Critical Errors and Omissions in WTC7 Report Uncovered

[Hitstirrer]

Who are you quoting there?

I wasn't quoting anyone. I was inserting into your quote the correct sequence of events. And the correct sequence has been given by NIST in NSTAR 1-A, -- quite a few times. As here :- For ease I will number the sequence in red, from 1 to 4. You will note that frequently the correct sequence is given in the wrong order.

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pdf page 64 / 130

Fire-induced thermal expansion of the floor system surrounding Column 79 ( 1 ) led to the collapse of Floor 13, ( 2 ) which triggered a cascade of floor failures. ( 3 )

In this case, the floor beams on the east side of the building expanded enough that they pushed the girder spanning between Columns 79 and 44 to the west on the 13th floor. This movement was enough for the girder to walk off of its support at Column 79. The unsupported girder ( 2 ) and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. ( 3 ) This left Column 79 with insufficient lateral support, and as a consequence, the column buckled eastward, ( 4 ) becoming the initial local failure for collapse initiation.

Pdf page 81 /130

Figure 2-2 shows the structural response of WTC 7 to the fire-induced damage on the east side. Floor 13 collapsed onto the floors below, causing a cascade of floor failures down to Floor 5. ( 3 ) The floor failures left Column 79 laterally unsupported and it buckled, ( 4 ) which was quickly followed by the buckling of Columns 80 and 81. The buckling of Column 79 ( 4 ) was the initiating event that led to the collapse of WTC 7, not the floor failures. ( 2 & 3 ) If Column 79 had not buckled, due to a larger section or bracing, for instance, the floor failures would not have been sufficient to initiate a progression of failure that would result in global collapse.

pdf page 84 / 130

The horizontal building motion started at nearly the same time as the cascading floor failures ( 3 ) started in the LS-DYNA analysis (-6.5 s), which preceded the buckling failure of Column 79. ( 4 )

pdf page 85 / 130

Table 3-1 ( confirms the sequence that cascade of floors preceded the 'initiating' event. )

pdf page 95 / 130

The buckling failure of Column 79 ( 4 ) between Floor 5 and Floor 14 was the initiating event that led to the global collapse of WTC 7. This resulted from thermal expansion ( 1 ) and failures of connections, beams, and girders ( 2 ) in the adjacent floor systems.
At Column 79, heating and expansion of the floor beams in the northeast corner caused the loss of connection between the column and the key girder. ( 2 )

Pdf page 96 / 130

As Floor 13 fell onto the floor below, a cascade of floor failures continued ( 3 ) until the damage reached the massive Floor 5 slab, leaving Column 79 without lateral support for nine floors. The long unsupported length of Column 79 led to its buckling failure. ( 4 )

pdf page 101 / 130

The thermal expansion of the WTC 7 floor beams ( 1 ) that initiated the probable collapse sequence occurred primarily at temperatures below approximately 400 °C (750 ºF).

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For ease of reference :-

( 1 ) = thermal expansion causing floor 13 to break from its shear studs and allow beams to thermally expand.

( 2 ) = Expanding beam enables the girder between 44 and 79 to walk-off its seat at 79.

( 3 ) = Floor 13 drops when the girder drops causing a cascade of floors and leaves 79 with no lateral support.

( 4 ) = column 79 buckles to 'initiate' global collapse.


All of the above are direct quotes from NIST's final report setting out their 'most likely hypothesis'.

 

[Mick West]

But you are overlapping a specific "probable sequence", with a couple of descriptions of the more general hypotheses. The cascade of floors is describes in several places without reference to the girder walk off.

THere's the general hypothesis:

This resulted from thermal expansion ( 1 ) and failures of connections, beams, and girders ( 2 ) in the adjacent floor systems.

And a more specific hypothesis:

In this case, the floor beams on the east side of the building expanded enough that they pushed the girder spanning between Columns 79 and 44 to the west on the 13th floor. This movement was enough for the girder to walk off of its support at Column 79. The unsupported girder ( 2 ) and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor.

Even if you invalidate the specific, the general still remains. And even the specific says "and other local fire-induced damage". Just change "and" to "and/or", and we are good to go.

 

[Hitstirrer]

And even the specific says "and other local fire-induced damage". Just change "and" to "and/or", and we are good to go.

Sorry but you arn't allowed to re-write NIST's final report so that it suits your own hypothesis.

 

[Mick West]

Sorry but you arn't allowed to re-write NIST's final report so that it suits your own hypothesis.

I'm not. I'm say you can remove that bit if you like. Isn't that what you want? You want to demonstrate that the girde cold not have walked off? Okay. So then what. Now you have to show that it is critical. If you remove it, what is left?

What's left is the general hypothesis, and all the evidence that supports that general hypothesis.

