Do we agree the towers were designed to withstand jetliner crash?

Does anyone have an image copy of the Lawrence Wien ad in the New york Times from just before the towers were built showing an airplane about to hit the propsed strucures?
 
The discrepancy between my numbers and Beachnuts was bothering me so I decided to doublecheck my figures and run through it again.

According to this site: http://www.ieer.org/clssroom/unitconv.html

joules * 2.38095x10-10 = tons TNT


So if I have a plane which is going 944 km/h, that translates to 944,000 meters per hour, 3600 seconds in an hour, which gives us 262.2 m/s for the velocity. Man, that's really fast.

Other plane, said to be travelling at 290 km/h would convert to 80.6 m/s.

So, if we use the formula of 1/2m*v^2 to find the energy we get:
(.5) 119,000 * (80.6*80.6)
which works out to
59,500(6496.36) = 386,533,420 joules. (707 plane)

And:
(.5)125,000 * (262.2*262.2)
gives us
62,500 * (68748.84) = 4,296,802,500 joules (767 on 9/11)

If we use the new conversion number I get 1.022638995 tons of TNT or 2045.25 lbs. for the Sept. 11 plane and 0.0920316746349 tons or 184.06 lbs of TNT for the 707.

Those are so close as to not really quarrel with his numbers at all. It looks like my first set of numbers was off due to converting the units at the end instead of the beginning, and having a bad number for the joules to TNT conversion.

The ratio is still about 11 times the amount of energy from one scenario to the other, just as it was in my initial equation, and CurtC's, and Beachnut's.
 
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TjW said:
By assuming he thought his simile of a mosquito and mosquito netting was a good one. The reason for mosquito netting is so that mosquitos don't get through it.
If the aircraft didn't penetrate the wall of the building, it would fall down.
"Bounce off" is perhaps a little hyperbole, but not very much. Clearly De Martini was mistaken.
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But as quoted he didn't say a mosquito and mosquito netting. He said a pencil and mosquito netting. One would expect the pencil to leave a neat hole, not bounce off.
 
Holy thread resurrection batman!

Although in saying that, I hadn't read this one before, good one to read through.
 
Here is the only post you'll ever need to read on the subject:

http://www.internationalskeptics.com/forums/showthread.php?p=6993609#post6993609

Short version:
- In 1964, a calculation inituated by the Port Authority of NY and NJ and signed of by a structural engineering firm concluded that the lateral force (shear stress) that the towers would be subjected to if a fully laden 707 crashed at 600 mph would not exceed the safety margin for the maximum lateral force from wind that the towers were designed for. This calculation did in no way take into account the structural damage at the impact floor or the fire situation. The question was merely: Would the tower be pushed over, i.e. break near its foot? And it would not (and it didn't).

- Another crude calculation considered the structural damage from cutting perimeter columns along the wingspan of a 707 - with no accounting for more damage to floors and core, and no consideration of fires. Again, it was found that the loads would redistribute to other columns and the towers would remain standing after a 707 cut perimter columns (and they did).

- But it is an urban myth that the towers were indeed designed to withstand the entire effects of a plane crash - an impossible task given the low computational powers in the early 60s. Remember, buildings were drawn with pencils on paper, and structural calculations carried out with slide rulkes and mechanical calculating machines - and certainly often by crunching numbers with pencil on paper.
 
And maybe this has been mentioned, but my favorite paper

Wierzbicki, T. and Teng, X. (2003). “How the airplane wing cut through the exterior columns of the World Trade Center.” J. of Impact Enrg. 28, pp.601–625

contains calculations relevant to this issue. They concluded (p. 642) that
...had the plane hit the base of the Towers which were made of high strength steel with the yield stress of sy ¼ 700 MPa; the airplane might have been deflected by the exterior walls.
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Engineers don't need computers to understand structures. The WTC design would stop a 707 at 180 mph. Engineering design point confirmed by a study after 911. By increasing the strength of the structure, the 911 impacts could have been stopped. Is that practical?

