Sidney > There's no way to explain the center of the building collapsing because it was so strong and didn't rely on the floors for any support.
Some references.
serendipity.li
>>American Free Press has learned of pools of "molten steel" found at the base of the collapsed twin towers weeks after the collapse. Although the energy source for these incredibly hot areas has yet to be explained, New York seismometers recorded huge bursts of energy, which caused unexplained seismic "spikes" at the beginning of each collapse. These spikes suggest that massive underground explosions may have literally knocked the towers off their foundations causing them to collapse.
In the basements of the collapsed towers, where the 47 central support columns connected with the bedrock, hot spots of "literally molten steel" were discovered more than a month after the collapse. Such persistent and intense residual heat, 70 feet below the surface, could explain how these crucial structural supports failed.
Peter Tully, president of Tully Construction of Flushing, New York, told AFP that he saw pools of "literally molten steel" at the World Trade Center. Tully was contracted on September 11 to remove the debris from the site.
Construction steel has an extremely high melting point of about 2,800° Fahrenheit (1535° Celsius).
Kerosene-based jet fuel, paper, or the other combustibles normally found in the towers, however, cannot generate the heat required to melt steel, especially in an oxygen-poor environment like a deep basement.
...maximum temperature that can be reached by hydrocarbons like jet-fuel, burning in air is 1520° F (825° C). Because the WTC fires were fuel rich (as evidenced by the thick black smoke) it is argued that they did not reach this upper limit of 825° C.
The hottest spots at the surface of the rubble, where abundant oxygen was available, were much cooler than the molten steel found in the basements. Five days after the collapse, on September 16, the National Aeronautics and Space Administration (NASA) used an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) to locate and measure the site's hot spots. Dozens of hot spots were mapped, the hottest being in the east corner of the South Tower where a temperature of 1377° F (747° C) was recorded. This is, however, less than half as hot at the molten steel in the basement. <<
septembereleventh.org
>>There continues to be a number of "experts" making public claims about how the WTC buildings fell. One such person, Dr. Hyman Brown from the WTC construction crew, claims that the buildings collapsed due to fires at 2000F melting the steel (1). He states "What caused the building to collapse is the airplane fuel…burning at 2,000 degrees Fahrenheit. The steel in that five-floor area melts." Additionally, the newspaper that quotes him says "Just-released preliminary findings from a National Institute of Standards and Technology study of the World Trade Center collapse support Brown’s theory."
We know that the steel components were certified to ASTM E119. The time temperature curves for this standard require the samples to be exposed to temperatures around 2000F for several hours. And as we all agree, the steel applied met those specifications. Additionally, I think we can all agree that even un-fireproofed steel will not melt until reaching red-hot temperatures of nearly 3000F (2). Why Dr. Brown would imply that 2000F would melt the high-grade steel used in those buildings makes no sense at all.
.... most perimeter panels (157 of 160) saw no temperature above 250C." To soften steel for the purposes of forging, normally temperatures need to be above 1100C (6). However, this new summary report suggests that much lower temperatures were be able to not only soften the steel in a matter of minutes, but lead to rapid structural collapse.
This story just does not add up. 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. That fact should be of great concern to all Americans. << |
