 (76th) and A-A-130 (78th skylobby): Stairwells A and C transfer OUTSIDE the core envelope at the NORTH end (A northeast, C northwest), sheets agree within ~3.5 ft, values from A-A-130 (labeled); Stairwell B shifts from north-center to south-center across floor 76 (core plan A-A-131, 78th). All three stairs transfer at floor 76 (NCSTAR 1-7 sec 2.2.2). Supersedes the A-A-124 core-plan corridor readings, which captured the transfer corridors, not the shafts","uncertaintyFt":4.0,"stairs":{"A":{"rectFt":[[73.0,-40.9],[81.8,-30.2]]},"C":{"rectFt":[[-79.6,-39.5],[-70.8,-28.9]]},"B":{"rectFt":[[4.0,14.5],[14.5,24.3]]}}},{"floors":[82,92],"evidenceType":"LERA PAC1 TOWER A core plan A-A-153 (96th-100th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; corroborated within 2-3 ft by A-A139 (82), A-A-148 (89-93), A-A-158 (103), A-A-162 (105), A-A-166 (107), A-A-170 (108). Stairwell B ends at 107 (A-A-170 shows no Stair 3 at 108); A/C end at 110 \u2014 the floor-110 roof-stair room (A-A-175, west end) is not separately modeled","uncertaintyFt":3.0,"stairs":{"A":{"rectFt":[[20.4,-23.1],[27.9,-14.3]]},"C":{"rectFt":[[-16.3,-22.8],[-9.0,-14.5]]},"B":{"rectFt":[[3.4,12.7],[14.4,21.6]],"endsAtFloor":92}}},{"floors":[93,93],"revision":"wtc1-impact-93-95-circulation-v1","uncertaintyFt":0.75,"evidenceType":"Original-plan stair enclosure/opening geometry and corroborated shared flights; Stair B eastern departure10+9 corrected in impact flight review","stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":93,"upperFloor":94,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2918,1250],"lastRiserPx":[2751,1250],"id":"lower","firstRiserFt":[26.774749559669317,-21.406822254154804],"lastRiserFt":[19.680533723008182,-21.42498273172442],"widthFt":3.6666666666666665,"goingFt":0.788248786791024,"nominalGoingDifferenceIn":-0.04101455850771174,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2751,1346],"lastRiserPx":[2900,1346],"id":"upper","firstRiserFt":[19.670155794732068,-17.344584083326914],"lastRiserFt":[25.999725613070453,-17.328381022501326],"widthFt":3.6666666666666665,"goingFt":0.7911988196757217,"nominalGoingDifferenceIn":-0.0056141638913391745,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[15.607178175746682,-23.305605001541437],[19.68529027346807,-23.295165445573275],[19.665074934013546,-15.346888911715638],[15.586962836292159,-15.3573284676838]],"sourcePixels":[[2655,1206],[2751,1206],[2751,1393],[2655,1393]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-148.tif","sha256":"d66fd3674acc3e45b30a2ecc0c95a11ff5030a3aac2897c5bd107242b7d53034","evidence":"A-A-148 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-150.tif","sha256":"a409006d00d769ac0dc152bc3e92176f5c6623164c049aff6ed630179c67b1ac","evidence":"A-A-150 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[148,150],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":93,"upperFloor":94,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[1945,1253],"lastRiserPx":[2115,1253],"id":"lower","firstRiserFt":[-14.558940074369502,-21.385119045944684],"lastRiserFt":[-7.337283234654578,-21.366632332251065],"widthFt":3.6666666666666665,"goingFt":0.8024089446375688,"nominalGoingDifferenceIn":0.12890733565082613,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2115,1346],"lastRiserPx":[1964,1346],"id":"upper","firstRiserFt":[-7.347336852672058,-17.41374614161598],"lastRiserFt":[-13.761867339712964,-17.4301666931909],"widthFt":3.6666666666666665,"goingFt":0.8018189380606299,"nominalGoingDifferenceIn":0.12182725672755801,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[-7.33252668419469,-23.23681504609992],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-7.352525816810115,-15.373546817417228]],"sourcePixels":[[2115,1209],[2187,1209],[2187,1394],[2115,1394]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-148.tif","sha256":"d66fd3674acc3e45b30a2ecc0c95a11ff5030a3aac2897c5bd107242b7d53034","evidence":"A-A-148 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-150.tif","sha256":"a409006d00d769ac0dc152bc3e92176f5c6623164c049aff6ed630179c67b1ac","evidence":"A-A-150 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[148,150],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":93,"upperFloor":94,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2555,2167],"lastRiserPx":[2555,1994],"id":"lower","firstRiserFt":[11.255257354439536,17.530011097554237],"lastRiserFt":[11.273959246020453,10.176792699921236],"widthFt":4.666666666666667,"goingFt":0.8170269089365321,"nominalGoingDifferenceIn":0.30432290723838484,"baseOffsetFt":0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2437,1994],"lastRiserPx":[2437,2148],"id":"upper","firstRiserFt":[6.261279792571273,10.16396074571037],"lastRiserFt":[6.244631865961679,16.70960024418136],"widthFt":4.666666666666667,"goingFt":0.8182075836604283,"nominalGoingDifferenceIn":0.3184910039251392,"baseOffsetFt":6.315789473684211,"topOffsetFt":12}],"intermediateLanding":{"polygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.567897300988733,10.182664950153324],[3.8399007345492038,10.157762259354271]],"sourcePixels":[[2380,1883],[2609,1883],[2609,1994],[2380,1994]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-148.tif","sha256":"d66fd3674acc3e45b30a2ecc0c95a11ff5030a3aac2897c5bd107242b7d53034","evidence":"A-A-148 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-150.tif","sha256":"a409006d00d769ac0dc152bc3e92176f5c6623164c049aff6ed630179c67b1ac","evidence":"A-A-150 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[148,150],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}}}},{"floors":[94,94],"revision":"wtc1-impact-93-95-circulation-v1","uncertaintyFt":0.75,"evidenceType":"Original-plan stair enclosure/opening geometry and corroborated shared flights; Stair B eastern departure10+9 corrected in impact flight review","stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":94,"upperFloor":95,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2918,1250],"lastRiserPx":[2751,1250],"id":"lower","firstRiserFt":[26.774749559669317,-21.406822254154804],"lastRiserFt":[19.680533723008182,-21.42498273172442],"widthFt":3.6666666666666665,"goingFt":0.788248786791024,"nominalGoingDifferenceIn":-0.04101455850771174,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2751,1346],"lastRiserPx":[2900,1346],"id":"upper","firstRiserFt":[19.670155794732068,-17.344584083326914],"lastRiserFt":[25.999725613070453,-17.328381022501326],"widthFt":3.6666666666666665,"goingFt":0.7911988196757217,"nominalGoingDifferenceIn":-0.0056141638913391745,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[15.607178175746682,-23.305605001541437],[19.68529027346807,-23.295165445573275],[19.665074934013546,-15.346888911715638],[15.586962836292159,-15.3573284676838]],"sourcePixels":[[2655,1206],[2751,1206],[2751,1393],[2655,1393]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-150.tif","sha256":"a409006d00d769ac0dc152bc3e92176f5c6623164c049aff6ed630179c67b1ac","evidence":"A-A-150 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-151.tif","sha256":"3f397507e6d692d9f4d7c9189fc0b4157edda65b6baae8581217984a6543307a","evidence":"A-A-151 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[150,151],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":94,"upperFloor":95,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[1945,1253],"lastRiserPx":[2115,1253],"id":"lower","firstRiserFt":[-14.558940074369502,-21.385119045944684],"lastRiserFt":[-7.337283234654578,-21.366632332251065],"widthFt":3.6666666666666665,"goingFt":0.8024089446375688,"nominalGoingDifferenceIn":0.12890733565082613,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2115,1346],"lastRiserPx":[1964,1346],"id":"upper","firstRiserFt":[-7.347336852672058,-17.41374614161598],"lastRiserFt":[-13.761867339712964,-17.4301666931909],"widthFt":3.6666666666666665,"goingFt":0.8018189380606299,"nominalGoingDifferenceIn":0.12182725672755801,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[-7.33252668419469,-23.23681504609992],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-7.352525816810115,-15.373546817417228]],"sourcePixels":[[2115,1209],[2187,1209],[2187,1394],[2115,1394]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-150.tif","sha256":"a409006d00d769ac0dc152bc3e92176f5c6623164c049aff6ed630179c67b1ac","evidence":"A-A-150 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-151.tif","sha256":"3f397507e6d692d9f4d7c9189fc0b4157edda65b6baae8581217984a6543307a","evidence":"A-A-151 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[150,151],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":94,"upperFloor":95,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2555,2167],"lastRiserPx":[2555,1994],"id":"lower","firstRiserFt":[11.255257354439536,17.530011097554237],"lastRiserFt":[11.273959246020453,10.176792699921236],"widthFt":4.666666666666667,"goingFt":0.8170269089365321,"nominalGoingDifferenceIn":0.30432290723838484,"baseOffsetFt":0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2437,1994],"lastRiserPx":[2437,2148],"id":"upper","firstRiserFt":[6.261279792571273,10.16396074571037],"lastRiserFt":[6.244631865961679,16.70960024418136],"widthFt":4.666666666666667,"goingFt":0.8182075836604283,"nominalGoingDifferenceIn":0.3184910039251392,"baseOffsetFt":6.315789473684211,"topOffsetFt":12}],"intermediateLanding":{"polygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.567897300988733,10.182664950153324],[3.8399007345492038,10.157762259354271]],"sourcePixels":[[2380,1883],[2609,1883],[2609,1994],[2380,1994]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-150.tif","sha256":"a409006d00d769ac0dc152bc3e92176f5c6623164c049aff6ed630179c67b1ac","evidence":"A-A-150 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-151.tif","sha256":"3f397507e6d692d9f4d7c9189fc0b4157edda65b6baae8581217984a6543307a","evidence":"A-A-151 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[150,151],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}}}},{"floors":[95,95],"revision":"wtc1-impact-93-95-circulation-v1","uncertaintyFt":0.75,"evidenceType":"Original-plan stair enclosure/opening geometry and corroborated shared flights; Stair B eastern departure10+9 corrected in impact flight review","stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":95,"upperFloor":96,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2918,1250],"lastRiserPx":[2751,1250],"id":"lower","firstRiserFt":[26.774749559669317,-21.406822254154804],"lastRiserFt":[19.680533723008182,-21.42498273172442],"widthFt":3.6666666666666665,"goingFt":0.788248786791024,"nominalGoingDifferenceIn":-0.04101455850771174,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2751,1346],"lastRiserPx":[2900,1346],"id":"upper","firstRiserFt":[19.670155794732068,-17.344584083326914],"lastRiserFt":[25.999725613070453,-17.328381022501326],"widthFt":3.6666666666666665,"goingFt":0.7911988196757217,"nominalGoingDifferenceIn":-0.0056141638913391745,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[15.607178175746682,-23.305605001541437],[19.68529027346807,-23.295165445573275],[19.665074934013546,-15.346888911715638],[15.586962836292159,-15.3573284676838]],"sourcePixels":[[2655,1206],[2751,1206],[2751,1393],[2655,1393]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-151.tif","sha256":"3f397507e6d692d9f4d7c9189fc0b4157edda65b6baae8581217984a6543307a","evidence":"A-A-151 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[151,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":95,"upperFloor":96,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[1945,1253],"lastRiserPx":[2115,1253],"id":"lower","firstRiserFt":[-14.558940074369502,-21.385119045944684],"lastRiserFt":[-7.337283234654578,-21.366632332251065],"widthFt":3.6666666666666665,"goingFt":0.8024089446375688,"nominalGoingDifferenceIn":0.12890733565082613,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2115,1346],"lastRiserPx":[1964,1346],"id":"upper","firstRiserFt":[-7.347336852672058,-17.41374614161598],"lastRiserFt":[-13.761867339712964,-17.4301666931909],"widthFt":3.6666666666666665,"goingFt":0.8018189380606299,"nominalGoingDifferenceIn":0.12182725672755801,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[-7.33252668419469,-23.23681504609992],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-7.352525816810115,-15.373546817417228]],"sourcePixels":[[2115,1209],[2187,1209],[2187,1394],[2115,1394]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-151.tif","sha256":"3f397507e6d692d9f4d7c9189fc0b4157edda65b6baae8581217984a6543307a","evidence":"A-A-151 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[151,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"A-A-153 circulation template corroborated on independent A-A-148/150/151 registrations; sourcePixels remain A-A-153 template pixels","uncertaintyFt":0.75,"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75},"reviewRevision":"wtc1-impact-93-95-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":95,"upperFloor":96,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2555,2167],"lastRiserPx":[2555,1994],"id":"lower","firstRiserFt":[11.255257354439536,17.530011097554237],"lastRiserFt":[11.273959246020453,10.176792699921236],"widthFt":4.666666666666667,"goingFt":0.8170269089365321,"nominalGoingDifferenceIn":0.30432290723838484,"baseOffsetFt":0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2437,1994],"lastRiserPx":[2437,2148],"id":"upper","firstRiserFt":[6.261279792571273,10.16396074571037],"lastRiserFt":[6.244631865961679,16.70960024418136],"widthFt":4.666666666666667,"goingFt":0.8182075836604283,"nominalGoingDifferenceIn":0.3184910039251392,"baseOffsetFt":6.315789473684211,"topOffsetFt":12}],"intermediateLanding":{"polygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.567897300988733,10.182664950153324],[3.8399007345492038,10.157762259354271]],"sourcePixels":[[2380,1883],[2609,1883],[2609,1994],[2380,1994]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-151.tif","sha256":"3f397507e6d692d9f4d7c9189fc0b4157edda65b6baae8581217984a6543307a","evidence":"A-A-151 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[151,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}}}},{"floors":[96,96],"revision":"wtc1-aa153-common-circulation-v1","evidenceType":"Original-plan stair enclosure/opening geometry and corroborated shared flights; Stair B eastern departure10+9 corrected in impact flight review","uncertaintyFt":0.75,"stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"LERA A-A-153 main96th\u2013100th core plan; shared circulation template applied to96/99, with floor100 exceptions deferred","uncertaintyFt":0.75,"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-aa153-common-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":96,"upperFloor":97,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2918,1250],"lastRiserPx":[2751,1250],"id":"lower","firstRiserFt":[26.774749559669317,-21.406822254154804],"lastRiserFt":[19.680533723008182,-21.42498273172442],"widthFt":3.6666666666666665,"goingFt":0.788248786791024,"nominalGoingDifferenceIn":-0.04101455850771174,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2751,1346],"lastRiserPx":[2900,1346],"id":"upper","firstRiserFt":[19.670155794732068,-17.344584083326914],"lastRiserFt":[25.999725613070453,-17.328381022501326],"widthFt":3.6666666666666665,"goingFt":0.7911988196757217,"nominalGoingDifferenceIn":-0.0056141638913391745,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[15.607178175746682,-23.305605001541437],[19.68529027346807,-23.295165445573275],[19.665074934013546,-15.346888911715638],[15.586962836292159,-15.3573284676838]],"sourcePixels":[[2655,1206],[2751,1206],[2751,1393],[2655,1393]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"LERA A-A-153 main96th\u2013100th core plan; shared circulation template applied to96/99, with floor100 exceptions deferred","uncertaintyFt":0.75,"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-aa153-common-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":96,"upperFloor":97,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[1945,1253],"lastRiserPx":[2115,1253],"id":"lower","firstRiserFt":[-14.558940074369502,-21.385119045944684],"lastRiserFt":[-7.337283234654578,-21.366632332251065],"widthFt":3.6666666666666665,"goingFt":0.8024089446375688,"nominalGoingDifferenceIn":0.12890733565082613,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2115,1346],"lastRiserPx":[1964,1346],"id":"upper","firstRiserFt":[-7.347336852672058,-17.41374614161598],"lastRiserFt":[-13.761867339712964,-17.4301666931909],"widthFt":3.6666666666666665,"goingFt":0.8018189380606299,"nominalGoingDifferenceIn":0.12182725672755801,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[-7.33252668419469,-23.23681504609992],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-7.352525816810115,-15.373546817417228]],"sourcePixels":[[2115,1209],[2187,1209],[2187,1394],[2115,1394]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"LERA A-A-153 main96th\u2013100th core plan; shared circulation template applied to96/99, with floor100 exceptions deferred","uncertaintyFt":0.75,"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75},"reviewRevision":"wtc1-aa153-common-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":96,"upperFloor":97,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2555,2167],"lastRiserPx":[2555,1994],"id":"lower","firstRiserFt":[11.255257354439536,17.530011097554237],"lastRiserFt":[11.273959246020453,10.176792699921236],"widthFt":4.666666666666667,"goingFt":0.8170269089365321,"nominalGoingDifferenceIn":0.30432290723838484,"baseOffsetFt":0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2437,1994],"lastRiserPx":[2437,2148],"id":"upper","firstRiserFt":[6.261279792571273,10.16396074571037],"lastRiserFt":[6.244631865961679,16.70960024418136],"widthFt":4.666666666666667,"goingFt":0.8182075836604283,"nominalGoingDifferenceIn":0.3184910039251392,"baseOffsetFt":6.315789473684211,"topOffsetFt":12}],"intermediateLanding":{"polygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.567897300988733,10.182664950153324],[3.8399007345492038,10.157762259354271]],"sourcePixels":[[2380,1883],[2609,1883],[2609,1994],[2380,1994]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}}}},{"floors":[97,97],"revision":"wtc1-f97-architectural-openings-v1","evidenceType":"Original-plan stair enclosure/opening geometry and corroborated shared flights; Stair B eastern departure10+9 corrected in impact flight review","uncertaintyFt":0.75,"stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"LERA A-A-153 main plan, floor97","uncertaintyFt":0.75,"flightModel":{"revision":"wtc1-f97-stair-surfaces-v1","classification":"architectural plan reconstruction","floor":97,"upperFloor":98,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2918,1250],"lastRiserPx":[2751,1250],"id":"lower","firstRiserFt":[26.774749559669317,-21.406822254154804],"lastRiserFt":[19.680533723008182,-21.42498273172442],"widthFt":3.6666666666666665,"goingFt":0.788248786791024,"nominalGoingDifferenceIn":-0.04101455850771174,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2751,1346],"lastRiserPx":[2900,1346],"id":"upper","firstRiserFt":[19.670155794732068,-17.344584083326914],"lastRiserFt":[25.999725613070453,-17.328381022501326],"widthFt":3.6666666666666665,"goingFt":0.7911988196757217,"nominalGoingDifferenceIn":-0.0056141638913391745,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[15.607178175746682,-23.305605001541437],[19.68529027346807,-23.295165445573275],[19.665074934013546,-15.346888911715638],[15.586962836292159,-15.3573284676838]],"sourcePixels":[[2655,1206],[2751,1206],[2751,1393],[2655,1393]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"Floor97 plan, identities, arrows, riser lines and return landing boundaries"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p.27: flight widths; p.249: nominal egress-model rise/going"},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Documented floor97-to-98 rise; 12 ft"}],"riseMethod":"Nineteen equal risers span the documented 12 ft floor97-to-98 elevation difference: 144/19 in each. Intermediate elevation is proportional to the departure flight count; equal half-story landings would make unequal risers. This is a reconstruction from plan count and story height, not a measured stair elevation.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Floor97-to-98 walking and riser surfaces only. No inferred material thickness, nosing, stringers, rails, doors or enclosure wall assembly. Entry landings remain the floor slab; return landing boundaries follow the architectural enclosure. Equal riser heights and continuation of the floor97 plan into its upper flight are explicit reconstruction assumptions. The floor97/98 stair entry boundaries are reconciled against the shared 96th\u2013100th plan in analysis/core-floor98-review; structural trimming and later alterations remain unresolved. A-AB-204/205 typical stair details are listed in the drawing index but absent from local sources.","physicalThicknessFt":null},"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]}},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"LERA A-A-153 main plan, floor97","uncertaintyFt":0.75,"flightModel":{"revision":"wtc1-f97-stair-surfaces-v1","classification":"architectural plan reconstruction","floor":97,"upperFloor":98,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[1945,1253],"lastRiserPx":[2115,1253],"id":"lower","firstRiserFt":[-14.558940074369502,-21.385119045944684],"lastRiserFt":[-7.337283234654578,-21.366632332251065],"widthFt":3.6666666666666665,"goingFt":0.8024089446375688,"nominalGoingDifferenceIn":0.12890733565082613,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2115,1346],"lastRiserPx":[1964,1346],"id":"upper","firstRiserFt":[-7.347336852672058,-17.41374614161598],"lastRiserFt":[-13.761867339712964,-17.4301666931909],"widthFt":3.6666666666666665,"goingFt":0.8018189380606299,"nominalGoingDifferenceIn":0.12182725672755801,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[-7.33252668419469,-23.23681504609992],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-7.352525816810115,-15.373546817417228]],"sourcePixels":[[2115,1209],[2187,1209],[2187,1394],[2115,1394]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"Floor97 plan, identities, arrows, riser lines and return landing boundaries"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p.27: flight widths; p.249: nominal egress-model rise/going"},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Documented floor97-to-98 rise; 12 ft"}],"riseMethod":"Nineteen equal risers span the documented 12 ft floor97-to-98 elevation difference: 144/19 in each. Intermediate elevation is proportional to the departure flight count; equal half-story landings would make unequal risers. This is a reconstruction from plan count and story height, not a measured stair elevation.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Floor97-to-98 walking and riser surfaces only. No inferred material thickness, nosing, stringers, rails, doors or enclosure wall assembly. Entry landings remain the floor slab; return landing boundaries follow the architectural enclosure. Equal riser heights and continuation of the floor97 plan into its upper flight are explicit reconstruction assumptions. The floor97/98 stair entry boundaries are reconciled against the shared 96th\u2013100th plan in analysis/core-floor98-review; structural trimming and later alterations remain unresolved. A-AB-204/205 typical stair details are listed in the drawing index but absent from local sources.","physicalThicknessFt":null},"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]}},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"LERA A-A-153 main plan, floor97","uncertaintyFt":0.75,"flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":97,"upperFloor":98,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2555,2167],"lastRiserPx":[2555,1994],"id":"lower","firstRiserFt":[11.255257354439536,17.530011097554237],"lastRiserFt":[11.273959246020453,10.176792699921236],"widthFt":4.666666666666667,"goingFt":0.8170269089365321,"nominalGoingDifferenceIn":0.30432290723838484,"baseOffsetFt":0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2437,1994],"lastRiserPx":[2437,2148],"id":"upper","firstRiserFt":[6.261279792571273,10.16396074571037],"lastRiserFt":[6.244631865961679,16.70960024418136],"widthFt":4.666666666666667,"goingFt":0.8182075836604283,"nominalGoingDifferenceIn":0.3184910039251392,"baseOffsetFt":6.315789473684211,"topOffsetFt":12}],"intermediateLanding":{"polygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.567897300988733,10.182664950153324],[3.8399007345492038,10.157762259354271]],"sourcePixels":[[2380,1883],[2609,1883],[2609,1994],[2380,1994]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."