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To: finnman69;dead
Again, huge fires fueled by massive diesel tanks meant for emergency generators led to to the collapse. These tanks were set on fire sometime during the collapses or the plane impacts. The tanks were directly underneath a transfer beam that supported some 40+ stories of structure above it. Much in the same way the building in OKC fell after a key column was blown away, 7 WTC fell after this main transfer beam failed, leading to the collapse of a key major column. When this collapsed, the entire building went. Again, your nominal 2 hours of fireproofing burnt off after 2 hours. Rememeber this building did not collapse until late in the afternoon.

Yes - what you state is very plausible.

My thesis is that had other methods of insulating the steel columns been used (i.e., concrete encased steel columns, or wet asbestos), the buildings would have stayed up longer.

Those methods generally would provide 4 hours of protection, less in the case of the WTC bombings because of the inordinate amount of heat.

What happened as reported by the New York Times 4/28/1970 was that the construction companies were ordered to stop using wet asbestos (the were up to the 67th floor at the time with insulation), they immediately found a new technique (they couldn't use the older concrete encased steel beams technique at this point) which was "claimed" was just as good.

BTW - Today's Newsday (New York Long Island newspaper), carried an article about the collapse of the towers and mentions the effectiveness (or lack of), of the fireproofing.

63 posted on 05/01/2002 7:42:42 AM PDT by Tuco-bad
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To: Tuco-bad
I think in the future you may see 4hour rated fireproofing (concrete cladding)applied in a more common fashion although it is very expensive. The new AOL Time Warner building in NYC is in fact cladding key columns with concrete to provide additional steel protection. This additional protection was added after the 9/11 attacks and is above and beyond current fire protection requirements.

I attended a fire safety luncheon yesterday, specifically regarding fire rated glass technology which is improving. Someone asked a question if say 2 hour rated glazing (Very expensive $200/sf and 3 inches thick, it's amazing stuff, actually it's a ceramic. Many new government buildings are using it. It can burn on one side for hours and you can put your hand on the other side which remains cool.) had been used,would it have made a difference in the WTC. The speaker who was there to sell his product said no.

Even if you had a 4 hour rating, I still think both towers would have eventually collapsed as it is impossible to fight a fire that big in that tall a building. Whether or not asbestos was used is a moot question. Perhaps more people might have escaped, but I think the buildings still would have failed. That's why 7 WTC came down. An uncontrolled fire burning for several hours will collapse a steel building. Buildings are simply not designed to withstand fires of that magnitude and modern aircraft impacts.

The authorities should concentrate on keeping from aircraft being used as guided missiles, and improving evacuation routes in buildings. I think you may see new rules calling for better protection of stairwells using solid CMU walls instead of fire rated sheetrock. There will also be more attention paid to the weakest link in steel construction. At the WTC attention is focused on the clips connecting the floor trusses to the perimieter columns, likely the point of failure for most of the trusses. You will also see engineering design focus on redundant structure. 7 WTC and the OKC buildings collapsed after key structural members were destroyed resulting in catostrophic failure. On the other hand the WTC stood up after having gaping holes punched in it because it in fact had redundant structure. What brought down the towers was a combination of fire, damage, and increased stresses as floors failed in the fire, trusses separated from the walls, and perimeter columns eventually buckled under the weight.

64 posted on 05/01/2002 8:08:16 AM PDT by finnman69
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To: Tuco-bad
My thesis is that had other methods of insulating the steel columns been used (i.e., concrete encased steel columns, or wet asbestos), the buildings would have stayed up longer.

Again with the revisionist history!

Your thesis was this:

WTC collapsed because the towers were built "on the cheap".

This is typical of the liberal/luddite, blame “the man”, evil corporation thesis that anti-capitalist statists like yourself always wallow in.

The fact of the matter is that maybe the asbestos insulation (which was prohibited by unnecessary, environmentalist-driven law, not economics) would have helped the buildings stand a little longer. Maybe not. Either way, they still would have fallen in roughly the same time frame.

Despite your thesis, the building were not built “on the cheap”. The just released FEMA report (which is considerably more relevant than a single article in the NYTs from 1970) found no substandard structural problems with the WTC construction, and in many cases the towers surpassed building code requirements.

65 posted on 05/01/2002 8:44:48 AM PDT by dead
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