 

[Hitstirrer]

I'm not. I'm say you can remove that bit if you like. Isn't that what you want? You want to demonstrate that the girde cold not have walked off? Okay. So then what. Now you have to show that it is critical. If you remove it, what is left?

I have just shown the sequence as hypothesised by NIST.

Its a sequence. 1-2-3-4. Their sequence. Quite specific and detailed.

If #2 can't happen then 3 + 4 can't happen. So I don't think its unreasonable to conclude that the action of #2 is critical in that sequence. If you are claiming that a different #2 can be substituted for the #2 that NIST claim then you ARE wanting to re-write their report.

If they had wanted to say, "either this #2 or that #2 or perhaps this different #2 or maybe that fourth #2" - wouldnt they have done that ? They didn't. They were quite specific and single minded. They even stated that it 'was no longer a mystery'.

The absence of #2 is critical to the sequence.

 

[Mick West]

I have just shown the sequence as hypothesised by NIST.

Its a sequence. 1-2-3-4. Their sequence. Quite specific and detailed.

If #2 can't happen then 3 + 4 can't happen. So I don't think its unreasonable to conclude that the action of #2 is critical in that sequence. If you are claiming that a different #2 can be substituted for the #2 that NIST claim then you ARE wanting to re-write their report.

If they had wanted to say, "either this #2 or that #2 or perhaps this different #2 or maybe that fourth #2" - wouldnt they have done that ? They didn't. They were quite specific and single minded. They even stated that it 'was no longer a mystery'.

The absence of #2 is critical to the sequence.

In the "probable collapse sequence", yeah, but not in the overall hypothesis. I'm saying take it out, not replace it with something.

 

[Tony Szamboti]

I'm not. I'm say you can remove that bit if you like. Isn't that what you want? You want to demonstrate that the girde cold not have walked off? Okay. So then what. Now you have to show that it is critical. If you remove it, what is left?

What's left is the general hypothesis, and all the evidence that supports that general hypothesis.

With the northeast corner floor failure removed from the NIST report all that is left is a hand wave that the building was on fire and that caused it to collapse.

 

[Mick West]

With the northeast corner floor failure removed from the NIST report all that is left is a hand wave that the building was on fire and that caused it to collapse.

But the floor failure is not removed, just this particular individual initiating event for that failure.

 

[dunbar]

If they had wanted to say, "either this #2 or that #2 or perhaps this different #2 or maybe that fourth #2" - wouldnt they have done that ? They didn't.

They didn't because they couldn't. They went with the column 79 walk-off because after 6 years of working it they had eliminated all other possible explanations as too preposterous to proffer while keeping a straight face. The explanation they went with was the least improbable of all the highly improbable and extremely unrealistic explanations available, and even that, as was demonstrated in this thread quite conclusively, is terribly problematic and completely unable to hold up against any bit of rigorous scrutiny.

To paraphrase Sherlock Holmes: when you have eliminated the convenient and expedient, whatever remains, however uncomfortable, must be the truth.

 

[Mick West]

What's wrong with "however improbable"? Too close to reality?

How about NIST just mea culpa, and say "floors collapsed for unknown reasons"? Would that be okay?

 

[Hitstirrer]

How about NIST just mea culpa, and say "floors collapsed for unknown reasons"? Would that be okay?

I just went outside to check for flying pigs.

 

[Mick West]

I just went outside to check for flying pigs.

But what if? What if they accepted the walk of was improbable, but the general hypothesis was sound. Then where would you be?

 

[Josh Heuer]

But what if? What if they accepted the walk of was improbable, but the general hypothesis was sound. Then where would you be?

Yeah, but what if NIST never meant to prove what happened, only to give a convenient explanation that people would buy into?

 

[Mick West]

Yeah, but what if NIST never meant to prove what happened, only to give a convenient explanation that people would buy into?

Then that's a big illegal conspiracy.

Your turn.

 

[judgeme]

I don't understand where "what if" fit into this supposedly getting into the fine details?

 

[Hitstirrer]

But what if? What if they accepted the walk of was improbable, but the general hypothesis was sound. Then where would you be?

We could ask them to prove their new hypothesis of course. And ask why the original 'guess' wasn't peer reviewed before release to avoid all this trauma. We would then be able to also ask them why they 'invented' simulations to match their improbable hypothesis and then told the world that this was 'no longer a mystery'. We could ask for their professional licences to be revoked due to blatant 'drylabbing' - using millions of $'s of taxpayer funds.

Oh - and then demand a real independent investigation of course.

 

[Mick West]

I don't understand where "what if" fit into this supposedly getting into the fine details?

The thread started out with a rather vaguely defined claims that there were "critical" errors. So I'm try to be precise about if they are actually critical. So the question is if NIST were to admit that the walk-off was impossible, does that mean the entire report is invalidated.

