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A quick questio nabout the collapse

IIRC, sagging floor trusses that supported the massive acre sized concrete floor slabs are thought to be responsible for initiating the collapse. There are several collapse pictures and at least one video (Why The Towers Fell, PBS) that clearly show the core elements were the last to fall.

I know of no building code regarding core construction, sorry. Perhaps one of the architects can answer your question. However your friend should be able to cite which law he's referring to if he's that familiar with it.
 
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Rika said:
I was talking with a friend about 9/11 conspracies. and he said there was a law that mandated reinforcement of a certain kind of the core columns in WTC.

He also said that NIST hadn't addressed this (!). Is there such a law, or..?
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If he knows the law exists, he should be able to tell you where to find it. He learned about this somewhere, right? Ask him to track it down for you.


Maybe he'll figure out that he just accepted some nutbag's bald assertion without question.
 
Rika said:
I was talking with a friend about 9/11 conspracies. and he said there was a law that mandated reinforcement of a certain kind of the core columns in WTC.

He also said that NIST hadn't addressed this (!). Is there such a law, or..?
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There's probably one by now, as a result of the WTC collapses. But truthers aren't all that good on causality.

Dave
 
Rika said:
I was talking with a friend about 9/11 conspracies. and he said there was a law that mandated reinforcement of a certain kind of the core columns in WTC.
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Might be talking about fireproofing and we know that the WTC towers were sub-standard.

In Report From Ground Zero (pgs 310-311), FDNY structures expert Vincent Dunn describes how the WTC towers had effectively no fireproofing when compared to the older steel buildings, built to standards that required 2 inches of brick and masonry on all structural steel. Dunn also says that the WTC towers were unique in the minimal fireproofing.

Source: http://snurl.com/j54ud [Page 310, Report From Ground Zero]

Who is Vincent Dunn?
http://unjobs.org/authors/vincent-dunn
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While I don't know the specifics of the deviations, the fact that the World Trade Center had design elements that required exemptions from NYC code is documented. A quick Google search digs up a couple of mentions (first link, second; the second link is to a .pdf file), although they don't go into any real detail. But again, my point is that this issue is hardly a secret; in fact, it's one of the things that Dr. Astaneh-Asl has chosen to shine a light on.

This might be what your friend is referring to, but if it is, keep in mind that the deviations from standards was in fact approved by the relevant authority in the New York City government. Experts appear to now believe that such exemptions were a mistake, but nowadays they have the benefit of hindsight to inform such a conclusion. Back then, I can't see the deviations as being unreasonable, not with the level of knowledge they had at the time.
 
I'm happy to comment on the technical aspects of this if you can provide more detail.
 
If can, obtain Feb or March 2009 copy of FireHouse (cant remember correct issue)

Has article by Vincent Dunn - goes into detail about previous to WTC fireground
commanders didn't worry about global building collapse of High rise building. Dunn
points out this now a concern. Details how fire and damage to building quickly caused
a global collapse of entire structures

Will check my firehouse see if can get correct issuse
 
njslim said:
If can, obtain Feb or March 2009 copy of FireHouse (cant remember correct issue)

Has article by Vincent Dunn - goes into detail about previous to WTC fireground
commanders didn't worry about global building collapse of High rise building. Dunn
points out this now a concern. Details how fire and damage to building quickly caused
a global collapse of entire structures

Will check my firehouse see if can get correct issuse
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I believe that this is incorrect, but partially correct. We didn't worry much about structural collapse in a protected structure that we could fight the fire in. Protected meaning a steel framed building that had fire-resistant foam sprayed on the exposed steel. This foam provided 1-2 hours of protection. Usually a fire was extinguished well within that time frame. I know the LTs and Capt's always thought about it, but didn't worry too much about it, unless we were in the building for an extended period of time.
Heck, I was just a nozzleman, and I thought about it. ALOT. Even before 9/11. Even moreso after 9/11. I cannot tell you how it felt to go back into a burning building after 9/11, knowing it was a steel framed building. My rear was puckered so tight I don't think I took a crap for a week. And I am being COMPLETLY serious!!

So, in conclusion, I believe that he may be correct, but just a little misspoken. I could be wrong though, as I do not know the content of said article.
 
I have an email sent to him - may be a few days until he responds. I do know it wasn't fireproofing. When I attempted to explain to him (and my explanation despite having attempted to pay attention to arguments in this forum is simplistic/wrong) that it was a core failure after the perimeter and core columns buckled at the floor of impact causing the upper mass to crash down, he said that all core columns were reinforced by a NY Law. He wasn't able to cite which but said that the WTC towers were retrofit.
 
Rika said:
I have an email sent to him - may be a few days until he responds. I do know it wasn't fireproofing. When I attempted to explain to him (and my explanation despite having attempted to pay attention to arguments in this forum is simplistic/wrong) that it was a core failure after the perimeter and core columns buckled at the floor of impact causing the upper mass to crash down, he said that all core columns were reinforced by a NY Law. He wasn't able to cite which but said that the WTC towers were retrofit.
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His claim is laughable. To retrofit the core of a building would be an enormous task, second only to the actual construction of the building. There certainly would be record of such a project and would most likely have been discussed here.

I call BS.
 
There was no retrofitted core reinforcement.

