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."

Kevin Ryan asserts that 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. Since then, NIST has admitted that the temperatures got hotter, but the fact remains that if the fires alone were responsible, it shouldn't have gotten any hotter. Given this fact, his views on the subject make perfect sense, as has been reported:
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Ryan wrote that the institute's preliminary reports suggest the WTC's supports were probably exposed to fires no hotter than 500 degrees [F] -- only half the 1,100-degree temperature needed to forge steel, Ryan said. That's also much cooler, he wrote, than the 3,000 degrees needed to melt bare steel with no fire-proofing.
"This story just does not add up," Ryan wrote in his e-mail to Frank Gayle, deputy chief of the institute's metallurgy division, who is playing a prominent role in the agency investigation. "If steel from those buildings did soften or melt, I'm sure we can all agree that this was certainly not due to jet fuel fires of any kind, let alone the briefly burning fires in those towers.
He added, "Alternatively, the contention that this steel did fail at temperatures around (500 degrees [F]) suggests that the majority of deaths on 9/11 were due to a safety-related failure. That suggestion should be of great concern to my company."
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In his article "Propping Up the War on Terror", Kevin Ryan explains the aftermath of his letter:

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Five days after I sent my letter, I was fired by UL for doing so. The company made a few brief statements in an attempt to discredit me, then quickly began to make it clear that its relationship with the government, perhaps due to its tax-exempt status, was more important than its commitment to public safety.

For example, in spite of Tom Chapin's previous statements, UL suggested that it had played only a "limited" role in the investigation. Despite what our CEO, Loring Knoblauch, had written and copied to several executives, UL said there was "no evidence" that any firm had tested the steel used in the WTC buildings. In doing so, UL implied that its CEO not only had fabricated this story about testing the WTC steel but had also spoken and written about it for several years without anyone in the company correcting him. As I see it, the only other option was that the company claiming to be our "Public Safety Guardian" was lying to us about the most important safety issue of our lives.
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