Wtc 7

[ElMondoHummus]

There is no evidence that explosives demolitions were used in at 7 World Trade. Recovered steel shows no signs of such use. No sounds of demolitions were recorded. Fire personnel agree that the building showed signs of collapse.

The following links contain information central to understanding what is currently known about that collapse:
http://wtc7lies.googlepages.com/wtc7engineeringpapers%2Ccollapsehypotheses
http://news.bbc.co.uk/1/hi/programmes/conspiracy_files/
http://www.debunking911.com/pull.htm
http://911myths.com/html/wtc7_fire.html
http://911myths.com/html/wtc7_squibs.html
http://911myths.com/html/wtc7_damage.html

Now, regarding the "single column failure" theory: As best as I understand things, that was proposed by NIST in 2004, and explained by Gilsanz and Ng in 2007.
http://www.structuremag.org/Archives/2007-11/SF-WTC7-Gilsanz-Nov07.pdf

The video, photographic, and first-person account evidence of the collapse of WTC 7 suggests that the impact of debris and resulting fire contributed to the collapse through the weakening of key structural components. The sequence of collapse, most notably the observed behavior of the penthouses, points to several key columns as the first to fail. The failure of column 79 was pivotal in the subsequent global collapse. As shown in the computerized non-linear structural model, its failure initiated the vertical collapse progression. WTC 7's properties of load transfer at floors 5 and 7, when combined with the failure of column 79, led to a horizontal collapse progression, which in turn ultimately resulted in global collapse.

So in response to the post challenging this hypothesis:

Well first off, i don't understand how even if one critical beam did fail somehow, which i believe it would have had to have failed over 3 consecutive floors or something, how that would even explain the collapse as it occurred. We are talking about a very fast and symmetrical collapse that would have required multiple simultaneous failures across the structure.

It's a bit more complicated than simply a "critical beam failing". Again:

WTC 7's properties of load transfer at floors 5 and 7, when combined with the failure of column 79, led to a horizontal collapse progression, which in turn ultimately resulted in global collapse.

The way the building handled the load distribution imposed by the discontinuous columns played a part. Plus, if you read the article, the hypothesis is that multiple columns on the east side failed; the significance of column 79 is because the modeling shows that it's the point where global collapse became inevitable; failures beforehand apparently shouldn't have been any more than local.

If one piece did fail, wouldn't you expect the force to be distributed unevenly, and the collapse to progress from the point of initial failure, and for at least part of the building to resist collapse, causing it to slow down or force a non-uniform collapse.

First of all, the hypothesis is not that only one piece failed. It says that 6 columns failed; it just so happens that one of them was the failure that doomed the rest of the building.

Also: The forces were indeed distributed unevenly. Columns on one side of the building failed; ergo, forces are no longer balanced or "even". I'll let one of the engineers or architects here expound further on that, but simple common sense tells you that when failures to some supports occur, others are stressed relative to their position to the failures.

The distribution of stress is evidenced by the kink in the east penthouse roof, followed by the sinking of the other penthouse, and then the development of a kink in the facade of the building. These stresses progressed from one side of the building to another.

And: It was a non-uniform collapse. The progression of failure went from lower floors up the east side, through to the west, and only then became global. The fact that the debris pile was more or less contained doesn't mean that the collapse was symmetric or uniform at all.

Is there any other case where a failure of a collumn has caused a collapse in this manner to proceed? No there isn't. Can the designers of the building say that if that collumn or collumns failed, that the rest of the structure should have collapsed in that fashion? Doubt it.

To the first question: Who knows? The point of the single column failure hypothesis is that unique features of the building led to a collapse. As to the second question: Doubt is fine, but it's not an answer. The engineers who've elucidated the single column hypothesis have in fact studied the original design to identify why the collapse progressed as it did. Whether the designers of the building agree or disagree is irrelevant to the discussion. The important part is whether the hypothesis properly explains observations and makes predictions that can be studied. So far, the hypothesis explains the collapse sequence.

