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Originally Posted by Tactics
What do people make of the NIST report?
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It is evident that the narrative was written by spin doctors as opposed to physicists. In the WTC7 report, for example, they mixed up Figures 11-51 and 11-52 in NCSTAR1-9Vol2, and then failed to spot the mistake in the accompanying description.
Both of these graphs show NIST's predicted results for a W24x55 floor beam, given various SFRM (fireproofing) thicknesses. Their "ASTEM E 119" [sic] referred to in Fig. 11-52 is the ASTM E119 or E-119 temperature profile. In Fig. 11-51, the beam is assumed to have been "subject to a uniform 1100 C gas temperature".
The time-temperature curve for the ASTM E119 standard fire test is shown here (Figure 1).
Source:
http://bulletresistantproducts.prote...re%20Tests.pdf
Note that those temperatures are shown in Fahrenheit. The furnace temperature is defined as:
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The temperature within the furnace is determined to be the mathematical average of thermocouples located symmetrically within the furnace and positioned six inches away from the exposed face of the test specimen.
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It takes 240 minutes for the furnace to reach 2000 F (1093 C), which is still lower than 1100 C.
Fahrenheit to Celsius converter.
Or see this ASTM E119 curve in Celsius:
Source:
http://www.cement.org/buildings/high_strength_fire.asp
Again, the furnace takes about 4 hours to reach 1100 C, and is between 800 and 900 C after 30 minutes.
Yet in a comparison of like for like - the green 0.53" SFRM curve (the actual amount of fireproofing on these floor beams according to NIST) for each of NIST's graphs Fig. 11-51 and 11-52 - we find that NIST predicts 1 hour for the beam to reach 600 C in Fig. 11-51, the "uniform 1100 C gas temperature", and only half an hour to reach 600 C in Fig. 11-52, which is the ASTM E119 profile that has only reached a gas temperature of 1550 F (843 C) after 30 minutes!
My own computations showed that an insulated W24x55 beam (0.53" of Monokote MK-5) would peak at about 380 C in a typical 40 kg/m^2 fire (higher than NIST's assumed fuel load of 20 to 32 kg/m^2), or a W33x130 girder correspondingly at about 300 C. In order to obtain their 'predictions', NIST assume unrealistically high gas temperatures which are not only at variance with conditions in real world fires, but with NIST's own admission that in any given zone on some particular floor, the combustibles would have burnt out and temperatures fallen after about 20 minutes. This can be seen graphically here:
Source:
http://brandveilig.be/wp-content/lec...ngineering.pdf
In 1-9 Vol 1 Table 8-1, NIST claim a max. steel temp. of 740 C for WTC7.
FEMA 403 C states that steel temperatures had "approached 1,000 C" in a WF member from WTC7 in which intergranular melting was "readily visible".
NIST's WTC7 'report' also contains a formula predicting that the 180 kip shear capacity of four bolts in a seated connection would be exceeded when the steel heats up from 20 C to 32 C and the force to completely resist the thermal expansion is 191 kip. Funny thing is, before 9/11, no steel-framed high-rise had ever collapsed from fire, let alone from air conditioning failure!
As for the Towers, NIST's claims of inward bowing of the WTC1 perimeter columns between floors 94 to 100 peaking at 55 inches at column 316 on the 96th floor cannot be reconciled with the fact that the columns' moment of inertia or second moment of area was at least 342 ins^4 along the minor axis, and a maximum deflection of 55 inches given fixed - fixed boundary conditions and a distributed load would have required the failure within 102 minutes of at least ten consecutive floors, many of which did not have any fireproofing 'dislodged' by a plane and did not even experience substantial fires.
Here's an experiment that NIST or the dwindling band of "It was a suicidal Arabs conspiracy" theorists could try:
Apparatus: 1 ton of wood, plastics and paper; 13 tons of sand or concrete dust; 7 tons of iron bars; 145 lb of aluminum sheet; 800 lb of SFRM (fireproofing); 10 tons of air conditioning / mechanical / electrical / ceilings / floor covering.
Method: Ignite isolated sheets of paper, surrounded by all above except sand / concrete. When 60 lb of fuel is burning or burnt, smother with 13 tons of sand / concrete dust. Return after 6 weeks and observe whether any metal is molten or even red-hot.
Conclusion: WTC was a controlled demolition.
The NIST reports are speculation based on heavily tweaked computer models that bear no relation to the forensic evidence, and in any case describe highly improbable hypotheses. As with the 'intelligence' regarding Iraq's weapons and the decision to go to war, NIST starts out with the desired conclusion and adjusts its assumptions accordingly.