(4) That the phenomenon of Martensitic Transformation (phase change) was present whereby steel heated above 1,335ºF recrystalizes as austenite and softens and/or melts as temperatures increase. Thus, jet fuel from the aircraft was said to have caused fires hot enough to reach those temperatures simultaneously and throughout the Towers 110 floors of steel columns and beams.
In the case of the 47-story Building No. 7, minimal fires said to be from Tower debris never reached temperatures sufficient to blow out the windows, and FEMA could not single out a definitive cause for the collapse.
(5) That steel floor trusses were of a lighter weight than the columns and beams and therefore subject to a more rapid Martensitic Transformation from the jet-fueled fires. The theory provided suggests that when heat rapidly expanded the trusses, it caused “thermal bowing.” That, in turn, exerted “pull-in forces” on the exterior columns thus compressing the trusses. Compounded by shear forces within the trusses, the “diagonal struts” buckled, setting off cracking and buckling of an exterior column wall. The “explosive” sounds were attributed to the snapping of columns and beams.
That supposedly set off a chain-reaction, forcing tilting of the Towers, which then spread buckling to all walls and into the structures’ core. The combination of tilting top sections and their overwhelming weight then were to have led to the buildings’ rapid vertical collapses nearly into their own footprints. This phenomenon is called “progressive failure” (pancaking).
The phenomenon of dust instead of concrete rubble was explained as an ongoing energy transfer sufficient enough “to have crushed more than 90% of the floor concrete to particles well within the observed particle size range.” Too, doubts about the concrete quality were raised about the possibilities of “freezing during curing or too much air or water being added during construction.”
The volcano-like plumes of smoke were attributed to compression of air in elevator and air-conditioning shafts as floors collapsed. The “squibs” (ejections of materials) seen in photographs and videography were said to be light reflected from broken bits of aluminum cladding from the buildings’ exterior.
Further, the broken windows and detached marble panels in the lobby and witness accounts of explosions first occurring in the basements were attributed to “torque forces” from aircraft strikes above the 92nd floor in No. 1 and the 78th floor in No. 2.
As to molten metal that reportedly burned for weeks under the sites of No. 1 and 7, the cause was said to be the WTC’s still-operational continuous battery systems.
(6) That NIST panelists admitted in their 10,000-page WTC report (October 2007) the free-fall vertical collapses of the Towers——by symmetrical progression——in less than 11 seconds just outside their footprints, was “inexplicable.”
Their most important conclusion was that though the Tower fires were fed by building furnishings, these oxygen-starved, jet-fueled fires never exceeded 500ºF. Steel only begins to soften at 1,000ºF and melts at 1,500ºF, they noted.
They also ruled out “pancaking” because resistance met by floors below would have added considerable time to actual collapse durations: 110 seconds minimum.
the collapses were attributable either to missiles or bomb-laden military aircraft, not commercial airliners. This theory challenges the evidence of on-site witnesses, passenger lists and the victims’ family and friends. Yet Air Force and Air Force Academy sources have speculated that the planes could have been E-10s.
Aircraft designers, pilots and civil aviation examiners also are aware that any jet aircraft could be taken over remotely. For example, the Global Hawk remote-control system is frequently cited in the literature concerning the Department of Defense’s weaponry.
But after the air attack on the North Tower, some spectators said a plane struck the South Tower. Minute examination of the photographic and videographic evidence has suggested the possibility of a pod in the undercarriage of a plane that could have contained high-yield explosives.
(8) That when steel (not concrete) buildings are impacted by aircraft, destroying several columns and beams——as demonstrated in 1945 when a B-25D struck the Empire State Building——the stress is “redistributed.” Remaining columns become a “truss network to bridge over the missing columns.” The Towers’ head structural engineer, John Skillings, noted that they were designed to withstand the same kinetic energy whether expended by a Boeing 707 or a 767.
As to heat dissolving steel beams and columns, even fires involving 10,000 gallons of jet fuel——combined with office materials——none exceeded 500ºF, far too low to have any impact on those structures. If they had had impact, structural experts have posited that the collapses would have been gradual, in less than 10 seconds, because the beams and columns would not have gradually relinquished their structural strength.