What's the best popular account of the WTC collapses?

Jeffrey Orling

Senior Member
Isn't this forum about how to explain things to (i.e., debunk) conspiracy theorists? Telling someone who is genuinely curious/puzzled about how the buildings could completely destroy themselves that "no one cares" isn't very effective. Besides, engineers do care about progressive collapse and do see WTC as a prime example. For example, as I mentioned above, Uwe Starossek.

The NIST report may have completely satisfied you. But it obviously didn't close the question for everyone; and research, like I say, continues to this day. There's a government report on the 2008 financial crisis too; but that doesn't mean people aren't still writing books about it.
Kevin Beachy describes simply the two parts of the collapse.... Upper part "loses integrity/support" and falls the intact floor slab below which can't support these loads. This begins the rapid floor slab collapse one after the other.. Columns did not collapse with floors... but as a consequence of their losing the lateral bracing required for them to stand. Columns needed floors for strength and stability... floors needed columns to hold them "up". Floors went first columns had to follow.
 

Jeffrey Orling

Senior Member
I'm not sure about this, but it does raise an interesting question that, again, a good book would answer. How many consecutive floors could have been removed between floors 70 and 90 before the whole building would come down in any case (without fire or other structural damage) for lack of lateral support on the core? According to NIST's calculation, each floor could carry the weight of about 11 floors. So suppose floors 71-80 were detached, lowered gently, and stacked on the 70th floor. Would the lack of lateral support on the core now cause it to fail? What is the maximum amount floors that could be detached in this way without initiating a global collapse?

Looking into all of this teaches people like me (who don't have the benefit of an engineering degree) many interesting things about structures. Like the way lateral support effectively shortens a column for the purpose of calculating buckling load. And the important difference between dynamic and static loads. Like I say, the WTC collapses would provide plenty of material for a masterclass in engineering. It's surprising that no one has made use of it yet. Even a good 45 minute presentation might inoculate quite a few people against conspiracy theories (without, like I say, even mentioning them). An ounce of education is worth a pound of debunking?
Kind of silly navel gazing. Look up the work of Euler on slender columns. Essentially bracing makes a column's unsupported length shorter and stronger than if it did not have bracing. It would also matter where in the height the 20 floor slabs were removed. But if it leads to Euler buckling... the building will collapse.
 

Oystein

Senior Member
The idea of writing a popular structural engineering book focused on the reality of the WTC towers is intriguing.

It would have a scope different from the NIST reports and almost all scholarly works.
It would have a target audience different from the NIST reports and almost all scholarly works.

So any reference to the NIST reports and scholarly works doesn't address the concept.

Now obviously, such a book has not been written, or else someone here would have heard of it, if not read it.

Which opens the questions:
WHY has it not been written yet?
WHO should be writing it, or would be capable of writing it?
Is there a MARKET for it?

Secondarily, we could speculate whether such a book, if it existed, might pull some CT-leaning people out of the rabbit hole, or prevent others from slipping down it.

In this day and age, I believe a book would not be the medium that would satisfy those "debunking" objectives: CTers are mostly informed by (moving) images. Some sort of presentation, with animations as well as filmed real-world experiments, well-narrated, with links to original sources (including NIST and scholarly works), ways to navigate the presentation (skip aspects you don't care for or that you already understand; skip back to repeat; branch out to specific issues on the side...

I suspect the market for this would be tiny, and wouldn't pay an attractive sum of money relative to the work to put in. The 9/11 Truth Movement is tiny, at least that part of it actually interested in the physics of buildings and fires.
 

Landru

Moderator
Staff member
It failed? What sort of nonsense is that statement.... what is "it"? what as its failure?
NIST provides a reason
https://www.nist.gov/topics/disaster-failure-studies/faqs-nist-wtc-towers-investigation
Watch the politeness.
 

Jeffrey Orling

Senior Member
NIST provides a reason
https://www.nist.gov/topics/disaster-failure-studies/faqs-nist-wtc-towers-investigation
Watch the politeness.
OK.... that quote in my opinion is hardly a good description of what likely happened though it does contain elements which did happen.

Sagging trusses pulling in some areas of the perimeter (if they did enough to buckle the columns would hardly produce the chain reaction we witnessed.

Understanding is informed by accurate observations and technical understanding.

the planes did damage multiple columns and sections of floor slabs. This damage itself did not cause additional "collapse". Fires were started and raged.

The question to ask and try to answer... is what was the structural impact of the fires?

The initial movement was NOT collapsing floor slab (material) It was in both towers to downward motion (and tilting in 2wtc) of the "upper blocks"... the mass of building above the plane strike zone.

What would cause these massive blocks to move downward (and tilt)?

The answer is they lost the axial support that held them up. So some of that support was the columns that were severed by the plane impact. But we know that loss of THOSE columns left enough axial support for the upper blocks to "stay put".

