Quote:
Originally Posted by Rochard
It didn't need to be hot enough or long enough; The fire didn't disintegrate the towers. A huge amount of the support was missing, and it failed to support the floors above the impact zone. Keep in mind here that at the moment of impact, entire floors were destroy. Eventually, the floors above the impact fell because the support at the impact was either gone or weakened.
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This is why NIST stops at the initiation of collapse; they would not be able to follow through logically on their "probable collapse sequence".
While the fire didn't disintegrate the towers, the towers
did disintegrate.
A huge amount of support was
not missing. Even by worst-case estimates, NIST says 35 of 235 exterior columns were compromised, and they conjecture via computer-animation 1 to 3 core columns were severed and maybe up to ten more were damaged, probably by the engine core/s. NIST calculated the building lost 15% of its structural integrity in total.
This isn't "most of the support"; they were made to take more than this.
The first plane hit between floors 90 and 100, taking out most of those
on one side, not all four, not "entire floors", which leaves ten floors above to entirely crush and ditintegrate the remaining structurally undamaged 90 floors.
The second hit somewhere between floors 70 and 75,
on one side, not entire floors. This means 25 floors crushing down on 70 structurally unaffected floors.
Yet both buildings fell the same way. And took out the spindle or core of 45 or 50 massive central columns? How could inward bowing explain a falling object crushing another object that is roughly five to ten times it's own mass? Basic pyhsics says it can't.
Quote:
Originally Posted by Rochard
The fire was in fact fueled by tens of thousands of jet fuel. I'm sure it burned off in ten minutes of jet fuel is enough to make that a burning inferno.
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The point is that the jet fuel ignited a huge office fire, it didn't fuel that fire; fuel is what sustains a fire. If it burned off in 10 minutes, then it didn't fuel the fire.
Quote:
Originally Posted by Rochard
The fires burned from impact until the towers fell.
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Some probably did. But even NIST and FEMA describe them as office fires.
Quote:
Originally Posted by Rochard
Stop making it sound like "some office furniture caught on fire". Fifty thousand people worked in those towers; There was enough fuel in the towers to keep burning for weeks.
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What's your point? There were less than 7000 people in the towers when it happened; there were no tourists and workers hadn't all started their shifts.
In theory the towers should have been able to burn for weeks, without collapsing.
Quote:
Originally Posted by Rochard
The lobby is huge, massive, four - six stories tall, and for the most part all stone, marble, granite, concrete, and steel. Yes, the fireball that shot down to the lobby quickly burned itself out. There wasn't much of anything to catch on fire in the lobby.
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That's what I said...
Quote:
Originally Posted by Rochard
Doesn't matter. It was enough to damage what was left of structure to cause it to fail.
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What makes you say that? Most of the structure was intact, the jet fuel burned off right away; the fire would have to have burned six times hotter for four to six hours to melt steel, and at it's hottest would have to have sustained itself for about three hours to soften steel.
For the buildings to "give out" means somehow all vertical and horizontal support and all joints were heated equally over their entire surface to compromise their mass enough to "prepare" them to give out instantly without resistance - a feat that not only would have taken much more than an hour to an hour and a half at the reported temperatures, it would be physically impossible under the circumstances.
Quote:
Originally Posted by Rochard
No, it wasn't a "relatively small fire in comparison with building size". Entire floors were missing form the building, and dozens of floors were instantly on fire.
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Entire floors were never missing from any of the buildings. Sections of floors were taken out and collapsed internally without affecting exterior columns and especially not core columns; core columns never reached, at their hottest, the average temperature of the fires on the floors.
Quote:
Originally Posted by Rochard
Re-read what you wrote here and try hard not to laugh.
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Volatility means that the fuel is quick-burning though, unless under the right conditions, not "explosive". It certainly means there's no way it can burn very hot in an open environement for very long.
Quote:
Originally Posted by Rochard
From Wikipedia article....
"While calling for further study, FEMA suggested that the collapses were probably initiated by weakening of the floor joists by the fires that resulted from the aircraft impacts". |
That is a theory, a suggestion of probability, not established by investigation or fact. Unfortunately FEMA was taken off the case.
Quote:
Originally Posted by Rochard
"NIST also emphasized the role of the fires, but it did not attribute the collapses to failing floor joists. Instead, NIST found that sagging floors pulled inward on the perimeter columns: "This led to the inward bowing of the perimeter columns and failure of the south face of WTC 1 and the east face of WTC 2, initiating the collapse of each of the towers."
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FEMA and the American Society of Engineers (?) said the perimeter columns bowed out.
All agreed this occurred on one of four faces of the building/s.
This could have initiated a partial collapse of portions of the towers.
But a portion of the uppermost perimeter facade pulling in or out, whether from horizontal sagging or thermal expansion, doesn't explain why the undamaged, unmelted, unsoftened core wasn't left standing or why the building experienced a global collapse.
Quote:
Originally Posted by Rochard
Not at all. The buildings both had the exact kind of damage - a large airplane destroyed most of the support structure, fires in both buildings weakened the towers, up to the point where the impact zone was unable to support the floors above it and then it all fell down.
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That is generalized or similar damage. One building, in theory, due to probability based on the plane's trajectory, had some core columns damaged.
The other building had little to no core columns damaged, again because the plane trajectory put it out of the path of the core.
Quote:
Originally Posted by Rochard
Take a look at this picture:
It looks to me like the entire side of the building is gone for four - eight stories. It's stunning that the towers were able to continue to support it's weight for as long as it did. And keep in mind here, that's only the damage we can see. |
This is not "entire side of the building" being gone damage - it's significant damage across as many stories as you say.
Actually it's exactly the kind of damage it was built to withstand.
:D