WTC 7 - was it leaning all afternoon and going to collapse - or is it just an urban myth?

reply to post by Swampfox46_1999

Tezzajw, is more than able to defend himself without your help. Ive already told him that if he did not like "tezzie" I would stop using it.

You shouldn’t have been doing it in the first place. I know Tezzajw can take care of himself. Sorry if I ruffled your feathers. By the way, you are off topic “again”.

So let me ask you this, why didn’t anyone take any close up pictures of this allege gash on WTC 7, they had all day to take these pictures yet they didn’t why is that?

The bank across the street suffered a long gash, yet we got to see close-up pictures of this damage. We got to see close-up pictures of WTC 7 on all “three” sides but not of the side of this alleged gash, can you explain this.

Originally posted by impressme
The bank across the street suffered a long gash, yet we got to see close-up pictures of this damage. We got to see close-up pictures of WTC 7 on all “three” sides but not of the side of this alleged gash, can you explain this.

Yes, the street in front of WTC7 was filled with debris, there was smoke exiting the entire south face of WTC7 and from early in the afternoon, even firefighters were prevented from approaching it due to collapse risk.

This is why there are few good photographs, because it was dangerous and difficult to get them, and so the best we have are helicopter shots and a couple from Steve Spak who was allowed to get close due to being an honourary firefighter.

The Deutsche Bank building did not collapse, and so it has been photographed thousands of times since 911.

d) they could not verify Peter Hayden's story.

Hopefully "d" is true, as I'm not sure any of the other options reflect well on NIST or the credibility of its report. But then "d" also doesn't speak well for Peter Hayden's story, either.

In Feb 2002 attended seminar featuring several FDNY chiefs who recounted operations at WTC both on 9/11 and afterwards during
cleanup and recovery phase.

During the presentation described operations at WTC 7 including setting up
the transit in early afternoon (approx 1pm) focusing on bulge in SW
corner of building. The building had been abandoned earlier in day and
firefighting operations ceased do to danger - debris was falling off building
facade and roof, no water was available and internal standpipes/sprinklers
damaged and not operable.

By 2pm could see that building was beginning to move or creep from
fires.

At 3pm (or there about) decision made to create collapse zone around
WTC 7 and clear area for collapse of structure.

As personal note was in my firehouse in NJ on standby (live only dozen miles west of NYC) listening to radio transmissions from neighboring city
which had committed entire day shift to NY - we were standing by in case
needed in NY or to back up their department in case of incident.

Heard chief on scene passing orders down to clear area - they were at
World Financial Center 3 putting out fires started by debris from collapse
of WTC 1

So option d is false....

Originally posted by exponent
Are these actually from NIST? I was under the impression these were from PBS. Not only this but these refer to WTC1 and 2 where the failure mode was completely different. Your source please?

They are from the PBS NOVA special where they interviewed the NIST WTC team and discussed their report. I may have gotten threads confused but I was referring to the fact that this failure mechanism is totally unprecedented and has not been proven, ever, by anyone.

If you don't think this illustrates the mechanism they describe, then lay it out correctly, and more importantly show me where anyone has proven it. That's what it keeps coming back to, because if you don't prove your freaking hypothesis, then you don't have anything to stand on.

a square superstructure leaning on its side will fall down pretty much. Towers do not, the fall at angles. wtc7 was very square-like.

reply to post by Gorman91


Not going to mention the fact that what you say doesn't make sense in general, but WTC7 was not shaped like a square:

Originally posted by bsbray11
If you don't think this illustrates the mechanism they describe, then lay it out correctly

An increase in the temperature of floor trusses designed to brace the structure lead to their top chord sagging entirely into tension. As a result of this a significant (6kips) inward force was felt along several sections of the perimeter wall.

By pulling inwards on the outer structure, the deformations lower the building's exterior column load carrying capacity. This is eventually overwhelmed as a series of perimeter column sections on the East of WTC2 and on the south of WTC1 fail. This failure becomes progressive around the majority of that side of the towers, leading to the entire upper section tilting.

This tilting, combined with impacts from the disconnected floors, severs most columns supporting the upper section, and as it contains enough energy to easily overwhelm a single floor's carrying capacity the collapse is progressive. Due to the long span truss design of the WTC, this progressive collapse is global and catastrophic.

and more importantly show me where anyone has proven it.

