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1 Dial 9/11 for Evidence World Trade Center Building 7.

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Presentation on theme: "1 Dial 9/11 for Evidence World Trade Center Building 7."— Presentation transcript:

1 1 Dial 9/11 for Evidence World Trade Center Building 7

2 2 The World Trade Center

3 3

4 4 FEMA: WTC 1 & 2 Debris

5 5 FEMA: South Tower Debris

6 6 FEMA: North Tower Debris

7 7 WTC7: before noon

8 8 WTC7: west side

9 9 WTC7 final damage Pedestrian bridge, south side

10 10 WTC7 final damage 1st floor, southeast

11 11 WTC7 final damage Lobby, 1st floor (note atrium)

12 12 WTC7 final damage Lobby, 3rd floor

13 13 WTC7 final damage NIST schematic: south face 1-19

14 14 FEMA: Building 7 Debris

15 15 Building 7 Debris: 9/23

16 16 FEMA: Building 7 Debris W S E N

17 17 FEMA: Building 7 Debris E W SN

18 18 Ground Zero Debris

19 19 Larry’s New Toys

20 20 NIST: WTC7 Structure Basic framing layout: floors 8-20, 24-45

21 21 NIST: WTC7 Structure Columns and framing

22 22 FEMA: WTC7 Structure 5th floor: 14” concrete w/embedded steel T-sections 7th floor, same, 8” concrete

23 23 FEMA: WTC7 Structure Trusses: floors 5-7 (transfer weight from upper columns to foundation columns)

24 24 FEMA: WTC7 Structure Weight transfer trusses & girders (floors 5-7)

25 25 NIST: Collapse Mechanism Thermal expansion of floor beams against girder

26 26 NIST: Collapse Mechanism Column 79 girder connection

27 27 NIST: Collapse Mechanism Column 79

28 28 NIST: Collapse Mechanism Columns 80 & 81

29 29 NIST: Collapse Mechanism Unsupported east floors fall on Truss 2

30 30 NIST: Collapse Mechanism Truss 2 fails

31 31 NIST: Collapse Mechanism Columns 77-78-78A buckle

32 32 NIST: Collapse Mechanism Core column collapse progression

33 33 NIST: Collapse Mechanism Damage to south face, from south

34 34 NIST: Collapse Mechanism Damage to south face, from west

35 35 WTC7 Structure Multiple-floor atrium

36 36 NIST: Collapse Mechanism Global collapse: part 1

37 37 NIST: Collapse Mechanism Global collapse: part 2

38 38 NIST: Collapse Mechanism Time comparison: model vs. observed

39 39 NIST: Free Fall NOT Roof-center pixel change

40 40 NIST: Free Fall NOT Roof-center fall distance

41 41 NIST: Free Fall NOT Roof center fall velocity

42 42 NIST: Fuel Fires NOT Heat would have stopped the generators that powered the fuel pumps Fire couldn’t have been hot/long enough to raise the concrete/steel temps to point of strength loss Would have generated visible smoke through lourves, none was observed Emergency generator “day” tanks on 5,7,9 floors –wouldn’t have added much to combustible load –safety measures in place would have prevented reloading –weren’t near probable collapse initiation points Fuel line rupture couldn’t create the problem:

43 43 NIST: Fire Observations Diagrams based on photos (starting ch 5.6.5, vol 1, p. “290”)

44 44 WTC7 Steel Only one piece examined by FEMA (App C) –liquid iron/oxygen/sulfur eutectic moved along intergranular boundaries, weakening the beam –eutectic mixture evidenced only 1000C, much lower than expected for melting steel Possibilities raised by FEMA –long-term heating in the ground –pre-collapse, accelerated steel weakening Not examined further by NIST Raises the larger question of WTC steel removal

45 45 Removal of WTC Steel Not all bite-sized pieces Indicates not total dismemberment, but confuses issue of what melted prior to collapse

46 46 Removal of WTC Steel Why is it an important issue? Largest crime in U.S. history Law requires preservation of evidence 350,000 tons removed (acc. to FEMA) Bloomberg: looking at steel doesn’t tell anything, need computer models Yet said to be “highly sensitive”

47 47 Removal of WTC Steel Reasons given WTC1-2: Needed to find survivors WTC7 –Needed to find survivors (but evacuated) –Putting pressure on Verizon building (but could have just moved that) In any case, could have labeled, docu- mented location, and saved elsewhere

48 48 Removal of WTC Steel What happened to it? Thousands of pieces trucked to 4 landfills Immediate result: –Most sent to Asia –Some used to build warship U.S.S. New York –150 pieces saved (in off-limits hangar at JFK) Only parts from underground and lobby area Who decided? Later (January 2007) found more –2 columns, 3 connected perim columns (under road excavated for human remains) –1 burned column at edge of site (city: cutoff)

49 49 Removal of WTC Steel What did FEMA look for? Exterior column trees & interior core columns from 1 & 2 above the impact zone or exposed to fire and/or aircraft-impacted Badly burnt pieces from WTC 7. Connections from WTC 1, 2, and 7, such as seat connections, single shear plates, and column splices. Bolts from WTC 1, 2, and 7 that were exposed to fire, fractured, and/or that appeared undamaged. Floor trusses, including stiffeners, seats, other components. Any piece that, in the engineer's professional opinion, might be useful for evaluation. When there was any doubt about a particular piece, the piece was kept while more information was gathered. A conservative approach was taken to avoid having important pieces processed in salvage yard operations.

50 50 Removal of WTC Steel What about FEMA? 62 trips to landfills Oct-Feb No access to Ground Zero No permission to collect or store steel No subpoena power to obtain building plans (to make intelligent choices) Their observation of anomalies dropped

51 51 Removal of WTC Steel “Highly sensitive” Nov 26: Trucks monitored by GPS http://securitysolutions.com/ar/security_gps_job_massive/ http://securitysolutions.com/ar/security_gps_job_massive/ –Sept: criminal scheme to divert steel –Oct: found 250 tons of scrap in LI and NJ –“Geofenced” zones, “geofenced” corridors –Improved efficiency and gridlock Driver behavior monitored, checked, analyzed (1.5hr lunch -> firing) “Loads consisted of highly sensitive material”


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