If you have any more doubts about the single column theory, then by all means, post them. It may be that the hypothesis is indeed flawed; after all, it's only a proposed model of the collapse, not the final word. I don't know what NIST's ultimate findings will be, and they may depart radically from this thesis. But if you do posts these doubts, I would ask that you actually study the basics of that hypothesis first; your post betrays the fact that you haven't looked into the details of the model you seek to falsify.

 

[Grizzly Bear]

Well first off, i don't understand how even if one critical beam did fail somehow, which i believe it would have had to have failed over 3 consecutive floors or something, how that would even explain the collapse as it occurred.

The building was constructed on top of a substation located in the lower floors. The upper 40 stories were supported by three vertical trusses that extended in the core up to the 7th floor. The remainder was cantilevered and transferred loads to the main truss system from the upper floors. Columns inside the tower held unusually large spans, often in the range of 2000 sq ft of floor space per column

Please keep in mind that this was not the traditional post and beam design used in WTC 5, & 6....

We are talking about a very fast and symmetrical collapse

Very fast? The entire collapse from start to finish; the collapse of the east penthouse to the completion of the global collapse, took 18 seconds. This is a common misconception that people assert about the collapse time.

As for symmetrical... it collapsed to the south and east, leaned debris against the verizon building, and severely damaged 30 west broadway. What is your definition of symmetrical here? Lest not forget the failure was interior.

that would have required multiple simultaneous failures across the structure.

Progressive collapses do not necessitate multiple simultaneous failure. It's a domino effect of individual failures that collectively lead to global collapse.

If one piece did fail, wouldn't you expect the force to be distributed unevenly, and the collapse to progress from the point of initial failure, and for at least part of the building to resist collapse, causing it to slow down or force a non-uniform collapse.

(Bolded): Dependent on where the failure takes place. A critical failure inside the building may not lead to uneven tilting. You also need to study the construction. As for the red, the building did provide resistance, 6 hours worth after being ignited and stuck by a nearby collapsing tower. It provided 8 seconds worth of resistance following an internal structural failure of the east penthouse. To make such a claim based on the last 6 seconds of the collapse is disengenuous.

Is there any other case where a failure of a collumn has caused a collapse in this manner to proceed?

Is there another building constructed quite like WTC 7, clearly not. If you want to convince somone otherwise, it needs to be an apples and apples comparison.

Can the designers of the building say that if that collumn or collumns failed, that the rest of the structure should have collapsed in that fashion?

As long as they know the design. We know several things about WTC 7 that were unique to it:

Columns supported unusually large floor spans (2,000 sq ft)

Three vertical trusses supported the upper 40 floors above floor 7, all structural members from above that point were cantilevered, and transferred floor and service loads to the trusses.

Finally, we can all agree that the final outcome of the collapse was very similar to a cd.

ALL is aan overtatement unfortunately. To determine the method of collapse based entirely on appearance isn't by any standard a way to validate a controlled demo theory.

We had a uniform, straight down collapse into the footprint,

Remember the difference between WTC 7 and the collapse of the other two towers? The twin towers were top down, and resulted in massive amounts of debris impact damage to multiple structures. WTC 7's collapse initiation occured nearer to the bottom resulting in a vastly different debris distribution. Collateral damage would not be nearly as wide spread.

with minimal collateral damage to other buildings.

In part for the verizon building this can be accredited to it's post and beam design, which more efficiently redistributed loads from members which were compromised. It also did not catch fire. 30 west broadway (Fitterman hall) on the other hand is a different story, the collapse of WTC 7 rendered the structure uninhabitable, and to this date is still being deconstructed.

Please explain the lack of loud explosions that are distinctive of controlled demolition, also while you're at it, explain why seismic readings never picked up such explosions...

This collapse could revolutionize the demolition industry. Apparently local failure of a single collumn or 2 can result in simultaneous and catastrophic failure of the entire structure!

Study the construction of WTC 7 and you will realize that the principals you are applying do not accurately paint the picture for it.

Can you please elaborate on how fire caused this collapse now?

As has been stated before, it was a combination of structural damage and fire that lead to connection failures throughout the towers' interior. Although such buildings are fireproofed, such protection is given a range of on average 3 hours resistance to thermal heating. The fires in WTC 7 burned for much longer than that unfought, with damage to infrastructure that disable other fire suppression systems inside the building.