Such a theory cannot be proven in the classical sense without a full scale reproduction, but all required elements are testable and indeed are either
1. So well known the formulas for calculating them are in every engineering textbook (heat vs yield strength, truss deflection etc)
2. Tested by NIST in either full scale mock up or simulation

That's what it keeps coming back to, because if you don't prove your freaking hypothesis, then you don't have anything to stand on.

True enough, but 'proof' does not equal universal fact. Evolution has been proven, but it is not 100% correct. The same goes for non locally testable theories such as black holes, dark matter, hawking radiation, gravity waves etc.

I have no doubt that with appropriate funding and time, you could recreate a full scale WTC collapse. It would howver likely take several goes and cost billions upon billions. I'm sure as hell not going to fund it, but as I have said all along, I encourage truthers to put their money where their mouth is and actually conduct their own investigations.

Originally posted by thedman
By 2pm could see that building was beginning to move or creep from
fires.

At 3pm (or there about) decision made to create collapse zone around
WTC 7 and clear area for collapse of structure.

thedman, where is the proof?

I've lost count, is this maybe the third or fourth time that I've asked for the transit results?

How much did the building move or creep, over what time frame? If all this is true, then why wasn't it investigated in the NIST report?

Originally posted by tezzajw
How much did the building move or creep, over what time frame? If all this is true, then why wasn't it investigated in the NIST report?

As far as I know, no figures are available. One presumes that the firefighters simply checked for changes in measurement, rather than writing them down. I imagine it should be possible to locate who actually set up the equipment, the names of people aware of it are available as part of the oral accounts. You can probably get hold of them by phoning the appropriate fire house.

reply to post by tezzajw


Just curious if you apply this logic to every facet of your life....

Originally posted by exponent
[..]

I have no doubt that with appropriate funding and time, you could recreate a full scale WTC collapse. It would howver likely take several goes and cost billions upon billions. I'm sure as hell not going to fund it, but as I have said all along, I encourage truthers to put their money where their mouth is and actually conduct their own investigations.

Well, luckily we already have had several thousand burning steel-framed buildings, some planes flying into steel-framed buildings, some toppling buildings, etc. All those 'experiments of history' give us an extensive pool of data about steel structures, experiments worth billions of dollars (except noone calls them experiments, because they are unintentional). You can't get more accurate real-life results; not even with the bestestest computer model of the world! That's because the real world is always more accurate than a simulated one.

The thing is - do you accept this pool of data?

[edit on 8-6-2009 by scraze]

reply to post by tezzajw

Tezzajw,

NIST Report Vol 1, p. 301 quotes Deputy Chief Peter Hayden saying that "early on we saw a bulge in the southwest corner between floors 10 and 13 and we had put a transit on that, and we were pretty sure she [WTC7] was going to collapse." The reference is Firehouse Magazine, April 2002, p.97.

Probably, an actual measure of the bulge was not made as the information required by on-scene people is probably one of "stable or moving." The experience of the FDNY and the fact that they had a transit ready to sight on the building says that they have done this before and that their conclusions are based on experience with building fires.

Originally posted by scraze
Well, luckily we already have had several thousand burning steel-framed buildings, some planes flying into steel-framed buildings, some toppling buildings, etc. All those 'experiments of history' give us an extensive pool of data about steel structures, experiments worth billions of dollars (except noone calls them experiments, because they are unintentional). You can't get more accurate real-life results; not even with the bestestest computer model of the world! That's because the real world is always more accurate than a simulated one.

The thing is - do you accept this pool of data?

Of course!

I know what you're going to say next, either that "no steel framed building has ever collapsed due to fire" (which is incorrect) or "no steel framed high rise building has ever collapsed due to fire" (which is partially correct).

This does not establish a rule though, only a trend that buildings are generally well protected against fire. This trend holds firm with the WTC buildings too if you consult NIST. Their investigation found that fire alone would likely not be enough to bring the building down. WTC7 is the only case on 911 where a building was found to have failed soley from fire, and this is only because of its exceptional construction.

We cannot rely on past events to validate a theory, as this presumes we have a complete understanding of events, which of course we do not. Phenomena once thought to be little more than magic are now commonplace, and we do not express disbelief that these acts occur. Why should this be the same for an exceptionally unlikely circumstance leading to an exceptionally unlikely result?

Originally posted by exponent
An increase in the temperature of floor trusses designed to brace the structure lead to their top chord sagging entirely into tension. As a result of this a significant (6kips) inward force was felt along several sections of the perimeter wall.

So why didn't they reproduce this in a lab? Why couldn't they even measure the tensions produced, and compare them to the tension required to displace a column so far? All of these things, they neglected entirely to do, so that you have nothing to support this theory.

