What exaclty caused the towers to collapse?

[robywar]

I read an article recently by Kevin Barrett, who quotes former Bush Department of Labor economist, Morgan Reynolds. He makes a case that Bush planned the WTC collapse to help get America behind a ‘long war’ in the middle east, and that the towers had to have been laced with explosives in order to collapse, because a kerosene fire cannot heat steel enough for it to lose integrity. The url for the article I read is: http://milwaukee.indymedia.org/en/2006/03/205195.shtml.
So what’s the straight dope? Could the towers and WTC7 have collapsed from the fires and impact alone?

[Fir na tine]

Yes.

Please see the ohter 5,000 previous threads about this subject.

[RealityChuck]

Yes. See http://www.tms.org/pubs/journals/JOM/0112/Eagar/Eagar-0112.html for a technical explanation from a journal covering materials science.

[Uncommon Sense]

Yes, the only evidence we have is that the planes crashed into the buildings, started a fire (which if anything warped the structure rather than melted it) and the buildings collapsed under the resulting stress.
There is NO evidence of any type of planted charges.
The next poster will probably have eleventy-seven links of past threads.

[robywar]

Sorry, I looked for a search function, but if there is one it's too well hidden for me to bother looking for. Thanks for the link.

Fir na tine, thanks for being such a snob- what a great welcome to the forum.

[clairobscur]

Sorry, I looked for a search function, but if there is one it's too well hidden for me to bother looking for. Thanks for the link.
.


That's because guests don't have access to the search function.

[Johnny L.A.]

Sorry, I looked for a search function, but if there is one it's too well hidden for me to bother looking for. Thanks for the link.

The search function is not usable by Guests. On one hand, it's a perq for ponying up the membership fee. On the other hand, it results in common questions being asked repeatedly.

[Uncommon Sense]

Sorry, I looked for a search function, but if there is one it's too well hidden for me to bother looking for. Thanks for the link.

Fir na tine, thanks for being such a snob- what a great welcome to the forum.
It's OK, Fir na tine is a newbie. He/she probably forgot the search feature is disabled for guests.
Anyway, welcome to the boards.

[Johnny L.A.]

Here is a recent thread (http://boards.straightdope.com/sdmb/showthread.php?t=364515) on 9/11/2001 conspiracy theories.

[What Exit?]

Welcome to the SDMB
With a thread that start off with Bush planned the WTC disaster, you need to expect some unfriendly reaction. Conspiracy theories are firmly in the realm of the Tinfoil hat brigade.

4½ years later, there have been numerous factual reports showing why the towers collapsed and why they pancaked downward.
An exoskeleton building is nowhere near as strong as an interlocking Hot Riveted building like the Empire State Building. What brought the Towers down, would have probably only damaged the Empire State Building. The Heat of the Fuel and the various combustibles including the plane itself overcame the fireproofing of the WTC, Main beams warped and floors started collapsing downward. As they collapse downward they cannot support the additional weight and the building went down rapidly once it started to pancake. All of this is a not quite precise summary of what brought the towers down.

Jim

[robywar]

It's ok- I know enough about forum ettiquite that before you post something you should look for previous threads about it. Sorry I couldn't in this case, and thanks to all of you for being helpful and forgiving about it.

Thanks again for the link!

[robywar]

With a thread that start off with Bush planned the WTC disaster, you need to expect some unfriendly reaction. Conspiracy theories are firmly in the realm of the Tinfoil hat brigade.

I agree- I don't think there was any great conspiracy, but the statements he made about the fires not being hot enough to have structurally damaged the building got me curious. I actually was one of the thousands to enlist in the military after 9/11, and am finishing up my term this year.

I don't frequently agree with Bush, but I didn't mean this thread to bash him or his administration, just wanted to know if the backbone of the case against him (according to this guy) had any merit.

[Stranger On A Train]

Sorry, I looked for a search function, but if there is one it's too well hidden for me to bother looking for. Thanks for the link.

Fir na tine, thanks for being such a snob- what a great welcome to the forum.Guests don't have access to the search function. You have to pony up the fee for that.

You'll find that unsubstantiated conspiracy theories such as this, pseudoscientific claims (Aquatic Ape Hypothesis, Intelligent Design), and pop etymology, among other topics, don't get much leeway here. This particular topic and the conspiracy theories connected to it have been extensively discussed and debunked. There's always some turk who makes some kind of wonky claim regarding the flaws of the official explanation, but in this case the failure modes and effects are pretty well understood. See this site (http://www.pbs.org/wgbh/nova/wtc/collapse.html) for a fairly extensive but nontechnical explanation of why the towers failed.

