Kevin Ryan makes it clear that the fires should have had a negligible effect on the WTC towers, as he made clear in his letter to NIST.

In post 29, shaman_ argued that Mr. Ryan bases that belief on the belief that the steel didn't reach temperatures over 250C and that that view is mistaken.

This is true. But as I pointed out in post 44, it's understandable that Ryan was misled in this regard, shaman's feelings on the matter notwithstanding. Mr. Ryan explains in his letter to Frank Gayle of NIST:
"Your comments suggest that the steel was probably exposed to temperatures of only about 500F (250C), which is what one might expect from a thermodynamic analysis of the situation."

shaman_'s feelings on the matter aside, the fires should have only brought the steel to around 250C/500F and at the time NIST was apparently turning a blind eye to any evidence that suggested otherwise, as can be seen in NIST's conclusion in its 2004 report titled Federal Building and Fire Safety Investigation of the World Trade Center Disaster Project #3: Analysis of Structural Steel Update.

In post 45, shaman_ contests the fire calculations, stating:
"Based on what? You have picked this number from the samples."

The number is apparently what NIST was suggesting in its interim report and was certainly a number that Kevin Ryan felt was reasonable. He says as much in his letter to NIST's Frank Gayle:
***********************
Your comments suggest that the steel was probably exposed to temperatures of only about 500F (250C), which is what one might expect from a thermodynamic analysis of the situation.
***********************

http://www.sciforums.com/showpost.php?p=2090188&postcount=24

In post 64, shaman_ stated:

"No that is what Ryan wanted to believe from reading the interim report. Their report from 2004 (is that the one we are talking about?) had estimates of temperatures far above 250C. Didn't they estimated pockets reaching 2000F very early on? Even the conspiracy theorists quote that one. Where do you get the idea that NIST don’t think the temperature went over 250C? Do you even know? You are just mindlessly repeating what Ryan said without even computing that the number was cherry picked from the steel tests.
The belief from the beginning was that the fire got very hot, near 1000C. "

In post 67, I counter:

"Just to make sure that we're arguing about the same thing, here's the relevant excerpt of Kevin Ryan's letter to NIST's Frank Gayle:
"Your comments suggest that the steel was probably exposed to temperatures of only about 500F (250C), which is what one might expect from a thermodynamic analysis of the situation."
He is claiming 2 things:
1- NIST's Frank Gayle, who led the 2004 investigation, is the one who was suggesting that steel temperatures were probably only exposed to temperatures of about 500F/250C. In post 87, shaman_ disagrees with this assertion, but in post 169, Headspin makes it clear that the assertion is valid.
2- That this is what one might expect from a thermodynamic analysis of the situation. If he's claiming this, I assume that such an analysis was actually -done-, but if so, I don't have it on hand." In post 87, shaman_ disagrees with this assertion.