You can't cop out to saying you have to rebuild an entire floor to test the mechanisms here either. There is a definitely figure as to how much force would be required to deflect a column from its bolts and spandrel plates locally, and the tension produced from heating would obviously have to reach and/or surpass that amount of tension to cause deflection. You've worked a free-body diagram, right? This is no different. Where are the technical details? Where do they show the forces are sufficient?

Personally, I think the truss seats would have given way, long before the columns themselves deflect. Have you seen how the trusses were connected, and the relative size of the perimeter columns? If you have, YOU would probably want to see this theory tested too. The truss connections are tiny assemblies compared to both the perimeter and the core columns, and both the perimeter and the core had other means of lateral bracing. NIST's own investigation produced simulations early on showing that up to 5 floors could be gutted entirely of trusses without major problems as long as wind conditions weren't severe, that is probably still on their website.

and more importantly show me where anyone has proven it.

Such a theory cannot be proven in the classical sense without a full scale reproduction, but all required elements are testable and indeed are either
1. So well known the formulas for calculating them are in every engineering textbook (heat vs yield strength, truss deflection etc)
2. Tested by NIST in either full scale mock up or simulation

Show me the mock-ups and/or simulations that prove the theory, then. This should be your bread and butter.

[edit on 8-6-2009 by bsbray11]

reply to post by exponent


I agree, what happened on 9/11 was in fact quite unique, two planes shaking the foundations within a few hours, then two massive buildings collapsing on the foundation as well.. Therefore we cannot use past data as absolute proof. But they can give us a probability of the events, in an indirect way. For instance, steel-framed buildings have collapsed due to fire before, and we can study the correlation between the fire-retardentness of the steel and the percentage of the core of the building collapsed along with number of stories collapsed.
To calculate the probabilities for the WTC, we would have the factor X, namely the unique circumstances of 9/11 (shocking foundation etc.) - and the probability of a fire collapsing a steel-framed building on any other day. Note: all numbers hereafter are fictional and are to be viewed conceptually. Say the probability of a fire-retardant steel-framed building collapsing due to fire is 1 in 1000, and that those cases result in a complete pancake 1 out of 100 times. Pancaking completely due to fire alone would then be 1 in 100,000 or .000001. Let's dub this probability 'P'. The probability of WTC7 collapsing would be P*X = .000001 * X. We can't figure out the X accurately (anymore), so we can't put out a single probability, and that's that - we won't be able to say give a single number.

But we can make a range of estimates for X, using the pool of data of history. X would be the predisposition to a collapse due to fire; the range of estimates of X would be simply from the lowest possible estimate to the highest estimate (more about the range later). Let's say our pool of data shows us that 1 out of 10 steel-framed building lost their fire-retardant coating when the foundation was hit by a quake of some sort. This means that in 1 out of 10 cases, the probability of a complete pancake of WTC 7 is not 1 in 100,000: instead, it is 1 in 100,000 for 9 out of 10 cases and for the case in which the coating was lost, we use the probability of a complete pancake for non-fire-retardant steel-framed buildings, say 1 in 50. X would then be .02/P = 20000, meaning that a shaking foundation increases the chance of a collapse by 20,000 times. The probability of this disposition is 1 out of 10 =. 1, the chance of the coating getting off. Let's add a variable stating WTC 7's design should have prevented a complete collapse (fictional) - it had 10 times more chance to keep up than other buildings. But the design works in only 4 out of 5 circumstances/fires - certain types of fire just win. X would be .1 and the probability of this X would be 8 out of 10 = .8. For this simple thought experiment, we have an X range from .1 to 20000 with a respective probability of .8 to .1. An actual regression analysis would give a far more indicative result, but nonetheless - the more factors you add, the more stability you get in the range of X's.

I think I went a bit over-the-top.. But my point should be clear; just because we cannot be absolutely sure, does not mean we cannot make an elaborate analysis of the probabilities, and at the least gain an understanding of the relation between the factors that lead to the collapse.

Originally posted by bsbray11
So why didn't they reproduce this in a lab? Why couldn't they even measure the tensions produced, and compare them to the tension required to displace a column so far? All of these things, they neglected entirely to do, so that you have nothing to support this theory.

No fire facility exists of this scale, but the equations are well known. If you were to search the JREF forums you will find that a poster called 'Newtons Bit' has done the calculations for exactly how much force would be expected to develop. As you mention later in the post the technical details should be good enough, and you should find those in your search.