 

[Mick West]

We could ask them to prove their new hypothesis of course. And ask why the original 'guess' wasn't peer reviewed before release to avoid all this trauma. We would then be able to also ask them why they 'invented' simulations to match their improbable hypothesis and then told the world that this was 'no longer a mystery'. We could ask for their professional licences to be revoked due to blatant 'drylabbing' - using millions of $'s of taxpayer funds.

Oh - and then demand a real independent investigation of course.

But the simulations don't match the walk-off scenario, so how could they be drylabbing?

 

[Josh Heuer]

Then that's a big illegal conspiracy.

Your turn.

No, it's illegal when the details are no longer classified. For now, it's a classified case, with a very vague report explaining how maybe, somehow, someway, in the ideal conditions, things might have turned out.

 

[Hitstirrer]

But the simulations don't match the walk-off scenario, so how could they be drylabbing?

They drylabbed column 79 buckling. Had to have done. They started with the result and worked backwards. Classic drylabbing.

 

[Mick West]

They drylabbed column 79 buckling. Had to have done. They started with the result and worked backwards. Classic drylabbing.

Maybe you could explain that a bit more in a new thread. Sounds like a pretty damning allegation if true.

 

[judgeme]

The thread started out with a rather vaguely defined claims that there were "critical" errors. So I'm try to be precise about if they are actually critical. So the question is if NIST were to admit that the walk-off was impossible, does that mean the entire report is invalidated.

Well clearly, in the absence of what ifs!

 

[Mick West]

Well clearly, in the absence of what ifs!

"Clearly" to you maybe, but how do you make the case?

 

[dunbar]

What's wrong with "however improbable"? Too close to reality?

Improbable is a matter of perspective and one must be very careful when employing the absurdity heuristic:

The absurdity heuristic classifies highly untypical situations[ or events] as "absurd", or impossible. While normally very useful as a form of epistemic hygiene, allowing to detect nonsense, it suffers from the same problems as representativeness heuristic.

There is a number of situations where absurdity heuristic is wrong. A deep theory has to override the intuitive expectation. Where you don't expect intuition to construct an adequate model of reality, classifying an idea as impossible may be overconfident.

 

[Mick West]

Improbable is a matter of perspective and one must be very careful when employing the absurdity heuristic:

Like when people say "no highrise has collapsed from fire before, what are the odds that three buildings would collapse from fire on the same day!!!?"

 

[dunbar]

Like when people say "no highrise has collapsed from fire before, what are the odds that three buildings would collapse from fire on the same day!!!?"

Yes, exactly. But when one considers that the odds in favor of such an event occurring are infinitesimal, and those against, astronomical, then a more likely explanation is recommended to the rational mind.

 

[Pete Tar]

Odds against something happening being infinitesimal have no bearing on it actually happening.
A 'rational' mind that decides against something based on that is not being rational. It's employing 'common sense' which is different and can be wrong.

 

[dunbar]

Which is the precise reason I invoked Sherlock Holmes and his famous maxim. Sherlock is a deductions man who relies heavily on the old empirics. Purely rational explanations do not trump empirical facts and the NIST hypothesis began with a faulty rationalization and ended when it failed to account for and overcome indisputable physical realities.

 

[Tony Szamboti]

Maybe you could explain that a bit more in a new thread. Sounds like a pretty damning allegation if true.

There was no fire on the 10th floor of WTC 7, so there is a problem eliminating the lateral support of column 79 from the girders under the 11th floor. Column 79 could provably go without lateral support from five contiguous floors and not buckle.

The lateral support at each story also only needs to be about 0.6% of the load on the column. So if column 79 supported an area of 2,000 sq. feet at 87.5 psf for 47 stories it would have a total load of somewhere in the neighborhood of 8 million lbs. at the first floor. At the 11th floor that would be about 6.5 million lbs. The lateral support in this area would need to be about 39,000 in each direction. The five inch thick slab does that easily.

The fires were on floors 7 to 9 and 11 to 13. This only allows for breaking the girder connections at three contiguous floors at a time and the slabs would have to come down also.

Of course, in the report it is simply stated that the girder under the 13th floor pushed column 79 to the east enough to break the welds to the column of the two foot long knife connection brackets on the girder from the west under floor 11 which were 26 feet below. This is a bare assertion, with no evidence or calculations to support it given. My calculations say otherwise.

For the above reasons, buckling of column 79 is extremely unlikely if not impossible also.

 

[Jazzy]

My calculations say otherwise.

Then you had better show them.

 

[Tony Szamboti]

Then you had better show them.

When NIST shows theirs l will show mine.

 

[Jazzy]

When NIST shows theirs l will show mine.

