The Progressive Collapse Challenge

msdos, how are the models coming? Come up with anything meets all five challenges yet? Do you have access to a leaf-blower that can generate a 100 mph current? Maybe ask a neighbor or a teacher or something?

I got an idea, how about instead of berating people for not meeting your ridiculous challenge you actually provide proof, beyond your opinion, that the buildings were actually demolished.

Oh wait, all of your evidence depends entirely on your opinion. After all you don't have the evidence to prove it either way.

Another rant post.

In case you haven't noticed yet, dude, you guys are constantly on the defensive. You've never had to prove your claims, and so you seem to have forgotten that there's not as much behind them as you'd like to imagine.

So, maybe just this once, one of you guys can scrape up the gonads to present your case.

Again, NIST only tries to describe the failure of the first floors. They simply state that, by that point, global collapse was "inevitable." Is that proof? Well, if it is, then let me say that global collapse was not inevitable. Uh oh! That has exactly the exact same evidence going for it as NIST's claim: absolutely nothing! So now you should have a problem, unless you're.... biased!

So step up to the plate, man, and prove to us for once and all that gravity alone brought those towers down, from top to bottom, into a pile of dust and steel shards.

What exactly do you expect to happen after an entire floor collapsed?

I have heard a lot of talk about momentum, but I think the more appropriate facet would be inertia.

Every body continues in its state of rest or of uniform motion in a right line unless it is compelled to change that state by forces impressed on it.

NIST did not necesarily have to describe the collapse in it's entirety. Once they had the failure of one floor, inertia took it the rest of the way.

Since you believe that an extra source of energy was needed please explain to us what you think would have happened without explosives.

Originally posted by LeftBehind
What exactly do you expect to happen after an entire floor collapsed?

I have heard a lot of talk about momentum, but I think the more appropriate facet would be inertia.

If you want to get technical, you're not right, either. Momentum represents the basic idea, the actual relevant term is impulse. Look it up. But we haven't got there yet.

You guys have enough trouble trying to understand how 13 light floors shouldn't have enough energy to destroy 97 heavier ones. God forbid we get any more complicated than that. Your imaginations could go to town.

NIST did not necesarily have to describe the collapse in it's entirety. Once they had the failure of one floor, inertia took it the rest of the way.

Well I'm going to assert that there wasn't enough energy to destroy the whole buildings. Wow! I bet you would've never guessed I would argue that! And I have just as much evidence. A general rule of thumb with actual scientific research, is to avoid making assumptions. They aren't scientific. You're making quite an assumption, too, here, as you claim 13 light floors will obliterate 97 more massive floors while losing no speed. In fact, the 13 floors objects are totally destroyed and still crush further floors. That is some nice common sense, I have to say. More like doublethink or some other totally Orwellian refusal to think logically.

Again, offer PROOF. You guys are supposed to be the ones with the answers! You have the best and brightest on your side, don't you know! So where is the evidence that there was enough energy? You just make assertions and assumptions and expect us, the conspiracy theorists, to offer the only hard evidence? You have to be joking! Come on, man. Get to it!

[edit on 6-1-2006 by bsbray11]

Since it seems you only want to go around in circles about this, here is some proof not coming from NIST or America, so it hardly fits into your conspiracy without thousands being involved.

www.civil.usyd.edu.au...

The gigantic dynamic impact forces caused by the huge mass of the falling structure landing on the floors below is very much greater than the static load they were designed to resist.

The facts are very much different than some would have us believe.

Now, if you can provide some evidence from civil engineers at a university that oppose the conclusions reached in the above site, it would be greatly appreciated.

So far every site or movie offered to prove the demolition theory on ATS has had major flaws in it.

And no I'm not going to repeat these same flaws as you have been present in all of the relevant threads.

Originally posted by LeftBehind
Since it seems you only want to go around in circles about this, here is some proof not coming from NIST or America, so it hardly fits into your conspiracy without thousands being involved.

www.civil.usyd.edu.au...

The gigantic dynamic impact forces caused by the huge mass of the falling structure landing on the floors below is very much greater than the static load they were designed to resist.

The facts are very much different than some would have us believe.

No, wait - stop...

That's proof? Wt... That's just another baseless assertion! And you've been on our case this whole time, while we've been offering more than that!

Sucks when the shoe's on the other foot, doesn't it, LeftBehind? You guys ain't got squat for a case and you know it.

The claim is that the floors below wouldn't be able to withstand the falling weight of the caps. Well, how many floors wouldn't be able to withstand it? You don't seriously expect us to believe, again, that 13 light, thin-columned floors can obliterate 97 heavy, thick-columned floors? Do I have to repeat this problem until its significance strikes you?

