It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Thank you.
Some features of ATS will be disabled while you continue to use an ad-blocker.
It is known that structural steel begins to soften around 425°C and loses about half of its strength at 650°C.4 This is why steel is stress relieved in this temperature range. But even a 50% loss of strength is still insufficient, by itself, to explain the WTC collapse. It was noted above that the wind load controlled the design allowables. The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable, which is roughly one-fifth of the yield strength of the steel. Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.
Originally posted by Damocles there were no responders OR better yet engineers in there looking at the impact zones to determine just how much damage had been done and so all we are doing is speculating off incomplete data.
Originally posted by Damocles
now nist fema et al may not be speculating but lets face it, they have more data than we do. they just arent sharing and are doing a pretty piss poor job in explaining things
NIST’s investigation of the WTC towers fires and collapses was conducted under the National Construction Safety Team (NCST) Act. The act gives NIST the responsibility for conducting fact-finding investigations of building-related failures that result in substantial loss of life. NIST has no regulatory authority under the NCST Act.
The NCST Act also states that no part of any report resulting from a NIST investigation into a structural failure or from an investigation under the Act may be used in any suit or action for damages arising out of any matter mentioned in the report.
Originally posted by ULTIMA1
Well we know NIST kind of screwed up. Like not testing for explosives or chemicales.
Originally posted by Disclosed
[ Isnt that like a dead person with a gunshot to the head being tested for an aneurism to see if that caused the death? Or why not test the wiring in the building for possibly a spark causing the fires.
NIST’s investigation of the WTC towers fires and collapses was conducted under the National Construction Safety Team (NCST) Act. The act gives NIST the responsibility for conducting fact-finding investigations of building-related failures that result in substantial loss of life. NIST has no regulatory authority under the NCST Act.
The NCST Act also states that no part of any report resulting from a NIST investigation into a structural failure or from an investigation under the Act may be used in any suit or action for damages arising out of any matter mentioned in the report.
Originally posted by Disclosed
Would there be a lawsuit about the jet fuel making the fires cooler, that would require NIST info? I don't think there would be...
A jet fuel fire would produce great quantities of smoke, which would reduce the radiant heat energy entering structural components. According to G. Charles Clifton HERA structural engineer, speaking of the fires in the Towers; In my opinion, based on available evidence, there appears no indication that the fires were as severe as a fully developed multi-story fire in an initially undamaged building would typically be.(Elaboration..., p5)
Originally posted by ULTIMA1
FEMA thought it was improtant enough to do testing for explosives and chemicles.
Originally posted by Damocles
ive not read the fema report. if i ask nicely could you by chance tell me which chapter/page number their findings are on? dont feel well of late and it would simply save me time.
Findings reported in Appendix C of FEMA's World Trade Center Building Performance Study seem to fit the thermite theory remarkably well.
Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure. A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel.
...
The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified
CLimited Metallurgical Examination
C.1 Introduction
Two structural steel members with unusual erosion patterns were observed in the WTC debris field. The first appeared to be from WTC 7 and the second from either WTC 1 or WTC 2. Samples were taken from these beams and labeled Sample 1 and Sample 2, respectively. A metallurgic examination was conducted.
C.2 Sample 1 (From WTC 7)
Several regions in the section of the beam shown in Figures C-1 and C-2 were examined to determine microstructural changes that occurred in the A36 structural steel as a result of the events of September 11, 2001, and the subsequent fires. Although the exact location of this beam in the building was not known, the severe erosion found in several beams warranted further consideration. In this preliminary study, optical and scanning electron metallography techniques were used to examine the most severely eroded regions as exemplified in the metallurgical mount shown in Figure C-3. Evidence of a severe high temperature.