},"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75}}}},{"floors":[98,98],"revision":"wtc1-f98-stair-interfaces-v1","evidenceType":"Original-plan stair enclosure/opening geometry and corroborated shared flights; Stair B eastern departure10+9 corrected in impact flight review","uncertaintyFt":0.75,"stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"LERA A-A-153 main 96th\u2013100th Floor Core Plan, applied to floor98; companion A-A-152 corroborates floor coverage","uncertaintyFt":0.75,"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":98,"upperFloor":99,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2918,1250],"lastRiserPx":[2751,1250],"id":"lower","firstRiserFt":[26.774749559669317,-21.406822254154804],"lastRiserFt":[19.680533723008182,-21.42498273172442],"widthFt":3.6666666666666665,"goingFt":0.788248786791024,"nominalGoingDifferenceIn":-0.04101455850771174,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2751,1346],"lastRiserPx":[2900,1346],"id":"upper","firstRiserFt":[19.670155794732068,-17.344584083326914],"lastRiserFt":[25.999725613070453,-17.328381022501326],"widthFt":3.6666666666666665,"goingFt":0.7911988196757217,"nominalGoingDifferenceIn":-0.0056141638913391745,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[15.607178175746682,-23.305605001541437],[19.68529027346807,-23.295165445573275],[19.665074934013546,-15.346888911715638],[15.586962836292159,-15.3573284676838]],"sourcePixels":[[2655,1206],[2751,1206],[2751,1393],[2655,1393]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"LERA A-A-153 main 96th\u2013100th Floor Core Plan, applied to floor98; companion A-A-152 corroborates floor coverage","uncertaintyFt":0.75,"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":98,"upperFloor":99,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[1945,1253],"lastRiserPx":[2115,1253],"id":"lower","firstRiserFt":[-14.558940074369502,-21.385119045944684],"lastRiserFt":[-7.337283234654578,-21.366632332251065],"widthFt":3.6666666666666665,"goingFt":0.8024089446375688,"nominalGoingDifferenceIn":0.12890733565082613,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2115,1346],"lastRiserPx":[1964,1346],"id":"upper","firstRiserFt":[-7.347336852672058,-17.41374614161598],"lastRiserFt":[-13.761867339712964,-17.4301666931909],"widthFt":3.6666666666666665,"goingFt":0.8018189380606299,"nominalGoingDifferenceIn":0.12182725672755801,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[-7.33252668419469,-23.23681504609992],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-7.352525816810115,-15.373546817417228]],"sourcePixels":[[2115,1209],[2187,1209],[2187,1394],[2115,1394]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"LERA A-A-153 main 96th\u2013100th Floor Core Plan, applied to floor98; companion A-A-152 corroborates floor coverage","uncertaintyFt":0.75,"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75},"flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":98,"upperFloor":99,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2555,2167],"lastRiserPx":[2555,1994],"id":"lower","firstRiserFt":[11.255257354439536,17.530011097554237],"lastRiserFt":[11.273959246020453,10.176792699921236],"widthFt":4.666666666666667,"goingFt":0.8170269089365321,"nominalGoingDifferenceIn":0.30432290723838484,"baseOffsetFt":0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2437,1994],"lastRiserPx":[2437,2148],"id":"upper","firstRiserFt":[6.261279792571273,10.16396074571037],"lastRiserFt":[6.244631865961679,16.70960024418136],"widthFt":4.666666666666667,"goingFt":0.8182075836604283,"nominalGoingDifferenceIn":0.3184910039251392,"baseOffsetFt":6.315789473684211,"topOffsetFt":12}],"intermediateLanding":{"polygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.567897300988733,10.182664950153324],[3.8399007345492038,10.157762259354271]],"sourcePixels":[[2380,1883],[2609,1883],[2609,1994],[2380,1994]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}}}},{"floors":[99,99],"revision":"wtc1-aa153-common-circulation-v1","evidenceType":"Original-plan stair enclosure/opening geometry and corroborated shared flights; Stair B eastern departure10+9 corrected in impact flight review","uncertaintyFt":0.75,"stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"LERA A-A-153 main96th\u2013100th core plan; shared circulation template applied to96/99, with floor100 exceptions deferred","uncertaintyFt":0.75,"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-aa153-common-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":99,"upperFloor":100,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2918,1250],"lastRiserPx":[2751,1250],"id":"lower","firstRiserFt":[26.774749559669317,-21.406822254154804],"lastRiserFt":[19.680533723008182,-21.42498273172442],"widthFt":3.6666666666666665,"goingFt":0.788248786791024,"nominalGoingDifferenceIn":-0.04101455850771174,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2751,1346],"lastRiserPx":[2900,1346],"id":"upper","firstRiserFt":[19.670155794732068,-17.344584083326914],"lastRiserFt":[25.999725613070453,-17.328381022501326],"widthFt":3.6666666666666665,"goingFt":0.7911988196757217,"nominalGoingDifferenceIn":-0.0056141638913391745,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[15.607178175746682,-23.305605001541437],[19.68529027346807,-23.295165445573275],[19.665074934013546,-15.346888911715638],[15.586962836292159,-15.3573284676838]],"sourcePixels":[[2655,1206],[2751,1206],[2751,1393],[2655,1393]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"LERA A-A-153 main96th\u2013100th core plan; shared circulation template applied to96/99, with floor100 exceptions deferred","uncertaintyFt":0.75,"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-aa153-common-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":99,"upperFloor":100,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[1945,1253],"lastRiserPx":[2115,1253],"id":"lower","firstRiserFt":[-14.558940074369502,-21.385119045944684],"lastRiserFt":[-7.337283234654578,-21.366632332251065],"widthFt":3.6666666666666665,"goingFt":0.8024089446375688,"nominalGoingDifferenceIn":0.12890733565082613,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2115,1346],"lastRiserPx":[1964,1346],"id":"upper","firstRiserFt":[-7.347336852672058,-17.41374614161598],"lastRiserFt":[-13.761867339712964,-17.4301666931909],"widthFt":3.6666666666666665,"goingFt":0.8018189380606299,"nominalGoingDifferenceIn":0.12182725672755801,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0}],"intermediateLanding":{"polygonFt":[[-7.33252668419469,-23.23681504609992],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-7.352525816810115,-15.373546817417228]],"sourcePixels":[[2115,1209],[2187,1209],[2187,1394],[2115,1394]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"LERA A-A-153 main96th\u2013100th core plan; shared circulation template applied to96/99, with floor100 exceptions deferred","uncertaintyFt":0.75,"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75},"reviewRevision":"wtc1-aa153-common-circulation-v1","flightModel":{"revision":"wtc1-impact-stair-flights-v1","classification":"shared architectural flight geometry corroborated on original plans","floor":99,"upperFloor":100,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"risers":10,"firstRiserPx":[2555,2167],"lastRiserPx":[2555,1994],"id":"lower","firstRiserFt":[11.255257354439536,17.530011097554237],"lastRiserFt":[11.273959246020453,10.176792699921236],"widthFt":4.666666666666667,"goingFt":0.8170269089365321,"nominalGoingDifferenceIn":0.30432290723838484,"baseOffsetFt":0,"topOffsetFt":6.315789473684211},{"risers":9,"firstRiserPx":[2437,1994],"lastRiserPx":[2437,2148],"id":"upper","firstRiserFt":[6.261279792571273,10.16396074571037],"lastRiserFt":[6.244631865961679,16.70960024418136],"widthFt":4.666666666666667,"goingFt":0.8182075836604283,"nominalGoingDifferenceIn":0.3184910039251392,"baseOffsetFt":6.315789473684211,"topOffsetFt":12}],"intermediateLanding":{"polygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.567897300988733,10.182664950153324],[3.8399007345492038,10.157762259354271]],"sourcePixels":[[2380,1883],[2609,1883],[2609,1994],[2380,1994]],"offsetFt":6.315789473684211},"planUncertaintyFt":0.75,"sources":[{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","evidence":"A-A-153 plan count, UP/DN handedness and terminal riser witnesses"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","goingMethod":"Retain the registered first and last drawn riser positions and divide into n-1 tread intervals. Compare, but do not silently force, the NIST 9.5 in nominal going. The measured raster going is not fabrication precision.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","physicalThicknessFt":null,"estimated":false,"sourceFloor":97,"sourceSheets":[153,153],"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100."}}}},{"floors":[100,100],"revision":"wtc1-f100-circulation-v1","uncertaintyFt":0.75,"evidenceType":"A-A-153 floor100 circulation and corrected stair B entry enclosure; flights unresolved","stairs":{"A":{"stair":"A","enclosurePx":[2655,1206,3056,1393],"openingPx":[2655,1206,2905,1393],"flightZonePx":[2748,1206,2905,1393],"floorLandingPx":[2905,1206,3056,1393],"legacyOpening":10,"interpretation":"Stair1=A. Floor-level landing at east/right entry; flights project west toward the return landing. The west opening limit follows the visible inside wall next to the separate A.C. shaft. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[15.586962836292159,-23.30560500154143],[32.641792250603686,-15.313721572441793]],"enclosurePolygonFt":[[15.607178175746682,-23.30560500154143],[32.641792250603686,-23.261998106299423],[32.62157691114916,-15.313721572441793],[15.586962836292159,-15.357328467683793]],"floorOpeningPolygonFt":[[15.607178175746682,-23.305605001541437],[26.779506110129205,-23.27700496800366],[26.769344388692176,-19.2816146247811],[26.004698370369425,-19.283572041525126],[25.99464475235193,-15.330685850890049],[15.586962836292159,-15.3573284676838]],"floorLandingPolygonsFt":[[[26.779506110129205,-23.27700496800366],[32.641792250603686,-23.26199810629943],[32.62157691114916,-15.313721572441793],[25.99464475235193,-15.330685850890049],[26.004698370369425,-19.283572041525126],[26.769344388692176,-19.2816146247811]]],"flightZonePolygonFt":[[19.557849270414266,-23.29549168169728],[26.227261763562765,-23.278418657874347],[26.207046424108242,-15.33014212401671],[19.537633930959743,-15.347215147839641]],"sourcePixels":[[2655,1206],[3056,1206],[3056,1393],[2655,1393]],"source":"A-A-153 main96th\u2013100th plan with separately aligned100th-floor insets","uncertaintyFt":0.75,"openingPolygonPx":[[2655,1206],[2918,1206],[2918,1300],[2900,1300],[2900,1393],[2655,1393]],"floorLandingPolygonPx":[[2918,1206],[3056,1206],[3056,1393],[2900,1393],[2900,1300],[2918,1300]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-f100-circulation-v1"},"C":{"stair":"C","enclosurePx":[1808,1209,2187,1394],"openingPx":[1948,1209,2187,1394],"flightZonePx":[1948,1209,2107,1394],"floorLandingPx":[1808,1209,1948,1394],"legacyOpening":3,"interpretation":"Stair2=C. Floor-level landing at west/left entry; flights project east toward the return landing. Exact structural trimming and half-landing elevations unresolved. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[-20.393988462648252,-23.270199876123094],[-4.273942610903646,-15.365717150441107]],"enclosurePolygonFt":[[-20.373989330032828,-23.270199876123094],[-4.273942610903646,-23.22898537912379],[-4.2939417435190705,-15.365717150441107],[-20.393988462648252,-15.406931647440409]],"floorOpeningPolygonFt":[[-14.554183523909614,-23.25530175979354],[-4.273942610903646,-23.2289853791238],[-4.2939417435190705,-15.365717150441107],[-13.767056303851021,-15.389967368992146],[-13.756894582413992,-19.3853577122147],[-14.56402093508801,-19.3874238743334]],"floorLandingPolygonsFt":[[[-20.373989330032828,-23.2701998761231],[-14.554183523909614,-23.25530175979354],[-14.56402093508801,-19.3874238743334],[-13.756894582413992,-19.3853577122147],[-13.767056303851021,-15.389967368992146],[-20.393988462648252,-15.406931647440409]]],"flightZonePolygonFt":[[-14.426742520855825,-23.25497552366953],[-7.672369359004804,-23.237685009097262],[-7.692368491620229,-15.374416780414577],[-14.44674165347125,-15.391707294986844]],"sourcePixels":[[1808,1209],[2187,1209],[2187,1394],[1808,1394]],"source":"A-A-153 main96th\u2013100th plan with separately aligned100th-floor insets","uncertaintyFt":0.75,"openingPolygonPx":[[1945,1209],[2187,1209],[2187,1394],[1964,1394],[1964,1300],[1945,1300]],"floorLandingPolygonPx":[[1808,1209],[1945,1209],[1945,1300],[1964,1300],[1964,1394],[1808,1394]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"reviewRevision":"wtc1-f100-circulation-v1"},"B":{"stair":"B","enclosurePx":[2380,1883,2609,2324],"openingPx":[2380,1883,2609,2148],"flightZonePx":[2380,1994,2609,2148],"floorLandingPx":[2380,2148,2609,2324],"legacyOpening":15,"interpretation":"Stair3=B. Floor-level entry landing is south of the flights. The northern return-landing footprint is inside the stair opening, not a continuous floor-level concrete plate. Stair risers and half-landing height remain unmodeled. Entry boundary refined to the staggered first/last riser lines; original rectangular masks are superseded.","rectFt":[[3.804226606100059,5.43980132214466],[13.579896780558002,24.20903530401975]],"enclosurePolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]],"floorOpeningPolygonFt":[[3.851900214118473,5.43980132214466],[13.579896780558002,5.464704012943713],[13.549195409407815,17.535883347786324],[8.748917627714945,17.523595120448803],[8.75097159268627,16.716016221286793],[3.8232528079396104,16.70340175782526]],"floorLandingPolygonsFt":[[[3.8232528079396104,16.703401757825276],[8.75097159268627,16.716016221286793],[8.748917627714945,17.523595120448803],[13.549195409407815,17.535883347786324],[13.532223172539588,24.20903530401975],[3.804226606100059,24.184132613220697]]],"flightZonePolygonFt":[[3.8399007345492038,10.157762259354271],[13.567897300988733,10.182664950153324],[13.55124937437914,16.72830444862433],[3.8232528079396104,16.703401757825276]],"sourcePixels":[[2380,1883],[2609,1883],[2609,2324],[2380,2324]],"source":"A-A-153 main96th\u2013100th plan with separately aligned100th-floor insets","uncertaintyFt":0.75,"openingPolygonPx":[[2380,1883],[2609,1883],[2609,2167],[2496,2167],[2496,2148],[2380,2148]],"floorLandingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2253],[2380,2253]],"entryInterfaceReview":{"revision":"wtc1-f97-f98-stair-interfaces-v1","floors":[97,98],"interpretation":"The first/last riser lines at the entry differ by one tread across the two lanes. Trace a stepped landing boundary through the center divider rather than replacing both endpoints by one averaged line. Each opening and entry landing partition the complete enclosure.","supersedesRectangles":["openingPx","floorLandingPx"]},"landingExtentReview":{"revision":"wtc1-aa153-stair-b-landing-extent-v1","floors":[96,97,98,99,100],"previousSouthPx":2253,"southInsideWallPx":2324,"enclosurePx":[2380,1883,2609,2324],"landingPolygonPx":[[2380,2148],[2496,2148],[2496,2167],[2609,2167],[2609,2324],[2380,2324]],"insideWitnessPx":[[2415,2290],[2500,2300],[2580,2280]],"outsideWitnessPx":[[2450,2340],[2550,2340]],"evidence":"The former south limit followed a horizontal dimension/reference line through the door zone, short of the enclosing wall. A-A-153 main-plan inside wall is at approximatelyv2324; the labeled stair3 and strip radiator lie north of that wall. The floor100 mail-room inset independently depicts the same south enclosure. Opening and terminal-riser polygons remain unchanged.","uncertaintyFt":0.75},"reviewRevision":"wtc1-f100-circulation-v1"}}},{"floors":[101,110],"evidenceType":"LERA PAC1 TOWER A core plan A-A-153 (96th-100th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; corroborated within 2-3 ft by A-A139 (82), A-A-148 (89-93), A-A-158 (103), A-A-162 (105), A-A-166 (107), A-A-170 (108). Stairwell B ends at 107 (A-A-170 shows no Stair 3 at 108); A/C end at 110 \u2014 the floor-110 roof-stair room (A-A-175, west end) is not separately modeled","uncertaintyFt":3.0,"stairs":{"A":{"rectFt":[[20.4,-23.1],[27.9,-14.3]]},"C":{"rectFt":[[-16.3,-22.8],[-9.0,-14.5]]},"B":{"rectFt":[[3.4,12.7],[14.4,21.6]],"endsAtFloor":107}}}],"transferCorridors":[{"floor":26,"stair":"A","rectFt":[[41.1,18.5],[52.7,23.5]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 26th floor core plan A-A-50: 'STAIR #1 SUSP. GYP. BD. CEILING (+8-0)' corridor connecting Fl 25 lower shaft exit to Fl 26 upper shaft entry along south hallway; FEMA 403 ch2","description":"Floor 26 Stair A ~19 ft west jog connecting Fl 25 shaft to Fl 26 shaft along south core corridor"},{"floor":42,"stair":"A","rectFt":[[41.1,18.5],[74.0,23.5]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 42nd floor plan A-A-65: 'STAIR PASSAGE' corridor running east north of express elevator bank PE 1-3 through east core wall","description":"Floor 42 Stair A east corridor north of express bank PE 1-3"},{"floor":42,"stair":"A","rectFt":[[71.0,23.5],[77.4,35.0]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 42nd floor plan A-A-65: corridor turning south outside east core wall into southeast exterior stair shaft","description":"Floor 42 Stair A south corridor into SE exterior shaft"},{"floor":42,"stair":"C","rectFt":[[-72.0,18.5],[-53.2,23.5]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 42nd floor plan A-A-65: 'STAIR PASSAGE' corridor running west north of express elevator PE 11 through west core wall","description":"Floor 42 Stair C west corridor north of express bank PE 11"},{"floor":42,"stair":"C","rectFt":[[-76.0,23.5],[-71.7,35.0]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 42nd floor plan A-A-65: corridor turning south outside west core wall into southwest exterior stair shaft","description":"Floor 42 Stair C south corridor into SW exterior shaft"},{"floor":48,"stair":"A","rectFt":[[72.0,24.5],[78.0,35.0]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 48th floor core plan A-A-81: 'STAIR PASSAGE SUSP. CEIL. (+8-0)' north leg from SE exterior shaft into core","description":"Floor 48 Stair A north leg from SE exterior shaft into core corridor"},{"floor":48,"stair":"A","rectFt":[[22.5,21.0],[74.0,25.6]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 48th floor core plan A-A-81: west corridor heading directly into 'STAIR #1 SUSP. GYP. BD. CEIL (+8-0)' landing","description":"Floor 48 Stair A west corridor into core shaft landing"},{"floor":48,"stair":"C","rectFt":[[-78.0,24.5],[-72.0,35.0]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 48th floor core plan A-A-81: 'STAIR PASSAGE SUSP. CEIL. (+8-0)' north leg from SW exterior shaft into core","description":"Floor 48 Stair C north leg from SW exterior shaft into core corridor"},{"floor":48,"stair":"C","rectFt":[[-74.0,21.0],[-31.9,25.6]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 48th floor core plan A-A-81: east corridor heading directly into 'STAIR #2 SUSP. GYP. BD. CEIL (+8-0)' landing","description":"Floor 48 Stair C east corridor into core shaft landing"},{"floor":76,"stair":"B","rectFt":[[1.0,-5.0],[6.0,16.0]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 76th floor core plan A-A-124: 'STAIR PASSAGE FIN. FL. EL. (+19-6) SUSP. CEIL. (+8-0)' connecting 'STAIR #3 FIN. FL. EL. (+18-0)' north-center lower shaft to south-center upper shaft","description":"Floor 76 Stair B central corridor shift from north-center to south-center"},{"floor":76,"stair":"A","rectFt":[[21.0,-10.0],[26.0,18.0]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 76th floor core plan A-A-124: north corridor leading from 'STAIR #1' south-east lower shaft toward east-west corridor","description":"Floor 76 Stair A north corridor from Fl 75 shaft"},{"floor":76,"stair":"A","rectFt":[[24.0,-15.0],[74.0,-9.5]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 76th floor core plan A-A-124: 'STAIR PASSAGE FOR 75-76 FIN. FL. EL. (+19-6)' corridor heading east south of express bank X78 through east core wall","description":"Floor 76 Stair A east corridor south of express bank X78"},{"floor":76,"stair":"A","rectFt":[[71.0,-32.0],[76.0,-9.5]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 76th floor core plan A-A-124: north leg outside east core wall into northeast exterior stair shaft","description":"Floor 76 Stair A north leg into NE exterior shaft"},{"floor":76,"stair":"C","rectFt":[[-74.0,18.0],[-24.3,24.0]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 76th floor core plan A-A-124: 'CORRIDOR FIN. FL. EL. (+18-0)' leading west from 'STAIR #2' south-west lower shaft south of elevator machine room","description":"Floor 76 Stair C west corridor from Fl 75 shaft south of Z2D"},{"floor":76,"stair":"C","rectFt":[[-76.0,-30.0],[-70.0,20.0]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 76th floor core plan A-A-124: north corridor outside west core wall toward northwest exterior shaft","description":"Floor 76 Stair C north corridor outside west core wall"},{"floor":76,"stair":"C","rectFt":[[-79.6,-39.5],[-70.0,-28.9]],"heightFt":9.0,"evidenceType":"LERA PAC1 TOWER A 76th floor core plan A-A-124: west connector into northwest exterior stair shaft","description":"Floor 76 Stair C west connector into NW exterior shaft"},{"floor":82,"stair":"A","rectFt":[[71.0,-31.0],[76.0,-18.0]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 82nd floor core plan A-A139: 'STAIR PASSAGE SUSP. CEIL. (+8-0)' south leg entering core from NE exterior shaft","description":"Floor 82 Stair A south leg from NE exterior shaft"},{"floor":82,"stair":"A","rectFt":[[27.9,-23.0],[73.0,-18.0]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 82nd floor core plan A-A139: west corridor heading directly into 'STAIR #1 SUSP. CEIL. (+8-0)' landing","description":"Floor 82 Stair A west corridor into Fl 82 shaft landing"},{"floor":82,"stair":"C","rectFt":[[-76.0,-30.0],[-70.0,-18.0]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 82nd floor core plan A-A139: 'STAIR PASSAGE SUSP. CEIL. (+8-0)' south leg entering core from NW exterior shaft","description":"Floor 82 Stair C south leg from NW exterior shaft"},{"floor":82,"stair":"C","rectFt":[[-72.0,-23.0],[-16.3,-18.0]],"heightFt":8.5,"evidenceType":"LERA PAC1 TOWER A 82nd floor core plan A-A139: east corridor heading directly into 'STAIR #2 SUSP. CEIL. (+8-0)' landing","description":"Floor 82 Stair C east corridor into Fl 82 shaft landing"}],"impactFlightReview":{"revision":"wtc1-impact-stair-flights-v1","tower":1,"floors":[93,94,95,96,97,98,99],"sources":[{"sheet":148,"floor":93,"source":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-148.tif","sha256":"d66fd3674acc3e45b30a2ecc0c95a11ff5030a3aac2897c5bd107242b7d53034","controls":[[502,1014,730],[507,3165,744],[1002,995,2705],[1007,3155,2715]],"independentControls":[[704,1977,1637],[706,2421,1602]],"matrix":[[0.04237030853490859,-0.00023551678539200665],[0.000311487340580114,0.042319562620541644],[-88.76242337830327,-72.44736135012103]],"controlResidualsFt":[0.10434619190996731,0.10456015569535193,0.10391240668303701,0.10412637046834682],"heldOutResidualsFt":[0.06325950231746447,0.2654318356873586]},{"sheet":150,"floor":94,"source":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-150.tif","sha256":"a409006d00d769ac0dc152bc3e92176f5c6623164c049aff6ed630179c67b1ac","controls":[[502,998,767],[507,3152,759],[1002,1001,2738],[1007,3162,2729]],"independentControls":[[704,1978,1664],[706,2421,1632]],"matrix":[[0.04233228550351521,0.00016696014120168434],[-0.00013962105077520108,0.04237447839405886],[-87.73297984566264,-74.42816676586578]],"controlResidualsFt":[0.07493186218055532,0.0749687889947267,0.07468896893427282,0.07472589574886195],"heldOutResidualsFt":[0.3197562370743736,0.21512498718939582]},{"sheet":151,"floor":95,"source":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-151.tif","sha256":"3f397507e6d692d9f4d7c9189fc0b4157edda65b6baae8581217984a6543307a","controls":[[502,992,713],[507,3154,720],[1002,983,2688],[1007,3147,2695]],"independentControls":[[704,1972,1617],[706,2413,1581]],"matrix":[[0.04222474181852171,-0.0001368217403288212],[0.00017103696391787988,0.04227792679790072],[-87.65443780903747,-71.75850308288247]],"controlResidualsFt":[0.021122207763560347,0.0211222769535248,0.021102686537596244,0.02110275572763837],"heldOutResidualsFt":[0.430990082883384,0.16812929902732413]},{"sheet":153,"floors":[96,97,98,99,100],"source":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-153.tif","sha256":"ceeb8f2226cd74af636993af825e4b5f0bc611f6dbd926741f89ab41660c3433","matrix":[[0.04248033435126433,0.00010874537466834442],[-0.00010810341954288495,0.04250415258747399],[-97.0477368028914,-74.85433199177952]],"registrationBasis":"Existing A-A-153 registration; its main plan explicitly covers96\u2013100."}],"corroboratingSources":[{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27 gives44/56-inch widths; AppendixD p249 approximate9.5-inch going is comparison only."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Every departing story93\u201399 has a12ft rise."},{"path":"sources/LERA - PLANS-022102/PAC1 TOWER A/A-A-152.tif","sha256":"6be11270576741ef577831505fd4d6742a92399e585dc0a391160d2001572b1b","evidence":"Companion96th\u2013100th Floor Plan confirms shared plan coverage."}],"sourcePixelConvention":"Native TIFF rotated180 degrees, no resampling. Sheet148 has3637 rows,150 has3633,151 has3639,153 has3638; all4896 columns.","planUncertaintyFt":0.75,"geometryMethod":"Retain the registered A-A-153 common flight footprints where independent148/150/151 terminal-line and lane-center witnesses corroborate them within0.75ft. These are shared-template instances, not independently surveyed footprints. Pair lower on departure plan with upper on next-floor plan. Shared153 explicitly supplies96\u2013100.","correction":"Stair B lower flight is the eastern lane,2167\u21921994 in153:10 risers northward. Upper flight is the western lane,1994\u21922148:9 risers southward. The prior97 model reversed these lanes and used9+10. UP/DN annotations and broken/full flight representation agree on148/150/151/153.","riseMethod":"19 equal risers span12ft. The10-riser lower flight reaches120/19ft; the9-riser upper flight reaches12ft. Equal rise is a reconstruction assumption.","limits":"Original architectural-plan reconstruction, not verified2001 conditions. Shared-template placement uncertainty0.75ft is not construction tolerance. The93rd-floor insets alter rooms/services, not these three main stair flights. Later tenant stairs and openings on99/100 are separate unresolved evidence. Rails, doors, wall assemblies, nosings, stringers, landing thickness and soffits remain unresolved. No post-impact passability claim. Existing core openings, elevator shafts and framing are unchanged.","maxEndpointResidualFt":0.7306181161297991}},"wtc2":{"derivation":"Original Tower B plans: B77\u201385, outer A/C77\u201381, terminal floor openings and return passages82, upper A/C83\u201385. The inner82 first-flight envelopes use the upper-plan reference; remaining tower bands retain earlier derivation.","bands":[{"floors":[1,1],"evidenceType":"derived from WTC 1 band by documented core rotation; NCSTAR 1-7 p.27: only main Stair B reaches the concourse; A/C begin at plaza floor 2. A-A-20 central 'STAIR #3' is B, not C. Preserve B's alignment with floors 2-25 per NIST p.28 (B transfers only at 76); cellar exit geometry remains unresolved.","uncertaintyFt":8.0,"stairs":{"B":{"rectFt":[[-16.1,-12.2],[-4.7,-1.6]]}}},{"floors":[2,2],"evidenceType":"derived from WTC 1 band by documented core rotation; A-A-22 re-registered to column symbols 501/508/1001/1008 and LERA workbook coordinates; main STAIR #1 east = A, STAIR #2 west = C, central STAIR #3 = B. Source pixels and affine fit: analysis/tower-accuracy-review/plan-registration.json. B passes through floor 2 without a mezzanine exit; alignment with band 3-25 preserved (NCSTAR 1-7 pp.27-28).","uncertaintyFt":6.0,"stairs":{"A":{"rectFt":[[15.05,-62.7],[23.15,-49.32]]},"C":{"rectFt":[[15.17,51.28],[23.18,60.12]]},"B":{"rectFt":[[-16.1,-12.2],[-4.7,-1.6]]}}},{"floors":[3,25],"evidenceType":"derived from WTC 1 band by documented core rotation; LERA PAC1 TOWER A core plan A-A-45 (20th-23rd), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; A and C in south half of core north of PE 1-11, B north-center. Floors 3-8 assumed identical (core plans A-A-24..34 not yet digitized); 9-10 corroborated for B by A-A-38","uncertaintyFt":8.0,"stairs":{"A":{"rectFt":[[14.8,-60.9],[23.5,-52.7]]},"C":{"rectFt":[[14.8,52.5],[23.5,60.3]]},"B":{"rectFt":[[-16.1,-12.2],[-4.7,-1.6]]}}},{"floors":[26,41],"evidenceType":"derived from WTC 1 band by documented core rotation; LERA PAC1 TOWER A core plan A-A-59 (35th-39th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; Stairwell A jogged ~19 ft west at the floor-26 transfer documented by FEMA 403 ch2 (Stairway 1 transfer at 26); both A and C in south half","uncertaintyFt":7.0,"stairs":{"A":{"rectFt":[[14.5,-41.1],[23.5,-33.9]]},"C":{"rectFt":[[14.5,53.2],[23.5,60.4]]},"B":{"rectFt":[[-13.8,-9.1],[-1.8,0.3]]}}},{"floors":[42,47],"evidenceType":"derived from WTC 1 band by documented core rotation; LERA PAC1 TOWER A full-floor plans A-A-65/70/72/74/76/78 (42nd-47th) and core plan A-A-66 (Stair 3): Stairwells A and C transfer OUTSIDE the core envelope at the SOUTH end of the building (A southeast, C southwest; NCSTAR 1-7 sec 2.2.2 '>100 ft transfer corridors with right-angle turns'); six sheets agree within 2-5 ft, values from A-A-72 (44th skylobby, labeled); B in place north-center","uncertaintyFt":8.0,"stairs":{"A":{"rectFt":[[30.7,-85.8],[39.3,-77.4]]},"C":{"rectFt":[[31.4,71.7],[39.5,80.0]]},"B":{"rectFt":[[-16.4,-11.7],[-3.6,-0.6]]}}},{"floors":[48,48],"evidenceType":"derived from WTC 1 band by documented core rotation; LERA PAC1 TOWER A core plan A-A-81 (48th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; A and C transfer back inside the core in the south half (z +16.6..+25.6, NCSTAR 1-7); continuous shaft alignment clears local bank Z2C and south restaurant cars PE 7 / CE 6","uncertaintyFt":8.0,"stairs":{"A":{"rectFt":[[16.6,-22.5],[25.6,-15.2]]},"C":{"rectFt":[[16.6,24.3],[25.6,31.9]]},"B":{"rectFt":[[-16.1,-11.7],[-6.1,-3.2]]}}},{"floors":[49,74],"evidenceType":"derived from WTC 1 band by documented core rotation; LERA PAC1 TOWER A core plan A-A-90 (57th-58th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; corroborated by A-A-105 (66th) and A-A-113 (70th-71st); Stairs A and C run continuous in south half north of Row 900 (z +16.6..+25.6), B north-center in place; NCSTAR 1-7 Table 2-2 corroborates south half placement; 66-68 jog below read precision","uncertaintyFt":7.0,"stairs":{"A":{"rectFt":[[16.6,-22.5],[25.6,-15.2]]},"C":{"rectFt":[[16.6,24.3],[25.6,31.9]]},"B":{"rectFt":[[-16.5,-9.2],[-4.7,0.9]]}}},{"floors":[75,75],"evidenceType":"Original Tower B A-B-128/130 plans and A-B-131C/132E/G sections; source-traced75 departures and76 arrivals.","uncertaintyFt":1,"stairs":{"A":{"rectFt":[[15.404384954445888,-25.779455495271918],[23.239789266696434,-10.229043164292122]],"volumePolygonFt":[[15.404384954445888,-10.257157924995937],[15.41169598731365,-25.779455495271918],[23.239789266696434,-25.751340734568103],[23.232478233828672,-10.229043164292122]],"enclosurePolygonFt":[[15.404384954445888,-10.257157924995937],[15.41169598731365,-25.779455495271918],[23.239789266696434,-25.751340734568103],[23.232478233828672,-10.229043164292122]],"flightModel":{"revision":"wtc2-floor76-approach-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":75,"upperFloor":76,"storyRiseFt":14,"departureOffsetFt":0,"arrivalOffsetFt":0,"walkingRiseFt":14,"riserCount":22,"riserHeightFt":0.6363636363636364,"flights":[{"id":"lower","risers":8,"firstRiserFt":[21.355080038216613,-20.3553119106854],"lastRiserFt":[21.352454529175702,-14.781006153403979],"widthFt":3.6666666666666665,"goingFt":0.7963294822273378,"baseOffsetFt":0.0,"topOffsetFt":5.090909090909091,"sourceSheet":"A-B-128","sourcePlanFloor":75,"sourcePixels":[[2794,2197],[2664,2197]],"nominalGoingDifferenceIn":0.055953786728053956},{"id":"upper","risers":14,"firstRiserFt":[17.07514635406872,-14.351805387044138],"lastRiserFt":[17.04858496409645,-24.680215476905303],"widthFt":3.6666666666666665,"goingFt":0.7944957110410493,"baseOffsetFt":5.090909090909091,"topOffsetFt":14.0,"sourceSheet":"A-B-130","sourcePlanFloor":76,"sourcePixels":[[2645,2092],[2887,2092]],"nominalGoingDifferenceIn":0.033948532492591}],"intermediateLanding":{"polygonFt":[[15.406525754125397,-14.80236108093311],[15.24181908312627,-14.347090651652472],[15.404384954445888,-10.257157924995937],[23.232478233828672,-10.229043164292122],[23.23461903350818,-14.774246320229295]],"offsetFt":5.090909090909091,"sourceSheet":"A-B-128","sourcePixels":[[2558,2058],[2664,2058],[2664,2241],[2558,2241]],"registrationJoinExtensionFt":0.16449221948043355},"floorLandings":[{"polygonFt":[[15.409151263166308,-20.376666838214533],[15.41169598731365,-25.779455495271918],[23.239789266696434,-25.751340734568103],[23.237244542549092,-20.348552077510718]],"offsetFt":0,"role":"departure landing"},{"polygonFt":[[15.127066479581245,-24.686109050162642],[15.117956581367608,-28.228497634701796],[18.875592728864035,-28.216972424776344],[18.884702627077658,-24.67458384023719]],"offsetFt":14,"role":"arrival landing"}],"datumReading":"A-B-128 Stair1 FIN FL EL (+0-0); A-B-130 arrival (+14-0). The adjacent mail-room finish (+0-6) is not the stair datum.","planUncertaintyFt":1,"sources":[{"sheet":"A-B-128","floors":[75],"path":"analysis/wtc2-independent-core-review/sources/A-B-128.