The simulations you request may be found (as well as in various other non NIST publications) in NCSTAR 1-6B and NCSTAR 1-6C. Specifically 1-6C pages 45-52 and 77 onwards.

NCSTAR 1-6C is essential reading for a good understanding of the WTC 1 and 2 failure modes, but this is getting somewhat off topic. I make no complaints, only a note that we should also be discussing WTC7.

Originally posted by scraze
I think I went a bit over-the-top.. But my point should be clear; just because we cannot be absolutely sure, does not mean we cannot make an elaborate analysis of the probabilities, and at the least gain an understanding of the relation between the factors that lead to the collapse.

I don't disagree, but such a method of analysis is only useful when we have no other facts to hand, when we're trying to determine what could potentially happen.

In the case of 911, we're actually trying to determine what did happen, and we have many facts to hand, many pieces of information which must be analysed and correlated, tested and theorised upon to find a more verifiable solution than that derived from probabilities.

This is what NIST, FEMA, the 911 commission and countless other groups have attempted to do, and many do not appreciate just how broad in scope that 'Official Story' is. Many criticisms are levelled at many aspects, but these criticisms attack only a small part of an immense undertaking which has a reliable conclusion.

I guess I sound like i'm proslytising but I beg of you to read in full the 911 commission report and at least the summaries of the NIST report. The amount of information contained within is considerable.

Originally posted by exponent
You can probably get hold of them by phoning the appropriate fire house.

Considering that I am not making any claims about the results of the transit, I'm quite willing for other people who do make the transit claims to come up with the proof.

If I had the time and means to conduct a proper investigation, then I would telephone the firehouse.

In fact, wasn't NIST paid to do a proper investigation and they didn't show the results of the alleged transit. What hope do I have - I'm not as well paid or resourced as NIST!

Originally posted by Swampfox46_1999
reply to post by tezzajw

 

Just curious if you apply this logic to every facet of your life....

Just curious why you would ask such an off topic, personal question, Swampfox?

The rest of my life isn't as suspicious or important as the events of 9/11.

Originally posted by exponent
No fire facility exists of this scale

Of what scale? Stop making things up, I just told you I DIDN'T mean rebuilding a whole floor.

The simulations you request may be found (as well as in various other non NIST publications) in NCSTAR 1-6B and NCSTAR 1-6C. Specifically 1-6C pages 45-52 and 77 onwards.

Here are some quotes from NCSTAR 1-6B:

From the "conclusion" of "2-D Analysis of a Building Frame Under Gravity Load and Fire":

For the particular temperature distribution we selected from among those assumed by Usmani et al. [1], the diagonals of the heated trusses buckle inelastically, causing considerable sag in the fire floors. This behavior puts a high tension demand on the truss connections to the perimeter column, which remains at moderate temperatures in this model and does not experience buckling. This is the major difference between our results and Usmani’s, even though the heated trusses in our model are exposed to a much higher temperature and the column to a more severe load that reflects load redistribution in the damaged structure. One possible explanation for the difference is that failure modes may be very sensitive to material properties.

www.fire.nist.gov...

Italics were already there, I added the bold part. I wonder if the contradiction was ever resolved beyond the "one possible explanation"?

The assumptions by Usmani et al that are being referred to are from a theoretical article. This simulation also assumed steel heated to 1273 K, something also not consistent with scientific studies of fire applied to steel frames (and if any studies HAVE shown steel realistically heated to this temperature, let me know -- I know Cardington's tests certainly didn't, and in fact contradict it).

I looked through 1-6C pages 45-52, and saw a lot about the capacities of the connections to take various tensile forces at various assumed temperatures, and theoretical failure mechanisms for the connections themselves, but nothing about the perimeter columns themselves being pulled in. After page 77, figure 5-32a shows that a perimeter column is deflected less than one inch by a truss heated to about 450 C, and more and less heat both reduce that deformation. At temperatures and tensile forces much greater than that, the connection itself fails.

www.fire.nist.gov...

So, look back over that yourself, and see that I'm getting this right, that a perimeter column is being deflected a maximum of less than 1 inch horizontally by an optimally-heated and sagging truss. I have a feeling when we apply Euler's formula to this problem (a horizontal deformation of an inch), and even assume a generous percentage of perimeter columns suffering from their trusses being so uniformly heated, we still aren't going to be looking at anything impressive, especially when the perimeter columns' safety factors are taken into account.