By Judy Shelton and Chris Sarns
In their June 2004 report (and in the actual shop drawings*), NIST referred to the use of shear studs in World Trade Center 7. Shear studs are used to keep steel floor beams and girders in place; they impart stability and strength to buildings. But in their August 2008 final report, NIST re-worded their comments on shear studs to make it appear that none were used on the floor girders.
Why would they do this? To know the answer, you need to understand NIST's collapse theory. This is how it goes:
1. The key girder between column 79 and the exterior wall fails at floor 13.
2. Its failure causes the collapse of floors 13 through 6.
3. Column 79, now unsupported laterally by these floors, buckles and brings down the entire building.
This scenario is easier to posit if the key girder isn't being held firmly with shear studs. Thus, in the August 2008 report, NIST did what it had to do to make it more reasonable that the girder would fail: It magically omitted the shear studs.
Compare these two paragraphs. In the excerpted paragraph of the 2004 report, NIST says that studs were used with both beams and girders, although the studs "were not indicated on the design drawings for many of the core girders" (the girder associated with column 79, by the way, was not a core girder). In the 2008 report, however, not only does NIST drop the association of girders with shear studs ( first sentence of excerpted paragraph), but then they go on to imply that studs were not indicated at all on the girders (last sentence of excerpted paragraph):
June 2004 NIST L pg 6 [10 on pg counter]
Most of the beams and girders were made composite with the slabs through the use of shear studs. Typically, the shear studs were 0.75 in. in diameter by 5 in. long, spaced 1 ft to 2 ft on center. Studs were not indicated on the design drawings for many of the core girders .
http://wtc.nist.gov/progress_report_june04/appendixl.pdf
August 2008 NCSTAR 1-9 vol.1 pg 15 [59]
Most of the beams [the words "and girders" are deleted] were made composite with the slabs through the use of shear studs. Typically, the shear studs were 0.75 in. in diameter by 5 in. long, spaced [the words "1 to" are deleted] 2 ft on center**. Studs were not indicated on the design drawings for [the words "many of the core" are deleted] the girders.
Then, in this paragraph of the 2008 report, they use the "absence" of shear studs to help make their case:
August 2008 NCSTAR 1A pg 49 [87]
At Column 79, heating and expansion of the floor beams in the northeast corner caused the loss of connection between the column and the key girder. Additional factors that contributed to the failure of the critical north-south girder were (1) the absence of shear studs that would have provided lateral restraint and (2) the one-sided framing of the east floor beams that allowed the beams to push laterally on the girders, due to thermal expansion of the beams.
This deliberate distortion of the evidence can only be called fraud. Even those who have accepted the official story must acknowledge that NIST's misstatements of its own report are not mistakes. They are bending the facts to accommodate a theory that cannot, so to speak, stand up.
*NCSTAR 1-9, Vol. 2, Fig. 12-4
** "on center" - a term that means "apart"
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