Regarding the specific claim, to wit: "a kerosene fire cannot heat steel enough for it to lose integrity," you have to appreciate that it isn't the temperature at which kerosene burns but the amount of total heat energy it pumps into the system while it is combusting which determines the temperature (and thus reduction in material properties) of the steel structural members. You can cause steel to soften in the embers of even a relatively cool soft pine wood fire. Pour enough kerosene into an enclosed environment and it is no surprise that critical load-bearing connections in a skyscraper can fail.

Stranger

[newcrasher]

The WTC was built with its main support structure on the outside. Consider it s square tube. The individual floors were built on the ground and craned into place then bolted to the main supports. This gave the WTC its unique open floor spaces that provided maximum configurability to the clients who rented space there.

The individual floors also served the purpose to keep the building "in square". The massive forces excerted by gravity would be delivered directly down the structure and all is well.

Once several of the trussed floors were destroyed or compromised by heat, the means of keeping the building "in square" was greatly diminished. A minor twist in the structure would shift the load so that it was no longer distributed straight down. Now the steel support structure is no longer only transferring the weight of the building directly down to the ground as it was designed, but it is having to take up the job the individual floors failed at, keeping the building "in square". After enough of the floors failed the steel support structures could no longer maintain the square integrity of the building and it collapsed.

[lieu]

You'll find dopers to be a pretty helpful lot and quite interested in getting to the truth of any matter. Shame the same apparently cannot be said for your Kevin Barrett.

[newcrasher]

Yes.

Please see the ohter 5,000 previous threads about this subject.

Be nice to visitors.

[What Exit?]

I agree- I don't think there was any great conspiracy, but the statements he made about the fires not being hot enough to have structurally damaged the building got me curious. I actually was one of the thousands to enlist in the military after 9/11, and am finishing up my term this year.

I don't frequently agree with Bush, but I didn't mean this thread to bash him or his administration, just wanted to know if the backbone of the case against him (according to this guy) had any merit.
Don't sweat it, this board does a large amount of Bush bashing, but usually over known facts and disagreements not conspiracy theories. The people who regularly bash the Bush Administration are also among those who will most vehemently argue against unproven allegations, Conspiracy theories and sweeping generalizations. This is a pretty good place overall.

Jim

[PBear42]

Here's the most recent thread on the topic, 9/11 Conspiracy Theories! (http://boards.straightdope.com/sdmb/showthread.php?t=364515). Other threads include Loose Change video: 9/11 conspiracy (http://boards.straightdope.com/sdmb/showthread.php?threadid=357264), Is someone else responsible for 9/11? (http://boards.straightdope.com/sdmb/showthread.php?threadid=362124), Debunk this 9/11 conspiracy theory (http://boards.straightdope.com/sdmb/showthread.php?t=289916), Missile hitting the Pentagon (http://boards.straightdope.com/sdmb/showthread.php?t=279774), WTC Conspiracy Theory (http://boards.straightdope.com/sdmb/showthread.php?t=263578) and Bush 9/11 movie, must read/see (http://boards.straightdope.com/sdmb/showthread.php?t=247263).

As for substance, the theory has been around for over four years and (IMHO) has been thoroughly debunked. Among the sites worth looking at: David Corn (http://www.alternet.org/story/12536/); Snopes (http://www.snopes2.com/rumors/pentagon.htm); 911 Myths (http://911myths.com/); rotten.com (http://www.rotten.com/library/conspiracy/september_11_conspiracy_theories/); Boutin & Di Justo (http://paulboutin.weblogger.com/2002/03/14); William Jasper (http://www.thenewamerican.com/artman/publish/article_1253.shtml); and Shalom & Albert (http://www.zmag.org/content/Instructionals/shalalbcon.cfm). On the WTC collapse, 911 Myths is particularly good.

[Fir na tine]

Be nice to visitors.

I did not intend for my remark to be taken offensively and for that I apologize. :smack:

It just astounds and amazes me when someone actually takes stories like this seriously.

[robywar]

It just astounds and amazes me when someone actually takes stories like this seriously.

Which is why I came here to ask people with more education in relevent subjects (physics, thermodynamics, structural engeneering) than I have about it...Isn't that the point of this forum? Did I ever say I believe this claim? I wanted to know if there was any reason I SHOULD take this story seriously.

[PBear42]

Robywar, I agree. Fir na tine remarks are unhelpful. You got several helpful responses. Why don't you talk to them?

[robywar]

I'm reading through all the links and threads now. Seems this sort of thing has been done to death.

I'm willing to be that most people that subscribe to theories like this are piggybacking on other's claims without researching it at all. The old "I heard a fireman at groud zero said" then-it-must-be-true-type thing. It all sounds very compelling, and even if you don't want it to be true, you think that maybe there is a posibility, so it only feeds the fire.