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":346,"sha256":"67777bc84e16c0f2d98550d24b15d23847dbbd0bbcf165c1299b6f7630e5ec69","controls":[[502,1247,724],[507,3381,720],[1002,1258,2673],[1007,3384,2675]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","matrix":[[2.019622339161032e-05,-0.04287927505601098],[0.04277646600755616,0.00015363257215204363],[-72.68124402854043,99.11185183479124]],"controlResidualsFt":[0.10722895795279706,0.10689945326257169,0.1076329185259029,0.10730341383554652]},{"sheet":"A-B-130","floors":[76],"path":"analysis/wtc2-independent-core-review/sources/A-B-130.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":348,"sha256":"1cf39117cb565ae0ff4555c95c8999b9e65a2c46d7d629db5ba8f67f2ad9e6c0","controls":[[502,1236,711],[507,3373,716],[1002,1239,2666],[1007,3382,2672]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00010975780980276587,-0.04267938053661639],[0.042700410767004746,0.0001309682946074087],[-71.96380356357689,98.26117045998753]],"controlResidualsFt":[0.06495099466615482,0.06491834604060416,0.064769281118794,0.06473663249333084]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"limits":"Original architectural plan/section reconstruction with1 ft plan uncertainty. Source counts and raised departure datums replace repeated references; equal riser heights within each story remain an assumption. Passage height uses the8 ft suspended-ceiling notes; local soffits, ducts, doors, railings, finishes and landing thickness are unresolved. The raised vestibule next to incoming A is excluded from walking surfaces. No floor75/76 structural slab, pit, framing, or elevator change. Connections below75 and floor75 slab/finish interfaces still need review.","physicalThicknessFt":null},"reviewRevision":"wtc2-floor76-approach-v1","source":"A-B-128 floor75 stair envelope; floor75 slab/finish interface unresolved."},"B":{"rectFt":[[-23.86731909665906,-13.742776080600379],[-4.527872899650731,-4.154135095553215]],"volumePolygonFt":[[-23.86731909665906,-4.2235770181659404],[-23.862835535066125,-13.742776080600379],[-4.527872899650731,-13.673334157987654],[-4.53235646124368,-4.154135095553215]],"enclosurePolygonFt":[[-23.86731909665906,-4.2235770181659404],[-23.862835535066125,-13.742776080600379],[-4.527872899650731,-13.673334157987654],[-4.53235646124368,-4.154135095553215]],"flightModel":{"revision":"wtc2-floor76-approach-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":75,"upperFloor":76,"storyRiseFt":14,"departureOffsetFt":0.6666666666666666,"arrivalOffsetFt":0,"walkingRiseFt":13.333333333333334,"riserCount":21,"riserHeightFt":0.634920634920635,"flights":[{"id":"lower","risers":12,"firstRiserFt":[-18.388538482162083,-11.407630258340319],"lastRiserFt":[-9.576586484605514,-11.375981948477005],"widthFt":4.666666666666667,"goingFt":0.8010917118324209,"baseOffsetFt":0.6666666666666666,"topOffsetFt":8.285714285714285,"sourceSheet":"A-B-128","sourcePlanFloor":75,"sourcePixels":[[2582,1268],[2582,1474]],"nominalGoingDifferenceIn":0.11310054198905028},{"id":"upper","risers":9,"firstRiserFt":[-9.848013734953646,-6.346703769252599],"lastRiserFt":[-16.16767452847035,-6.366087076854498],"widthFt":4.666666666666667,"goingFt":0.7899613148926756,"baseOffsetFt":8.285714285714285,"topOffsetFt":14.0,"sourceSheet":"A-B-130","sourcePlanFloor":76,"sourcePixels":[[2455.5,1461],[2455.5,1313]],"nominalGoingDifferenceIn":-0.020464221287891604}],"intermediateLanding":{"polygonFt":[[-9.575495888542363,-13.6914628015016],[-9.840857100051862,-8.680026127398024],[-9.855170369855431,-4.013381411107174],[-4.53235646124368,-4.154135095553215],[-4.527872899650731,-13.673334157987654]],"offsetFt":8.285714285714285,"sourceSheet":"A-B-128","sourcePixels":[[2414,1474],[2636,1474],[2636,1592],[2414,1592]],"registrationJoinExtensionFt":0.3177634913491387},"floorLandings":[{"polygonFt":[[-23.86731909665906,-4.2235770181659404],[-23.862835535066125,-13.742776080600379],[-18.387447886098933,-13.723111111364915],[-18.391931447691874,-4.203912048930476]],"offsetFt":0.6666666666666666,"role":"raised departure landing"},{"polygonFt":[[-24.61571551284422,-3.8099162767214807],[-24.640411020049847,-13.412776897460162],[-16.185729688182903,-13.386845175127888],[-16.161034180977282,-3.783984554389207]],"offsetFt":14,"role":"arrival landing"}],"datumReading":"A-B-128 Stair3 FIN FL EL (+0-8); A-B-132G 13ft4in /21 risers to76; A-B-130 arrival (+14-0).","planUncertaintyFt":1,"sources":[{"sheet":"A-B-128","floors":[75],"path":"analysis/wtc2-independent-core-review/sources/A-B-128.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":346,"sha256":"67777bc84e16c0f2d98550d24b15d23847dbbd0bbcf165c1299b6f7630e5ec69","controls":[[502,1247,724],[507,3381,720],[1002,1258,2673],[1007,3384,2675]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","matrix":[[2.019622339161032e-05,-0.04287927505601098],[0.04277646600755616,0.00015363257215204363],[-72.68124402854043,99.11185183479124]],"controlResidualsFt":[0.10722895795279706,0.10689945326257169,0.1076329185259029,0.10730341383554652]},{"sheet":"A-B-130","floors":[76],"path":"analysis/wtc2-independent-core-review/sources/A-B-130.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":348,"sha256":"1cf39117cb565ae0ff4555c95c8999b9e65a2c46d7d629db5ba8f67f2ad9e6c0","controls":[[502,1236,711],[507,3373,716],[1002,1239,2666],[1007,3382,2672]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00010975780980276587,-0.04267938053661639],[0.042700410767004746,0.0001309682946074087],[-71.96380356357689,98.26117045998753]],"controlResidualsFt":[0.06495099466615482,0.06491834604060416,0.064769281118794,0.06473663249333084]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"limits":"Original architectural plan/section reconstruction with1 ft plan uncertainty. Source counts and raised departure datums replace repeated references; equal riser heights within each story remain an assumption. Passage height uses the8 ft suspended-ceiling notes; local soffits, ducts, doors, railings, finishes and landing thickness are unresolved. The raised vestibule next to incoming A is excluded from walking surfaces. No floor75/76 structural slab, pit, framing, or elevator change. Connections below75 and floor75 slab/finish interfaces still need review.","physicalThicknessFt":null},"reviewRevision":"wtc2-floor76-approach-v1","source":"A-B-128 floor75 stair envelope; floor75 slab/finish interface unresolved."},"C":{"rectFt":[[15.384229123501058,14.098270306818293],[23.22100677894224,32.56447334160683]],"volumePolygonFt":[[15.384229123501058,32.53635858090301],[15.392913499559455,14.098270306818293],[23.22100677894224,14.126385067522108],[23.212322402883842,32.56447334160683]],"enclosurePolygonFt":[[15.384229123501058,32.53635858090301],[15.392913499559455,14.098270306818293],[23.22100677894224,14.126385067522108],[23.212322402883842,32.56447334160683]],"flightModel":{"revision":"wtc2-floor76-approach-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":75,"upperFloor":76,"storyRiseFt":14,"departureOffsetFt":0.6666666666666666,"arrivalOffsetFt":0,"walkingRiseFt":13.333333333333334,"riserCount":21,"riserHeightFt":0.634920634920635,"flights":[{"id":"lower","risers":12,"firstRiserFt":[21.332904584932635,26.726132100814652],"lastRiserFt":[21.336984222057737,18.06451853950044],"widthFt":3.6666666666666665,"goingFt":0.7874195020066125,"baseOffsetFt":0.6666666666666666,"topOffsetFt":8.285714285714285,"sourceSheet":"A-B-128","sourcePlanFloor":75,"sourcePixels":[[1696,2197],[1898,2197]],"nominalGoingDifferenceIn":-0.050965975920650664},{"id":"upper","risers":9,"firstRiserFt":[16.924478334968924,18.382559158920287],"lastRiserFt":[16.940722490819724,24.699107478339513],"widthFt":3.6666666666666665,"goingFt":0.7895711508486462,"baseOffsetFt":8.285714285714285,"topOffsetFt":14.0,"sourceSheet":"A-B-130","sourcePlanFloor":76,"sourcePixels":[[1878,2086.5],[1730,2086.5]],"nominalGoingDifferenceIn":-0.025146189816245723}],"intermediateLanding":{"polygonFt":[[15.392913499559455,14.098270306818293],[15.091151064026473,18.38727389431195],[18.757805605911376,18.377844423528625],[23.219148726390202,18.071278372675124],[23.22100677894224,14.126385067522108]],"offsetFt":8.285714285714285,"sourceSheet":"A-B-128","sourcePixels":[[1898,2058],[1990,2058],[1990,2241],[1898,2241]],"registrationJoinExtensionFt":0.4564586786815919},"floorLandings":[{"polygonFt":[[19.533546326234017,32.55126094040175],[19.536293012615275,26.719679532784255],[23.2150690892651,26.732891933989336],[23.212322402883842,32.56447334160683]],"offsetFt":0.6666666666666666,"role":"raised departure landing"},{"polygonFt":[[14.975458584967512,32.58870285191432],[14.95515339015401,24.693017452640277],[23.281733489719926,24.718556270088726],[23.302038684533443,32.61424166936277]],"offsetFt":14,"role":"arrival landing"}],"datumReading":"A-B-128 Stair2 FIN FL EL (+0-8); A-B-132E 13ft4in /21 risers to76; A-B-130 arrival (+14-0).","planUncertaintyFt":1,"sources":[{"sheet":"A-B-128","floors":[75],"path":"analysis/wtc2-independent-core-review/sources/A-B-128.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":346,"sha256":"67777bc84e16c0f2d98550d24b15d23847dbbd0bbcf165c1299b6f7630e5ec69","controls":[[502,1247,724],[507,3381,720],[1002,1258,2673],[1007,3384,2675]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","matrix":[[2.019622339161032e-05,-0.04287927505601098],[0.04277646600755616,0.00015363257215204363],[-72.68124402854043,99.11185183479124]],"controlResidualsFt":[0.10722895795279706,0.10689945326257169,0.1076329185259029,0.10730341383554652]},{"sheet":"A-B-130","floors":[76],"path":"analysis/wtc2-independent-core-review/sources/A-B-130.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":348,"sha256":"1cf39117cb565ae0ff4555c95c8999b9e65a2c46d7d629db5ba8f67f2ad9e6c0","controls":[[502,1236,711],[507,3373,716],[1002,1239,2666],[1007,3382,2672]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00010975780980276587,-0.04267938053661639],[0.042700410767004746,0.0001309682946074087],[-71.96380356357689,98.26117045998753]],"controlResidualsFt":[0.06495099466615482,0.06491834604060416,0.064769281118794,0.06473663249333084]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"limits":"Original architectural plan/section reconstruction with1 ft plan uncertainty. Source counts and raised departure datums replace repeated references; equal riser heights within each story remain an assumption. Passage height uses the8 ft suspended-ceiling notes; local soffits, ducts, doors, railings, finishes and landing thickness are unresolved. The raised vestibule next to incoming A is excluded from walking surfaces. No floor75/76 structural slab, pit, framing, or elevator change. Connections below75 and floor75 slab/finish interfaces still need review.","physicalThicknessFt":null},"reviewRevision":"wtc2-floor76-approach-v1","source":"A-B-128 floor75 stair envelope; floor75 slab/finish interface unresolved."}}},{"floors":[76,76],"evidenceType":"Tower B A-B-130 departure enclosures and A-B-131/132 flight sections;76 incoming routes/transfer passage geometry retain earlier references.","uncertaintyFt":8.0,"stairs":{"A":{"rectFt":[[-44.53922297769835,-80.05311788669037],[-28.250390554085442,-70.86343036867866]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":76,"upperFloor":77,"storyRiseFt":14.0,"riserCount":22,"riserHeightFt":0.6363636363636364,"flights":[{"id":"lower","risers":11,"firstRiserPx":[4135.0,757],"lastRiserPx":[4135.0,947],"firstRiserFt":[-40.09344115648874,-78.11892505990345],"lastRiserFt":[-31.98036311075783,-78.09404108392802],"goingFt":0.8113116207005863,"nominalGoingDifferenceIn":0.23573944840703476,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":7.0,"sourceSheet":"A-B-130","sourcePlanFloor":76},{"id":"upper","risers":11,"firstRiserPx":[4130.0,935],"lastRiserPx":[4130.0,752],"firstRiserFt":[-32.43432548027627,-74.00282672661878],"lastRiserFt":[-40.27030612781909,-74.07319900461],"goingFt":0.7836296635922817,"nominalGoingDifferenceIn":-0.09644403689262049,"widthFt":3.6666666666666665,"baseOffsetFt":7.0,"topOffsetFt":14.0,"sourceSheet":"A-B-135","sourcePlanFloor":77}],"intermediateLanding":{"polygonFt":[[-31.985302212198953,-80.01461320807577],[-32.420867111651866,-79.74451492440944],[-32.43884508167999,-72.0746478542264],[-28.585084107478608,-72.0400385371815],[-28.250390554085442,-72.23557170878077],[-28.270366475469544,-80.00321896644495]],"sourceSheet":"A-B-130","sourcePixels":[[3998,947],[4180,947],[4180,1034],[3998,1034]],"offsetFt":7.0,"planReadingsFt":[[[-31.96532629081485,-72.24696595041159],[-31.985302212198953,-80.01461320807577],[-28.270366475469544,-80.00321896644495],[-28.250390554085442,-72.23557170878077]],[[-32.43884508167999,-72.0746478542264],[-32.420867111651866,-79.74451492440944],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.5038983742534563},"floorLandings":[{"polygonFt":[[-44.5293447748161,-76.2119736383949],[-44.53922297769835,-80.05311788669037],[-40.09838025792986,-80.0394971840512],[-40.08850205504761,-76.19835293575572]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-45.480834857556566,-79.86180205439483],[-45.498812827584686,-72.19193498421178],[-40.27482572922281,-72.14502013221762],[-40.265786526415376,-76.00137787700238],[-39.4950343315751,-75.99445601359342],[-39.48609556435441,-79.8079653389917]],"offsetFt":14.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-130","floors":[76],"path":"analysis/wtc2-independent-core-review/sources/A-B-130.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":348,"sha256":"1cf39117cb565ae0ff4555c95c8999b9e65a2c46d7d629db5ba8f67f2ad9e6c0","controls":[[502,1236,711],[507,3373,716],[1002,1239,2666],[1007,3382,2672]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00010975780980276587,-0.04267938053661639],[0.042700410767004746,0.0001309682946074087],[-71.96380356357689,98.26117045998753]],"controlResidualsFt":[0.06495099466615482,0.06491834604060416,0.064769281118794,0.06473663249333084]},{"sheet":"A-B-135","floors":[77],"path":"analysis/wtc2-independent-core-review/sources/A-B-135.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":353,"sha256":"a1c2789af352b5265f967840e6c6f73cde617b66ae7283ac00fac47e77746a20","controls":[[502,1335,723],[507,3467,720],[1002,1353,2675],[1007,3484,2668]],"pixelConvention":"Native embedded raster rotated180 degrees; no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"controlResidualsFt":[0.044016617895944264,0.044107072724772295,0.04403655167689833,0.04412700650567758]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"enclosurePolygonFt":[[-44.515625048590756,-70.87705107131784],[-44.53922297769835,-80.05311788669037],[-28.270366475469544,-80.00321896644495],[-28.250390554085442,-72.23557170878077],[-40.07840433654576,-72.27184992638702],[-40.074782328822266,-70.86343036867866]],"volumePolygonFt":[[-44.515625048590756,-70.87705107131784],[-44.53922297769835,-80.05311788669037],[-28.270366475469544,-80.00321896644495],[-28.250390554085442,-72.23557170878077],[-40.07840433654576,-72.27184992638702],[-40.074782328822266,-70.86343036867866]],"floorLandingPolygonsFt":[[[-44.5293447748161,-76.2119736383949],[-44.53922297769835,-80.05311788669037],[-40.09838025792986,-80.0394971840512],[-40.08850205504761,-76.19835293575572]]],"nominalFloorSolid":true,"enclosureReview":{"revision":"wtc2-outer-stair-flights-v1","sourceSheet":"A-B-130","uncertaintyFt":1.0},"source":"Original Tower B A-B-130 departure enclosure; sloping soffits unresolved"},"C":{"rectFt":[[-44.36198722863553,71.88482198219097],[-27.944285268052987,80.00151672874071]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":76,"upperFloor":77,"storyRiseFt":14.0,"riserCount":22,"riserHeightFt":0.6363636363636364,"flights":[{"id":"lower","risers":11,"firstRiserPx":[478.0,751],"lastRiserPx":[478.0,941],"firstRiserFt":[-39.948259310642044,77.95878375273506],"lastRiserFt":[-31.835181264911142,77.98366772871046],"goingFt":0.8113116207005856,"nominalGoingDifferenceIn":0.23573944840702765,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":7.0,"sourceSheet":"A-B-130","sourcePlanFloor":76},{"id":"upper","risers":11,"firstRiserPx":[670.0,953],"lastRiserPx":[670.0,767],"firstRiserFt":[-32.01108041558852,74.25962621407166],"lastRiserFt":[-39.97551976227139,74.18810029217892],"goingFt":0.7964760515200241,"nominalGoingDifferenceIn":0.057712618240289615,"widthFt":3.6666666666666665,"baseOffsetFt":7.0,"topOffsetFt":14.0,"sourceSheet":"A-B-135","sourcePlanFloor":77}],"intermediateLanding":{"polygonFt":[[-31.85076687390314,71.92319569251093],[-32.00635994301131,72.24575050290628],[-32.02524183332017,80.30125334756781],[-28.385578691018864,80.33393992477686],[-27.944285268052987,80.00151672874071],[-27.965029494105707,71.9351138073202]],"sourceSheet":"A-B-130","sourcePixels":[[431,941],[620,941],[620,1032],[431,1032]],"offsetFt":7.0,"planReadingsFt":[[[-31.830022647850413,79.98959861393143],[-31.85076687390314,71.92319569251093],[-27.965029494105707,71.9351138073202],[-27.944285268052987,80.00151672874071]],[[-32.02524183332017,80.30125334756781],[-32.00635994301131,72.24575050290628],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.5284008845918885},"floorLandings":[{"polygonFt":[[-44.34124300258281,79.95122490361146],[-44.351560236704266,75.93936313316952],[-39.95341792770278,75.95285286751408],[-39.943100693581314,79.96471463795602]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-45.40888421995613,72.12538698918354],[-45.427766110265,80.18088983384507],[-39.090470286022715,80.23780293298553],[-39.081029340868284,76.21005151065476],[-39.98024023484861,76.2019760033443],[-39.97079928969417,72.17422458101353]],"offsetFt":14.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-130","floors":[76],"path":"analysis/wtc2-independent-core-review/sources/A-B-130.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":348,"sha256":"1cf39117cb565ae0ff4555c95c8999b9e65a2c46d7d629db5ba8f67f2ad9e6c0","controls":[[502,1236,711],[507,3373,716],[1002,1239,2666],[1007,3382,2672]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00010975780980276587,-0.04267938053661639],[0.042700410767004746,0.0001309682946074087],[-71.96380356357689,98.26117045998753]],"controlResidualsFt":[0.06495099466615482,0.06491834604060416,0.064769281118794,0.06473663249333084]},{"sheet":"A-B-135","floors":[77],"path":"analysis/wtc2-independent-core-review/sources/A-B-135.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":353,"sha256":"a1c2789af352b5265f967840e6c6f73cde617b66ae7283ac00fac47e77746a20","controls":[[502,1335,723],[507,3467,720],[1002,1353,2675],[1007,3484,2668]],"pixelConvention":"Native embedded raster rotated180 degrees; no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"controlResidualsFt":[0.044016617895944264,0.044107072724772295,0.04403655167689833,0.04412700650567758]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"enclosurePolygonFt":[[-44.34124300258281,79.95122490361146],[-44.36198722863553,71.88482198219097],[-27.965029494105707,71.9351138073202],[-27.944285268052987,80.00151672874071]],"volumePolygonFt":[[-44.34124300258281,79.95122490361146],[-44.36198722863553,71.88482198219097],[-27.965029494105707,71.9351138073202],[-27.944285268052987,80.00151672874071]],"floorLandingPolygonsFt":[[[-44.34124300258281,79.95122490361146],[-44.351560236704266,75.93936313316952],[-39.95341792770278,75.95285286751408],[-39.943100693581314,79.96471463795602]]],"nominalFloorSolid":true,"enclosureReview":{"revision":"wtc2-outer-stair-flights-v1","sourceSheet":"A-B-130","uncertaintyFt":1.0},"source":"Original Tower B A-B-130 departure enclosure; sloping soffits unresolved"},"B":{"rectFt":[[4.863926452803398,-13.96246851393569],[23.84925070770616,-3.661267262342065]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":76,"upperFloor":77,"storyRiseFt":14.0,"riserCount":22,"riserHeightFt":0.6363636363636364,"flights":[{"id":"lower","risers":12,"firstRiserPx":[2574.5,2132],"lastRiserPx":[2574.5,1930],"firstRiserFt":[18.79090071034001,-11.337670327428384],"lastRiserFt":[10.165417735405043,-11.364125922939081],"goingFt":0.7841385042177916,"nominalGoingDifferenceIn":-0.09033794938649997,"widthFt":4.666666666666667,"baseOffsetFt":0.0,"topOffsetFt":7.636363636363637,"sourceSheet":"A-B-130","sourcePlanFloor":76},{"id":"upper","risers":10,"firstRiserPx":[2560.5,1925],"lastRiserPx":[2560.5,2093],"firstRiserFt":[9.799411582535967,-6.371530012017274],"lastRiserFt":[16.99309873437855,-6.306925953533508],"goingFt":0.799330804392855,"nominalGoingDifferenceIn":0.09196965271426016,"widthFt":4.666666666666667,"baseOffsetFt":7.636363636363637,"topOffsetFt":14.0,"sourceSheet":"A-B-135","sourcePlanFloor":77}],"intermediateLanding":{"polygonFt":[[4.863926452803398,-13.96246851393569],[4.635770060441857,-13.895109498988091],[4.612469004316026,-3.954276201320667],[4.8902683271560505,-3.719417185147762],[10.18511926226465,-3.7031771166164447],[10.158777387911982,-13.946228445404373]],"sourceSheet":"A-B-130","sourcePixels":[[2395,1806],[2635,1806],[2635,1930],[2395,1930]],"offsetFt":7.636363636363637,"planReadingsFt":[[[4.8902683271560505,-3.719417185147762],[4.863926452803398,-13.96246851393569],[10.158777387911982,-13.946228445404373],[10.18511926226465,-3.7031771166164447]],[[4.612469004316026,-3.954276201320667],[4.635770060441857,-13.895109498988091],[9.816937592423713,-13.84857919496109],[9.793636536297882,-3.9077458972936654]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.44170930571829253},"floorLandings":[{"polygonFt":[[18.797541057833072,-8.755567804963093],[18.784260362846936,-13.919772849893675],[23.822908833353495,-13.904318591129993],[23.83618952833963,-8.74011354619941]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[23.70999560980289,-3.7827678079649587],[23.73329666592872,-13.723601105632383],[17.01062474426631,-13.783975136477324],[16.998873780616634,-8.770710068257117],[16.987323688140464,-3.843141838809899]],"offsetFt":14.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-130","floors":[76],"path":"analysis/wtc2-independent-core-review/sources/A-B-130.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":348,"sha256":"1cf39117cb565ae0ff4555c95c8999b9e65a2c46d7d629db5ba8f67f2ad9e6c0","controls":[[502,1236,711],[507,3373,716],[1002,1239,2666],[1007,3382,2672]],"pixelConvention":"Native embedded raster rotated180 degrees, no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00010975780980276587,-0.04267938053661639],[0.042700410767004746,0.0001309682946074087],[-71.96380356357689,98.26117045998753]],"controlResidualsFt":[0.06495099466615482,0.06491834604060416,0.064769281118794,0.06473663249333084]},{"sheet":"A-B-135","floors":[77],"path":"analysis/wtc2-independent-core-review/sources/A-B-135.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":353,"sha256":"a1c2789af352b5265f967840e6c6f73cde617b66ae7283ac00fac47e77746a20","controls":[[502,1335,723],[507,3467,720],[1002,1353,2675],[1007,3484,2668]],"pixelConvention":"Native embedded raster rotated180 degrees; no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"controlResidualsFt":[0.044016617895944264,0.044107072724772295,0.04403655167689833,0.04412700650567758]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"enclosurePolygonFt":[[4.8902683271560505,-3.719417185147762],[4.863926452803398,-13.96246851393569],[23.822908833353495,-13.904318591129993],[23.84925070770616,-3.661267262342065]],"volumePolygonFt":[[4.8902683271560505,-3.719417185147762],[4.863926452803398,-13.96246851393569],[23.822908833353495,-13.904318591129993],[23.84925070770616,-3.661267262342065]],"floorLandingPolygonsFt":[[[18.797541057833072,-8.755567804963093],[18.784260362846936,-13.919772849893675],[23.822908833353495,-13.904318591129993],[23.83618952833963,-8.74011354619941]]],"nominalFloorSolid":true,"enclosureReview":{"revision":"wtc2-outer-stair-flights-v1","sourceSheet":"A-B-130","uncertaintyFt":1.0},"source":"Original Tower B A-B-130 departure enclosure; sloping soffits unresolved"}}},{"floors":[77,77],"evidenceType":"Original Tower B A-B-135/137/139/141/143/145 and stair sections131/132; detailed scope in component records","uncertaintyFt":1.0,"stairs":{"A":{"floor":77,"stair":"A","sourceSheet":"A-B-135","enclosurePx":[[4085,630],[4264,630],[4264,1025],[4085,1025]],"voidWitnessPx":[4174.5,980],"landingWitnessPx":[4174.5,685],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-45.498812827584686,-72.19193498421178],[-45.480834857556566,-79.86180205439483],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]],"floorOpeningPolygonFt":[[-40.27482572922281,-72.14502013221762],[-40.265786526415376,-76.00137787700238],[-39.4950343315751,-75.99445601359342],[-39.48609556435441,-79.8079653389917],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]],"voidWitnessFt":[-30.50297560956524,-75.89227673079547],"landingWitnessFt":[-43.13474769166978,-76.00571838110922],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-135; sections A-B-131/132","rectFt":[[-45.498812827584686,-79.86180205439483],[-28.56710613745048,-72.0400385371815]],"volumePolygonFt":[[-45.498812827584686,-72.19193498421178],[-45.480834857556566,-79.86180205439483],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]],"floorLandingPolygonsFt":[[[-45.480834857556566,-79.86180205439483],[-45.498812827584686,-72.19193498421178],[-40.27482572922281,-72.14502013221762],[-40.265786526415376,-76.00137787700238],[-39.4950343315751,-75.99445601359342],[-39.48609556435441,-79.8079653389917]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":77,"upperFloor":78,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[4219.5,770],"lastRiserPx":[4219.5,935],"firstRiserFt":[-39.49056494796475,-77.90121067629256],"lastRiserFt":[-32.425336495262215,-77.8377602617103],"goingFt":0.7850570400286966,"nominalGoingDifferenceIn":-0.07931551965564054,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-135","sourcePlanFloor":77},{"id":"upper","risers":9,"firstRiserPx":[4159.0,922],"lastRiserPx":[4159.0,776],"firstRiserFt":[-31.977608115739528,-73.99867360136885],"lastRiserFt":[-38.150267256192734,-74.0081278304183],"goingFt":0.7715832975798391,"nominalGoingDifferenceIn":-0.24100042904193053,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-137","sourcePlanFloor":78}],"intermediateLanding":{"polygonFt":[[-32.420867111651866,-79.74451492440944],[-32.43884508167999,-72.0746478542264],[-28.585084107478608,-72.0400385371815],[-28.29452346629477,-72.24400592837215],[-28.31525139478014,-79.7093949039466]],"sourceSheet":"A-B-135","sourcePixels":[[4085,935],[4264,935],[4264,1025],[4085,1025]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-32.43884508167999,-72.0746478542264],[-32.420867111651866,-79.74451492440944],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]],[[-31.972751858208667,-72.2496396128057],[-31.99347978669404,-79.71502858838015],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.49786043078011905},"floorLandings":[{"polygonFt":[[-45.480834857556566,-79.86180205439483],[-45.498812827584686,-72.19193498421178],[-40.27482572922281,-72.14502013221762],[-40.265786526415376,-76.00137787700238],[-39.4950343315751,-75.99445601359342],[-39.48609556435441,-79.8079653389917]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-45.05753235107788,-79.73503788136834],[-45.03680442259251,-72.26964890579389],[-38.14541099866187,-72.25909384185515],[-38.15512351372359,-75.75716181898146],[-39.71942754246858,-75.75955775374057],[-39.73044295589224,-79.72687875218871]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-135","floors":[77],"path":"analysis/wtc2-independent-core-review/sources/A-B-135.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":353,"sha256":"a1c2789af352b5265f967840e6c6f73cde617b66ae7283ac00fac47e77746a20","controls":[[502,1335,723],[507,3467,720],[1002,1353,2675],[1007,3484,2668]],"pixelConvention":"Native embedded raster rotated180 degrees; no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"controlResidualsFt":[0.044016617895944264,0.044107072724772295,0.04403655167689833,0.04412700650567758]},{"sheet":"A-B-137","floors":[78],"path":"analysis/wtc2-independent-core-review/sources/A-B-137.