If you seriously do not believe in that explanation then do some studies for WTC 5, as it suffered similar fire damage to structural steel connections on the interior. In fact, such failure lead to a significant internal structural failure. And it was a protected steel frame.

Since you seem to have not taken such factor into account for WTC 7, I'll emphasize that WTC 5 had a much different construction than WTC 7, and it was much shorter. Such factors affect collapse vulnerability

 

[papasmurf]

THANK YOU ELMONDOHUMMUS FOR BEING THE ONLY PERSON HERE TO ATTEMPT TO ANSWER MY QUESTION.

All of you take notes on his post. It is the way a debate SHOULD be. He took my concerns, and addressed them. Now i have something to look into, rather than arguing with SDC about whether or not i am really an engineering student or not...

 

[A W Smith]

THANK YOU ELMONDOHUMMUS FOR BEING THE ONLY PERSON HERE TO ATTEMPT TO ANSWER MY QUESTION.

All of you take notes on his post. It is the way a debate SHOULD be. He took my concerns, and addressed them. Now i have something to look into, rather than arguing with SDC about whether or not i am really an engineering student or not...

I had linked to some of that in several posts but you did not bother to follow the links. the resource is in my sig. another point to consider is that the building had 360 degrees of X bracing on the exterior columns on some levels which caused the collapse to appear uniform

 

[ElMondoHummus]

THANK YOU ELMONDOHUMMUS FOR BEING THE ONLY PERSON HERE TO ATTEMPT TO ANSWER MY QUESTION.

All of you take notes on his post. It is the way a debate SHOULD be. He took my concerns, and addressed them. Now i have something to look into, rather than arguing with SDC about whether or not i am really an engineering student or not...

Papasmurf, to be blunt, you brought the reaction you received upon yourself. Next time, do not come new into a forum and fire insults without expecting some to be fired back. What you got was what you dished out first, and it was no more than simple balance.

If you wish to debate rationally, then post rationally. This:

You people are hilarious. Are you all like self-proclaimed intellectuals who haven't made it in the real world, so you have to come on here to make a name for yourself?

I don't understand how you can make 5 pages of posts, and not a single one has a single shred of intelligence that would change any rational persons mind on their doubts of the collapse of wtc7.

How can you possibly watch the video of the collapse and think that a fire brought that down? Has NIST been able to fabricate a logical explanation yet?

Please enlighten me on how it is so clear to you people that wtc7 was not demolished.

... this

Hmmm.... tell me this intelligent ones, why should i have to prove my theory against a massive cover-up that blocks the necessary evidence for me to do so, when your idea is open to all evidence and investigation presented.

I simply asked for a reason why i should believe that fire brought down wtc7, and you continue making this thread a joke as i have already pointed out.

... and this:

You guys can attack me all you want, but i didn't come on here to start a pissing contest. I came on here to break up your

Edited by prewitt81: 

Indecent remark removed.

of giggling over the truth movement and get you guys to talk some sense. I want to know what has you so guys so convinced that NIST and BBC can really prove that fire brought down wtc 7.

... are NOT examples of civilized behavior. You are the one who needs to take notes from my example. I will ask that you proceed in a civil fashion from here on out and argue rationally, refrain from insults, and try providing examples for your arguments, rather than just argue from incredulity. If you do not do that, then I will request that the mods consign your posts to AAH and put you on ignore.

 

[papasmurf]

http://www.youtube.com/watch?v=iroOdvjOK8k

here you can hear a huge explosion in wtc 7 (this is after the first 2 collapsed). It could be possible that they gradually crippled the building until the final global collapse of the building. By the way you talk about the building collapse taking 13 seconds or whatever, but if you actually start timing the global collapse- when the entire structure from top to bottom begins to fall, it does so in a period of 6 to 7 seconds. This is indisputable. It doesn't matter if the initial collapse involved a creeping of the penthouse; for a period of time, the building fell at near free fall speed.