Thanks to everyone for all the links and information. I appreciate your help!

[tomndebb]

so it only feeds the fire. SEE! There was more than kerosene burning, there.

RUMORS brought down the WTC.


What?

[handsomeharry]

I'm reading through all the links and threads now. Seems this sort of thing has been done to death.

I'm willing to be that most people that subscribe to theories like this are piggybacking on other's claims without researching it at all. The old "I heard a fireman at groud zero said" then-it-must-be-true-type thing. It all sounds very compelling, and even if you don't want it to be true, you think that maybe there is a posibility, so it only feeds the fire.

Thanks to everyone for all the links and information. I appreciate your help!
Well, there's an upside to overdoing some questions, particularly conspiracies. If one recalls, J. Edgar Hoover kept caterwauling that there was no such thing as organized crime/Mafia/whatever, and dismissing claims to the contrary as belonging to the tinfoil hat club. His bona fides were immaculate, at the time. Plus, somewhere in my head I have the concept that many actual engineers/physicists in the 30s-40s were saying that what we call the atomic bomb would not be possible. So, it pays to keep asking, because those in the know ain't always in the know. Hopefully, one can be an irritant in the process! :cool:
hh

[Fish]

I haven't troubled myself to research the tinfoil-hat claims that planes alone could not have brought the towers down. Do these people have no idea how much a commercial airliner weighs?

[tomndebb]

I haven't troubled myself to research the tinfoil-hat claims that planes alone could not have brought the towers down. Do these people have no idea how much a commercial airliner weighs?To their claims, the weight is irrelevant. The towers stood for a long time after the crashes; the crashes, themselves, did not bring down the towers.

Now, the weights of the planes do figure into some of the stories surrounding the eventual collapses, but the proximate causes of each building's collapse was fire, not the crashes.

[flex727]

To their claims, the weight is irrelevant. The towers stood for a long time after the crashes; the crashes, themselves, did not bring down the towers.

Now, the weights of the planes do figure into some of the stories surrounding the eventual collapses, but the proximate causes of each building's collapse was fire, not the crashes.
I rarely see it mentioned that the towers did not collapse in the order they were hit. The first building hit stood for much longer than the second. It clear why, it seems to me, since the first tower was hit much higher up. The second tower was hit lower down and thus the weakened structural elements had more weight to support.

[AndrewL]

I rarely see it mentioned that the towers did not collapse in the order they were hit. The first building hit stood for much longer than the second. It clear why, it seems to me, since the first tower was hit much higher up. The second tower was hit lower down and thus the weakened structural elements had more weight to support.
The second tower was also hit more off-center, taking out nearly an entire corner or the building. That would have made the load on the remaining beams more uneven.

[CurtC]

The WTC was built with its main support structure on the outside.My understanding is that the main weight-bearing supports were the center columns in the WTC towers. The perimeter beams were for stiffness mainly, to handle the wind forces.

The second tower was also hit more off-center, taking out nearly an entire corner or the building. That would have made the load on the remaining beams more uneven.And you can see that this tower fails when the top 30 floors or so start tipping over, towards the side where the airliner hit. Of course, buildings are made to support themselves vertically, so soon after the tipping started, it all came crashing down.

[rocking chair]

basicly structural failure.

tower one fell due to structual failure in the core, tower two fell to structual failure of the southeast corner floor (appx 80th floor) . (fema report from sept. 2002)

wtc 7 is still a bit of a mystery.

[KGS]

Actually, all of you are wrong. The towers never collapsed, it was an optical illusion. They are still there.

Wait until the Democrats get back in power, and the truth will be revealed.

I know this is true because my cat told me.

[What Exit?]

Actually, all of you are wrong. The towers never collapsed, it was an optical illusion. They are still there.

Wait until the Democrats get back in power, and the truth will be revealed.

I know this is true because my cat told me.
Was your cat wearing a Tinfoil hat?
BTW, where do you purchase Tinfoil these days? All we ever get is Aluminum foil.

[Triskadecamus]

In the true spirit of fighting ignorance, I feel it is a good idea to mention that wearing a foil hat, whether aluminum, or tin can cause your head to overheat. It reflects radiative cooling back into the head, and blocks air movement thus reducing evaporative cooling.

I am not able to report the actual measured effect on brain temperature, since my own experiment was monitored only by the wearer's report of extreme discomfort. However, the hypothesis that such headwear might be statistically associated with impaired intellectual function is not incompatible with my research.

Tris
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"We better get back, cause it'll be dark soon, and they mostly come at night, mostly." ~ Newt, Aliens