wrt carl's comments on architecture.
-- Eugen* Leitl <a href="http://www.lrz.de/~ui22204/">leitl</a> ______________________________________________________________ ICBMTO : N48 10'07'' E011 33'53'' http://www.lrz.de/~ui22204 57F9CFD3: ED90 0433 EB74 E4A9 537F CFF5 86E7 629B 57F9 CFD3
---------- Forwarded message ---------- Date: Tue, 11 Sep 2001 13:25:30 -0700 From: John Young <jya at pipeline.com> To: CYBERIA-L at LISTSERV.AOL.COM Subject: Re: New York Report
The '45 Empire State Building crash is oft studied in architectural and structural engineering to learn why the building withstood the hit. The plane was a B-24, I believe, but in any case a much smaller craft than the ones which hit the WTC and the Pentagon. The '45 plane's engines did penetrate the building, shooting out the far side and falling to the ground and killing passersby, but most of the plane remained inside the structure for it was made of far more fragile materials than a building. A relative small amount of damage was done to the structure of the building though fire was devastating, especially from flaming gasoline cascading inside.
The fireball that shot from the second WTC tower hit, opposite where the jetliner penetrated, blew out windows and perhaps part of the latticework exterior structure. Flaming fuel probably cascaded down the shafts of elevators and ductwork and stairwells whose fire-protection enclosures would have been destroyed by the explosive crash and ballistic heavy plane parts. These fuel flames, and fires started from them, would have weakened interior structural support beyond protection provided by code-required fireproofing. Once the interior structural supports were weakened, and the exterior lattice lost its integrity collapse was inevitable.
I modify my first evaluation to speculate that the interior supports appear to have given way before the exterior lattice (whose girdle of closely-space columns and thin vertical windows between gave the buildings a unique look compared to use of large panes of glass elswhere) The lattice amazingly contained the interior collapse and the whole mess dropped vertically, almost, as newscasters report, as if executed by a demo expert.
I did not expect the Twin Towers to collapse. To suffer terrible fires and localized interior damage but not total collapse. The first was unbelievable, and as I said, I thought only the portion
above the crash fell. Then the smoke cleared momentarily to show the totality. Then the second tower, collapsing in a near-perfect copy of the first. The sudden dropping of the floors above the crash, that impacting load overpowering the remaining system, and the straight drop collapse, neither tower falling much to the side, indicated what had happened.
Close-ups of the exterior show the latticework bridging the crash penetrations, reminding of sales pitches from the 19th Century when cast-iron manufacturers promoted their architecture with structural compoments missing with no apparent destabilization -- the load automatically shifting to remaining components. Their prognostications failed at the first intense fire which overheated and cracked the cast iron, sometimes collapsing more quickly than predecessor masonry bearing wall and wood floor system composites.
Humbling news: My daughter is safe and sound. She heard the first crash and saw the tower blazing on the way to work and thought it was merely (!) a fire. Her office remained at work unaware of what had happened, and was happening, without TV or radio, until telephoned from overseas headquarters which ordered everyone home. At first the office dismissed the alarm, saying, hey, this is New York, no problema, we have work to do, our customers come first, sure that would impress the venal bastards. Then someone was sent outside to check reality.
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