I'm always in training to be a patient person. Some day…

 

[gerrycan]

The thread started out with a rather vaguely defined claims that there were "critical" errors. So I'm try to be precise about if they are actually critical. So the question is if NIST were to admit that the walk-off was impossible, does that mean the entire report is invalidated.

Yes.

 

[MikeC]

Doesn't seem to be anything more than a bunch of 9/11 "truthers" getting together to pat themselves on the back and confirm to themselves that they are correct.

The method for reaching this consensus was a survey of people who were already known to support various conspiracy theories:

Ranking Methodology
The members of the Panel were asked to rate the validity of the points as follows:
1. strongly agree
2. agree
3. agree, but with (stated) reservations
4. disagree
5. strongly disagree
6. uncertain
If points were rated 4 (disagree) or 5 (strongly disagree), they were either dropped or modified until rankings of 1 (strongly agree) or 2 (agree) were reached by at least 85% of respondents.
If points were rated 3 (agree with reservations) or 6 (uncertain), they were, whenever possible, modified as suggested.
If Panelists were unavailable to vote or refrained from voting through insufficient knowledge, the percentages were calculated on the number who did vote.

which then becomes:

By integrating 3-4 rounds of anonymous feedback from 20 experts, this scientific process has yielded an unprecedented degree of credibility for specific points of evidence opposing the official account of the events of September 11, 2001.

This is not a "scientific process", and there is nothing on their site that shows that any peer review has taken place, other than their statements that it has done so.

 

[Syrez]

Doesn't seem to be anything more than a bunch of 9/11 "truthers" getting together to pat themselves on the back and confirm to themselves that they are correct.

You sir, are a web forum contributor, and this is fine, no doubt, however the link that was immediately deleted was published by the Assistant Secretary to the Treasury of the United States of America, under the Ronald Reagan administration. He disagrees with your web forum opinion. In the piece he published was this:

However, a recent FOIA request has produced WTC 7 architectural drawings showing that the NIST simulations omitted basic structural supports that would have made this girder failure impossible.

This pertains to Gerrycan's thesis. It was deleted as off-topic. This is what this thread is about. I offered it in good faith to those who may have been interested.

 

[WeedWhacker]

however the link that was immediately deleted was published by the Assistant Secretary to the Treasury of the United States of America, under the Ronald Reagan administration.

I'm curious.....you posted a comment that was published by the Ronald Reagan administration, and this somehow was applicable to the events of 11 September, 2001 HOW??

(Just for the record....Pres. Ronald Reagan's administration ended in 1988...or, if pedantic, January 1989).

 

[Syrez]

Yes, I'll leave you to think about that as what I wrote was quite clear, sir. I have given the former Assistant Secretary to the Treasury of the United States a link to this thread. Should he be interested in responding to the above comment:

Doesn't seem to be anything more than a bunch of 9/11 "truthers" getting together to pat themselves on the back and confirm to themselves that they are correct.

Or to any other points raised here, as well as the fact the link to his website posting was immediately deleted as "off-topic" (when it seemed very relevant to me) then he can of course do so.

 

[Svartbjørn]

Yes, I'll leave you to think about that as what I wrote was quite clear, sir. I have given the former Assistant Secretary to the Treasury of the United States a link to this thread. Should he be interested in responding to the above comment:


Or to any other points raised here, as well as the fact the link to his website posting was immediately deleted as "off-topic" (when it seemed very relevant to me) then he can of course do so.

Awesome! Maybe he can help me wrap my head around Reaganomics while he's at it.

 

[MikeC]

Yes, I'll leave you to think about that as what I wrote was quite clear, sir. I have given the former Assistant Secretary to the Treasury of the United States a link to this thread. Should he be interested in responding to the above comment:


Or to any other points raised here, as well as the fact the link to his website posting was immediately deleted as "off-topic" (when it seemed very relevant to me) then he can of course do so.

That wasn't what I was commenting on - I was commenting on the "consensus", and is obvious shortcomings.

Why the FORMER secretary of the TREASURY of an administration that was out of office for over 12 years should be considered an authority on building construction and failure escapes me - perhaps you could explain that further?

 

[Jazzy]

Yes.

This answer - "yes" - is wrong, in that the appropriate report never claimed "the walk-off happened" as THE primary initiator in the first place. It did not claim that that single event was crucial, but that it was just the more likely of many possible near-simultaneous events that occurred immediately prior to collapse.

This thread has been an exercise in semantics, and calculated rudeness, and more.

We knew before it began why and how materials expanded when heated.

We have learned from it since that some "contributors" could refuse to join in debate consistently for days, weeks, and months - before they inevitably ended up in the cooler.

Edit: We have also failed to learn anything at all about DYNAMICS, when it must be apparent to all that a static analysis is never going to explain a dynamical process, which is precisely what a COLLAPSE is. Or in simple terms, a building still holding its loading may fail when then being made to vibrate.

Syrez, take note.