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":355,"sha256":"4104f2443ccdc80c02eb64bb075a876d4d0386b9cce0c788cdc0ba65efa7b97f","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1354,681],[507,3494,691],[1002,1356,2660],[1007,3498,2662]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"controlResidualsFt":[0.0871589862320893,0.08751283502580527,0.08707694451071928,0.08743079330455591]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":77,"stair":"A","region":"tenant","polygonFt":[[-40.27482572922281,-72.14502013221762],[-40.265786526415376,-76.00137787700238],[-39.4950343315751,-75.99445601359342],[-39.48609556435441,-79.8079653389917],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]],"sourceSheet":"A-B-135","sourcePixels":[[4085,752],[4175,752],[4175,770],[4264,770],[4264,1025],[4085,1025]],"registrationMatrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"C":{"floor":77,"stair":"C","sourceSheet":"A-B-135","enclosurePx":[[529,640],[717,640],[717,1038],[529,1038]],"voidWitnessPx":[623.0,993],"landingWitnessPx":[623.0,695],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-45.427766110265,80.18088983384507],[-45.40888421995613,72.12538698918354],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]],"floorOpeningPolygonFt":[[-39.090470286022715,80.23780293298553],[-39.081029340868284,76.21005151065476],[-39.98024023484861,76.2019760033443],[-39.97079928969417,72.17422458101353],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]],"voidWitnessFt":[-30.30301823296513,76.28888384392366],"landingWitnessFt":[-43.06324901420972,76.1742885497084],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-135; sections A-B-131/132","rectFt":[[-45.427766110265,72.12538698918354],[-28.366696800710002,80.33393992477686]],"volumePolygonFt":[[-45.427766110265,80.18088983384507],[-45.40888421995613,72.12538698918354],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]],"floorLandingPolygonsFt":[[[-45.40888421995613,72.12538698918354],[-45.427766110265,80.18088983384507],[-39.090470286022715,80.23780293298553],[-39.081029340868284,76.21005151065476],[-39.98024023484861,76.2019760033443],[-39.97079928969417,72.17422458101353]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":77,"upperFloor":78,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[576.0,788],"lastRiserPx":[576.0,953],"firstRiserFt":[-39.085749813445496,78.22392722182015],"lastRiserFt":[-32.02052136074296,78.28737763640243],"goingFt":0.7850570400286967,"nominalGoingDifferenceIn":-0.07931551965564054,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-135","sourcePlanFloor":77},{"id":"upper","risers":9,"firstRiserPx":[682.5,916],"lastRiserPx":[682.5,771],"firstRiserFt":[-31.81950393429466,74.30622228915325],"lastRiserFt":[-37.94988458748448,74.2968328150973],"goingFt":0.7662984804731275,"nominalGoingDifferenceIn":-0.30441823432246906,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-137","sourcePlanFloor":78}],"intermediateLanding":{"polygonFt":[[-32.00635994301131,72.24575050290628],[-32.02524183332017,80.30125334756781],[-31.802507032936653,80.4278412491243],[-27.99744317923262,80.43366919853833],[-28.019829341996825,72.37104910491793],[-28.366696800710002,72.27843708011531]],"sourceSheet":"A-B-135","sourcePixels":[[529,953],[717,953],[717,1038],[529,1038]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-32.02524183332017,80.30125334756781],[-32.00635994301131,72.24575050290628],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]],[[-31.802507032936653,80.4278412491243],[-31.824893195700852,72.36522115550389],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.4007431890307815},"floorLandings":[{"polygonFt":[[-45.40888421995613,72.12538698918354],[-45.427766110265,80.18088983384507],[-39.090470286022715,80.23780293298553],[-39.081029340868284,76.21005151065476],[-39.98024023484861,76.2019760033443],[-39.97079928969417,72.17422458101353]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-44.76211029829456,72.34540612749618],[-44.73972413553036,80.40802622111656],[-39.53947020213485,80.41599108531575],[-39.551077842086656,76.23537325899406],[-37.94449532607829,76.23783394874665],[-37.955273848890684,72.35583168144795]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-135","floors":[77],"path":"analysis/wtc2-independent-core-review/sources/A-B-135.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":353,"sha256":"a1c2789af352b5265f967840e6c6f73cde617b66ae7283ac00fac47e77746a20","controls":[[502,1335,723],[507,3467,720],[1002,1353,2675],[1007,3484,2668]],"pixelConvention":"Native embedded raster rotated180 degrees; no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"controlResidualsFt":[0.044016617895944264,0.044107072724772295,0.04403655167689833,0.04412700650567758]},{"sheet":"A-B-137","floors":[78],"path":"analysis/wtc2-independent-core-review/sources/A-B-137.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":355,"sha256":"4104f2443ccdc80c02eb64bb075a876d4d0386b9cce0c788cdc0ba65efa7b97f","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1354,681],[507,3494,691],[1002,1356,2660],[1007,3498,2662]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"controlResidualsFt":[0.0871589862320893,0.08751283502580527,0.08707694451071928,0.08743079330455591]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":77,"stair":"C","region":"tenant","polygonFt":[[-39.090470286022715,80.23780293298553],[-39.081029340868284,76.21005151065476],[-39.98024023484861,76.2019760033443],[-39.97079928969417,72.17422458101353],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]],"sourceSheet":"A-B-135","sourcePixels":[[529,788],[623,788],[623,767],[717,767],[717,1038],[529,1038]],"registrationMatrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"B":{"floor":77,"stair":"B","sourceSheet":"A-B-135","enclosurePx":[[2503,1804],[2735,1804],[2735,2250],[2503,2250]],"voidWitnessPx":[2550,2010],"landingWitnessPx":[2640,2200],"phase":"inner stair story","interpretation":"A-B-135 stair3 clear enclosure and flight/half-landing opening; A-B-132 section H confirms continuous stair76\u201381. No full-height future-knockout slot is inferred.","enclosurePolygonFt":[[4.612469004316026,-3.954276201320667],[4.635770060441857,-13.895109498988091],[23.73329666592872,-13.723601105632383],[23.70999560980289,-3.7827678079649587]],"floorOpeningPolygonFt":[[4.612469004316026,-3.954276201320667],[4.635770060441857,-13.895109498988091],[17.01062474426631,-13.783975136477324],[16.998873780616634,-8.770710068257117],[16.998873780616634,-8.770710068257117],[16.987323688140464,-3.843141838809899]],"voidWitnessFt":[13.438020151176403,-5.88893503125],"landingWitnessFt":[21.58277696618677,-9.672228662273369],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-135; sections A-B-131/132","rectFt":[[4.612469004316026,-13.895109498988091],[23.73329666592872,-3.7827678079649587]],"volumePolygonFt":[[4.612469004316026,-3.954276201320667],[4.635770060441857,-13.895109498988091],[23.73329666592872,-13.723601105632383],[23.70999560980289,-3.7827678079649587]],"floorLandingPolygonsFt":[[[23.70999560980289,-3.7827678079649587],[23.73329666592872,-13.723601105632383],[17.01062474426631,-13.783975136477324],[16.998873780616634,-8.770710068257117],[16.987323688140464,-3.843141838809899]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":77,"upperFloor":78,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2676.5,2093],"lastRiserPx":[2676.5,1925],"firstRiserFt":[17.004749262441464,-11.277342602367213],"lastRiserFt":[9.811062110598883,-11.34194666085098],"goingFt":0.799330804392855,"nominalGoingDifferenceIn":0.09196965271426016,"widthFt":4.666666666666667,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-135","sourcePlanFloor":77},{"id":"upper","risers":9,"firstRiserPx":[2574.5,1909],"lastRiserPx":[2574.5,2059],"firstRiserFt":[9.938935399986534,-6.340995669665233],"lastRiserFt":[16.28070848949325,-6.331282420641827],"goingFt":0.7927225660066838,"nominalGoingDifferenceIn":0.012670792080205828,"widthFt":4.666666666666667,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-137","sourcePlanFloor":78}],"intermediateLanding":{"polygonFt":[[4.633100450314814,-13.9211274333626],[4.612469004316026,-3.954276201320667],[4.6609350971380366,-3.896176523305499],[9.9457460050603,-3.8880821491193416],[9.917911358237092,-13.913033059176442]],"sourceSheet":"A-B-135","sourcePixels":[[2503,1804],[2735,1804],[2735,1925],[2503,1925]],"offsetFt":6.315789473684211,"planReadingsFt":[[[4.612469004316026,-3.954276201320667],[4.635770060441857,-13.895109498988091],[9.816937592423713,-13.84857919496109],[9.793636536297882,-3.9077458972936654]],[[4.6609350971380366,-3.896176523305499],[4.633100450314814,-13.9211274333626],[9.917911358237092,-13.913033059176442],[9.9457460050603,-3.8880821491193416]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.15337520490434034},"floorLandings":[{"polygonFt":[[23.70999560980289,-3.7827678079649587],[23.73329666592872,-13.723601105632383],[17.01062474426631,-13.783975136477324],[16.998873780616634,-8.770710068257117],[16.987323688140464,-3.843141838809899]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[23.93992528923846,-3.86664824627438],[23.91209064241525,-13.89159915633148],[17.908545451015556,-13.900794365406952],[17.92275888769123,-8.78167049644162],[16.273897884419483,-8.784195941187704],[16.287519094567017,-3.8783689000959356]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-135","floors":[77],"path":"analysis/wtc2-independent-core-review/sources/A-B-135.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":353,"sha256":"a1c2789af352b5265f967840e6c6f73cde617b66ae7283ac00fac47e77746a20","controls":[[502,1335,723],[507,3467,720],[1002,1353,2675],[1007,3484,2668]],"pixelConvention":"Native embedded raster rotated180 degrees; no resampling","reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"controlResidualsFt":[0.044016617895944264,0.044107072724772295,0.04403655167689833,0.04412700650567758]},{"sheet":"A-B-137","floors":[78],"path":"analysis/wtc2-independent-core-review/sources/A-B-137.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":355,"sha256":"4104f2443ccdc80c02eb64bb075a876d4d0386b9cce0c788cdc0ba65efa7b97f","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1354,681],[507,3494,691],[1002,1356,2660],[1007,3498,2662]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"controlResidualsFt":[0.0871589862320893,0.08751283502580527,0.08707694451071928,0.08743079330455591]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":77,"stair":"B","region":"core","polygonFt":[[4.612469004316026,-3.954276201320667],[4.635770060441857,-13.895109498988091],[17.01062474426631,-13.783975136477324],[16.998873780616634,-8.770710068257117],[16.998873780616634,-8.770710068257117],[16.987323688140464,-3.843141838809899]],"sourceSheet":"A-B-135","sourcePixels":[[2503,1804],[2735,1804],[2735,2093],[2618,2093],[2618,2093],[2503,2093]],"registrationMatrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}}},"stairTransitionRevision":"wtc2-stair-transition-v1"},{"floors":[78,78],"evidenceType":"Original Tower B A-B-135/137/139/141/143/145 and stair sections131/132; detailed scope in component records","uncertaintyFt":1.0,"stairs":{"A":{"floor":78,"stair":"A","sourceSheet":"A-B-137","enclosurePx":[[4118,613],[4293,613],[4293,1009],[4118,1009]],"voidWitnessPx":[4205.5,964],"landingWitnessPx":[4205.5,668],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-45.03680442259251,-72.26964890579389],[-45.05753235107788,-79.73503788136834],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]],"floorOpeningPolygonFt":[[-38.14541099866187,-72.25909384185515],[-38.15512351372359,-75.75716181898146],[-39.71942754246858,-75.75955775374057],[-39.73044295589224,-79.72687875218871],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]],"voidWitnessFt":[-30.20741935738947,-75.97961439086639],"landingWitnessFt":[-42.7218515873494,-75.99878186893922],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-137; sections A-B-131/132","rectFt":[[-45.05753235107788,-79.73503788136834],[-28.29452346629477,-72.24400592837215]],"volumePolygonFt":[[-45.03680442259251,-72.26964890579389],[-45.05753235107788,-79.73503788136834],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]],"floorLandingPolygonsFt":[[[-45.05753235107788,-79.73503788136834],[-45.03680442259251,-72.26964890579389],[-38.14541099866187,-72.25909384185515],[-38.15512351372359,-75.75716181898146],[-39.71942754246858,-75.75955775374057],[-39.73044295589224,-79.72687875218871]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":78,"upperFloor":79,"storyRiseFt":14.0,"riserCount":22,"riserHeightFt":0.6363636363636364,"flights":[{"id":"lower","risers":11,"firstRiserPx":[4246.5,739],"lastRiserPx":[4246.5,922],"firstRiserFt":[-39.724935249180405,-77.74321825296464],"lastRiserFt":[-31.987972079982214,-77.73136808915608],"goingFt":0.7736972244225231,"nominalGoingDifferenceIn":-0.21563330692972293,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":7.0,"sourceSheet":"A-B-137","sourcePlanFloor":78},{"id":"upper","risers":11,"firstRiserPx":[4101.5,909],"lastRiserPx":[4101.5,724],"firstRiserFt":[-32.347020829204745,-73.80578997700442],"lastRiserFt":[-40.19809571778791,-73.8800433426114],"goingFt":0.7851426014963466,"nominalGoingDifferenceIn":-0.07828878204384004,"widthFt":3.6666666666666665,"baseOffsetFt":7.0,"topOffsetFt":14.0,"sourceSheet":"A-B-139","sourcePlanFloor":79}],"intermediateLanding":{"polygonFt":[[-32.32641503129946,-79.71802760660071],[-32.35393902128124,-71.82081488836738],[-28.74668839679709,-71.78669847714255],[-28.29452346629477,-72.24400592837215],[-28.31525139478014,-79.7093949039466]],"sourceSheet":"A-B-137","sourcePixels":[[4118,922],[4293,922],[4293,1009],[4118,1009]],"offsetFt":7.0,"planReadingsFt":[[[-31.972751858208667,-72.2496396128057],[-31.99347978669404,-79.71502858838015],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]],[[-32.35393902128124,-71.82081488836738],[-32.32641503129946,-79.71802760660071],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.5737545621438787},"floorLandings":[{"polygonFt":[[-45.05753235107788,-79.73503788136834],[-45.03680442259251,-72.26964890579389],[-38.14541099866187,-72.25909384185515],[-38.15512351372359,-75.75716181898146],[-39.71942754246858,-75.75955775374057],[-39.73044295589224,-79.72687875218871]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-45.015449580955504,-79.83803710020334],[-45.042973570937285,-71.94082438197],[-40.20501390986442,-71.89506825397436],[-40.19117752571141,-75.86501843124842],[-39.384850915532596,-75.8573924099158],[-39.37116330970382,-79.78465495087508]],"offsetFt":14.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-137","floors":[78],"path":"analysis/wtc2-independent-core-review/sources/A-B-137.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":355,"sha256":"4104f2443ccdc80c02eb64bb075a876d4d0386b9cce0c788cdc0ba65efa7b97f","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1354,681],[507,3494,691],[1002,1356,2660],[1007,3498,2662]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"controlResidualsFt":[0.0871589862320893,0.08751283502580527,0.08707694451071928,0.08743079330455591]},{"sheet":"A-B-139","floors":[79],"path":"analysis/wtc2-independent-core-review/sources/A-B-139.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":357,"sha256":"e27aba4efdd09c4dec076dd309bea7a3c1260481f31d1c913b4d529b8f8d20d1","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1302,697],[507,3439,690],[1002,1318,2665],[1007,3460,2657]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"controlResidualsFt":[0.054516765598682286,0.05454396264017155,0.054389242271355165,0.054416439312851755]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":78,"stair":"A","region":"tenant","polygonFt":[[-38.14541099866187,-72.25909384185515],[-38.15512351372359,-75.75716181898146],[-39.71942754246858,-75.75955775374057],[-39.73044295589224,-79.72687875218871],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]],"sourceSheet":"A-B-137","sourcePixels":[[4118,776],[4200,776],[4200,739],[4293,739],[4293,1009],[4118,1009]],"registrationMatrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"C":{"floor":78,"stair":"C","sourceSheet":"A-B-137","enclosurePx":[[539,610],[728,610],[728,1006],[539,1006]],"voidWitnessPx":[633.5,961],"landingWitnessPx":[633.5,665],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-44.73972413553036,80.40802622111656],[-44.76211029829456,72.34540612749618],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]],"floorOpeningPolygonFt":[[-39.53947020213485,80.41599108531575],[-39.551077842086656,76.23537325899406],[-37.94449532607829,76.23783394874665],[-37.955273848890684,72.35583168144795],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]],"voidWitnessFt":[-29.911168187466735,76.39944517702111],"landingWitnessFt":[-42.425600417426665,76.38027769894828],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-137; sections A-B-131/132","rectFt":[[-44.76211029829456,72.34540612749618],[-27.99744317923262,80.43366919853833]],"volumePolygonFt":[[-44.73972413553036,80.40802622111656],[-44.76211029829456,72.34540612749618],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]],"floorLandingPolygonsFt":[[[-44.76211029829456,72.34540612749618],[-44.73972413553036,80.40802622111656],[-39.53947020213485,80.41599108531575],[-39.551077842086656,76.23537325899406],[-37.94449532607829,76.23783394874665],[-37.955273848890684,72.35583168144795]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":78,"upperFloor":79,"storyRiseFt":14.0,"riserCount":22,"riserHeightFt":0.6363636363636364,"flights":[{"id":"lower","risers":11,"firstRiserPx":[588.0,733],"lastRiserPx":[588.0,916],"firstRiserFt":[-39.54527402211075,78.3256821721549],"lastRiserFt":[-31.808310852912555,78.33753233596345],"goingFt":0.7736972244225238,"nominalGoingDifferenceIn":-0.21563330692971405,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":7.0,"sourceSheet":"A-B-137","sourcePlanFloor":78},{"id":"upper","risers":11,"firstRiserPx":[634.5,927],"lastRiserPx":[634.5,742],"firstRiserFt":[-32.09894691175803,74.19946977810865],"lastRiserFt":[-39.9500218003412,74.12521641250166],"goingFt":0.7851426014963473,"nominalGoingDifferenceIn":-0.07828878204383294,"widthFt":3.6666666666666665,"baseOffsetFt":7.0,"topOffsetFt":14.0,"sourceSheet":"A-B-139","sourcePlanFloor":79}],"intermediateLanding":{"polygonFt":[[-32.092177498005746,72.2571823257864],[-32.12029660128444,80.32514558927883],[-31.802507032936653,80.4278412491243],[-27.99744317923262,80.43366919853833],[-28.019829341996825,72.37104910491793],[-28.61224160144456,72.29009462837976]],"sourceSheet":"A-B-137","sourcePixels":[[539,916],[728,916],[728,1006],[539,1006]],"offsetFt":7.0,"planReadingsFt":[[[-31.802507032936653,80.4278412491243],[-31.824893195700852,72.36522115550389],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]],[[-32.12029660128444,80.32514558927883],[-32.092177498005746,72.2571823257864],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.6473484488888163},"floorLandings":[{"polygonFt":[[-44.76211029829456,72.34540612749618],[-44.73972413553036,80.40802622111656],[-39.53947020213485,80.41599108531575],[-39.551077842086656,76.23537325899406],[-37.94449532607829,76.23783394874665],[-37.955273848890684,72.35583168144795]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-45.20559447407169,72.13315913674555],[-45.233713577350386,80.20112240023798],[-39.12260663704781,80.25891961454829],[-39.10802636127367,76.07553125570035],[-39.95679121409347,76.06750386482392],[-39.94325238658892,72.18292896017941]],"offsetFt":14.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-137","floors":[78],"path":"analysis/wtc2-independent-core-review/sources/A-B-137.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":355,"sha256":"4104f2443ccdc80c02eb64bb075a876d4d0386b9cce0c788cdc0ba65efa7b97f","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1354,681],[507,3494,691],[1002,1356,2660],[1007,3498,2662]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"controlResidualsFt":[0.0871589862320893,0.08751283502580527,0.08707694451071928,0.08743079330455591]},{"sheet":"A-B-139","floors":[79],"path":"analysis/wtc2-independent-core-review/sources/A-B-139.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":357,"sha256":"e27aba4efdd09c4dec076dd309bea7a3c1260481f31d1c913b4d529b8f8d20d1","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1302,697],[507,3439,690],[1002,1318,2665],[1007,3460,2657]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"controlResidualsFt":[0.054516765598682286,0.05454396264017155,0.054389242271355165,0.054416439312851755]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":78,"stair":"C","region":"tenant","polygonFt":[[-39.53947020213485,80.41599108531575],[-39.551077842086656,76.23537325899406],[-37.94449532607829,76.23783394874665],[-37.955273848890684,72.35583168144795],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]],"sourceSheet":"A-B-137","sourcePixels":[[539,733],[637,733],[637,771],[728,771],[728,1006],[539,1006]],"registrationMatrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[4.6609350971380366,-3.896176523305499],[4.633100450314814,-13.9211274333626],[17.908545451015556,-13.900794365406952],[17.92275888769123,-8.78167049644162],[16.273897884419483,-8.784195941187704],[16.287519094567017,-3.8783689000959356]],"floorLandingPolygonsFt":[[[23.93992528923846,-3.86664824627438],[23.91209064241525,-13.89159915633148],[17.908545451015556,-13.900794365406952],[17.92275888769123,-8.78167049644162],[16.273897884419483,-8.784195941187704],[16.287519094567017,-3.8783689000959356]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":78,"upperFloor":79,"storyRiseFt":14.0,"riserCount":22,"riserHeightFt":0.6363636363636364,"flights":[{"id":"lower","risers":11,"firstRiserPx":[2692.0,2098],"lastRiserPx":[2692.0,1909],"firstRiserFt":[17.915652169353393,-11.341232430924293],"lastRiserFt":[9.92501807657493,-11.353471124693783],"goingFt":0.7990643465347375,"nominalGoingDifferenceIn":0.08877215841684993,"widthFt":4.666666666666667,"baseOffsetFt":0.0,"topOffsetFt":7.0,"sourceSheet":"A-B-137","sourcePlanFloor":78},{"id":"upper","risers":11,"firstRiserPx":[2535.5,1908],"lastRiserPx":[2535.5,2095],"firstRiserFt":[9.815796713406655,-6.555983333789371],"lastRiserFt":[17.751748087271807,-6.480927229094746],"goingFt":0.7936306296206322,"nominalGoingDifferenceIn":0.023567555447586486,"widthFt":4.666666666666667,"baseOffsetFt":7.0,"topOffsetFt":14.0,"sourceSheet":"A-B-139","sourcePlanFloor":79}],"intermediateLanding":{"polygonFt":[[4.664292928783269,-14.053942955063803],[4.633100450314814,-13.9211274333626],[4.629330022590196,-4.022348421091721],[4.6609350971380366,-3.896176523305499],[9.9457460050603,-3.8880821491193416],[9.917911358237092,-13.913033059176442],[9.841758530984066,-14.004975870717573]],"sourceSheet":"A-B-137","sourcePixels":[[2517,1784],[2752,1784],[2752,1909],[2517,1909]],"offsetFt":7.0,"planReadingsFt":[[[4.6609350971380366,-3.896176523305499],[4.633100450314814,-13.9211274333626],[9.917911358237092,-13.913033059176442],[9.9457460050603,-3.8880821491193416]],[[4.629330022590196,-4.022348421091721],[4.664292928783269,-14.053942955063803],[9.841758530984066,-14.004975870717573],[9.806795624790979,-3.97338133674549]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.1630434285295481},"floorLandings":[{"polygonFt":[[23.93992528923846,-3.86664824627438],[23.91209064241525,-13.89159915633148],[17.908545451015556,-13.900794365406952],[17.92275888769123,-8.78167049644162],[16.273897884419483,-8.784195941187704],[16.287519094567017,-3.8783689000959356]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[24.10848339480465,-3.8381198004776422],[24.143446300997724,-13.869714334449725],[16.92894505202942,-13.937947156899384],[16.911984323067657,-9.071556617015048],[17.76074917588747,-9.063529226138613],[17.74274699865613,-3.8983252320508655]],"offsetFt":14.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-137","floors":[78],"path":"analysis/wtc2-independent-core-review/sources/A-B-137.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":355,"sha256":"4104f2443ccdc80c02eb64bb075a876d4d0386b9cce0c788cdc0ba65efa7b97f","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1354,681],[507,3494,691],[1002,1356,2660],[1007,3498,2662]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"controlResidualsFt":[0.0871589862320893,0.08751283502580527,0.08707694451071928,0.08743079330455591]},{"sheet":"A-B-139","floors":[79],"path":"analysis/wtc2-independent-core-review/sources/A-B-139.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":357,"sha256":"e27aba4efdd09c4dec076dd309bea7a3c1260481f31d1c913b4d529b8f8d20d1","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1302,697],[507,3439,690],[1002,1318,2665],[1007,3460,2657]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"controlResidualsFt":[0.054516765598682286,0.05454396264017155,0.054389242271355165,0.054416439312851755]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":78,"stair":"B","region":"core","polygonFt":[[4.6609350971380366,-3.896176523305499],[4.633100450314814,-13.9211274333626],[17.908545451015556,-13.900794365406952],[17.92275888769123,-8.78167049644162],[16.273897884419483,-8.784195941187704],[16.287519094567017,-3.8783689000959356]],"sourceSheet":"A-B-137","sourcePixels":[[2517,1784],[2752,1784],[2752,2098],[2632,2098],[2632,2059],[2517,2059]],"registrationMatrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1","stairTransitionRevision":"wtc2-stair-transition-v1"},{"floors":[79,79],"evidenceType":"Original Tower B A-B-135/137/139/141/143/145 and stair sections131/132; detailed scope in component records","uncertaintyFt":1.0,"stairs":{"A":{"floor":79,"stair":"A","sourceSheet":"A-B-139","enclosurePx":[[4055,610],[4240,610],[4240,994],[4055,994]],"voidWitnessPx":[4147.5,949],"landingWitnessPx":[4147.5,665],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-45.042973570937285,-71.94082438197],[-45.015449580955504,-79.83803710020334],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]],"floorOpeningPolygonFt":[[-40.20501390986442,-71.89506825397436],[-40.19117752571141,-75.86501843124842],[-39.384850915532596,-75.8573924099158],[-39.37116330970382,-79.78465495087508],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]],"voidWitnessFt":[-30.642647320650745,-75.75336646573118],"landingWitnessFt":[-42.695108230691936,-75.86735541617648],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-139; sections A-B-131/132","rectFt":[[-45.042973570937285,-79.83803710020334],[-28.719164406815302,-71.78669847714255]],"volumePolygonFt":[[-45.042973570937285,-71.94082438197],[-45.015449580955504,-79.83803710020334],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]],"floorLandingPolygonsFt":[[[-45.015449580955504,-79.83803710020334],[-45.042973570937285,-71.94082438197],[-40.20501390986442,-71.89506825397436],[-40.19117752571141,-75.86501843124842],[-39.384850915532596,-75.8573924099158],[-39.37116330970382,-79.78465495087508]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":79,"upperFloor":80,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[4194.0,743],"lastRiserPx":[4194.0,909],"firstRiserFt":[-39.37800711261821,-77.82102368039546],"lastRiserFt":[-32.33325883421385,-77.75439633612109],"goingFt":0.7827848159062679,"nominalGoingDifferenceIn":-0.10658220912478455,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-139","sourcePlanFloor":79},{"id":"upper","risers":9,"firstRiserPx":[4214.5,995],"lastRiserPx":[4214.5,849],"firstRiserFt":[-32.29550267486381,-74.03803918862454],"lastRiserFt":[-38.4681048886062,-74.09163921600023],"goingFt":0.7716043660374152,"nominalGoingDifferenceIn":-0.2407476075510182,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-141","sourcePlanFloor":80}],"intermediateLanding":{"polygonFt":[[-32.29002508798399,-79.94627825994917],[-32.32641503129946,-79.71802760660071],[-32.35393902128124,-71.82081488836738],[-28.74668839679709,-71.78669847714255],[-28.449995311664196,-72.06365710584728],[-28.442718228733604,-79.91287002370814]],"sourceSheet":"A-B-139","sourcePixels":[[4055,909],[4240,909],[4240,994],[4055,994]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-32.35393902128124,-71.82081488836738],[-32.32641503129946,-79.71802760660071],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]],[[-32.297302170914584,-72.09706534208831],[-32.29002508798399,-79.94627825994917],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.3589493480245595},"floorLandings":[{"polygonFt":[[-45.015449580955504,-79.83803710020334],[-45.042973570937285,-71.94082438197],[-40.20501390986442,-71.89506825397436],[-40.19117752571141,-75.86501843124842],[-39.384850915532596,-75.8573924099158],[-39.37116330970382,-79.78465495087508]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-44.381560931342364,-80.05127557384952],[-44.38883801427295,-72.20206265598867],[-38.469904384656964,-72.15066536946401],[-38.46630539255543,-76.03261306253648],[-39.227311144934625,-76.03922128508967],[-39.223633054105576,-80.00648650987804]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-139","floors":[79],"path":"analysis/wtc2-independent-core-review/sources/A-B-139.