 

[papasmurf]

I don't need to have my manners corrected by anyone here. I care less if you guys shut me out, it would just prove what cowards you were. If you read through this thread from beginning to end, you will see it is just a massive

Edited by prewitt81: 

Indecent remark removed.

of mockery. There is no discussion about why wtc 7 fell. If this is your idea of a debate, i have no interest being here. You people are delusional if you think you can just attack someone's rational concerns without even backing up your own beliefs.

Now, i complimented you on your post that addresses my questions... is there any real need to point out my non-polite responses that were merely defenses to an onslaught of personal attacks?

papasmurf, your actions are under admin review. Stick to the issue and leave the indecency out of it.

Replying to this modbox in thread will be off topic  Posted By: prewitt81

 

[volatile]

Who are "they"?

 

[Grizzly Bear]

It could be possible that they grad...ave looked like as a damage induced collapse?

 

[R.Mackey]

here you can hear a huge explosion in wtc 7 (this is after the first 2 collapsed). It could be possible that they gradually crippled the building until the final global collapse of the building.

"Gradually crippling" is inconsistent with your claims that the structure all failed simultaneously. Therefore, according to you, this scenario should also result in a highly asymmetric collapse.

This is false. Building collapses of this magnitude are expected to be total, and rapid, without exception. See Appendix B of my whitepaper; see also comments in this thread (I think around Page 8) where I answer several questions regarding the evolution and failure of WTC 7.

ETA: I was way off -- the WTC 7 specific part of that discussion begins on Page 14, with my first response of interest at Post #539.

 

[papasmurf]

I find many statements about sound of collapse, the opinions of demolition experts, and the nature of the collapse that contradict what you have said in this analysis:

http://11syyskuu.blogspot.com/2006/02/destruction-of-wtc-7.html

Thought you might be interested.

Why was WTC 7 never mentioned in the commission report?

Why was it's collapse never again aired on TV after 9/11?

So many unanswered questions....

I can't wait for the NIST report that comes out next month. How about you?

 

[ElMondoHummus]

I don't need to have my manners corrected by anyone here. I care less if you guys shut me out, it would just prove what cowards you were. If you read through this thread from beginning to end, you will see it is just a massive

Edited by prewitt81: 

Indecent remark removed.

of mockery. There is no discussion about why wtc 7 fell. If this is your idea of a debate, i have no interest being here. You people are delusional if you think you can just attack someone's rational concerns without even backing up your own beliefs.

Now, i complimented you on your post that addresses my questions... is there any real need to point out my non-polite responses that were merely defenses to an onslaught of personal attacks?

This is the last post I will make regarding your behavior.

You started first. Your first post was insulting and dripping with condescension; subsequent posts since then did not change. You cannot throw the first insult then claim self defense.

Our engineering-trained poster, R.Mackey, has written a post of substance. So have others. I suggest you stick to the issues instead of trying to deflect blame for your behavior,and I sincerely suggest you drop the arrogance. If you have any commentary aobut the flaws of the single-column theory, then please present them. Without insults. And if you can, you should address Mackey's point as well. And Grizzly's. And A W Smith's. Etc.

Stick to substance, please. And end the condescension. You will get healthy debate with far less insults if you do not throw insults yourself.

 

[SDC]

Papasmurf, at least I am what I purport to be: a librarian and academic historian without a scientific or engineering background. When I read posts, I look for consistency, clarity, literacy, and signs that the poster actually has some idea of what he/ she is talking about. I'm still waiting for that from you. Unfortunately, along with all the other shortcomings of your postings, they are nasty in the extreme.

 

[A W Smith]

21 posts and suspended, all in 3 1/2 hours

 

[SDC]

It was a remarkable performance. Even the East German judges would give it an 8 or 9.

 

[beachnut]

THANK YOU ELMONDOHUMMUS FOR BEING THE ONLY PERSON HERE TO ATTEMPT TO ANSWER MY QUESTION.