The caps would could understandably take out a few floors at most of these massively strong structures, yes, but all of the floors below? 13 lightweights turning 97 heavyweights into piles of steel and clouds of dust? Again - where is the evidence? Not assertions, dude. And this isn't my case to defend. It's yours. If the official story doesn't have any evidence - you can't possibly criticize us by claiming that we don't. That's called hypocritical.

I notice you keep trying to shift the responsibility over onto me, asking me to disprove their work, rather than trying to establish any evidence on your own. All you would even have to do is post their proof, or the government's proof, but apparently there isn't any to be posted! Only assertions! Is it that uncomfortable trying to defend your case? It shouldn't be, should it? Considering who's on your side?

Again, dude, the government itself has been trying to prove this case since 2001. They've made their case public. You can use it. So why then is there no hard evidence to support the assertion you keep posting? Why is there no hard evidence to support the government claim that a small fraction of the floors of a skyscraper could so utterly destroy a much greater and heavier majority?

Science doesn't work by someone standing and saying, "Disprove what I say!" So when the government comes out with these assertions upon assertions with absolutely no hard evidence, and says "Disprove what we say!," you have already lost your case. Something more than these assertions, please. Some numbers, some reasoning as to how 13 floors could destroy 97 floors, when there is absolutely no advantage to those 13 floors, and they're even destroyed before the collapse is over. There is absolutely no logic in that! All you post in defense of this ridiculous assertion, is more assertions. I thought I asked for evidence?

I have to say, if your whole case is based upon unsupported and ridiculously absurd assertions, made as you try to ridicule us, then I'm really disappointed.

I'm going to bed. Maybe you can get something up by tomorrow morning that the government hasn't been able to produce for some five years. More than likely, though, you'll just try to shift the burden of proof over to us without bothering to offer up anything for the official line.

Typical, really, but at least now you have some perspective as to who's really lacking in the evidence department.

Originally posted by bsbray11
msdos, how are the models coming? Come up with anything meets all five challenges yet? Do you have access to a leaf-blower that can generate a 100 mph current? Maybe ask a neighbor or a teacher or something?

We do have some kind of leaf-blower... I don't know how fast wind it makes but noise is ear-splitting. It uses electricity.

Did you know, that if you take 2 cm x 2 cm x 100 cm and 2 cm x 2 cm x 200 cm pieces of copper and put the larger on top of smaller one to form a T, those beams can hande the forces. But if you scale it up to 2 m x 2 m x 100 m and 2 m x 2 m x 200 m, it will collapse. So, even if WTC 1 and 2 will always collapse as sawn, little model of it won't. Simply because it's on smaller scale. And I don't have resources to build new WTC 1 tower and to buy an aircraft to crash into it.

But ofcourse we can try to build a tower that is windproof and can stand some hard wind, and will collapse from top to bottom and spread to wide area. I think it's axiomatic that the model must be atleast 2 meters high, to get enough mass to colums. And those columns must be metal. They also must be attached to each other weakly enough. That can be tricky to do... Maybe we should email Myth Busters Would be great...

Once again BSbray you manage to dodge around the actual facts.


Please show me some civil engineers that disagree with the conclusions presented on that site.

We all are familiar with the fact that you don't believe any source that doesn't back up your case.

I provided a link.

You provided a rant.

I think I'll stick with the civil engineers, since you seem unable or unwilling to post proof to the contrary.

Or you could stop dodging and answer to us what you think would have happened without explosives.

Do you think that the collapse would stop half way down?

Do you think it should have tipped over sideways?

There is plenty of evidence that has been presented to you BSbray.

You choose to ignore it, while at the same time, I have seen you use Joe Vialls as proof of a mini nuke.

Please let's stop this double standard of proof.


Show me some civil engineers who disagree with my above posted site.

Tell us what you think would have happened to the towers in the absence of explosives.




[edit on 6-1-2006 by LeftBehind]

Excuse the quotes, but these are from the www.designcommunity.com forums, who are inhabited by architects and such like from what I make out.. I assume these guys know what they are talking about..
I realise the first quote is from an Electrical Engineer who did study civil engineering, but as I hear it is OK for an electrical engineer to peer review the famous Physics Professor Explosives theory, I'm assuming that in the same respect an electrical engineer's opinon is valid on this side of the lake too...