There were a few, local retrofits done to individual floors to carry particular tenant loads, and there was retrofitting of the sprayed-on fireproofing on some floors carried out in the 1990's after inspections turned up deficiencies. That's all. Nothing whatsoever to do with the columns. See NCSTAR1-1 for specifics.
 
AJM8125 said:
His claim is laughable. To retrofit the core of a building would be an enormous task, second only to the actual construction of the building. There certainly would be record of such a project and would most likely have been discussed here.

I call BS.
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Now, now, there's always the Citicorp building - another project which those of us who studied building structures were taken through. Fascinating.
 
Architect said:
Now, now, there's always the Citicorp building - another project which those of us who studied building structures were taken through. Fascinating.
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Good point. I hadn't considered that. But what if the building collapsed before they completed the welding job? Their coverup would've been exposed very quickly, I'd think. People who knew would be forced to tell the truth or be caught lying when the bolts were discovered.

Truthers jump on this in 3... 2... 1...
 
ElMondoHummus said:
While I don't know the specifics of the deviations, the fact that the World Trade Center had design elements that required exemptions from NYC code is documented. A quick Google search digs up a couple of mentions (first link, second; the second link is to a .pdf file), although they don't go into any real detail. But again, my point is that this issue is hardly a secret; in fact, it's one of the things that Dr. Astaneh-Asl has chosen to shine a light on...
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It would be news to me if the towers did not meet or exceed existing NYC building codes. I've never seen such stated or implied in the NIST reports, or in any other authoritative report.
 
Gravy said:
It would be news to me if the towers did not meet or exceed existing NYC building codes. I've never seen such stated or implied in the NIST reports, or in any other authoritative report.
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Don't get me wrong, I wasn't trying to imply that any deviations led to substandard construction. They were, after all, approved by the relevant authorities. All I was getting at was that there were deviations from code; Astaneh-Asl and Dean Poeth both made mention of them at the links I provided earlier, and I'm aware of NCSTAR 1-1 and 1-1A making references to them (Chapter 7 in 1-1, Chapter 8 in 1-1A). At any rate, don't take any of what I wrote as an implication that the permitted differences meant that the towers didn't actually meet the spirit of the code. I'm unqualified to answer that (plus, I really should read those segments of NCSTAR 1-1 and 1-1A; I only know they exist, and I've only very superficially leafed through them. I've never actually sat down and tried to read through them for comprehension). They may have, they may not have, but that's for someone with more knowledge than me to speak on.

Now, from the 911-engineers.blogspot.com post, I think it's pretty clear that Astaneh-Asl believes the deviations were contributory to the collapse. So sure, I'd say that his opinion is that those deviations led to substandard construction. After all, he's pretty explicit in identifying the code exemptions in his condemnations. But as I said before, if he's even right in fingering the deviations as being contributory, he's talking with the clear benefit of hindsight. In my opinion, that can not and should not be taken as an implication of the people who approved the changes way back then. Astaneh-Asl may differ on that, but that's his argument to make.

So in the end, I would agree with you: I don't see the exemptions as meaning the end product didn't meet or exceed the end result the building code was implemented to achieve, only that the exemptions differed from then-standard design. Maybe Architect or Newton's Bit could speak in more detail on this.
 
This gets a little strange, actually. What would become PANYNJ was not (and is not) required to comply with local building codes because it was "an interstate compact created under a clause of the U.S. Constitution" (reference NCSTAR 1-1B, Chapter 2, intro para.) and therefore is an authority unto itself. However, the Port Authority decided to have the architects and engineers use the New York City Building Code as a basis of design, except where the code was ambiguous or where technology made it obsolete, in which case the basis of design would be "acceptable engineering practice". So any exemptions requested by the design team would be awarded by the Port Authority, not the New York City Department of Buildings (the normal reviewer of building plans).

Interesting and perhaps relevant is the fact that New York City revised its building code during the design of the World Trade Center towers, switching from the 1938 edition to a completely rewritten code in 1968. According to NIST (NCSTAR 1-1B, Section 3.1, para. 2) the 1968 edition allowed for performance-based design, as opposed to the strictly prescriptive and empirical methods allowed under the 1938 edition. Had the Port Authority (and therefore the design team) stuck with the prevision version as a basis of design, one wonders how different the towers would have been, and if the horrible events of September 11th would have played out differently.
 
There's a direct comparison of building codes in NCSTAR1-1B, conveniently provided for you in tabular form...

The one area where the WTC might not have passed muster was in the size and design of emergency stairwells, as discussed in Chapter 2 of NCSTAR1-1D. Some of these issues were addressed or in work after the 1993 bombing.

Dr. Astaneh-asl, however, is correct to point out that the testing of the floor truss construction was inadequate, and if it had been properly tested, it would not have met the Port Authority-specific building code, or the New York City codes from which it was derived. The engineers who signed off on the tests did not recognize -- indeed, had no way to know -- that the floor trusses did not scale down to the tests that were carried out. Had the Towers been of a more conventional design, it is possible that the Towers would have stood longer or not collapsed at all, but there are far too many variables to state this with any certainty.

Ultimately, virtually everyone below the points of impact was able to escape, so both the egress issue and any possible extension of time before collapse are academic.
 
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R.Mackey said:
Ultimately, virtually everyone below the points of impact were able to escape, so both the egress issue and any possible extension of time before collapse are academic.
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Didn't the experience of the 1993 bombing result in upgrades to the exit paths?
 
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