jay howard
Muse
- Joined
- Jul 25, 2007
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NIST's base assumption of 4 lb/ft2 of fuel load was an estimate and was known to be low compared to similar office layouts.
So what? Does that mean they get to increase it at will?
It was an average figure.
Thanks for pointing out the obvious again. Do they get to increase it at will because it was an average? What kind of sense does that make?
Only case A assumed an even distribution of the fuel load throughout the affected floors.
Again, so what? Case B weighted combustibles towards the core--for what reason? Aircraft impact would not have pushed an increased pile of it towards the interior. They admit they didn't count the aircraft because the thermal modeling would only accept one fuel source, so how does one justify an increased fuel concentration in the core area? It's no secret the vast majority of combustible mass was between the core and the exterior. But you not only accept this as "good science," you use it to try to JUSTIFY the NIST report's manipulation of the data.
That figure also ignores combustibles within the aircraft. They appear to ignore paper in filing cabinets, although a greater range of cases could reasonably assume impact damage liberating some of this paper. They appear to have taken the conservative approach here. Cases B, C and D assume some redistribution of the fuel load, yet case C still - conservatively - assumes 4 lb/ft2
No, they appear to have increased the fuel load against their own estimates without any clear reason why. In their words:
"NIST estimated the combustible fuel loading on these floors to have been about 4 lb/ft2 (20 kg/m2)."(NCSTAR 1, 77)
“Simulations performed with doubled fuel loads slowed the fire spread well below the observed rates. Combined with the above results, this suggested that the estimated overall combustible load of 4 lb/ft2 was reasonable.”(NCSTAR 1, 129)
This one is particularly troubling for anyone who thinks NIST was justified in increasing the fuel load:
“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)
And
“The fact that the simulated fires encircled the building in roughly the same amount of time as the actual fires supported the estimate of the overall combustible load, 20 kg/m2 (4 lb/ft2). The fires burned for roughly 20 min to 30 min in any one location, consistent with the visual evidence (NIST NCSTAR 1-5A) and the multiple workstation fire experiments performed at NIST (Chapter 4).”(NCSTAR 1-5F, 107)
And what reasons do they give for the increase?
“For WTC 1, the changes made were designed to create a ‘more severe’ fire.”(NCSTAR 1-5F, 78)
Oh. That makes perfect sense.
In short - varying the figure from 4 lb/ft2 to 5 lb/ft2 across the 4 cases is perfectly reasonable.
Maybe you should read the reports before you say something completely unsubstantiated.
NIST could not possibly have known the precise fuel load.
So what? Does that mean they can increase it by 25% from their "reasonable" estimate at will and without any clear justification?
Your paranoid outlook, however, requires this approach to be viewed as conspiratorial and unscientific and labelled as "beefing up". It's no such thing.
Do you have any reason to say that other than you want it to be true?
Tell me, jay, if NIST consciously fiddled the 4 lb/ft2 to achieve a desired outcome why the hell wouldn't they just start with 5 lb/ft2 ?? Nobody would have had any grounds to doubt it.
Because "they" were several groups who were assigned a set of tasks. The leaders of those groups set out to do their jobs. This all fits into a straight-forward hierarchical-style framework. There is nothing unusual about this. When it was determined that under the "middle cases" the buildings would likely remain standing, someone was indeed tasked with increasing the fuel load.
Did that person/group ask why?
It doesn't matter what they asked. It was their job to do as they were told. Boss wants to increase the fuel loads in the scenarios; therefore they increased the fuel loads in the scenarios.
Can you find me reasonable explanation as to why? No. Should you be able to? Yes. Does that mean all the science in the NIST report is null and void? No. Does that mean the data was manipulated? It certainly looks that way. If the data was manipulated, does that mean all the people who worked on it are guilty of murder? Of course not. Are they guilty of bad science? Not likely. The people guilty of bad science are those who structured the argument.
For the very little it's worth, it strikes me that case A in particular is very conservative.
How would you know what conservative is? From what the NIST report says? Did you read the other things the NIST report said about Case A? Apparently not.