After seeing the extent of the fire I immediately thought that the towers were doomed. Why? I am not a civil engineer although I did study civil engineering for 2 years before changing to electrical engineering but that was almost 30 years ago. I knew no details of the WTC design except that it was like just about all US tall buildings - a steel structure. But I did remember something of my student days when one of civil engineering lecturers stated that no tall steel structure building could survive a widespread prolonged fire as these structures rely on steel in compression for the columns which will buckle when the temperature gets high enough. This is not a flaw in the design of this building but is a limitation of entire class of buildings.
[....]

Other comments have been critical of the 'pancake collapse'. Even the most simple calculation show that this was inevitable once one floor collapsed, the kinetic energy of the top part of WTC1 after having even fallen a mere 4 metres was very high - the impact of this hitting the floors below was massive, failure certain in any reasonable design. For those who doubt, compare a heavy steel ball resting on thin concrete to one dropped from a 4 metre window to see the difference of static load to dynamic impact. The vertical collapse was also inevitable as there was no outside force to rotate or lateraly shift the tower once it began its collapse.
[....]

In my mind (in other words a guess) the failure was caused by the aircraft impact stripping away large areas of insulation on the steel structural members and damaging the sprinker system. The subsequent fire quickly heated up the central steel support columns (not the exo-skeleton as the fire was much more intense in the interior and the exo-skeleton could conduct away heat far better) which buckled dropping the inside end of the floor beams which then transferred excessive torque to the exo-skeleton causing it to buckle and then collapse. A total guess by an electrical engineer - give it a validity factor of about 1%.
www.designcommunity.com...

Bob, if you go to this website's brief description of the construction of the World Trade Center you will see what happened. In a attempt to create floor space with no support visible, the architect supported the gravitational load on a weak central location. The result-burn through and collapse as you described. The Empire State Building could, (and has) taken the same hit with no problem because of multiple gravitational support. Notice how straight down both towers fell? Further weight to your argument. Notice how demolition people shoot buildings? Take out the gravitional support and down they come. (Straight down) These buildings were huge. I've been up there. The only way they could come down so straight is through gravity with no support! Why did'nt they tip over?(Nothing was holding them up)
www.designcommunity.com...

This brief write up was written on 9/11 by a lecturer in Civil Engineering in Sydney, as it says it is just an 'initial suggestion'. Note the lack of theories involving explosives, note how he is in Australia so either the conspiracy is a lot bigger than we thought or the guy shouldn't be lecturing.

Failure of the flooring system would have subsequently allowed the perimeter columns to buckle outwards. Regardless of which of these possibilities actually occurred, it would have resulted in the complete collapse of at least one complete storey at the level of impact.

Once one storey collapsed all floors above would have begun to fall. The huge mass of falling structure would gain momentum, crushing the structurally intact floors below, resulting in catastrophic failure of the entire structure. While the columns at say level 50 were designed to carry the static load of 50 floors above, once one floor collapsed and the floors above started to fall, the dynamic load of 50 storeys above is very much greater, and the columns were almost instantly destroyed as each floor progressively "pancaked" to the ground.
www.civil.usyd.edu.au...

The Bin-Laden empire revolves around construction, Osama himself holds a degree in civil engineering.

Osama bin Laden, one of 20 sons of a billionaire construction magnate, arrived in Afghanistan to join the jihad in 1980. An austere religious fanatic and business tycoon, bin Laden specialized in recruiting, financing and training the estimated 35,000 non-Afghan mercenaries who joined the mujaheddin.
[....]

In 1986, bin Laden brought heavy construction equipment from Saudi Arabia to Afghanistan. Using his extensive knowledge of construction techniques (he has a degree in civil engineering), he built “training camps”, some dug deep into the sides of mountains, and built roads to reach them.
www.conspiracyarchive.com...

An interesting theory brought up on the DesignCommunity Architecture forum is that if there was a design flaw in the WTC construction (which may be the answer for the apparant covering up of some info). Bin Laden may have been aware of this, what may be disturbing is how he may have been aware of it, but he may have known enough to realise that targetting a certain area would have the desired affect.

A design flaw could potentially have serious implications, it might effect insurance payouts and claims and could leave organisations or individuals open for suing. Depending on who knows who where and who has interests in what, this could obviously influence the outcome of the investigation for the right price or when staring at the possibility of losing money.

