Originally Posted by rwguinn
Actually, it's simpler than that.
The quote that "the Towers would likely remain standing" is based on the preliminary
models -- and also doesn't mean "likely to remain standing forever." It actually means that, under those cases, the Towers would still have collapsed, but it would have taken longer than it did in reality.
As it turns out, the fuel loading is actually not that relevant. More relevant is the fuel placement
, and how the fuel load determines the location -- not the intensity -- of the fires.
An increase in fuel load from 4 lb/ft2
to 5, i.e. 25%, is small compared to the increase that was tested during model sensitivity testing. That sensitivity testing, in which the fuel load was increased by 33%, found that the fuel load was relevant but only with respect to the duration of fires. See NCSTAR1-5F section 5.2 for the sensitivity analysis.
The overall effect of fuel load on the fires is described in Chapter 6 of NCSTAR1-5F:
Originally Posted by NCSTAR1-5F page 78
In Case C and D, of course, there was no change in the combustible load at all:
Originally Posted by NCSTAR1-5F page 100
Therefore, the complaint about increasing the fuel load in WTC 1 is groundless, and stems from lack of comprehension about the report.
It is similarly incorrect to state that the fuel loading or
placement defined Cases A and C versus B and D. More importantly, B and D involved more impact damage
, especially fireproofing damage. That makes a far greater difference than any change in the fuel load.
The reasons to prefer the higher impact damage estimates are given in NCSTAR1-2B. We've discussed them to death in this thread
(skipping most of the crap in that thread), and besides that cases B and D were seen to better simulate the leaning and floor behavior than cases A and C. This is why A and C were rejected:
Originally Posted by NCSTAR1-6, 8.3, pg. 235
For more information about this, please see Chapter 7 of NCSTAR1-6.