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":357,"sha256":"e27aba4efdd09c4dec076dd309bea7a3c1260481f31d1c913b4d529b8f8d20d1","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1302,697],[507,3439,690],[1002,1318,2665],[1007,3460,2657]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"controlResidualsFt":[0.054516765598682286,0.05454396264017155,0.054389242271355165,0.054416439312851755]},{"sheet":"A-B-141","floors":[80],"path":"analysis/wtc2-independent-core-review/sources/A-B-141.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":359,"sha256":"3956c28968825e0ccd92475e432a247cb0146c0937904847cbe94bba5bba7f78","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1408,773],[507,3546,773],[1002,1422,2750],[1007,3566,2746]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"controlResidualsFt":[0.07699832790613385,0.07715399216489915,0.07678139541870539,0.07693705967735691]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":79,"stair":"A","region":"tenant","polygonFt":[[-40.20501390986442,-71.89506825397436],[-40.19117752571141,-75.86501843124842],[-39.384850915532596,-75.8573924099158],[-39.37116330970382,-79.78465495087508],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]],"sourceSheet":"A-B-139","sourcePixels":[[4055,724],[4148,724],[4148,743],[4240,743],[4240,994],[4055,994]],"registrationMatrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"C":{"floor":79,"stair":"C","sourceSheet":"A-B-139","enclosurePx":[[491,618],[680,618],[680,1009],[491,1009]],"voidWitnessPx":[585.5,964],"landingWitnessPx":[585.5,673],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-45.233713577350386,80.20112240023798],[-45.20559447407169,72.13315913674555],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]],"floorOpeningPolygonFt":[[-39.12260663704781,80.25891961454829],[-39.10802636127367,76.07553125570035],[-39.95679121409347,76.06750386482392],[-39.94325238658892,72.18292896017941],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]],"voidWitnessFt":[-30.536022071928464,76.306014630654],"landingWitnessFt":[-42.88555068045658,76.18921609340195],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-139; sections A-B-131/132","rectFt":[[-45.233713577350386,72.13315913674555],[-28.61224160144456,80.35805789187219]],"volumePolygonFt":[[-45.233713577350386,80.20112240023798],[-45.20559447407169,72.13315913674555],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]],"floorLandingPolygonsFt":[[[-45.20559447407169,72.13315913674555],[-45.233713577350386,80.20112240023798],[-39.12260663704781,80.25891961454829],[-39.10802636127367,76.07553125570035],[-39.95679121409347,76.06750386482392],[-39.94325238658892,72.18292896017941]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":79,"upperFloor":80,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[540.0,762],"lastRiserPx":[540.0,927],"firstRiserFt":[-39.11531649916074,78.16722543512432],"lastRiserFt":[-32.11300646339737,78.23345140985487],"goingFt":0.7780692447261104,"nominalGoingDifferenceIn":-0.16316906328667535,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-139","sourcePlanFloor":79},{"id":"upper","risers":9,"firstRiserPx":[738.5,1008],"lastRiserPx":[738.5,863],"firstRiserFt":[-31.883360997662727,74.24860353875019],"lastRiserFt":[-38.01368511405071,74.19537063484967],"goingFt":0.7663194046261994,"nominalGoingDifferenceIn":-0.3041671444856071,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-141","sourcePlanFloor":80}],"intermediateLanding":{"polygonFt":[[-31.881442853520696,72.17965339464013],[-32.092177498005746,72.2571823257864],[-32.12029660128444,80.32514558927883],[-31.888996781997555,80.32747767350656],[-28.64036070472325,80.35805789187219],[-28.25308040951917,80.3590502923717],[-28.245526481042305,72.21122601350527]],"sourceSheet":"A-B-139","sourcePixels":[[491,927],[680,927],[680,1009],[491,1009]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-32.12029660128444,80.32514558927883],[-32.092177498005746,72.2571823257864],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]],[[-31.888996781997555,80.32747767350656],[-31.881442853520696,72.17965339464013],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.38728140181737},"floorLandings":[{"polygonFt":[[-45.20559447407169,72.13315913674555],[-45.233713577350386,80.20112240023798],[-39.12260663704781,80.25891961454829],[-39.10802636127367,76.07553125570035],[-39.95679121409347,76.06750386482392],[-39.94325238658892,72.18292896017941]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-44.184369183651064,72.07282046336388],[-44.191923112127924,80.22064474223032],[-38.78032665076474,80.26763654705286],[-38.77660901057194,76.25771255640655],[-38.01560325819274,76.26432077895973],[-38.01176696990868,72.1264204907396]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-139","floors":[79],"path":"analysis/wtc2-independent-core-review/sources/A-B-139.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":357,"sha256":"e27aba4efdd09c4dec076dd309bea7a3c1260481f31d1c913b4d529b8f8d20d1","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1302,697],[507,3439,690],[1002,1318,2665],[1007,3460,2657]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"controlResidualsFt":[0.054516765598682286,0.05454396264017155,0.054389242271355165,0.054416439312851755]},{"sheet":"A-B-141","floors":[80],"path":"analysis/wtc2-independent-core-review/sources/A-B-141.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":359,"sha256":"3956c28968825e0ccd92475e432a247cb0146c0937904847cbe94bba5bba7f78","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1408,773],[507,3546,773],[1002,1422,2750],[1007,3566,2746]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"controlResidualsFt":[0.07699832790613385,0.07715399216489915,0.07678139541870539,0.07693705967735691]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":79,"stair":"C","region":"tenant","polygonFt":[[-39.12260663704781,80.25891961454829],[-39.10802636127367,76.07553125570035],[-39.95679121409347,76.06750386482392],[-39.94325238658892,72.18292896017941],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]],"sourceSheet":"A-B-139","sourcePixels":[[491,762],[589,762],[589,742],[680,742],[680,1009],[491,1009]],"registrationMatrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[4.629330022590196,-4.022348421091721],[4.664292928783269,-14.053942955063803],[16.92894505202942,-13.937947156899384],[16.911984323067657,-9.071556617015048],[17.76074917588747,-9.063529226138613],[17.74274699865613,-3.8983252320508655]],"floorLandingPolygonsFt":[[[24.10848339480465,-3.8381198004776422],[24.143446300997724,-13.869714334449725],[16.92894505202942,-13.937947156899384],[16.911984323067657,-9.071556617015048],[17.76074917588747,-9.063529226138613],[17.74274699865613,-3.8983252320508655]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":79,"upperFloor":80,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2653.0,2075],"lastRiserPx":[2653.0,1908],"firstRiserFt":[16.920464687548545,-11.504751886957223],"lastRiserFt":[9.833278166503192,-11.571780600775412],"goingFt":0.787500387086427,"nominalGoingDifferenceIn":-0.04999535496287599,"widthFt":4.666666666666667,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-139","sourcePlanFloor":79},{"id":"upper","risers":9,"firstRiserPx":[2631.0,1992],"lastRiserPx":[2631.0,2142],"firstRiserFt":[9.793133969969688,-6.121861347826908],"lastRiserFt":[16.134848573129673,-6.066792826550497],"goingFt":0.7927442116822758,"nominalGoingDifferenceIn":0.012930540187308992,"widthFt":4.666666666666667,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-141","sourcePlanFloor":80}],"intermediateLanding":{"polygonFt":[[4.664292928783269,-14.053942955063803],[4.629330022590196,-4.022348421091721],[5.013375556461057,-3.6464791149033715],[9.790800557508248,-3.6049941622084845],[9.806795624790979,-3.97338133674549],[9.841758530984066,-14.004975870717573]],"sourceSheet":"A-B-139","sourcePixels":[[2475,1786],[2710,1786],[2710,1908],[2475,1908]],"offsetFt":6.315789473684211,"planReadingsFt":[[[4.629330022590196,-4.022348421091721],[4.664292928783269,-14.053942955063803],[9.841758530984066,-14.004975870717573],[9.806795624790979,-3.97338133674549]],[[5.013375556461057,-3.6464791149033715],[5.022590558215555,-13.585971559803255],[9.800015559262746,-13.544486607108368],[9.790800557508248,-3.6049941622084845]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.5893847792731842},"floorLandings":[{"polygonFt":[[24.10848339480465,-3.8381198004776422],[24.143446300997724,-13.869714334449725],[16.92894505202942,-13.937947156899384],[16.911984323067657,-9.071556617015048],[17.76074917588747,-9.063529226138613],[17.74274699865613,-3.8983252320508655]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[23.78485078181461,-3.4834762919252],[23.79406578356911,-13.422968736825084],[16.902735914801923,-13.482809863278788],[16.898187737970304,-8.577051789615766],[16.137181985591113,-8.583660012168934],[16.132515160668234,-3.5499256409320736]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-139","floors":[79],"path":"analysis/wtc2-independent-core-review/sources/A-B-139.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":357,"sha256":"e27aba4efdd09c4dec076dd309bea7a3c1260481f31d1c913b4d529b8f8d20d1","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1302,697],[507,3439,690],[1002,1318,2665],[1007,3460,2657]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"controlResidualsFt":[0.054516765598682286,0.05454396264017155,0.054389242271355165,0.054416439312851755]},{"sheet":"A-B-141","floors":[80],"path":"analysis/wtc2-independent-core-review/sources/A-B-141.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":359,"sha256":"3956c28968825e0ccd92475e432a247cb0146c0937904847cbe94bba5bba7f78","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1408,773],[507,3546,773],[1002,1422,2750],[1007,3566,2746]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"controlResidualsFt":[0.07699832790613385,0.07715399216489915,0.07678139541870539,0.07693705967735691]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":79,"stair":"B","region":"core","polygonFt":[[4.629330022590196,-4.022348421091721],[4.664292928783269,-14.053942955063803],[16.92894505202942,-13.937947156899384],[16.911984323067657,-9.071556617015048],[17.76074917588747,-9.063529226138613],[17.74274699865613,-3.8983252320508655]],"sourceSheet":"A-B-139","sourcePixels":[[2475,1786],[2710,1786],[2710,2075],[2596,2075],[2596,2095],[2475,2095]],"registrationMatrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1","stairTransitionRevision":"wtc2-stair-transition-v1"},{"floors":[80,80],"evidenceType":"Original Tower B A-B-135/137/139/141/143/145 and stair sections131/132; detailed scope in component records","uncertaintyFt":1.0,"stairs":{"A":{"floor":80,"stair":"A","sourceSheet":"A-B-141","enclosurePx":[[4169,709],[4353,709],[4353,1086],[4169,1086]],"voidWitnessPx":[4261.0,1041],"landingWitnessPx":[4261.0,764],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-44.38883801427295,-72.20206265598867],[-44.381560931342364,-80.05127557384952],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]],"floorOpeningPolygonFt":[[-38.469904384656964,-72.15066536946401],[-38.46630539255543,-76.03261306253648],[-39.227311144934625,-76.03922128508967],[-39.223633054105576,-80.00648650987804],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]],"voidWitnessFt":[-30.348871151146895,-76.00478412116061],"landingWitnessFt":[-42.059904118315664,-76.10647732378439],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-141; sections A-B-131/132","rectFt":[[-44.38883801427295,-80.05127557384952],[-28.442718228733604,-72.06365710584728]],"volumePolygonFt":[[-44.38883801427295,-72.20206265598867],[-44.381560931342364,-80.05127557384952],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]],"floorLandingPolygonsFt":[[[-44.381560931342364,-80.05127557384952],[-44.38883801427295,-72.20206265598867],[-38.469904384656964,-72.15066536946401],[-38.46630539255543,-76.03261306253648],[-39.227311144934625,-76.03922128508967],[-39.223633054105576,-80.00648650987804]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":80,"upperFloor":81,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[4306.5,831],"lastRiserPx":[4306.5,995],"firstRiserFt":[-39.2254720995201,-78.02285389748386],"lastRiserFt":[-32.29186413339852,-77.96264564755498],"goingFt":0.7704299301682555,"nominalGoingDifferenceIn":-0.25484083798093415,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-141","sourcePlanFloor":80},{"id":"upper","risers":9,"firstRiserPx":[4115.0,1176],"lastRiserPx":[4115.0,1029],"firstRiserFt":[-31.47511153570693,-74.04787249517433],"lastRiserFt":[-37.69244435053383,-74.13046439506972],"goingFt":0.7772351714596643,"nominalGoingDifferenceIn":-0.1731779424840294,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-143","sourcePlanFloor":81}],"intermediateLanding":{"polygonFt":[[-32.29002508798399,-79.94627825994917],[-32.297302170914584,-72.09706534208831],[-28.449995311664196,-72.06365710584728],[-27.727764701192093,-72.0784289151638],[-27.660209984296507,-79.75618475654774],[-28.442718228733604,-79.91287002370814]],"sourceSheet":"A-B-141","sourcePixels":[[4169,995],[4353,995],[4353,1086],[4169,1086]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-32.297302170914584,-72.09706534208831],[-32.29002508798399,-79.94627825994917],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]],[[-31.492000214930826,-72.12843353482835],[-31.42444549803524,-79.80618937621229],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.8768425867181029},"floorLandings":[{"polygonFt":[[-44.381560931342364,-80.05127557384952],[-44.38883801427295,-72.20206265598867],[-38.469904384656964,-72.15066536946401],[-38.46630539255543,-76.03261306253648],[-39.227311144934625,-76.03922128508967],[-39.223633054105576,-80.00648650987804]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-43.60534244136958,-79.96800207804812],[-43.67289715826516,-72.29024623666417],[-37.70933302975772,-72.21102543472374],[-37.67555567130994,-76.04990335541571],[-38.52145129237482,-76.06114034859873],[-38.48767393392703,-79.9000182692907]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-141","floors":[80],"path":"analysis/wtc2-independent-core-review/sources/A-B-141.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":359,"sha256":"3956c28968825e0ccd92475e432a247cb0146c0937904847cbe94bba5bba7f78","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1408,773],[507,3546,773],[1002,1422,2750],[1007,3566,2746]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"controlResidualsFt":[0.07699832790613385,0.07715399216489915,0.07678139541870539,0.07693705967735691]},{"sheet":"A-B-143","floors":[81],"path":"analysis/wtc2-independent-core-review/sources/A-B-143.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":361,"sha256":"f18e47bf68179d9367e28f78c9a0e7f7e13b4d8ed4b54ee2de85388f1f8034f0","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1306,960],[507,3446,937],[1002,1331,2930],[1007,3473,2915]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"controlResidualsFt":[0.08736685113023475,0.08701291204432997,0.08728973752246118,0.08693579843646554]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":80,"stair":"A","region":"tenant","polygonFt":[[-38.469904384656964,-72.15066536946401],[-38.46630539255543,-76.03261306253648],[-39.227311144934625,-76.03922128508967],[-39.223633054105576,-80.00648650987804],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]],"sourceSheet":"A-B-141","sourcePixels":[[4169,849],[4260,849],[4260,831],[4353,831],[4353,1086],[4169,1086]],"registrationMatrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"C":{"floor":80,"stair":"C","sourceSheet":"A-B-141","enclosurePx":[[596,717],[787,717],[787,1094],[596,1094]],"voidWitnessPx":[691.5,1049],"landingWitnessPx":[691.5,772],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-44.191923112127924,80.22064474223032],[-44.184369183651064,72.07282046336388],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]],"floorOpeningPolygonFt":[[-38.78032665076474,80.26763654705286],[-38.77660901057194,76.25771255640655],[-38.01560325819274,76.26432077895973],[-38.01176696990868,72.1264204907396],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]],"voidWitnessFt":[-30.15181782622873,76.26861759655556],"landingWitnessFt":[-41.8628507933975,76.1669243939318],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-141; sections A-B-131/132","rectFt":[[-44.191923112127924,72.07282046336388],[-28.245526481042305,80.3590502923717]],"volumePolygonFt":[[-44.191923112127924,80.22064474223032],[-44.184369183651064,72.07282046336388],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]],"floorLandingPolygonsFt":[[[-44.184369183651064,72.07282046336388],[-44.191923112127924,80.22064474223032],[-38.78032665076474,80.26763654705286],[-38.77660901057194,76.25771255640655],[-38.01560325819274,76.26432077895973],[-38.01176696990868,72.1264204907396]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":80,"upperFloor":81,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[643.0,845],"lastRiserPx":[643.0,1008],"firstRiserFt":[-38.77846783066834,78.2626745517297],"lastRiserFt":[-31.88713796190116,78.32251567818341],"goingFt":0.7657321866916199,"nominalGoingDifferenceIn":-0.31121375970056064,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-141","sourcePlanFloor":80},{"id":"upper","risers":9,"firstRiserPx":[644.5,1200],"lastRiserPx":[644.5,1049],"firstRiserFt":[-31.762529262574176,73.99700993843959],"lastRiserFt":[-38.149041201614054,73.9121706399076],"goingFt":0.7983844278259132,"nominalGoingDifferenceIn":0.08061313391095837,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-143","sourcePlanFloor":81}],"intermediateLanding":{"polygonFt":[[-31.74432701941064,71.9282812811778],[-31.881442853520696,72.17965339464013],[-31.888996781997555,80.32747767350656],[-28.25308040951917,80.3590502923717],[-28.220578386607997,80.08033633477767],[-28.14927062988488,71.97603850220574]],"sourceSheet":"A-B-141","sourcePixels":[[596,1008],[787,1008],[787,1094],[596,1094]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-31.888996781997555,80.32747767350656],[-31.881442853520696,72.17965339464013],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]],[[-31.815634776133756,80.03257911374973],[-31.74432701941064,71.9282812811778],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.30388672963953756},"floorLandings":[{"polygonFt":[[-44.184369183651064,72.07282046336388],[-44.191923112127924,80.22064474223032],[-38.78032665076474,80.26763654705286],[-38.77660901057194,76.25771255640655],[-38.01560325819274,76.26432077895973],[-38.01176696990868,72.1264204907396]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-44.85570914591635,71.75410788684061],[-44.927016902639465,79.85840571941254],[-38.921157993078786,79.93818837101216],[-38.886254722682736,75.97134785296379],[-38.16724344477758,75.98089929716937],[-38.13083895845052,71.84344198264581]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-141","floors":[80],"path":"analysis/wtc2-independent-core-review/sources/A-B-141.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":359,"sha256":"3956c28968825e0ccd92475e432a247cb0146c0937904847cbe94bba5bba7f78","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1408,773],[507,3546,773],[1002,1422,2750],[1007,3566,2746]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"controlResidualsFt":[0.07699832790613385,0.07715399216489915,0.07678139541870539,0.07693705967735691]},{"sheet":"A-B-143","floors":[81],"path":"analysis/wtc2-independent-core-review/sources/A-B-143.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":361,"sha256":"f18e47bf68179d9367e28f78c9a0e7f7e13b4d8ed4b54ee2de85388f1f8034f0","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1306,960],[507,3446,937],[1002,1331,2930],[1007,3473,2915]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"controlResidualsFt":[0.08736685113023475,0.08701291204432997,0.08728973752246118,0.08693579843646554]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":80,"stair":"C","region":"tenant","polygonFt":[[-38.78032665076474,80.26763654705286],[-38.77660901057194,76.25771255640655],[-38.01560325819274,76.26432077895973],[-38.01176696990868,72.1264204907396],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]],"sourceSheet":"A-B-141","sourcePixels":[[596,845],[690,845],[690,863],[787,863],[787,1094],[596,1094]],"registrationMatrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[5.013375556461057,-3.6464791149033715],[5.022590558215555,-13.585971559803255],[16.902735914801923,-13.482809863278788],[16.898187737970304,-8.577051789615766],[16.137181985591113,-8.583660012168934],[16.132515160668234,-3.5499256409320736]],"floorLandingPolygonsFt":[[[23.78485078181461,-3.4834762919252],[23.79406578356911,-13.422968736825084],[16.902735914801923,-13.482809863278788],[16.898187737970304,-8.577051789615766],[16.137181985591113,-8.583660012168934],[16.132515160668234,-3.5499256409320736]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":80,"upperFloor":81,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2747.5,2160],"lastRiserPx":[2747.5,1992],"firstRiserFt":[16.900461826386106,-11.02993082644727],"lastRiserFt":[9.79774147084693,-11.09160757027685],"goingFt":0.7892209040747982,"nominalGoingDifferenceIn":-0.029349151102422866,"widthFt":4.666666666666667,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-141","sourcePlanFloor":80},{"id":"upper","risers":9,"firstRiserPx":[2540.5,2171],"lastRiserPx":[2540.5,2321],"firstRiserFt":[10.017279491426095,-6.329795571767789],"lastRiserFt":[16.36149664941273,-6.24551812289495],"goingFt":0.793097113734351,"nominalGoingDifferenceIn":0.01716536481221098,"widthFt":4.666666666666667,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-143","sourcePlanFloor":81}],"intermediateLanding":{"polygonFt":[[5.05119230701149,-14.010430223912635],[5.022590558215555,-13.585971559803255],[4.961869959116214,-3.858730833638319],[5.013375556461057,-3.6464791149033715],[9.790800557508248,-3.6049941622084845],[9.994948904452286,-3.791870724199214],[10.084271252347548,-13.94357011447353]],"sourceSheet":"A-B-141","sourcePixels":[[2572,1879],[2805,1879],[2805,1992],[2572,1992]],"offsetFt":6.315789473684211,"planReadingsFt":[[[5.013375556461057,-3.6464791149033715],[5.022590558215555,-13.585971559803255],[9.800015559262746,-13.544486607108368],[9.790800557508248,-3.6049941622084845]],[[4.961869959116214,-3.858730833638319],[5.05119230701149,-14.010430223912635],[10.084271252347548,-13.94357011447353],[9.994948904452286,-3.791870724199214]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.4899683100997459},"floorLandings":[{"polygonFt":[[23.78485078181461,-3.4834762919252],[23.79406578356911,-13.422968736825084],[16.902735914801923,-13.482809863278788],[16.898187737970304,-8.577051789615766],[16.137181985591113,-8.583660012168934],[16.132515160668234,-3.5499256409320736]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[24.16370055728909,-3.6036510883832165],[24.253022905184366,-13.755350478657533],[17.147499688239336,-13.849741221395107],[17.102838514291705,-8.773891526257941],[16.38382723638655,-8.783442970463526],[16.339166062438906,-3.7075932753263743]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-141","floors":[80],"path":"analysis/wtc2-independent-core-review/sources/A-B-141.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":359,"sha256":"3956c28968825e0ccd92475e432a247cb0146c0937904847cbe94bba5bba7f78","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1408,773],[507,3546,773],[1002,1422,2750],[1007,3566,2746]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"controlResidualsFt":[0.07699832790613385,0.07715399216489915,0.07678139541870539,0.07693705967735691]},{"sheet":"A-B-143","floors":[81],"path":"analysis/wtc2-independent-core-review/sources/A-B-143.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":361,"sha256":"f18e47bf68179d9367e28f78c9a0e7f7e13b4d8ed4b54ee2de85388f1f8034f0","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1306,960],[507,3446,937],[1002,1331,2930],[1007,3473,2915]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"controlResidualsFt":[0.08736685113023475,0.08701291204432997,0.08728973752246118,0.08693579843646554]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":80,"stair":"B","region":"core","polygonFt":[[5.013375556461057,-3.6464791149033715],[5.022590558215555,-13.585971559803255],[16.902735914801923,-13.482809863278788],[16.898187737970304,-8.577051789615766],[16.137181985591113,-8.583660012168934],[16.132515160668234,-3.5499256409320736]],"sourceSheet":"A-B-141","sourcePixels":[[2572,1879],[2805,1879],[2805,2160],[2690,2160],[2690,2142],[2572,2142]],"registrationMatrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1","stairTransitionRevision":"wtc2-stair-transition-v1"},{"floors":[81,81],"evidenceType":"Original Tower B A-B-135/137/139/141/143/145 and stair sections131/132; detailed scope in component records","uncertaintyFt":1.0,"stairs":{"A":{"floor":81,"stair":"A","sourceSheet":"A-B-143","enclosurePx":[[4070,888],[4250,888],[4250,1265],[4070,1265]],"voidWitnessPx":[4160.0,1220],"landingWitnessPx":[4160.0,943],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-43.67289715826516,-72.29024623666417],[-43.60534244136958,-79.96800207804812],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]],"floorOpeningPolygonFt":[[-37.70933302975772,-72.21102543472374],[-37.67555567130994,-76.04990335541571],[-38.52145129237482,-76.06114034859873],[-38.48767393392703,-79.9000182692907],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]],"voidWitnessFt":[-29.597252490140292,-75.94259007051762],"landingWitnessFt":[-41.31290684188894,-76.0982224261028],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-143; sections A-B-131/132","rectFt":[[-43.67289715826516,-79.96800207804812],[-27.660209984296507,-72.0784289151638]],"volumePolygonFt":[[-43.67289715826516,-72.29024623666417],[-43.60534244136958,-79.96800207804812],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]],"floorLandingPolygonsFt":[[[-43.60534244136958,-79.96800207804812],[-43.67289715826516,-72.29024623666417],[-37.70933302975772,-72.21102543472374],[-37.67555567130994,-76.04990335541571],[-38.52145129237482,-76.06114034859873],[-38.48767393392703,-79.9000182692907]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":81,"upperFloor":82,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[4205.0,1009],"lastRiserPx":[4205.0,1176],"firstRiserFt":[-38.504562613150924,-77.98057930894471],"lastRiserFt":[-31.441334177259137,-77.8867504158663],"goingFt":0.7848724029252542,"nominalGoingDifferenceIn":-0.08153116489694945,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-143","sourcePlanFloor":81},{"id":"upper","risers":9,"firstRiserPx":[4125.0,956],"lastRiserPx":[4125.0,807],"firstRiserFt":[-31.96434046602279,-74.01367851284449],"lastRiserFt":[-38.27184668090925,-74.03143713489239],"goingFt":0.7884414017886842,"nominalGoingDifferenceIn":-0.03870317853579053,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-145","sourcePlanFloor":82}],"intermediateLanding":{"polygonFt":[[-31.973770260657005,-79.82756713390377],[-31.96122031338647,-72.08996536617046],[-28.066652717617643,-72.07900031094628],[-27.727764701192093,-72.0784289151638],[-27.660209984296507,-79.75618475654774],[-28.079202664888186,-79.8166020786796]],"sourceSheet":"A-B-143","sourcePixels":[[4070,1176],[4250,1176],[4250,1265],[4070,1265]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-31.492000214930826,-72.12843353482835],[-31.42444549803524,-79.80618937621229],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]],[[-31.96122031338647,-72.08996536617046],[-31.973770260657005,-79.82756713390377],[-28.079202664888186,-79.8166020786796],[-28.066652717617643,-72.07900031094628]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.5497405782306546},"floorLandings":[{"polygonFt":[[-43.60534244136958,-79.96800207804812],[-43.67289715826516,-72.29024623666417],[-37.70933302975772,-72.21102543472374],[-37.67555567130994,-76.04990335541571],[-38.52145129237482,-76.06114034859873],[-38.48767393392703,-79.9000182692907]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-43.23415048320599,-79.85927044574761],[-43.22160053593545,-72.1216686780143],[-38.26872652827293,-72.10772398821835],[-38.27496683354557,-75.95515028156642],[-38.40196360297281,-75.95550783771502],[-38.40827324497071,-79.84568331210026]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-143","floors":[81],"path":"analysis/wtc2-independent-core-review/sources/A-B-143.