Here are some more interesting quotes from people who hopefully know what they are talking about:

Richard, please accept the sad reality that just an effect of burning collapsed the WTC towers, and not without a reason. Have you ever seen a tall building with a floor support by trusses like in the WTC towers? The WTC towers seemed to be the only ones. It is not an accident that such a “warehouse” type of structure has not been used in tall buildings. There is a contradiction between its delicacy and sturdiness needed against wind pressure (without going into details). So, the WTC structural designers “improved” it… with the well known disastrous result. Funny is that FEMA did not miss that only very skillfully diverted attention from it, e.g. using silly schematics, calling the Study preliminary, using the very hypothetical mode for truth and speculative mode against it, hedging itself against being accused of incompetence. FEMA used very sophisticated tricks.
arch.designcommunity.com...&highlight=wtc

There is plenty to read in that thread, and I have only just started. It starts with a poster who is determined to blame it on the design of the building, but the fact is the discussion appears to be by civil engineers who do not have a motiviation to look for an elaborate conspiracy - so I am sure there is much that can be learned by observing.

[edit on 6-1-2006 by AgentSmith]

*PSA use "ex" instead of "quote" for sources outside of ATS*

[edit on 6-1-2006 by dbates]

here is an interesting paper.

Unfortunately you have to get it out of google's cache.

The type of design used in the WTC towers, a rigid tube, is alos used in a number of other buildings.

If that paper is supposed to provide any evidence for the official explanation, then perhaps you should just outline it here Howie.

I still want someone to explain to me how exactly the fires got hot enough to weaken the entire structures.

Jet fuel does NOT burn at temperatures hot enough to melt or even weaken the amount of steel required for this supposed gravity collapse.

And seeing how when the planes hit, much of the fuel was expended and blown out during the explosions, and the resulting smoke from both fires burned black, suggesting a cooler fire than what is offically sanctioned, I still dont see any evidence or solid data leading me to believe the steel trusses and the rest of the structure were weaken that bad within one hour. Maybe if the fires were burning hotter or at least for many many hours longer, and the structures had collapsed much slower and less "neatly" Id buy the whole story.

Reports from people in the second WTC who were above the impact zone who indeed escaped because they were able to use the stairways in the far undamaged corners of the buildings do not jive with offical party line claims that it got that hot and that damaged. Id think that if the steel got that hot and the building was that badly damaged, people on the floors above impact would not have been able to make it out alive like they did. Surely they would have burned up from heat, or would have been prevented from going down the stairs to escape.

You should also consider the fact that the second tower hit, supposedly, the plane went deeper and hit the core. The resulting fires would have been hot and big enough (this IS a 757 we are talking about) to prevent the escape.

Yet there were a number of people who were on floors above the crash zone who were able to make it out of the building. because obviously, conditions in the disaster zone still permitted them to go. And the area of damage was supposed to be HUGE. So how did they get out? other than thich choking smoke (which usually tells us the fire is smouldering out, not getting hotter) no one who was escaping down the far stairwell reported hair and clothing and skin singing heat (Im not talking about people who came within visuals of the fires).

Thats what I wanna know. Wheres the heat????????

Originally posted by Skadi_the_Evil_Elf
I still want someone to explain to me how exactly the fires got hot enough to weaken the entire structures.

That is because they didn’t weaken the entire structure, they just weakened enough critical components of a structure that was already seriously compromised by the impact damage.

Originally posted by Skadi_the_Evil_Elf
Jet fuel does NOT burn at temperatures hot enough to melt or even weaken the amount of steel required for this supposed gravity collapse.

Not true. The type of fuel is immaterial in terms of the total heat released.

Surprisingly high temperatures can easily be achieved in standard office fires with no jet fuel at all. The Cardigan fire tests clearly demonstrate that a typical office type fire can seriously deform steel beams and columns, and those tests were done on a much more robust structure than the WTC towers.

Originally posted by Skadi_the_Evil_Elf
And seeing how when the planes hit, much of the fuel was expended and blown out during the explosions,

No, not really. The wing tanks ffrom both wings hitthe core area of WTC 1 squarely, the left wing hit the core of WTC 2 squarely. That fuel splashed around and burned in the core.

Originally posted by Skadi_the_Evil_Elf
and the resulting smoke from both fires burned black, suggesting a cooler fire than what is offically sanctioned,

A myth, not supported by facts. In any case, the amount of heat released by the fires, either from the burning fuel or the burning office and building components was enormous.

Originally posted by Skadi_the_Evil_Elf
I still dont see any evidence or solid data leading me to believe the steel trusses and the rest of the structure were weaken that bad within one hour. Maybe if the fires were burning hotter or at least for many many hours longer, and the structures had collapsed much slower and less "neatly" Id buy the whole story.

Your opinion is based on what training, education or direct experience in building structural design and failure?

Originally posted by Skadi_the_Evil_Elf
Reports from people in the second WTC who were above the impact zone who indeed escaped because they were able to use the stairways in the far undamaged corners of the buildings do not jive with offical party line claims that it got that hot and that damaged. Id think that if the steel got that hot and the building was that badly damaged, people on the floors above impact would not have been able to make it out alive like they did. Surely they would have burned up from heat, or would have been prevented from going down the stairs to escape.