The two towers were the first structures outside of the military and nuclear industries designed to resist the impact of a jet airliner, the Boeing 707. It was assumed that the jetliner would be lost in the fog, seeking to land at JFK or at Newark. To the best of our knowledge, little was known about the effects of a fire from such an aircraft, and no designs were prepared for that circumstance. Indeed, at that time, no fireproofing systems were available to control the effects of such fires. http://www.nae.edu/Publications/The...ecurity/ReflectionsontheWorldTradeCenter.aspx
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It is a myth engineers could not calculate this stuff back in the 70s.
 
That's the beauty of it and a testament to the buildings' designers; they actually did withstand the impacts.
 
twinstead said:
That's the beauty of it and a testament to the buildings' designers; they actually did withstand the impacts.
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Indeed, most tall buildings probably would have collapsed a lot sooner if not immediately. Their massiveness prolonged the inevitable long enough to save most.
 
Justin39640 said:
Indeed, most tall buildings probably would have collapsed a lot sooner if not immediately. Their massiveness prolonged the inevitable long enough to save most.
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Frankly, I am at a complete loss to even imagine which facts and expertise led you to this opinion :confused:
 
Oystein said:
Frankly, I am at a complete loss to even imagine which facts and expertise led you to this opinion :confused:
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I believe... the towers had to be built out of especially strong concrete and steel just to be the size they were. If the same planes had crashed into smaller, and most likely weaker buildings, they wouldn't have collapsed so much as toppled over.

The towers were large and strong enough to absorb the initial impact, and were only taken out later when fires weakened the remaining supports. If they had hit, say, the CN Tower, it probably would have been chopped in half.
 
Oystein said:
Frankly, I am at a complete loss to even imagine which facts and expertise led you to this opinion :confused:
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I'm with you on this one. Nothing about the towers made them more resitsnt to collapse from impact. In fact, if the Empire State building was hit on 9/11, I have little doubt it would not be still standing today.
 
ehcks said:
I believe... the towers had to be built out of especially strong concrete and steel just to be the size they were. If the same planes had crashed into smaller, and most likely weaker buildings, they wouldn't have collapsed so much as toppled over.

The towers were large and strong enough to absorb the initial impact, and were only taken out later when fires weakened the remaining supports. If they had hit, say, the CN Tower, it probably would have been chopped in half.
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This shows how believes are actually wrong. Fortunately you don't seem to base reality on believes.
 
DGM said:
This shows how believes are actually wrong. Fortunately you don't seem to base reality on believes.
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*shrug* Just a guess at what he meant.

Though I stand by my disturbing mental image of the CN Tower being struck by a plane.
 
Yes you sucked me back into the waste of my time which is to talk with the shallow eggshell pretense of intelligence surrounding those at this forum. I assume you are now up to speed that Skilling did claim that he calculated for a fully loaded 707 traveling at 600 MPH, or are you still claculating for the little Cessna or whatever which hit the empire state building? Have you ever been able to admitt that Robertson's post 9/11 statements were in contradiction to his earlier statements? Any thoughts on why there were no stdies, or at least those known to the public, after the 93 bombing? Would it not make sense to have some information on how resistant the WTC was to bombs and fire? Maybe just answer the questions before your little intellectual scurrying leads you to all your famous diversionary tactics
 
Non Believer said:
Yes you sucked me back into the waste of my time which is to talk with the shallow eggshell pretense of intelligence surrounding those at this forum. I assume you are now up to speed that Skilling did claim that he calculated for a fully loaded 707 traveling at 600 MPH, or are you still claculating for the little Cessna or whatever which hit the empire state building? Have you ever been able to admitt that Robertson's post 9/11 statements were in contradiction to his earlier statements? Any thoughts on why there were no stdies, or at least those known to the public, after the 93 bombing? Would it not make sense to have some information on how resistant the WTC was to bombs and fire? Maybe just answer the questions before your little intellectual scurrying leads you to all your famous diversionary tactics
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Just wow.

I didn't read the complete thread, but are you attempting to sever the effect of the impact from the resulting fires?

If so, you're on a track coming out of left field.
 
Where's the debate? The towers survived the impacts of both aircraft, stood for up to an hour (even more in the case of the North Tower) and allowed thousands of people to escape. They did their job, they withstood an airliner impact and allowed many of the occupants to get out before the fires did their job and gravity did the rest.
 
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