Maar ik zou wel graag van jou willen weten wat je van wtc 7 vindt na de Zembla uitzending
Noot 5: Volgens de verklaring is het inzakken van deze toren, WTC-7, te wijten aan ongecontroleerde branden. Het gebouw was zwaarder beschadigd dan men initieel dacht. De branden werden gevoed door de diesel uit een opslagtank voor noodstroomvoorziening
in Loose change is helemaal niets gezegd over de diesel uit de opslagtank, terwijl dit wel in de officiele verklaring staat, dan vraag ik me af waarom dit is verzwegen.
With the collapse of both towers by 10:30 a.m., larger pieces of the twin towers had smashed parts of 7 World Trade and set whole clusters of floors ablaze. An hour later, the Fire Department was forced to abandon its last efforts to save the building as it burned like a giant torch. It fell in the late afternoon, hampering rescue efforts and hurling its beams into the ground like red-hot spears.
[quote]
"If the enclosures were damaged, then yes, this would be enough fuel to explain why the building collapsed," Dr. Barnett said.
Dr. Barnett and Mr. Baker are part of an assessment team organized by the American Society of Civil Engineers and the Federal Emergency Management Agency to examine the performance of several buildings during the attacks. If further studies of the debris confirm the findings of extremely high temperature, Dr. Barnett said, "the smoking gun would be the fuel."
Others experts agreed that the diesel fuel could have speeded the collapse, but said the building might have met the same fate simply because of how long it burned.
"The fuel absolutely could be a factor," said Silvian Marcus, executive vice president for the Cantor Seinuk Group and a structural engineer involved in the original design of the building, which was completed in 1987. But he added, "The tanks may have accelerated the collapse, but did not cause the collapse."
Because of those doubts, engineers hold open the possibility that the collapse had other explanations, like damage caused by falling debris or another source of heat.
The fuel tanks were not the only highly flammable materials in the building. But while some engineers have speculated that a high-pressure gas main ruptured and caught fire, there was none in the area, said David Davidowitz, vice president of gas engineering at Consolidated Edison. The building was served only by a four-inch, low-pressure line for the building's cafeteria, Mr. Davidowitz said.
The mayor's command bunker, built in 1998, included electrical generators on the seventh floor, where there was a small fuel tank, said Jerome M. Hauer, director of the mayor's Office of Emergency Management from 1996 to 2000. That tank was fed by a tank containing thousands of gallons of diesel fuel on a lower floor, he said.
Francis E. McCarton, a spokesman for the emergency management office, confirmed that assessment. "We did have a diesel tank in the facility," he said. "Yes, it was used for our generating system."
The manager of the building when it collapsed, Walter Weems, said the larger tank sat on a steel-and-concrete pedestal on the second floor and held 6,000 gallons of diesel fuel. He said an even larger cache, four tanks containing a total of 36,000 gallons of diesel fuel, sat just below ground level in the loading dock near the southwest corner of the building.
"I'm sure that with enough heat it would have burned," Mr. Hauer said of the diesel. "The question is whether the collapse caused the tank to rupture, or whether the material hitting the building caused the tank to rupture and enhance the fire."
Falling debris also caused major structural damage to the building, which soon began burning on multiple floors, said Francis X. Gribbon, a spokesman for the Fire Department. By 11:30 a.m., the fire commander in charge of that area, Assistant Chief Frank Fellini, ordered firefighters away from it for safety reasons.
A combination of an uncontrolled fire and the structural damage might have been able to bring the building down, some engineers said. But that would not explain steel members in the debris pile that appear to have been partly evaporated in extraordinarily high temperatures, Dr. Barnett said.
"Any structure anywhere in the world, if you put it in these conditions, it will not stand," Mr. Marcus said. "The buildings are not designed to be a torch."
bron :
http://www.prisonplanet.com/engineers_are_baffled_over_the_collapse_of_7_wtc.html