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":361,"sha256":"f18e47bf68179d9367e28f78c9a0e7f7e13b4d8ed4b54ee2de85388f1f8034f0","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1306,960],[507,3446,937],[1002,1331,2930],[1007,3473,2915]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"controlResidualsFt":[0.08736685113023475,0.08701291204432997,0.08728973752246118,0.08693579843646554]},{"sheet":"A-B-145","floors":[82],"path":"analysis/wtc2-independent-core-review/sources/A-B-145.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":363,"sha256":"d5ba0357c843bdf400f6e3c8d1fb9df0c1d553d0b3788f13bc9f0ac8ffb97569","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1326,720],[507,3460,724],[1002,1329,2693],[1007,3468,2696]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"controlResidualsFt":[0.05457040479916538,0.054598271635172974,0.05444274002128994,0.054470606857292]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":81,"stair":"A","region":"tenant","polygonFt":[[-37.70933302975772,-72.21102543472374],[-37.67555567130994,-76.04990335541571],[-38.52145129237482,-76.06114034859873],[-38.48767393392703,-79.9000182692907],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]],"sourceSheet":"A-B-143","sourcePixels":[[4070,1029],[4160,1029],[4160,1009],[4250,1009],[4250,1265],[4070,1265]],"registrationMatrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"C":{"floor":81,"stair":"C","sourceSheet":"A-B-143","enclosurePx":[[503,890],[693,890],[693,1285],[503,1285]],"voidWitnessPx":[598.0,1240],"landingWitnessPx":[598.0,945],"phase":"outer stair story","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","enclosurePolygonFt":[[-44.927016902639465,79.85840571941254],[-44.85570914591635,71.75410788684061],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]],"floorOpeningPolygonFt":[[-38.921157993078786,79.93818837101216],[-38.886254722682736,75.97134785296379],[-38.16724344477758,75.98089929716937],[-38.13083895845052,71.84344198264581],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]],"voidWitnessFt":[-30.08818965564243,76.00290418382986],"landingWitnessFt":[-42.565150066349474,75.83715853437995],"reviewRevision":"wtc2-stair-transition-v1","uncertaintyFt":1.0,"source":"PANYNJ A-B-143; sections A-B-131/132","rectFt":[[-44.927016902639465,71.75410788684061],[-28.14927062988488,80.08033633477767]],"volumePolygonFt":[[-44.927016902639465,79.85840571941254],[-44.85570914591635,71.75410788684061],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]],"floorLandingPolygonsFt":[[[-44.85570914591635,71.75410788684061],[-44.927016902639465,79.85840571941254],[-38.921157993078786,79.93818837101216],[-38.886254722682736,75.97134785296379],[-38.16724344477758,75.98089929716937],[-38.13083895845052,71.84344198264581]]],"flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":81,"upperFloor":82,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[549.5,1032],"lastRiserPx":[549.5,1200],"firstRiserFt":[-38.90370635788076,77.95476811198797],"lastRiserFt":[-31.798183140935734,78.04915885472555],"goingFt":0.7895722376733088,"nominalGoingDifferenceIn":-0.025133147920294974,"widthFt":3.6666666666666665,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-143","sourcePlanFloor":81},{"id":"upper","risers":9,"firstRiserPx":[660.5,951],"lastRiserPx":[660.5,804],"firstRiserFt":[-31.93578466376737,74.09026326362303],"lastRiserFt":[-38.15862636570234,74.07274301234091],"goingFt":0.7778582957244072,"nominalGoingDifferenceIn":-0.16570045130711364,"widthFt":3.6666666666666665,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-145","sourcePlanFloor":82}],"intermediateLanding":{"polygonFt":[[-31.74432701941064,71.9282812811778],[-31.939147494942077,72.0169279833188],[-31.925904180419025,80.18202156142414],[-28.158333354077442,80.19262906049971],[-28.14927062988488,71.97603850220574]],"sourceSheet":"A-B-143","sourcePixels":[[503,1200],[693,1200],[693,1285],[503,1285]],"offsetFt":6.315789473684211,"planReadingsFt":[[[-31.815634776133756,80.03257911374973],[-31.74432701941064,71.9282812811778],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]],[[-31.925904180419025,80.18202156142414],[-31.939147494942077,72.0169279833188],[-28.1715766686005,72.02753548239437],[-28.158333354077442,80.19262906049971]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.19403298394569973},"floorLandings":[{"polygonFt":[[-44.85570914591635,71.75410788684061],[-44.927016902639465,79.85840571941254],[-38.921157993078786,79.93818837101216],[-38.886254722682736,75.97134785296379],[-38.16724344477758,75.98089929716937],[-38.13083895845052,71.84344198264581]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-42.98786643511232,71.98582059838932],[-42.974623120589264,80.15091417649465],[-38.31807490825698,80.16402456861053],[-38.32459256043063,76.14560155111366],[-38.155263534527634,76.14607829264514],[-38.161989196877045,71.99940773203667]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-143","floors":[81],"path":"analysis/wtc2-independent-core-review/sources/A-B-143.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":361,"sha256":"f18e47bf68179d9367e28f78c9a0e7f7e13b4d8ed4b54ee2de85388f1f8034f0","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1306,960],[507,3446,937],[1002,1331,2930],[1007,3473,2915]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"controlResidualsFt":[0.08736685113023475,0.08701291204432997,0.08728973752246118,0.08693579843646554]},{"sheet":"A-B-145","floors":[82],"path":"analysis/wtc2-independent-core-review/sources/A-B-145.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":363,"sha256":"d5ba0357c843bdf400f6e3c8d1fb9df0c1d553d0b3788f13bc9f0ac8ffb97569","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1326,720],[507,3460,724],[1002,1329,2693],[1007,3468,2696]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"controlResidualsFt":[0.05457040479916538,0.054598271635172974,0.05444274002128994,0.054470606857292]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":81,"stair":"C","region":"tenant","polygonFt":[[-38.921157993078786,79.93818837101216],[-38.886254722682736,75.97134785296379],[-38.16724344477758,75.98089929716937],[-38.13083895845052,71.84344198264581],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]],"sourceSheet":"A-B-143","sourcePixels":[[503,1032],[596,1032],[596,1049],[693,1049],[693,1285],[503,1285]],"registrationMatrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[4.961869959116214,-3.858730833638319],[5.05119230701149,-14.010430223912635],[17.147499688239336,-13.849741221395107],[17.102838514291705,-8.773891526257941],[16.38382723638655,-8.783442970463526],[16.339166062438906,-3.7075932753263743]],"floorLandingPolygonsFt":[[[24.16370055728909,-3.6036510883832165],[24.253022905184366,-13.755350478657533],[17.147499688239336,-13.849741221395107],[17.102838514291705,-8.773891526257941],[16.38382723638655,-8.783442970463526],[16.339166062438906,-3.7075932753263743]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-outer-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":81,"upperFloor":82,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2659.5,2338],"lastRiserPx":[2659.5,2171],"firstRiserFt":[17.125169101265513,-11.311816373826531],"lastRiserFt":[10.061940665373726,-11.405645266904955],"goingFt":0.7848724029252542,"nominalGoingDifferenceIn":-0.08153116489694945,"widthFt":4.666666666666667,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-143","sourcePlanFloor":81},{"id":"upper","risers":9,"firstRiserPx":[2543,1943],"lastRiserPx":[2543,2094],"firstRiserFt":[9.927287374888564,-6.266838139098709],"lastRiserFt":[16.31945810272653,-6.248841146285088],"goingFt":0.799024507852963,"nominalGoingDifferenceIn":0.08829409423555568,"widthFt":4.666666666666667,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-145","sourcePlanFloor":82}],"intermediateLanding":{"polygonFt":[[5.05119230701149,-14.010430223912635],[4.92022453073227,-13.591011971638864],[4.936171977540141,-3.7587003330827002],[9.931378241678416,-3.744636457903866],[9.994948904452286,-3.791870724199214],[10.084271252347548,-13.94357011447353]],"sourceSheet":"A-B-143","sourcePixels":[[2481,2052],[2719,2052],[2719,2171],[2481,2171]],"offsetFt":6.315789473684211,"planReadingsFt":[[[4.961869959116214,-3.858730833638319],[5.05119230701149,-14.010430223912635],[10.084271252347548,-13.94357011447353],[9.994948904452286,-3.791870724199214]],[[4.936171977540141,-3.7587003330827002],[4.92022453073227,-13.591011971638864],[9.915430794870545,-13.576948096460029],[9.931378241678416,-3.744636457903866]]],"reconciliation":"Envelope of adjacent plan registrations; measured flight endpoints retained.","adjacentPlanBoundaryDistanceFt":0.4197853248963901},"floorLandings":[{"polygonFt":[[24.16370055728909,-3.6036510883832165],[24.253022905184366,-13.755350478657533],[17.147499688239336,-13.849741221395107],[17.102838514291705,-8.773891526257941],[16.38382723638655,-8.783442970463526],[16.339166062438906,-3.7075932753263743]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[22.58872292792708,-3.709000028425251],[22.572775481119223,-13.541311666981414],[17.154246652223463,-13.556567395988978],[17.162012365451645,-8.768659119822502],[16.315367235936677,-8.771042827479931],[16.323548969516366,-3.726639465090244]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-143","floors":[81],"path":"analysis/wtc2-independent-core-review/sources/A-B-143.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":361,"sha256":"f18e47bf68179d9367e28f78c9a0e7f7e13b4d8ed4b54ee2de85388f1f8034f0","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1306,960],[507,3446,937],[1002,1331,2930],[1007,3473,2915]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"controlResidualsFt":[0.08736685113023475,0.08701291204432997,0.08728973752246118,0.08693579843646554]},{"sheet":"A-B-145","floors":[82],"path":"analysis/wtc2-independent-core-review/sources/A-B-145.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":363,"sha256":"d5ba0357c843bdf400f6e3c8d1fb9df0c1d553d0b3788f13bc9f0ac8ffb97569","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1326,720],[507,3460,724],[1002,1329,2693],[1007,3468,2696]],"heldOut":[],"reading":"Same-floor clear stair faces and riser lines. Plan breaks identify the departing lower flight. The full arriving flight belongs to the preceding story.","matrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"controlResidualsFt":[0.05457040479916538,0.054598271635172974,0.05444274002128994,0.054470606857292]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27:44/56 in flight widths. p249:9.5 in nominal going for comparison."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Departing stories76 and78 are14 ft;77 and79\u201381 are12 ft."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-outer-stair-flights-v1","floorOpeningReview":{"floor":81,"stair":"B","region":"core","polygonFt":[[4.961869959116214,-3.858730833638319],[5.05119230701149,-14.010430223912635],[17.147499688239336,-13.849741221395107],[17.102838514291705,-8.773891526257941],[16.38382723638655,-8.783442970463526],[16.339166062438906,-3.7075932753263743]],"sourceSheet":"A-B-143","sourcePixels":[[2481,2052],[2719,2052],[2719,2338],[2600,2338],[2600,2321],[2481,2321]],"registrationMatrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1","stairTransitionRevision":"wtc2-stair-transition-v1"},{"floors":[82,82],"evidenceType":"Original Tower B A-B-135/137/139/141/143/145 and stair sections131/132; detailed scope in component records","uncertaintyFt":1.0,"stairs":{"A":{"stair":"A","enclosurePx":[[2792,1147],[3210,1147],[3210,1327],[2792,1327]],"openingPx":[[2792,1147],[3050,1147],[3050,1237],[3032,1237],[3032,1327],[2792,1327]],"positiveWitnessPx":[2950,1190],"landingWitnessPx":[3150,1290],"enclosurePolygonFt":[[-23.292389322948473,-15.082340273450143],[-23.313186361340186,-32.95561077093207],[-15.650651165296964,-32.92423508429199],[-15.62985412690525,-15.050964586810068]],"rectFt":[[-23.313186361340186,-32.95561077093207],[-15.62985412690525,-15.050964586810068]],"floorLandingPolygonsFt":[[[-23.292389322948473,-15.082340273450143],[-23.313186361340186,-32.95561077093207],[-15.650651165296964,-32.92423508429199],[-15.62985412690525,-15.050964586810068]]],"source":"PANYNJ A-B-147 upper enclosure reference; A-B-145 plan and A-B-131/132 first-flight sections","reviewRevision":"wtc2-stair-transition-v1","interpretation":"Upper enclosure reference locates the first inner flight above82. No floor82 hole is cut here: sections show closet/duct space and slab below. Exact sloping enclosure soffits unresolved.","floor":82,"phase":"first inner flight above a solid nominal floor","nominalFloorSolid":true,"volumePolygonFt":[[-23.292389322948473,-15.082340273450143],[-23.313186361340186,-32.95561077093207],[-15.650651165296964,-32.92423508429199],[-15.62985412690525,-15.050964586810068]],"flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":82,"upperFloor":83,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":14,"firstRiserPx":[3079,1201],"lastRiserPx":[2835,1201],"firstRiserFt":[-21.520411414851345,-29.26883472912901],"lastRiserFt":[-21.503493253889957,-18.838034556052023],"widthFt":3.6666666666666665,"goingFt":0.8023702994778785,"nominalGoingDifferenceIn":0.1284435937345414,"baseOffsetFt":0.0,"topOffsetFt":8.842105263157896,"sourceSheet":"A-B-145","sourcePlanFloor":82},{"id":"upper","risers":5,"firstRiserPx":[2879,1282],"lastRiserPx":[2954,1282],"firstRiserFt":[-17.54981649610764,-18.778843277084746],"lastRiserFt":[-17.553548022134855,-21.985769801752554],"widthFt":3.6666666666666665,"goingFt":0.8017321739094215,"nominalGoingDifferenceIn":0.12078608691305881,"baseOffsetFt":8.842105263157896,"topOffsetFt":12.0,"sourceSheet":"A-B-147","sourcePlanFloor":83}],"intermediateLanding":{"polygonFt":[[-23.323780282347123,-18.843159527515496],[-23.317817323975483,-15.166729958316239],[-23.292389322948473,-15.082340273450143],[-15.62985412690525,-15.050964586810068],[-15.444017619486345,-15.14456147710213],[-15.449980577857986,-18.820991046301387]],"sourcePixels":[[2749,1158],[2835,1158],[2835,1344],[2749,1344]],"sourceSheet":"A-B-145","offsetFt":8.842105263157896,"planReadingsFt":[[[-23.317817323975483,-15.166729958316239],[-23.323780282347123,-18.843159527515496],[-15.449980577857986,-18.820991046301387],[-15.444017619486345,-15.14456147710213]],[[-23.292389322948473,-15.082340273450143],[-23.29671789314005,-18.802375042064796],[-15.634182697096833,-18.77099935542472],[-15.62985412690525,-15.050964586810068]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-23.34069844330851,-29.2739597005925],[-23.346800075130652,-33.035887631866146],[-19.579229248789076,-33.02528013279057],[-19.573127616966936,-29.263352201516923]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-15.650651165296964,-32.92423508429199],[-23.313186361340186,-32.95561077093207],[-23.305126265121388,-26.02864947764961],[-19.473858667099776,-26.012961634329557],[-19.46918182114566,-21.993613723412565],[-15.63791422312405,-21.977925880092528]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-145","floors":[82],"path":"analysis/wtc2-independent-core-review/sources/A-B-145.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":363,"sha256":"d5ba0357c843bdf400f6e3c8d1fb9df0c1d553d0b3788f13bc9f0ac8ffb97569","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1326,720],[507,3460,724],[1002,1329,2693],[1007,3468,2696]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"controlResidualsFt":[0.05457040479916538,0.054598271635172974,0.05444274002128994,0.054470606857292]},{"sheet":"A-B-147","floors":[83],"path":"analysis/wtc2-independent-core-review/sources/A-B-147.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":365,"sha256":"b3847150838352cc96b6797a1b4f78c59c62443c88ed567ae61957e2baa20d4d","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1372,711],[507,3503,715],[1002,1375,2674],[1007,3516,2675]],"heldOut":[[702,1498,1574],[707,3385,1573]],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"controlResidualsFt":[0.11190055622484506,0.1120720997794811,0.11137685906012405,0.11154840261485546]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null}},"C":{"stair":"C","enclosurePx":[[1978,1147],[2355,1147],[2355,1325],[1978,1325]],"openingPx":[[2135,1147],[2355,1147],[2355,1325],[2153,1325],[2153,1237],[2135,1237]],"positiveWitnessPx":[2240,1290],"landingWitnessPx":[2030,1290],"enclosurePolygonFt":[[-23.251889827133034,19.723502274277777],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.674493911045843,19.754529342177406]],"rectFt":[[-23.27064696462986,3.6033516102809386],[-15.674493911045843,19.754529342177406]],"floorLandingPolygonsFt":[[[-23.251889827133034,19.723502274277777],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.674493911045843,19.754529342177406]]],"source":"PANYNJ A-B-147 upper enclosure reference; A-B-145 plan and A-B-131/132 first-flight sections","reviewRevision":"wtc2-stair-transition-v1","interpretation":"Upper enclosure reference locates the first inner flight above82. No floor82 hole is cut here: sections show closet/duct space and slab below. Exact sloping enclosure soffits unresolved.","floor":82,"phase":"first inner flight above a solid nominal floor","nominalFloorSolid":true,"volumePolygonFt":[[-23.251889827133034,19.723502274277777],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.674493911045843,19.754529342177406]],"flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":82,"upperFloor":83,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2054,1201],"lastRiserPx":[2220,1201],"firstRiserFt":[-21.449341271468455,14.549075834001727],"lastRiserFt":[-21.460851167860227,7.452711781826409],"widthFt":3.6666666666666665,"goingFt":0.7884859318184241,"nominalGoingDifferenceIn":-0.03816881817891016,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-145","sourcePlanFloor":82},{"id":"upper","risers":9,"firstRiserPx":[2265,1282],"lastRiserPx":[2118,1282],"firstRiserFt":[-17.51926773636478,7.475195204862359],"lastRiserFt":[-17.51195394535143,13.760771193211255],"widthFt":3.6666666666666665,"goingFt":0.7856975304312324,"nominalGoingDifferenceIn":-0.07162963482521079,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-147","sourcePlanFloor":83}],"intermediateLanding":{"polygonFt":[[-23.27064696462986,3.6033516102809386],[-23.2661691333972,7.45166343988231],[-15.688773217310015,7.482690507781939],[-15.576667517731245,7.4692785500455585],[-15.582769149553386,3.7073506187718976],[-15.693251048542677,3.6343786781805676]],"sourcePixels":[[2220,1160],[2308,1160],[2308,1340],[2220,1340]],"sourceSheet":"A-B-145","offsetFt":6.315789473684211,"planReadingsFt":[[[-23.196473683365895,7.447825181128678],[-23.202575315188035,3.6858972498550173],[-15.582769149553386,3.7073506187718976],[-15.576667517731245,7.4692785500455585]],[[-23.2661691333972,7.45166343988231],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.688773217310015,7.482690507781939]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-23.17636603304293,19.845087681916894],[-23.18496378697413,14.544189233303996],[-19.502057473584046,14.554558361613815],[-19.493459719652847,19.855456810226713]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-23.251889827133034,19.723502274277777],[-15.674493911045843,19.754529342177406],[-15.681459426296655,13.768266496130835],[-19.427587744362235,13.752927271551243],[-19.426542917074613,14.65086669845823],[-23.257810515096224,14.635178855138193]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-145","floors":[82],"path":"analysis/wtc2-independent-core-review/sources/A-B-145.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":363,"sha256":"d5ba0357c843bdf400f6e3c8d1fb9df0c1d553d0b3788f13bc9f0ac8ffb97569","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1326,720],[507,3460,724],[1002,1329,2693],[1007,3468,2696]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"controlResidualsFt":[0.05457040479916538,0.054598271635172974,0.05444274002128994,0.054470606857292]},{"sheet":"A-B-147","floors":[83],"path":"analysis/wtc2-independent-core-review/sources/A-B-147.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":365,"sha256":"b3847150838352cc96b6797a1b4f78c59c62443c88ed567ae61957e2baa20d4d","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1372,711],[507,3503,715],[1002,1375,2674],[1007,3516,2675]],"heldOut":[[702,1498,1574],[707,3385,1573]],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"controlResidualsFt":[0.11190055622484506,0.1120720997794811,0.11137685906012405,0.11154840261485546]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[4.936171977540141,-3.7587003330827002],[4.92022453073227,-13.591011971638864],[17.154246652223463,-13.556567395988978],[17.162012365451645,-8.768659119822502],[16.315367235936677,-8.771042827479931],[16.323548969516366,-3.726639465090244]],"floorLandingPolygonsFt":[[[22.58872292792708,-3.709000028425251],[22.572775481119223,-13.541311666981414],[17.154246652223463,-13.556567395988978],[17.162012365451645,-8.768659119822502],[16.315367235936677,-8.771042827479931],[16.323548969516366,-3.726639465090244]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":82,"upperFloor":83,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2660,2114],"lastRiserPx":[2660,1943],"firstRiserFt":[17.157990835387054,-11.248111619980136],"lastRiserFt":[9.919174978034135,-11.268492320451188],"widthFt":4.666666666666667,"goingFt":0.804316060885101,"nominalGoingDifferenceIn":0.1517927306212119,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-145","sourcePlanFloor":82},{"id":"upper","risers":9,"firstRiserPx":[2590,1927],"lastRiserPx":[2590,2075],"firstRiserFt":[9.92198010333881,-6.3090568582378665],"lastRiserFt":[16.222286820085458,-6.283259071444917],"widthFt":4.666666666666667,"goingFt":0.7875449416827581,"nominalGoingDifferenceIn":-0.04946069980690204,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-147","sourcePlanFloor":83}],"intermediateLanding":{"polygonFt":[[4.847436298210795,-13.855387251181469],[4.859178166776459,-3.764258453560103],[4.936171977540141,-3.7587003330827002],[9.924965324160581,-3.7435156385036095],[9.931378241678416,-3.744636457903866],[9.915430794870545,-13.576948096460029],[9.913223455594931,-13.834644436124975]],"sourcePixels":[[2484,1825],[2714,1825],[2714,1943],[2484,1943]],"sourceSheet":"A-B-145","offsetFt":6.315789473684211,"planReadingsFt":[[[4.936171977540141,-3.7587003330827002],[4.92022453073227,-13.591011971638864],[9.915430794870545,-13.576948096460029],[9.931378241678416,-3.744636457903866]],[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[9.913223455594931,-13.834644436124975],[9.924965324160581,-3.7435156385036095]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[22.58872292792708,-3.709000028425251],[22.572775481119223,-13.541311666981414],[17.154246652223463,-13.556567395988978],[17.162012365451645,-8.768659119822502],[16.315367235936677,-8.771042827479931],[16.323548969516366,-3.726639465090244]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[21.248489558313338,-3.697149346024389],[21.236747689747688,-13.788278143645755],[17.02235333192391,-13.8055347712978],[17.02812475884602,-8.845488413144935],[16.219301599263673,-8.84880029117916],[16.225272040907228,-3.7177178517106597]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-145","floors":[82],"path":"analysis/wtc2-independent-core-review/sources/A-B-145.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":363,"sha256":"d5ba0357c843bdf400f6e3c8d1fb9df0c1d553d0b3788f13bc9f0ac8ffb97569","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1326,720],[507,3460,724],[1002,1329,2693],[1007,3468,2696]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"controlResidualsFt":[0.05457040479916538,0.054598271635172974,0.05444274002128994,0.054470606857292]},{"sheet":"A-B-147","floors":[83],"path":"analysis/wtc2-independent-core-review/sources/A-B-147.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":365,"sha256":"b3847150838352cc96b6797a1b4f78c59c62443c88ed567ae61957e2baa20d4d","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1372,711],[507,3503,715],[1002,1375,2674],[1007,3516,2675]],"heldOut":[[702,1498,1574],[707,3385,1573]],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"controlResidualsFt":[0.11190055622484506,0.1120720997794811,0.11137685906012405,0.11154840261485546]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-145","sourcePixels":[[2484,1825],[2714,1825],[2714,2114],[2602,2114],[2602,2094],[2484,2094]],"registrationMatrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1","stairTransitionRevision":"wtc2-stair-transition-v1"},{"floors":[83,83],"evidenceType":"Tower B A-B-147 stair B; A/C independently reviewed on83\u201385 only. Other A/C and transfer corridors retain prior derivation.","uncertaintyFt":1.0,"stairs":{"A":{"stair":"A","enclosurePx":[[2792,1147],[3210,1147],[3210,1327],[2792,1327]],"positiveWitnessPx":[2950,1190],"landingWitnessPx":[3150,1290],"enclosurePolygonFt":[[-23.292389322948473,-15.082340273450143],[-23.313186361340186,-32.95561077093207],[-15.650651165296964,-32.92423508429199],[-15.62985412690525,-15.050964586810068]],"rectFt":[[-23.313186361340186,-32.95561077093207],[-15.62985412690525,-15.050964586810068]],"floorOpeningPolygonFt":[[-23.292389322948473,-15.082340273450143],[-23.305126265121388,-26.02864947764961],[-19.473858667099776,-26.012961634329557],[-19.46918182114566,-21.993613723412565],[-15.63791422312405,-21.977925880092528],[-15.62985412690525,-15.050964586810068]],"floorLandingPolygonsFt":[[[-15.650651165296964,-32.92423508429199],[-23.313186361340186,-32.95561077093207],[-23.305126265121388,-26.02864947764961],[-19.473858667099776,-26.012961634329557],[-19.46918182114566,-21.993613723412565],[-15.63791422312405,-21.977925880092528]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":83,"upperFloor":84,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[3048,1192],"lastRiserPx":[2879,1192],"firstRiserFt":[-21.389492466110582,-26.020805555989583],"lastRiserFt":[-21.381084094129243,-18.794531120404784],"widthFt":3.6666666666666665,"goingFt":0.802919925278177,"nominalGoingDifferenceIn":0.13503910333812463,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-147","sourcePlanFloor":83},{"id":"upper","risers":9,"firstRiserPx":[2790,1306],"lastRiserPx":[2939,1306],"firstRiserFt":[-17.114752514430748,-18.958128079368066],"lastRiserFt":[-17.09835231666105,-25.332089005892215],"widthFt":3.6666666666666665,"goingFt":0.7967477531673632,"nominalGoingDifferenceIn":0.06097303800835974,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":84}],"intermediateLanding":{"polygonFt":[[-23.266603724022232,-18.999098274022188],[-23.29671789314005,-18.802375042064796],[-23.292389322948473,-15.082340273450143],[-15.62985412690525,-15.050964586810068],[-15.116652724807672,-15.137490611643585],[-15.106856633522412,-18.944755863057352]],"sourcePixels":[[2792,1147],[2879,1147],[2879,1327],[2792,1327]],"sourceSheet":"A-B-147","offsetFt":6.315789473684211,"planReadingsFt":[[[-23.292389322948473,-15.082340273450143],[-23.29671789314005,-18.802375042064796],[-15.634182697096833,-18.77099935542472],[-15.62985412690525,-15.050964586810068]],[[-23.276399815307485,-15.19183302260842],[-23.266603724022232,-18.999098274022188],[-15.106856633522412,-18.944755863057352],[-15.116652724807672,-15.137490611643585]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-15.650651165296964,-32.92423508429199],[-23.313186361340186,-32.95561077093207],[-23.305126265121388,-26.02864947764961],[-19.473858667099776,-26.012961634329557],[-19.46918182114566,-21.993613723412565],[-15.63791422312405,-21.977925880092528]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-15.070644116299398,-33.01880381491269],[-23.23039120679922,-33.07314622587752],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-147","floors":[83],"path":"analysis/wtc2-independent-core-review/sources/A-B-147.