All of you take notes on his post. It is the way a debate SHOULD be. He took my concerns, and addressed them. Now i have something to look into, rather than arguing with SDC about whether or not i am really an engineering student or not...

http://wtc7lies.googlepages.com/introduction

Thanks for showing up prepared to discuss the facts.

http://wtc7lies.googlepages.com/introduction

You must of missed small tidbits of stuff that can help you.

http://wtc7lies.googlepages.com/introduction

Spewing ideas, which match verbatim, the hearsay lies of 9/11 truth earns you a badge of stupid ideas on 9/11. When you figure out 9/11 truth is making up lies, and remember thousands of people died on 9/11 due to terrorist, and 9/11 truth is basically blaming me (military), I find their disrespect pathetic and disgusting. Seems like you think it is okay to accuse people of murder and support people who tell lies, 9/11 truth.

After 6 years, you are just finding out people in the truth movement make up lies, and you believe them? There is no need to defend the idiot ideas of 9/11 truth, the people of 9/11 truth may be real nice, their ideas on 9/11 are false. Just like in school, your friends may flunk physics but they are still great people who do not make up lies!

Attack more and present your vast array of facts proving the so called "official story" wrong. Calling failed ideas dumb, is not good, please tell me how to act couth? The majority of posters here, except for 9/11 truth members, read the resources, do their own research before coming to a conclusion. Do you?

If this is you first time looking at 9/11 CTs, if you can figure it out in minutes, you are as good as the best, the Passengers on 93 had minutes, figured out 9/11 and took action. Go ahead try to beat that.

 

[Athyrio]

Tsk, tsk. Poor guy. Maybe a 24 chill will help. Came in here like gangbusters and this was the opening sentence of his first thread:

You people are hilarious. Are you all like self-proclaimed intellectuals who haven't made it in the real world, so you have to come on here to make a name for yourself?

Maybe he will have time to read over the forum and realize that this thread is not the only WTC7 discussion here. I never caught his "argument" that he was demanding to have addressed, only that he did not believe the building fell because of fire but that it was a CD. Why should that be addressed again without any new claim to back it?

 

[HawksFan]

Apparently because he said so.

 

[Kent1]

papasmurf:
Popular mechanics is a respectable article. I can't believe this idea is held by anyone here. Even when i did believe the official theory a few months ago, i despised this article for its ad hominem attacks and misinformation. It even goes as far as to use the proven-wrong pancake theory of collapse among other fallacies."


This is a common error by the truth movement. The Popular Mechanics article was in reference to the collapse (not the initiation). One of the sources used by Popular Mechanics was NIST (Shyam Sunder) the same source that truthers use to "prove" that it was not a pancake collapse. However NIST was making reference to the initiation in the often repeated FAQ.

"Like all office buildings, the WTC towers contained a huge volume of air. As they pancaked, all that air — along with the concrete and other debris pulverized by the force of the collapse — was ejected with enormous energy. "When you have a significant portion of a floor collapsing, it's going to shoot air and concrete dust out the window," NIST lead investigator Shyam Sunder tells PM. Those clouds of dust may create the impression of a controlled demolition, Sunder adds, "but it is the floor pancaking that leads to that perception."

It is not an error by any means from Popular Mechanics. Only a lack of understanding from the truth movement of how the collapse started vs how the building behaved as the collapse progressed. We also know there was pancaking as proven by the testimony and pictures showing many floors pancaked/smashed together.

 

[Stellafane]

Tsk, tsk. Poor guy. Maybe a 24 chill will help...

I kind of doubt it. I suspect he's basically yet another example of a particular breed of Truther, all insults and no evidence, who has no interest whatsoever in engaging in real debate and actually learning anything. The Truther movement just supplies him with an excuse to insult a whole lot of people over the internet.

...I never caught his "argument" that he was demanding to have addressed...

In all seriousness, I don't really think he had one. He just wanted to call people stupid.

...Why should that be addressed again without any new claim to back it?

Again, it's because the goal here isn't about such mundane things as evidence and debate, it's about calling people names because for some reason it makes you feel good. Papasmurf was probably fully aware his stay here was going to be a short one. But who cares? He got to insult a lot of people he knows full well are vastly more educated and qualified than he will ever be, and even if he never comes back here again, he'll get hours of pleasure just rereading this thread and seeing his sarcastic little comments posted here in perpetuity.