Only a few survived from above the impact zone on WTC2. How do you know that they didn’t escape early, before the fires had time to develop across the whole floor?

Originally posted by Skadi_the_Evil_Elf
You should also consider the fact that the second tower hit, supposedly, the plane went deeper and hit the core. The resulting fires would have been hot and big enough (this IS a 757 we are talking about) to prevent the escape.

I’m not sure I’m following you there. Parts of the plane went all the way through in both impacts. The nose wheel from the plane that hit WTC1 went out the other side and landed a few blocks away.

Originally posted by Skadi_the_Evil_Elf
Wheres the heat????????

Why don’t you calculate how much heat in BTUs is released by the combustion of, say 5,000 gallons of kerosene.

Anyway. . .

Back to the subject. I’ve found a few interesting papers on the subject of progressive collapse in building structures.

Investigation Of Progressive Collapse Phenomena In a Multi Story Building

Numerical Modeling . .


Progressive Analysis Procedure for Progressive Collapse (abstract only)


Dynamic Behavior Of Planar Frames During Progressive Collapse


Analytical Tools for Progressive Collapse Analysis

Presentation for the above paper

From the presentation of that last one, it is clear that building owners all over the place are quietly asking building engineers to evaluate their buildings for the risk of progressive collapse.

The thread is asking for a model of progressive collapse imitating the WTC collapses, Howard, and showing that they are indeed possible. Not "abstracts" and etc. relating to theories of how they work. The only full "progressive collapses" were at the WTC complex anyway. Go figure.

kthx.

Originally posted by HowardRoark

Originally posted by Skadi_the_Evil_Elf
Jet fuel does NOT burn at temperatures hot enough to melt or even weaken the amount of steel required for this supposed gravity collapse.

Not true. The type of fuel is immaterial in terms of the total heat released.

Surprisingly high temperatures can easily be achieved in standard office fires with no jet fuel at all. The Cardigan fire tests clearly demonstrate that a typical office type fire can seriously deform steel beams and columns, and those tests were done on a much more robust structure than the WTC towers.

Then why did the tests of steel samples from the WTC show so little heating? Between 200 and 300 degrees Celsius, and that's it?

Originally posted by Skadi_the_Evil_Elf
and the resulting smoke from both fires burned black, suggesting a cooler fire than what is offically sanctioned,

A myth, not supported by facts. In any case, the amount of heat released by the fires, either from the burning fuel or the burning office and building components was enormous.

The smoke color darkened in both towers as time passed and the jet fuel was exhausted. I'm not going to debate this with a shill. Watch a movie.



The first pic is when only WTC1 was hit. In the second, both have already been hit. Thus, time has elapsed, and the smoke is obviously darker.


And so it looks like Howard is doing the usual round of deceiving....

Originally posted by bsbray11
The smoke color darkened in both towers as time passed and the jet fuel was exhausted. I'm not going to debate this with a shill. Watch a movie.

So who are you going to debate it with? You seem to classify people as shills when they disagree with you, so are you only going to debate with people who agree? What is this the Bush white house?

And remember everyone black smoke always means a dying fire. Especially because a 9-11 conspiracy video says so.





Oh wait.

Looks like there can be many reasons for black smoke. Black smoke is not definitive evidence that the fires were dying.

Originally posted by LeftBehind

Originally posted by bsbray11
The smoke color darkened in both towers as time passed and the jet fuel was exhausted. I'm not going to debate this with a shill. Watch a movie.

So who are you going to debate it with? You seem to classify people as shills when they disagree with you, so are you only going to debate with people who agree? What is this the Bush white house?

I shouldn't debate that the smoke darkened with anybody - I just posted proof that it did indeed darken as time elapsed! To go any further I would have to explain basic common sense of the difference between light and dark!

And remember everyone black smoke always means a dying fire. Especially because a 9-11 conspiracy video says so.

It does not always mean a dying fire. With hydrocarbon fires, however, it DOES always mean that there is soot in the smoke.

There was not soot in the smoke coming out of the WTC earlier, or at least not as much, as the smoke was obviously lighter.

Soot is indicative of a poor burn; specifically, it means the fire is not making efficient use of its fuel sources. Darker smoke also carries away more heat than lighter smoke. Light smoke to dark smoke = higher efficiency to lower efficiency = cooler temperatures.

Unless you can prove that a crapload of additional fuel was at some point dumped into the buildings and caused the black smoke, the fires must have been cooling in this case. End of story.