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":365,"sha256":"b3847150838352cc96b6797a1b4f78c59c62443c88ed567ae61957e2baa20d4d","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1372,711],[507,3503,715],[1002,1375,2674],[1007,3516,2675]],"heldOut":[[702,1498,1574],[707,3385,1573]],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"controlResidualsFt":[0.11190055622484506,0.1120720997794811,0.11137685906012405,0.11154840261485546]},{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-147","sourcePixels":[[2792,1147],[3048,1147],[3048,1237],[2954,1237],[2954,1327],[2792,1327]],"registrationMatrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"uncertaintyFt":1.0}},"C":{"stair":"C","enclosurePx":[[1978,1147],[2355,1147],[2355,1325],[1978,1325]],"positiveWitnessPx":[2240,1290],"landingWitnessPx":[2030,1290],"enclosurePolygonFt":[[-23.251889827133034,19.723502274277777],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.674493911045843,19.754529342177406]],"rectFt":[[-23.27064696462986,3.6033516102809386],[-15.674493911045843,19.754529342177406]],"floorOpeningPolygonFt":[[-23.257810515096224,14.635178855138193],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.681459426296655,13.768266496130835],[-19.427587744362235,13.752927271551243],[-19.426542917074613,14.65086669845823]],"floorLandingPolygonsFt":[[[-23.251889827133034,19.723502274277777],[-15.674493911045843,19.754529342177406],[-15.681459426296655,13.768266496130835],[-19.427587744362235,13.752927271551243],[-19.426542917074613,14.65086669845823],[-23.257810515096224,14.635178855138193]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":83,"upperFloor":84,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2097,1192],"lastRiserPx":[2265,1192],"firstRiserFt":[-21.34217671608542,14.643022776798205],"lastRiserFt":[-21.350535334386393,7.459507361542322],"widthFt":3.6666666666666665,"goingFt":0.7981689198031569,"nominalGoingDifferenceIn":0.07802703763788266,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-147","sourcePlanFloor":83},{"id":"upper","risers":9,"firstRiserPx":[2173,1307],"lastRiserPx":[2026,1307],"firstRiserFt":[-17.139943553823578,7.436343628257859],"lastRiserFt":[-17.15612361471046,13.724748032278328],"widthFt":3.6666666666666665,"goingFt":0.7860531524537074,"nominalGoingDifferenceIn":-0.0673621705555103,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":84}],"intermediateLanding":{"polygonFt":[[-23.324389655761088,3.4594888831937993],[-23.334515952370566,7.395088918363086],[-23.2661691333972,7.45166343988231],[-15.688773217310015,7.482690507781939],[-15.345653617692733,7.448293268365305],[-15.335527321083255,3.5126932331960177]],"sourcePixels":[[2265,1147],[2355,1147],[2355,1325],[2265,1325]],"sourceSheet":"A-B-147","offsetFt":6.315789473684211,"planReadingsFt":[[[-23.2661691333972,7.45166343988231],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.688773217310015,7.482690507781939]],[[-23.334515952370566,7.395088918363086],[-23.324389655761088,3.4594888831937993],[-15.335527321083255,3.5126932331960177],[-15.345653617692733,7.448293268365305]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-23.251889827133034,19.723502274277777],[-15.674493911045843,19.754529342177406],[-15.681459426296655,13.768266496130835],[-19.427587744362235,13.752927271551243],[-19.426542917074613,14.65086669845823],[-23.257810515096224,14.635178855138193]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-23.365775389730246,19.54411511388564],[-15.37691305505242,19.597319463887857],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747],[-23.352897382085587,14.539058547420353]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-147","floors":[83],"path":"analysis/wtc2-independent-core-review/sources/A-B-147.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":365,"sha256":"b3847150838352cc96b6797a1b4f78c59c62443c88ed567ae61957e2baa20d4d","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1372,711],[507,3503,715],[1002,1375,2674],[1007,3516,2675]],"heldOut":[[702,1498,1574],[707,3385,1573]],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"controlResidualsFt":[0.11190055622484506,0.1120720997794811,0.11137685906012405,0.11154840261485546]},{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-147","sourcePixels":[[2097,1147],[2355,1147],[2355,1325],[2118,1325],[2118,1237],[2097,1237]],"registrationMatrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"uncertaintyFt":1.0}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[17.02235333192391,-13.8055347712978],[17.02812475884602,-8.845488413144935],[16.219301599263673,-8.84880029117916],[16.225272040907228,-3.7177178517106597]],"floorLandingPolygonsFt":[[[21.248489558313338,-3.697149346024389],[21.236747689747688,-13.788278143645755],[17.02235333192391,-13.8055347712978],[17.02812475884602,-8.845488413144935],[16.219301599263673,-8.84880029117916],[16.225272040907228,-3.7177178517106597]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":83,"upperFloor":84,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2708,2094],"lastRiserPx":[2708,1927],"firstRiserFt":[17.025239045384964,-11.32551159222136],"lastRiserFt":[9.916109169055972,-11.354621257048535],"widthFt":4.666666666666667,"goingFt":0.7899099415076319,"nominalGoingDifferenceIn":-0.021080701908417154,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-147","sourcePlanFloor":83},{"id":"upper","risers":9,"firstRiserPx":[2493,1942],"lastRiserPx":[2493,2092],"firstRiserFt":[10.023233334167003,-6.072032794515906],"lastRiserFt":[16.431411677491468,-6.029355508417851],"widthFt":4.666666666666667,"goingFt":0.8010400566470735,"nominalGoingDifferenceIn":0.1124806797648823,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":84}],"intermediateLanding":{"polygonFt":[[5.258822832811759,-14.01787683305949],[4.847436298210795,-13.855387251181469],[4.859178166776459,-3.764258453560103],[5.2324064068739915,-3.7510941326178937],[10.017179569889592,-3.7192284256646957],[10.04359599582736,-13.986011126106291]],"sourcePixels":[[2530,1808],[2766,1808],[2766,1927],[2530,1927]],"sourceSheet":"A-B-147","offsetFt":6.315789473684211,"planReadingsFt":[[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[9.913223455594931,-13.834644436124975],[9.924965324160581,-3.7435156385036095]],[[5.2324064068739915,-3.7510941326178937],[5.258822832811759,-14.01787683305949],[10.04359599582736,-13.986011126106291],[10.017179569889592,-3.7192284256646957]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[21.248489558313338,-3.697149346024389],[21.236747689747688,-13.788278143645755],[17.02235333192391,-13.8055347712978],[17.02812475884602,-8.845488413144935],[16.219301599263673,-8.84880029117916],[16.225272040907228,-3.7177178517106597]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[22.107276044295077,-3.63871061255972],[22.133692470232845,-13.905493313001315],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-147","floors":[83],"path":"analysis/wtc2-independent-core-review/sources/A-B-147.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":365,"sha256":"b3847150838352cc96b6797a1b4f78c59c62443c88ed567ae61957e2baa20d4d","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1372,711],[507,3503,715],[1002,1375,2674],[1007,3516,2675]],"heldOut":[[702,1498,1574],[707,3385,1573]],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"controlResidualsFt":[0.11190055622484506,0.1120720997794811,0.11137685906012405,0.11154840261485546]},{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-147","sourcePixels":[[2530,1808],[2766,1808],[2766,2094],[2650,2094],[2650,2075],[2530,2075]],"registrationMatrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1"},{"floors":[84,84],"evidenceType":"Tower B A-B-147 stair B; A/C independently reviewed on83\u201385 only. Other A/C and transfer corridors retain prior derivation.","uncertaintyFt":1.0,"stairs":{"A":{"stair":"A","enclosurePx":[[2792,1147],[3210,1147],[3210,1327],[2792,1327]],"positiveWitnessPx":[2950,1190],"landingWitnessPx":[3150,1290],"enclosurePolygonFt":[[-23.292389322948473,-15.082340273450143],[-23.313186361340186,-32.95561077093207],[-15.650651165296964,-32.92423508429199],[-15.62985412690525,-15.050964586810068]],"rectFt":[[-23.313186361340186,-32.95561077093207],[-15.62985412690525,-15.050964586810068]],"floorOpeningPolygonFt":[[-23.276399815307485,-15.19183302260842],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815],[-15.116652724807672,-15.137490611643585]],"floorLandingPolygonsFt":[[[-15.070644116299398,-33.01880381491269],[-23.23039120679922,-33.07314622587752],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":84,"upperFloor":85,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2957,1208],"lastRiserPx":[2790,1208],"firstRiserFt":[-21.283047602354372,-26.129980202009392],"lastRiserFt":[-21.301429032069393,-18.986010572952125],"widthFt":3.6666666666666665,"goingFt":0.7937770307469033,"nominalGoingDifferenceIn":0.025324368962840182,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-149","sourcePlanFloor":84},{"id":"upper","risers":9,"firstRiserPx":[2790,1306],"lastRiserPx":[2939,1306],"firstRiserFt":[-17.114752514430748,-18.958128079368066],"lastRiserFt":[-17.09835231666105,-25.332089005892215],"widthFt":3.6666666666666665,"goingFt":0.7967477531673632,"nominalGoingDifferenceIn":0.06097303800835974,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":85}],"intermediateLanding":{"polygonFt":[[-23.266603724022232,-18.999098274022188],[-23.276399815307485,-15.19183302260842],[-15.116652724807672,-15.137490611643585],[-15.106856633522412,-18.944755863057352]],"sourcePixels":[[2701,1162],[2790,1162],[2790,1353],[2701,1353]],"sourceSheet":"A-B-149","offsetFt":6.315789473684211,"planReadingsFt":[[[-23.276399815307485,-15.19183302260842],[-23.266603724022232,-18.999098274022188],[-15.106856633522412,-18.944755863057352],[-15.116652724807672,-15.137490611643585]],[[-23.276399815307485,-15.19183302260842],[-23.266603724022232,-18.999098274022188],[-15.106856633522412,-18.944755863057352],[-15.116652724807672,-15.137490611643585]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-15.070644116299398,-33.01880381491269],[-23.23039120679922,-33.07314622587752],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-15.070644116299398,-33.01880381491269],[-23.23039120679922,-33.07314622587752],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-149","sourcePixels":[[2701,1162],[2957,1162],[2957,1259],[2939,1259],[2939,1353],[2701,1353]],"registrationMatrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"uncertaintyFt":1.0}},"C":{"stair":"C","enclosurePx":[[1978,1147],[2355,1147],[2355,1325],[1978,1325]],"positiveWitnessPx":[2240,1290],"landingWitnessPx":[2030,1290],"enclosurePolygonFt":[[-23.251889827133034,19.723502274277777],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.674493911045843,19.754529342177406]],"rectFt":[[-23.27064696462986,3.6033516102809386],[-15.674493911045843,19.754529342177406]],"floorOpeningPolygonFt":[[-23.352897382085587,14.539058547420353],[-23.324389655761088,3.4594888831937993],[-15.335527321083255,3.5126932331960177],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747]],"floorLandingPolygonsFt":[[[-23.365775389730246,19.54411511388564],[-15.37691305505242,19.597319463887857],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747],[-23.352897382085587,14.539058547420353]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":84,"upperFloor":85,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2006,1208],"lastRiserPx":[2173,1208],"firstRiserFt":[-21.387722690132755,14.552146248490416],"lastRiserFt":[-21.369341260417727,7.408176619433149],"widthFt":3.6666666666666665,"goingFt":0.7937770307469033,"nominalGoingDifferenceIn":0.025324368962840182,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-149","sourcePlanFloor":84},{"id":"upper","risers":9,"firstRiserPx":[2173,1307],"lastRiserPx":[2026,1307],"firstRiserFt":[-17.139943553823578,7.436343628257859],"lastRiserFt":[-17.15612361471046,13.724748032278328],"widthFt":3.6666666666666665,"goingFt":0.7860531524537074,"nominalGoingDifferenceIn":-0.0673621705555103,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":85}],"intermediateLanding":{"polygonFt":[[-23.324389655761088,3.4594888831937993],[-23.334515952370566,7.395088918363086],[-15.345653617692733,7.448293268365305],[-15.335527321083255,3.5126932331960177]],"sourcePixels":[[2173,1162],[2265,1162],[2265,1349],[2173,1349]],"sourceSheet":"A-B-149","offsetFt":6.315789473684211,"planReadingsFt":[[[-23.334515952370566,7.395088918363086],[-23.324389655761088,3.4594888831937993],[-15.335527321083255,3.5126932331960177],[-15.345653617692733,7.448293268365305]],[[-23.334515952370566,7.395088918363086],[-23.324389655761088,3.4594888831937993],[-15.335527321083255,3.5126932331960177],[-15.345653617692733,7.448293268365305]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-23.365775389730246,19.54411511388564],[-15.37691305505242,19.597319463887857],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747],[-23.352897382085587,14.539058547420353]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-23.365775389730246,19.54411511388564],[-15.37691305505242,19.597319463887857],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747],[-23.352897382085587,14.539058547420353]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-149","sourcePixels":[[2006,1162],[2265,1162],[2265,1349],[2026,1349],[2026,1259],[2006,1259]],"registrationMatrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"uncertaintyFt":1.0}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[5.2324064068739915,-3.7510941326178937],[5.258822832811759,-14.01787683305949],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]],"floorLandingPolygonsFt":[[[22.107276044295077,-3.63871061255972],[22.133692470232845,-13.905493313001315],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":84,"upperFloor":85,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2619,2110],"lastRiserPx":[2619,1942],"firstRiserFt":[17.214261702307724,-11.414295151817925],"lastRiserFt":[10.03710195778433,-11.462093712247736],"widthFt":4.666666666666667,"goingFt":0.7974798786175301,"nominalGoingDifferenceIn":0.06975854341036225,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-149","sourcePlanFloor":84},{"id":"upper","risers":9,"firstRiserPx":[2493,1942],"lastRiserPx":[2493,2092],"firstRiserFt":[10.023233334167003,-6.072032794515906],"lastRiserFt":[16.431411677491468,-6.029355508417851],"widthFt":4.666666666666667,"goingFt":0.8010400566470735,"nominalGoingDifferenceIn":0.1124806797648823,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":85}],"intermediateLanding":{"polygonFt":[[5.258822832811759,-14.01787683305949],[5.2324064068739915,-3.7510941326178937],[10.017179569889592,-3.7192284256646957],[10.04359599582736,-13.986011126106291]],"sourcePixels":[[2438,1830],[2678,1830],[2678,1942],[2438,1942]],"sourceSheet":"A-B-149","offsetFt":6.315789473684211,"planReadingsFt":[[[5.2324064068739915,-3.7510941326178937],[5.258822832811759,-14.01787683305949],[10.04359599582736,-13.986011126106291],[10.017179569889592,-3.7192284256646957]],[[5.2324064068739915,-3.7510941326178937],[5.258822832811759,-14.01787683305949],[10.04359599582736,-13.986011126106291],[10.017179569889592,-3.7192284256646957]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[22.107276044295077,-3.63871061255972],[22.133692470232845,-13.905493313001315],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[22.107276044295077,-3.63871061255972],[22.133692470232845,-13.905493313001315],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-149","sourcePixels":[[2438,1830],[2678,1830],[2678,2110],[2558,2110],[2558,2092],[2438,2092]],"registrationMatrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1"},{"floors":[85,85],"evidenceType":"Tower B A-B-147 stair B; A/C independently reviewed on83\u201385 only. Other A/C and transfer corridors retain prior derivation.","uncertaintyFt":1.0,"stairs":{"A":{"stair":"A","enclosurePx":[[2792,1147],[3210,1147],[3210,1327],[2792,1327]],"positiveWitnessPx":[2950,1190],"landingWitnessPx":[3150,1290],"enclosurePolygonFt":[[-23.292389322948473,-15.082340273450143],[-23.313186361340186,-32.95561077093207],[-15.650651165296964,-32.92423508429199],[-15.62985412690525,-15.050964586810068]],"rectFt":[[-23.313186361340186,-32.95561077093207],[-15.62985412690525,-15.050964586810068]],"floorOpeningPolygonFt":[[-23.276399815307485,-15.19183302260842],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815],[-15.116652724807672,-15.137490611643585]],"floorLandingPolygonsFt":[[[-15.070644116299398,-33.01880381491269],[-23.23039120679922,-33.07314622587752],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":85,"upperFloor":86,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2957,1208],"lastRiserPx":[2790,1208],"firstRiserFt":[-21.283047602354372,-26.129980202009392],"lastRiserFt":[-21.301429032069393,-18.986010572952125],"widthFt":3.6666666666666665,"goingFt":0.7937770307469033,"nominalGoingDifferenceIn":0.025324368962840182,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-149","sourcePlanFloor":85},{"id":"upper","risers":9,"firstRiserPx":[2790,1306],"lastRiserPx":[2939,1306],"firstRiserFt":[-17.114752514430748,-18.958128079368066],"lastRiserFt":[-17.09835231666105,-25.332089005892215],"widthFt":3.6666666666666665,"goingFt":0.7967477531673632,"nominalGoingDifferenceIn":0.06097303800835974,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":86}],"intermediateLanding":{"polygonFt":[[-23.266603724022232,-18.999098274022188],[-23.276399815307485,-15.19183302260842],[-15.116652724807672,-15.137490611643585],[-15.106856633522412,-18.944755863057352]],"sourcePixels":[[2701,1162],[2790,1162],[2790,1353],[2701,1353]],"sourceSheet":"A-B-149","offsetFt":6.315789473684211,"planReadingsFt":[[[-23.276399815307485,-15.19183302260842],[-23.266603724022232,-18.999098274022188],[-15.106856633522412,-18.944755863057352],[-15.116652724807672,-15.137490611643585]],[[-23.276399815307485,-15.19183302260842],[-23.266603724022232,-18.999098274022188],[-15.106856633522412,-18.944755863057352],[-15.116652724807672,-15.137490611643585]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-15.070644116299398,-33.01880381491269],[-23.23039120679922,-33.07314622587752],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-15.070644116299398,-33.01880381491269],[-23.23039120679922,-33.07314622587752],[-23.248222294307205,-26.143067903079455],[-19.10426696562405,-26.11546992473606],[-19.106248197569386,-25.345461222202943],[-15.09045643575272,-25.3187167895815]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-149","sourcePixels":[[2701,1162],[2957,1162],[2957,1259],[2939,1259],[2939,1353],[2701,1353]],"registrationMatrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"uncertaintyFt":1.0}},"C":{"stair":"C","enclosurePx":[[1978,1147],[2355,1147],[2355,1325],[1978,1325]],"positiveWitnessPx":[2240,1290],"landingWitnessPx":[2030,1290],"enclosurePolygonFt":[[-23.251889827133034,19.723502274277777],[-23.27064696462986,3.6033516102809386],[-15.693251048542677,3.6343786781805676],[-15.674493911045843,19.754529342177406]],"rectFt":[[-23.27064696462986,3.6033516102809386],[-15.674493911045843,19.754529342177406]],"floorOpeningPolygonFt":[[-23.352897382085587,14.539058547420353],[-23.324389655761088,3.4594888831937993],[-15.335527321083255,3.5126932331960177],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747]],"floorLandingPolygonsFt":[[[-23.365775389730246,19.54411511388564],[-15.37691305505242,19.597319463887857],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747],[-23.352897382085587,14.539058547420353]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":85,"upperFloor":86,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2006,1208],"lastRiserPx":[2173,1208],"firstRiserFt":[-21.387722690132755,14.552146248490416],"lastRiserFt":[-21.369341260417727,7.408176619433149],"widthFt":3.6666666666666665,"goingFt":0.7937770307469033,"nominalGoingDifferenceIn":0.025324368962840182,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-149","sourcePlanFloor":85},{"id":"upper","risers":9,"firstRiserPx":[2173,1307],"lastRiserPx":[2026,1307],"firstRiserFt":[-17.139943553823578,7.436343628257859],"lastRiserFt":[-17.15612361471046,13.724748032278328],"widthFt":3.6666666666666665,"goingFt":0.7860531524537074,"nominalGoingDifferenceIn":-0.0673621705555103,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":86}],"intermediateLanding":{"polygonFt":[[-23.324389655761088,3.4594888831937993],[-23.334515952370566,7.395088918363086],[-15.345653617692733,7.448293268365305],[-15.335527321083255,3.5126932331960177]],"sourcePixels":[[2173,1162],[2265,1162],[2265,1349],[2173,1349]],"sourceSheet":"A-B-149","offsetFt":6.315789473684211,"planReadingsFt":[[[-23.334515952370566,7.395088918363086],[-23.324389655761088,3.4594888831937993],[-15.335527321083255,3.5126932331960177],[-15.345653617692733,7.448293268365305]],[[-23.334515952370566,7.395088918363086],[-23.324389655761088,3.4594888831937993],[-15.335527321083255,3.5126932331960177],[-15.345653617692733,7.448293268365305]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[-23.365775389730246,19.54411511388564],[-15.37691305505242,19.597319463887857],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747],[-23.352897382085587,14.539058547420353]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[-23.365775389730246,19.54411511388564],[-15.37691305505242,19.597319463887857],[-15.361833678579607,13.736697672385773],[-19.206740684574292,13.711091300726949],[-19.20894205340244,14.566656525763747],[-23.352897382085587,14.539058547420353]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-149","sourcePixels":[[2006,1162],[2265,1162],[2265,1349],[2026,1349],[2026,1259],[2006,1259]],"registrationMatrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"uncertaintyFt":1.0}},"B":{"stair":"B","enclosurePx":[[2530,1808],[2766,1808],[2766,2193],[2530,2193]],"positiveWitnessPx":[2570,1960],"landingWitnessPx":[2570,2140],"enclosurePolygonFt":[[4.859178166776459,-3.764258453560103],[4.847436298210795,-13.855387251181469],[21.236747689747688,-13.788278143645755],[21.248489558313338,-3.697149346024389]],"rectFt":[[4.847436298210795,-13.855387251181469],[21.248489558313338,-3.697149346024389]],"floorOpeningPolygonFt":[[5.2324064068739915,-3.7510941326178937],[5.258822832811759,-14.01787683305949],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]],"floorLandingPolygonsFt":[[[22.107276044295077,-3.63871061255972],[22.133692470232845,-13.905493313001315],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]]],"source":"PANYNJ A-B-147; independently registered Tower B plan","reviewRevision":"wtc2-independent-circulation-v1","interpretation":"Clear stair enclosure and stepped nominal-floor opening; entry landing retained. Flights, half-landing construction and exact slab trimming unresolved.","flightModel":{"revision":"wtc2-stair-flights-v1","classification":"architectural plan and section reconstruction","estimated":false,"floor":85,"upperFloor":86,"storyRiseFt":12.0,"riserCount":19,"riserHeightFt":0.631578947368421,"flights":[{"id":"lower","risers":10,"firstRiserPx":[2619,2110],"lastRiserPx":[2619,1942],"firstRiserFt":[17.214261702307724,-11.414295151817925],"lastRiserFt":[10.03710195778433,-11.462093712247736],"widthFt":4.666666666666667,"goingFt":0.7974798786175301,"nominalGoingDifferenceIn":0.06975854341036225,"baseOffsetFt":0.0,"topOffsetFt":6.315789473684211,"sourceSheet":"A-B-149","sourcePlanFloor":85},{"id":"upper","risers":9,"firstRiserPx":[2493,1942],"lastRiserPx":[2493,2092],"firstRiserFt":[10.023233334167003,-6.072032794515906],"lastRiserFt":[16.431411677491468,-6.029355508417851],"widthFt":4.666666666666667,"goingFt":0.8010400566470735,"nominalGoingDifferenceIn":0.1124806797648823,"baseOffsetFt":6.315789473684211,"topOffsetFt":12.0,"sourceSheet":"A-B-149","sourcePlanFloor":86}],"intermediateLanding":{"polygonFt":[[5.258822832811759,-14.01787683305949],[5.2324064068739915,-3.7510941326178937],[10.017179569889592,-3.7192284256646957],[10.04359599582736,-13.986011126106291]],"sourcePixels":[[2438,1830],[2678,1830],[2678,1942],[2438,1942]],"sourceSheet":"A-B-149","offsetFt":6.315789473684211,"planReadingsFt":[[[5.2324064068739915,-3.7510941326178937],[5.258822832811759,-14.01787683305949],[10.04359599582736,-13.986011126106291],[10.017179569889592,-3.7192284256646957]],[[5.2324064068739915,-3.7510941326178937],[5.258822832811759,-14.01787683305949],[10.04359599582736,-13.986011126106291],[10.017179569889592,-3.7192284256646957]]],"reconciliation":"Envelope of adjacent plan registrations; flights retain measured endpoints. This does not establish a fabrication tolerance."},"floorLandings":[{"polygonFt":[[22.107276044295077,-3.63871061255972],[22.133692470232845,-13.905493313001315],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]],"offsetFt":0,"role":"departure floor landing"},{"polygonFt":[[22.107276044295077,-3.63871061255972],[22.133692470232845,-13.905493313001315],[17.220755740350754,-13.93821256567648],[17.207547527381877,-8.80482121545569],[16.438566126182934,-8.809942489787446],[16.425357913214057,-3.676551139566641]],"offsetFt":12.0,"role":"arrival floor landing"}],"planUncertaintyFt":1.0,"sources":[{"sheet":"A-B-149","floors":[84,85,86],"path":"analysis/wtc2-independent-core-review/sources/A-B-149.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":367,"sha256":"aeb27f4dbe0f45a108069851c24d0057a0ef88abecc27d03c3c8648a7115d617","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1277,733],[507,3409,728],[1002,1287,2688],[1007,3425,2682]],"heldOut":[],"reading":"Independently registered plan; riser endpoints, arrows/plan breaks, return landing and entry opening traced in this pass.","matrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"controlResidualsFt":[0.06516861861114226,0.06520140767354467,0.06498548655415334,0.06501827561643093]},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"},{"path":"sources/NCSTAR1-7.pdf","sha256":"8954ff623795121b69b03d9fc30aac31bb0a015068a1251198f643b95a220cc0","evidence":"Printed p27: A/C44 in and B56 in flight widths; p249: nominal9.5 in going as a comparison, not a substitute for plan counts."},{"path":"site/data/floor_heights.json","sha256":"4bb4fc1bea6e243519564b941cf91b2ee479bd52698fba079f79c25241a1bf2e","evidence":"Tower B82\u201385 departing story rises are12 ft."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights.","physicalThicknessFt":null},"flightInterfaceRevision":"wtc2-stair-flights-v1","floorOpeningReview":{"revision":"wtc2-stair-flights-v1","sourceSheet":"A-B-149","sourcePixels":[[2438,1830],[2678,1830],[2678,2110],[2558,2110],[2558,2092],[2438,2092]],"registrationMatrix":[[0.00011006844140734303,-0.04277826125183997],[0.042721188955496425,0.00028451524065361904],[-73.21571624183557,100.02164390897182]],"uncertaintyFt":1.0}}},"revision":"wtc2-independent-circulation-v1"},{"floors":[86,110],"evidenceType":"derived from WTC 1 band by documented core rotation; LERA PAC1 TOWER A core plan A-A-153 (96th-100th), digitized in analysis/stairwell-data/wtc1_stair_digitization.json; corroborated within 2-3 ft by A-A139 (82), A-A-148 (89-93), A-A-158 (103), A-A-162 (105), A-A-166 (107), A-A-170 (108). 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FIN FL EL(+14-0), SUSP CEIL(+8-0) above finish.","description":"Source-traced floor76 C incoming landing","sourcePixels":[[1360,1855],[1730,1855],[1730,2235],[1360,2235]],"uncertaintyFt":1},{"floor":76,"stair":"C","id":"WTC2-F76-C-core-passage","rectFt":[[-19.079164012288757,40.37987555209163],[23.33386844937624,44.99126202498151]],"polygonFt":[[-19.067639442259463,44.86121050843635],[-19.079164012288757,40.37987555209163],[23.32234387934696,40.50992706863679],[23.33386844937624,44.99126202498151]],"heightFt":8,"walkingSurface":true,"walkingPolygonsFt":[[[-19.079164012288757,40.37987555209163],[-19.067639442259463,44.86121050843635],[23.33386844937624,44.99126202498151],[23.32234387934696,40.50992706863679]]],"walkingOffsetFt":0,"revision":"wtc2-floor76-approach-v1","role":"core-passage","evidenceType":"Original Tower B A-B-130 clear passage; FIN FL EL(+14-0), SUSP CEIL(+8-0) above finish.","description":"Source-traced floor76 C core passage","sourcePixels":[[1255,1242],[1360,1242],[1360,2235],[1255,2235]],"uncertaintyFt":1},{"floor":76,"stair":"C","id":"WTC2-F76-C-cross-passage","rectFt":[[-24.502116179698362,40.36324257867649],[-18.99794323303471,71.96261714918776]],"polygonFt":[[-24.420895400444316,71.94598417577262],[-24.502116179698362,40.36324257867649],[-19.079164012288757,40.37987555209163],[-18.99794323303471,71.96261714918776]],"heightFt":8,"walkingSurface":true,"walkingPolygonsFt":[[[-24.502116179698362,40.36324257867649],[-24.420895400444316,71.94598417577262],[-18.99794323303471,71.96261714918776],[-19.079164012288757,40.37987555209163]]],"walkingOffsetFt":0,"revision":"wtc2-floor76-approach-v1","role":"cross-passage","evidenceType":"Original Tower B A-B-130 clear passage; FIN FL EL(+14-0), SUSP CEIL(+8-0) above finish.","description":"Source-traced floor76 C cross passage","sourcePixels":[[620,1115],[1360,1115],[1360,1242],[620,1242]],"uncertaintyFt":1},{"floor":76,"stair":"C","id":"WTC2-F76-C-outer-passage","rectFt":[[-44.37559719705107,66.59257879565052],[-18.99794323303471,71.96261714918776]],"polygonFt":[[-44.36198722863553,71.88482198219097],[-44.37559719705107,66.59257879565052],[-19.011553201450255,66.67037396264733],[-18.99794323303471,71.96261714918776]],"heightFt":8,"walkingSurface":true,"walkingPolygonsFt":[[[-44.37559719705107,66.59257879565052],[-44.36198722863553,71.88482198219097],[-24.420895400444316,71.94598417577262],[-24.434505368859853,66.65374098923219]]],"walkingOffsetFt":0,"revision":"wtc2-floor76-approach-v1","role":"outer-passage","evidenceType":"Original Tower B A-B-130 clear passage; FIN FL EL(+14-0), SUSP CEIL(+8-0) above finish.","description":"Source-traced floor76 C outer passage","sourcePixels":[[620,648],[744,648],[744,1242],[620,1242]],"uncertaintyFt":1},{"floor":76,"stair":"C","id":"WTC2-F76-C-departure-landing","rectFt":[[-44.36198722863553,71.88482198219097],[-39.943100693581314,79.96471463795602]],"polygonFt":[[-44.34124300258281,79.95122490361146],[-44.36198722863553,71.88482198219097],[-39.96384491963404,71.89831171653552],[-39.943100693581314,79.96471463795602]],"heightFt":8,"walkingSurface":true,"walkingPolygonsFt":[[[-44.34124300258281,79.95122490361146],[-39.943100693581314,79.96471463795602],[-39.96384491963404,71.89831171653552],[-44.36198722863553,71.88482198219097]]],"walkingOffsetFt":0,"revision":"wtc2-floor76-approach-v1","role":"departure-landing","evidenceType":"Original Tower B A-B-130 clear passage; FIN FL EL(+14-0), SUSP CEIL(+8-0) above finish.","description":"Source-traced floor76 C departure landing","sourcePixels":[[431,648],[620,648],[620,751],[431,751]],"uncertaintyFt":1}],"independentReview":{"revision":"wtc2-independent-circulation-v1","stairB":[78,79,80,81,82,83,84,85],"stairsAC":[83,84,85],"limits":"Original design/revision drawings, not a September2001 survey. A-B-147 clear local-hoistway geometry and stair B are corroborated on78\u201385; upper A/C only83\u201385. Common boundaries are traced once, not independently traced on every floor. Read uncertainty1ft; four-column fit residuals are not construction tolerances. Express/freight shafts, floor77, the82 transfer, small services, machinery, complete slab topology, detailed stair flights and all158 NIST prototype beam sections/connections remain unresolved. Unreviewed openings outside the bounded circulation masks are retained."},"floorOpenings":[{"floor":77,"stair":"C","id":"WTC2-F77-outer-stair-C","polygonFt":[[-39.090470286022715,80.23780293298553],[-39.081029340868284,76.21005151065476],[-39.98024023484861,76.2019760033443],[-39.97079928969417,72.17422458101353],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-135; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":77,"stair":"C","region":"tenant","polygonFt":[[-39.090470286022715,80.23780293298553],[-39.081029340868284,76.21005151065476],[-39.98024023484861,76.2019760033443],[-39.97079928969417,72.17422458101353],[-28.366696800710002,72.27843708011531],[-28.385578691018864,80.33393992477686]],"sourceSheet":"A-B-135","sourcePixels":[[529,788],[623,788],[623,767],[717,767],[717,1038],[529,1038]],"registrationMatrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":77,"stair":"A","id":"WTC2-F77-outer-stair-A","polygonFt":[[-40.27482572922281,-72.14502013221762],[-40.265786526415376,-76.00137787700238],[-39.4950343315751,-75.99445601359342],[-39.48609556435441,-79.8079653389917],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-135; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":77,"stair":"A","region":"tenant","polygonFt":[[-40.27482572922281,-72.14502013221762],[-40.265786526415376,-76.00137787700238],[-39.4950343315751,-75.99445601359342],[-39.48609556435441,-79.8079653389917],[-28.56710613745048,-79.70990560736455],[-28.585084107478608,-72.0400385371815]],"sourceSheet":"A-B-135","sourcePixels":[[4085,752],[4175,752],[4175,770],[4264,770],[4264,1025],[4085,1025]],"registrationMatrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":78,"stair":"C","id":"WTC2-F78-outer-stair-C","polygonFt":[[-39.53947020213485,80.41599108531575],[-39.551077842086656,76.23537325899406],[-37.94449532607829,76.23783394874665],[-37.955273848890684,72.35583168144795],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-137; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":78,"stair":"C","region":"tenant","polygonFt":[[-39.53947020213485,80.41599108531575],[-39.551077842086656,76.23537325899406],[-37.94449532607829,76.23783394874665],[-37.955273848890684,72.35583168144795],[-28.019829341996825,72.37104910491793],[-27.99744317923262,80.43366919853833]],"sourceSheet":"A-B-137","sourcePixels":[[539,733],[637,733],[637,771],[728,771],[728,1006],[539,1006]],"registrationMatrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":78,"stair":"A","id":"WTC2-F78-outer-stair-A","polygonFt":[[-38.14541099866187,-72.25909384185515],[-38.15512351372359,-75.75716181898146],[-39.71942754246858,-75.75955775374057],[-39.73044295589224,-79.72687875218871],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-137; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":78,"stair":"A","region":"tenant","polygonFt":[[-38.14541099866187,-72.25909384185515],[-38.15512351372359,-75.75716181898146],[-39.71942754246858,-75.75955775374057],[-39.73044295589224,-79.72687875218871],[-28.31525139478014,-79.7093949039466],[-28.29452346629477,-72.24400592837215]],"sourceSheet":"A-B-137","sourcePixels":[[4118,776],[4200,776],[4200,739],[4293,739],[4293,1009],[4118,1009]],"registrationMatrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":79,"stair":"C","id":"WTC2-F79-outer-stair-C","polygonFt":[[-39.12260663704781,80.25891961454829],[-39.10802636127367,76.07553125570035],[-39.95679121409347,76.06750386482392],[-39.94325238658892,72.18292896017941],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-139; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":79,"stair":"C","region":"tenant","polygonFt":[[-39.12260663704781,80.25891961454829],[-39.10802636127367,76.07553125570035],[-39.95679121409347,76.06750386482392],[-39.94325238658892,72.18292896017941],[-28.61224160144456,72.29009462837976],[-28.64036070472325,80.35805789187219]],"sourceSheet":"A-B-139","sourcePixels":[[491,762],[589,762],[589,742],[680,742],[680,1009],[491,1009]],"registrationMatrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":79,"stair":"A","id":"WTC2-F79-outer-stair-A","polygonFt":[[-40.20501390986442,-71.89506825397436],[-40.19117752571141,-75.86501843124842],[-39.384850915532596,-75.8573924099158],[-39.37116330970382,-79.78465495087508],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-139; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":79,"stair":"A","region":"tenant","polygonFt":[[-40.20501390986442,-71.89506825397436],[-40.19117752571141,-75.86501843124842],[-39.384850915532596,-75.8573924099158],[-39.37116330970382,-79.78465495087508],[-28.719164406815302,-79.68391119537588],[-28.74668839679709,-71.78669847714255]],"sourceSheet":"A-B-139","sourcePixels":[[4055,724],[4148,724],[4148,743],[4240,743],[4240,994],[4055,994]],"registrationMatrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":80,"stair":"C","id":"WTC2-F80-outer-stair-C","polygonFt":[[-38.78032665076474,80.26763654705286],[-38.77660901057194,76.25771255640655],[-38.01560325819274,76.26432077895973],[-38.01176696990868,72.1264204907396],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-141; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":80,"stair":"C","region":"tenant","polygonFt":[[-38.78032665076474,80.26763654705286],[-38.77660901057194,76.25771255640655],[-38.01560325819274,76.26432077895973],[-38.01176696990868,72.1264204907396],[-28.245526481042305,72.21122601350527],[-28.25308040951917,80.3590502923717]],"sourceSheet":"A-B-141","sourcePixels":[[596,845],[690,845],[690,863],[787,863],[787,1094],[596,1094]],"registrationMatrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":80,"stair":"A","id":"WTC2-F80-outer-stair-A","polygonFt":[[-38.469904384656964,-72.15066536946401],[-38.46630539255543,-76.03261306253648],[-39.227311144934625,-76.03922128508967],[-39.223633054105576,-80.00648650987804],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-141; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":80,"stair":"A","region":"tenant","polygonFt":[[-38.469904384656964,-72.15066536946401],[-38.46630539255543,-76.03261306253648],[-39.227311144934625,-76.03922128508967],[-39.223633054105576,-80.00648650987804],[-28.442718228733604,-79.91287002370814],[-28.449995311664196,-72.06365710584728]],"sourceSheet":"A-B-141","sourcePixels":[[4169,849],[4260,849],[4260,831],[4353,831],[4353,1086],[4169,1086]],"registrationMatrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":81,"stair":"C","id":"WTC2-F81-outer-stair-C","polygonFt":[[-38.921157993078786,79.93818837101216],[-38.886254722682736,75.97134785296379],[-38.16724344477758,75.98089929716937],[-38.13083895845052,71.84344198264581],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-143; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":81,"stair":"C","region":"tenant","polygonFt":[[-38.921157993078786,79.93818837101216],[-38.886254722682736,75.97134785296379],[-38.16724344477758,75.98089929716937],[-38.13083895845052,71.84344198264581],[-28.14927062988488,71.97603850220574],[-28.220578386607997,80.08033633477767]],"sourceSheet":"A-B-143","sourcePixels":[[503,1032],[596,1032],[596,1049],[693,1049],[693,1285],[503,1285]],"registrationMatrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":81,"stair":"A","id":"WTC2-F81-outer-stair-A","polygonFt":[[-37.70933302975772,-72.21102543472374],[-37.67555567130994,-76.04990335541571],[-38.52145129237482,-76.06114034859873],[-38.48767393392703,-79.9000182692907],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-143; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":81,"stair":"A","region":"tenant","polygonFt":[[-37.70933302975772,-72.21102543472374],[-37.67555567130994,-76.04990335541571],[-38.52145129237482,-76.06114034859873],[-38.48767393392703,-79.9000182692907],[-27.660209984296507,-79.75618475654774],[-27.727764701192093,-72.0784289151638]],"sourceSheet":"A-B-143","sourcePixels":[[4070,1029],[4160,1029],[4160,1009],[4250,1009],[4250,1265],[4070,1265]],"registrationMatrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":82,"stair":"C","id":"WTC2-F82-outer-stair-C","polygonFt":[[-38.31807490825698,80.16402456861053],[-38.32459256043063,76.14560155111366],[-38.155263534527634,76.14607829264514],[-38.161989196877045,71.99940773203667],[-28.1715766686005,72.02753548239437],[-28.158333354077442,80.19262906049971]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-145; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":82,"stair":"C","region":"tenant","polygonFt":[[-38.31807490825698,80.16402456861053],[-38.32459256043063,76.14560155111366],[-38.155263534527634,76.14607829264514],[-38.161989196877045,71.99940773203667],[-28.1715766686005,72.02753548239437],[-28.158333354077442,80.19262906049971]],"sourceSheet":"A-B-145","sourcePixels":[[518,800],[612,800],[612,804],[709,804],[709,1040],[518,1040]],"registrationMatrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}},{"floor":82,"stair":"A","id":"WTC2-F82-outer-stair-A","polygonFt":[[-38.26872652827293,-72.10772398821835],[-38.27496683354557,-75.95515028156642],[-38.40196360297281,-75.95550783771502],[-38.40827324497071,-79.84568331210026],[-28.079202664888186,-79.8166020786796],[-28.066652717617643,-72.07900031094628]],"revision":"wtc2-stair-transition-v1","region":"tenant","source":"PANYNJ A-B-145; sections A-B-131/132","interpretation":"Clear-flight and half-landing void inferred from plan first-riser lines and stair sections A-B-131/132. The nominal entry landing is retained. Sectional finish offsets, framing around the hole and stair fabrication are unresolved.","flightInterfaceRevision":"wtc2-outer-stair-flights-v1","flightInterfaceSource":{"floor":82,"stair":"A","region":"tenant","polygonFt":[[-38.26872652827293,-72.10772398821835],[-38.27496683354557,-75.95515028156642],[-38.40196360297281,-75.95550783771502],[-38.40827324497071,-79.84568331210026],[-28.079202664888186,-79.8166020786796],[-28.066652717617643,-72.07900031094628]],"sourceSheet":"A-B-145","sourcePixels":[[4080,807],[4170,807],[4170,804],[4261,804],[4261,1048],[4080,1048]],"registrationMatrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"revision":"wtc2-outer-stair-flights-v1","uncertaintyFt":1.0}}],"stairTransitionReview":{"revision":"wtc2-stair-transition-v1","floors":[77,78,79,80,81,82],"sources":[{"sheet":"A-B-135","floors":[77],"path":"analysis/wtc2-independent-core-review/sources/A-B-135.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":353,"sha256":"a1c2789af352b5265f967840e6c6f73cde617b66ae7283ac00fac47e77746a20","controls":[[502,1335,723],[507,3467,720],[1002,1353,2675],[1007,3484,2668]],"pixelConvention":"Native embedded raster rotated180 degrees; no resampling","reading":"Four-column registration. Outer A/C clear enclosures and first-riser boundaries read separately on each same-floor sheet; 147 supplies only the upper enclosure reference.","matrix":[[0.00010043558674928612,-0.04284841938649753],[0.0428195663800154,0.0003845479671652751],[-72.88541901886522,102.60159299031649]],"controlResidualsFt":[0.044016617895944264,0.044107072724772295,0.04403655167689833,0.04412700650567758]},{"sheet":"A-B-137","floors":[78],"path":"analysis/wtc2-independent-core-review/sources/A-B-137.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":355,"sha256":"4104f2443ccdc80c02eb64bb075a876d4d0386b9cce0c788cdc0ba65efa7b97f","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1354,681],[507,3494,691],[1002,1356,2660],[1007,3498,2662]],"heldOut":[],"reading":"Four-column registration. Outer A/C clear enclosures and first-riser boundaries read separately on each same-floor sheet; 147 supplies only the upper enclosure reference.","matrix":[[-0.00011844530563070248,-0.042659365574711075],[0.04227848726337813,6.47549934893045e-05],[-70.46575934645607,103.36192371985736]],"controlResidualsFt":[0.0871589862320893,0.08751283502580527,0.08707694451071928,0.08743079330455591]},{"sheet":"A-B-139","floors":[79],"path":"analysis/wtc2-independent-core-review/sources/A-B-139.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":357,"sha256":"e27aba4efdd09c4dec076dd309bea7a3c1260481f31d1c913b4d529b8f8d20d1","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1302,697],[507,3439,690],[1002,1318,2665],[1007,3460,2657]],"heldOut":[],"reading":"Four-column registration. Outer A/C clear enclosures and first-riser boundaries read separately on each same-floor sheet; 147 supplies only the upper enclosure reference.","matrix":[[0.00014877832422587436,-0.04268763631477481],[0.0424382426409901,0.0004013695438215101],[-71.53359768667717,100.91270545271072]],"controlResidualsFt":[0.054516765598682286,0.05454396264017155,0.054389242271355165,0.054416439312851755]},{"sheet":"A-B-141","floors":[80],"path":"analysis/wtc2-independent-core-review/sources/A-B-141.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":359,"sha256":"3956c28968825e0ccd92475e432a247cb0146c0937904847cbe94bba5bba7f78","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1408,773],[507,3546,773],[1002,1422,2750],[1007,3566,2746]],"heldOut":[],"reading":"Four-column registration. Outer A/C clear enclosures and first-riser boundaries read separately on each same-floor sheet; 147 supplies only the upper enclosure reference.","matrix":[[3.954936375319717e-05,-0.04265876585793942],[0.042278097354399885,0.00036712347517607645],[-74.52889033602955,105.38204166186097]],"controlResidualsFt":[0.07699832790613385,0.07715399216489915,0.07678139541870539,0.07693705967735691]},{"sheet":"A-B-143","floors":[81],"path":"analysis/wtc2-independent-core-review/sources/A-B-143.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":361,"sha256":"f18e47bf68179d9367e28f78c9a0e7f7e13b4d8ed4b54ee2de85388f1f8034f0","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1306,960],[507,3446,937],[1002,1331,2930],[1007,3473,2915]],"heldOut":[],"reading":"Four-column registration. Outer A/C clear enclosures and first-riser boundaries read separately on each same-floor sheet; 147 supplies only the upper enclosure reference.","matrix":[[0.00037530398275323606,-0.04265419911879967],[0.04229478105324422,0.0005618496591522223],[-82.7581499433517,100.8134216795233]],"controlResidualsFt":[0.08736685113023475,0.08701291204432997,0.08728973752246118,0.08693579843646554]},{"sheet":"A-B-145","floors":[82],"path":"analysis/wtc2-independent-core-review/sources/A-B-145.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":363,"sha256":"d5ba0357c843bdf400f6e3c8d1fb9df0c1d553d0b3788f13bc9f0ac8ffb97569","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1326,720],[507,3460,724],[1002,1329,2693],[1007,3468,2696]],"heldOut":[],"reading":"Four-column registration. Outer A/C clear enclosures and first-riser boundaries read separately on each same-floor sheet; 147 supplies only the upper enclosure reference.","matrix":[[-6.933672525159592e-05,-0.04274918103720072],[0.04233225647574806,0.00011918538287158362],[-72.1479636651751,102.21275203958324]],"controlResidualsFt":[0.05457040479916538,0.054598271635172974,0.05444274002128994,0.054470606857292]},{"sheet":"A-B-147","floors":[83],"path":"analysis/wtc2-independent-core-review/sources/A-B-147.png","pdf":"sources/PANYNJ-12673-WTC.pdf","pdfPage":365,"sha256":"b3847150838352cc96b6797a1b4f78c59c62443c88ed567ae61957e2baa20d4d","pixelConvention":"Native embedded raster rotated180 degrees; no resampling","controls":[[502,1372,711],[507,3503,715],[1002,1375,2674],[1007,3516,2675]],"heldOut":[[702,1498,1574],[707,3385,1573]],"reading":"Four-column registration. Outer A/C clear enclosures and first-riser boundaries read separately on each same-floor sheet; 147 supplies only the upper enclosure reference.","matrix":[[-4.975368036295309e-05,-0.04275902032890408],[0.0425696399780179,0.00017430937022264173],[-71.98085410216164,104.10091163720467]],"controlResidualsFt":[0.11190055622484506,0.1120720997794811,0.11137685906012405,0.11154840261485546]}],"sections":[{"sheet":"A-B-131","path":"analysis/wtc2-independent-core-review/sources/A-B-131.png","pdfPage":349,"sha256":"65854b3990f279d969fbf17cd260109139f6a3c952088540f1d2154f73a7ccfa"},{"sheet":"A-B-132","path":"analysis/wtc2-independent-core-review/sources/A-B-132.png","pdfPage":350,"sha256":"aba4fec89880abd9fec0b9a4488754cbf5e634fa3bbdf1c7750e15ed1afe87f1"}],"sectionReadings":{"outerStairs":"A-B-131 section A and A-B-132 section D: outer stairs1/2 run from76 up to82 and end there. Their upper terminal rooms have a6ft suspended ceiling.","innerStairs":"A-B-131 section B and A-B-132 section F: the new inner stairs1/2 start on82 over closet/duct space and continue to83. No through-floor82 opening is indicated below these new first flights.","floor77B":"A-B-132 section H: stair3 continues from76 through81; independent77 plan differs from the prior rotated box."},"limits":"Original design/revision drawings, not a September2001 survey. Approximate1ft digitization uncertainty; registration residuals are not construction tolerances. Clear stair envelopes, nominal-floor flight voids and82 passage volumes are reconstructed. Stair flights, wall/door construction, finish offsets, support steel, passage ceiling steps and upper-story flight envelopes remain incomplete. The82 inner envelopes use the independently traced83 clear enclosure as a reference; they are not exact sloping soffits. Elevator terminal/machine levels and floor77 local pits remain unresolved. No framing or foundation changes."},"stairFlightReview":{"revision":"wtc2-stair-flights-v1","storyFloors":[82,83,84,85],"sectionReadings":[{"sheet":"A-B-131","section":"B","story":82,"stair":"A","risers":19,"lowerRisers":14,"upperRisers":5,"lowerRunIn":123.5,"upperRunIn":38,"reading":"19 risers in 12 ft. First long flight over duct/closet arrangement; short upper flight enters83. Run dimensions10 ft3.5 in and3 ft2 in corroborate14/5 at9.5 in going."},{"sheet":"A-B-131","section":"B","stories":[83,84],"stair":"A","risers":19,"lowerRisers":10,"upperRisers":9,"lowerRunIn":85.5,"upperRunIn":76},{"sheet":"A-B-132","section":"F","stories":[82,83,84],"stair":"C","risers":19,"lowerRisers":10,"upperRisers":9,"lowerRunIn":85.5,"upperRunIn":76},{"sheet":"A-B-132","section":"H","stories":[79,80],"stair":"B","risers":19,"lowerRisers":10,"upperRisers":9,"reading":"Handedness/typical split corroboration only;82\u201385 counts and lane positions independently read on145/147/149."}],"riseMethod":"Each departing lower flight is paired with the arriving upper flight on the NEXT floor plan. Nineteen equal risers span the documented12 ft story; the intermediate height follows the riser split, not half the story.","limits":"Original architectural drawings, not a September2001 survey. Raster and registration uncertainty1 ft; fine fractions/finish datums, nosing, rails, stringers, fireproofing, sloping soffits and physical landing thickness are unresolved.82 A has14+5 risers; other reviewed stories10+9. A-B-149 explicitly covers84\u201386; its typical flights are used for84\u219285 and85\u219286. No claim of post-impact passability. Floors outside82\u201385 retain reference flights."},"outerStairFlightReview":{"revision":"wtc2-outer-stair-flights-v1","storyFloors":[76,77,78,79,80,81],"sectionReadings":[{"sheet":"A-B-131","section":"A","stair":"A","stories":{"76":[11,11],"77":[10,9],"78":[11,11],"79":[10,9],"80":[10,9],"81":[10,9]}},{"sheet":"A-B-132","section":"D","stair":"C","stories":{"76":[11,11],"77":[10,9],"78":[11,11],"79":[10,9],"80":[10,9],"81":[10,9]}},{"sheet":"A-B-132","section":"H","stair":"B","stories":{"76":[12,10],"77":[10,9],"78":[11,11],"79":[10,9],"80":[10,9]},"reading":"H shows76\u201381;81\u219282 is paired from the actual143/145 plans."}],"riseMethod":"Pair the departing lower flight with the arriving upper flight on the next plan. Divide the documented story rise equally among the section/plan counted risers:22 over14 ft on76/78,19 over12 ft elsewhere. Finish offsets are not reconstructed.","limits":"Architectural reconstruction, not an as-built survey. Plan/tracing uncertainty1 ft; registration residuals are not construction tolerances.76 new departure envelopes are measured independently; the earlier76 transfer passages and lower incoming flights remain unresolved references. At82 the outer stairs terminate and the already traced inner flights take over. Rails, nosing, finishes, stringers, physical landing thickness, sloping soffits and damage/passability remain unresolved. Nominal slab interfaces only;76 mechanical surfaces are unchanged."},"floor76ApproachReview":{"revision":"wtc2-floor76-approach-v1","sourceStories":3,"transferPieces":13,"limits":"Original architectural plan/section reconstruction with1 ft plan uncertainty. Source counts and raised departure datums replace repeated references; equal riser heights within each story remain an assumption. Passage height uses the8 ft suspended-ceiling notes; local soffits, ducts, doors, railings, finishes and landing thickness are unresolved. The raised vestibule next to incoming A is excluded from walking surfaces. No floor75/76 structural slab, pit, framing, or elevator change. Connections below75 and floor75 slab/finish interfaces still need review."},"referenceOverlapReview":{"revision":"wtc2-floor76-approach-v1","elevatorDataSha256":"afdf59b46efeee610778cffa2b326ad20f93d489b61c6a142015c6a62668eeaa","conflicts":[{"kind":"stair","floor":75,"subjectId":"B","bank":"X78","bankRectFt":[[-36.84,-13.78],[-22.41,-6.27]],"boundingOverlapAreaFt2":10.890219287315972,"polygonOverlapAreaFt2":10.866075204349599,"overlapPolygonFt":[[-23.862835535066125,-13.742776080600379],[-23.866355227385597,-6.27],[-22.41,-6.27],[-22.41,-13.73755819139638]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-A-core-passage","bank":"X78","bankRectFt":[[-36.79,-25.56],[-22.41,-14.42]],"boundingOverlapAreaFt2":10.193306083434488,"polygonOverlapAreaFt2":10.03325899802099,"overlapPolygonFt":[[-24.654679535324206,-18.961096367220293],[-24.64315496529491,-14.479761410875582],[-22.41,-14.47291200375876],[-22.41,-18.95421161259145]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-A-cross-passage","bank":"X78","bankRectFt":[[-36.79,-25.56],[-22.41,-14.42]],"boundingOverlapAreaFt2":26.428944963875566,"polygonOverlapAreaFt2":24.909402606468568,"overlapPolygonFt":[[-24.64315496529491,-14.479761410875582],[-22.41,-14.47291200375876],[-22.41,-25.56],[-24.67164981935192,-25.56]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-A-cross-passage","bank":"X78","bankRectFt":[[-36.79,-35.85],[-22.41,-27.2]],"boundingOverlapAreaFt2":20.601335488937156,"polygonOverlapAreaFt2":19.695962674730517,"overlapPolygonFt":[[-24.675867378412367,-27.2],[-22.41,-27.2],[-22.41,-35.85],[-24.69811243077388,-35.85]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-A-cross-passage","bank":"X78","bankRectFt":[[-36.84,-46.44],[-22.45,-35.6]],"boundingOverlapAreaFt2":25.383564936425287,"polygonOverlapAreaFt2":24.5136630294138,"overlapPolygonFt":[[-24.697469510185396,-35.6],[-22.45,-35.6],[-22.45,-46.44],[-24.72534654690202,-46.44]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-A-cross-passage","bank":"X78","bankRectFt":[[-36.84,-56.78],[-22.45,-45.64]],"boundingOverlapAreaFt2":26.086062121012713,"polygonOverlapAreaFt2":25.48401407507526,"overlapPolygonFt":[[-24.723289201018872,-45.64],[-22.45,-45.64],[-22.45,-56.78],[-24.751937742441676,-56.78]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-A-cross-passage","bank":"X78","bankRectFt":[[-36.84,-67.33],[-22.45,-57.37]],"boundingOverlapAreaFt2":23.32290652830221,"polygonOverlapAreaFt2":23.069969651004648,"overlapPolygonFt":[[-24.753455035030495,-57.37],[-22.45,-57.37],[-22.45,-67.33],[-24.779068991275658,-67.33]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-A-outer-passage","bank":"X78","bankRectFt":[[-36.84,-67.33],[-22.45,-57.37]],"boundingOverlapAreaFt2":5.34205010099531,"polygonOverlapAreaFt2":4.8878976732548765,"overlapPolygonFt":[[-22.45,-66.96825867868864],[-22.45,-67.33],[-36.84,-67.33],[-36.84,-67.01239487610567]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-B-incoming-landing","bank":"X78","bankRectFt":[[-36.84,-13.78],[-22.41,-6.27]],"boundingOverlapAreaFt2":15.931328305852599,"polygonOverlapAreaFt2":15.858096527298205,"overlapPolygonFt":[[-24.640411020049847,-13.412776897460162],[-24.62204206674457,-6.27],[-22.41,-6.27],[-22.41,-13.405935906417628]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-B-central-passage","bank":"F17","bankRectFt":[[-36.79,2.63],[-22.41,13.43]],"boundingOverlapAreaFt2":1.6561185391555449,"polygonOverlapAreaFt2":1.3251409353077892,"overlapPolygonFt":[[-24.597605474226768,3.2321815118202295],[-22.41,3.238891212103832],[-22.41,2.63],[-24.599154093794578,2.63]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-B-central-passage","bank":"F49","bankRectFt":[[-11.6,2.59],[-0.42,13.39]],"boundingOverlapAreaFt2":8.841485282912034,"polygonOverlapAreaFt2":7.816970677575665,"overlapPolygonFt":[[-0.42,3.306337701415885],[-0.42,2.59],[-11.6,2.59],[-11.6,3.272047035180835]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-B-central-passage","bank":"F50","bankRectFt":[[-0.63,2.63],[8.31,13.43]],"boundingOverlapAreaFt2":6.71242490422483,"polygonOverlapAreaFt2":6.1632693770589215,"overlapPolygonFt":[[8.31,3.33311386565846],[8.31,2.63],[-0.63,2.63],[-0.63,3.3056936012451015]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-C-cross-passage","bank":"X78","bankRectFt":[[-36.84,54.95],[-22.49,66.09]],"boundingOverlapAreaFt2":22.414974241839772,"polygonOverlapAreaFt2":21.837512541905603,"overlapPolygonFt":[[-24.435955131614055,66.09],[-22.49,66.09],[-22.49,54.95],[-24.46460367303686,54.95]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-C-cross-passage","bank":"X78","bankRectFt":[[-36.96,44.4],[-22.45,55.2]],"boundingOverlapAreaFt2":22.162854740742326,"polygonOverlapAreaFt2":21.90075664132378,"overlapPolygonFt":[[-24.463960752448376,55.2],[-22.45,55.2],[-22.45,44.4],[-24.49173492187084,44.4]],"status":"unresolved reference-envelope overlap"},{"kind":"corridor","floor":76,"subjectId":"WTC2-F76-C-cross-passage","bank":"X78","bankRectFt":[[-36.84,34.4],[-22.49,42.84]],"boundingOverlapAreaFt2":4.983523680633035,"polygonOverlapAreaFt2":4.969427073367083,"overlapPolygonFt":[[-24.502116179698362,40.36324257867649],[-24.495746746342974,42.84],[-22.49,42.84],[-22.49,40.36941402808116]],"status":"unresolved reference-envelope overlap"}],"interpretation":"These explicit overlaps remain unresolved. Source stair/passage geometry has not been clipped to older elevator envelopes. Original75/76 elevator clear faces and wall/finish datums require a dedicated reconciliation; no clearance certification."}}}}