What might have happened to the axial support (columns)?

The could have grown weaker... presumably from heat. Where was the heat concentrated? How would this lead to weakening of enough columns such that the remaining ones could not hold up the upper blocks? Was the burning fuel enough and the main flammable substance? If floors sagged from weakening do they and their connections have the "strength" robustness to buckle the columns?

What NIST failed to study from what I can tell... is what would have happened inside the core where the bracing was being heated from fires below? Would those beams sag? Would the expand? If they are restrained... what gives? The answer to this is that although ALL the core columns in the static building WERE restrained in n-s and e-w axes.... not all the core columns survived the plane strike. VOILA.... this loss of some core columns allows, facilitated... pick your verb... the expanding braces in the core to push against columns which were no longer restrained. So what would happen? A now unrestrained column was subject to increasing lateral forces from the heat expanded bracing, The core was warping... I suspect some columns were literally pushed off the column below they rested on and were "loosely" spliced to. No lateral forces were expected for the connections which were 4' or 9' from the bracing elevation.

How much would the end to end joint have to displace for all hell to break loose? If you look at the cross sectional area of those columns... a displacement of as little as perhaps 1" would destroy the bearing area... and the column would experience web and flange crippling. These are meant to be axially aligned to "perform". Was there evidence of web and flange crippling/buckling? I think so... look at some of the pics of the steel debris of the columns of the plane strike zone. What else could cause this? Sagging floor trusses? I have a bridge for sale.

So what happened in the core? In 1 wtc... the north side central areas lost columns and the fire raged in the core (like the fuel had momentum right?) The fires/heat in the core caused the column end connections "adjacent" in plan to the plane destroyed one to be pushed into the space of where the plane had destroyed the columns. So effectively OVER time the column "damage" 1wtc radiated to from the damaged area to the south, SE and SW.... working its way to the center of the core.

When the damage extended into the center of the core.... it was being structurally "hollowed out". But the core perimeter was more or less OK and supporting the floors. In 1wtc when the central columns of the core "failed"... axially to support the columns above...the columns above do what things without support do... they drop. The center of the core "dropped" and they pulled apart the central portion of the hat truss. It HAD been supported on all the core perimeter columns and the 2 central rows in each axis. The hat truss could do what it was designed to do at that point... support the 360 ton concentrated load in the center of the building. But as the hat truss failed it redirected all sorts of forces laterally and multiple core columns displaced from the one below they were bearing on. The antenna collapsed into the tower... the upper block core collapsed pulling with it the floors it supported. The facade lost bracing of the floors... was subject to asymmetrical lateral forces and it DISPLACED enough to drop down. That's what we saw. Floor truss had nothing to do with the top block's collapse. But they were puny and did an unstoppable avalanche to the street level.

2wtc was similar but it lost core support not in the center but in the SE corner... which grew nw until the entire top block was "cantilevered" from the NW core columns... which could hold it up and the "cantilever" failed, the block tipped SE and fell. Floor trusses played no role in this.

This is the "summary version" of what caused the two towers to collapse.

edit.... I am adding a graphic
 

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Landru

Moderator
Staff member
OK.... that quote in my opinion is hardly a good description of what likely happened though it does contain elements which did happen.

Sagging trusses pulling in some areas of the perimeter (if they did enough to buckle the columns would hardly produce the chain reaction we witnessed.

Understanding is informed by accurate observations and technical understanding.

the planes did damage multiple columns and sections of floor slabs. This damage itself did not cause additional "collapse". Fires were started and raged.

The question to ask and try to answer... is what was the structural impact of the fires?

The initial movement was NOT collapsing floor slab (material) It was in both towers to downward motion (and tilting in 2wtc) of the "upper blocks"... the mass of building above the plane strike zone.

What would cause these massive blocks to move downward (and tilt)?

The answer is they lost the axial support that held them up. So some of that support was the columns that were severed by the plane impact. But we know that loss of THOSE columns left enough axial support for the upper blocks to "stay put".

What might have happened to the axial support (columns)?

The could have grown weaker... presumably from heat. Where was the heat concentrated? How would this lead to weakening of enough columns such that the remaining ones could not hold up the upper blocks? Was the burning fuel enough and the main flammable substance? If floors sagged from weakening do they and their connections have the "strength" robustness to buckle the columns?

What NIST failed to study from what I can tell... is what would have happened inside the core where the bracing was being heated from fires below? Would those beams sag? Would the expand? If they are restrained... what gives? The answer to this is that although ALL the core columns in the static building WERE restrained in n-s and e-w axes.... not all the core columns survived the plane strike. VOILA.... this loss of some core columns allows, facilitated... pick your verb... the expanding braces in the core to push against columns which were no longer restrained. So what would happen? A now unrestrained column was subject to increasing lateral forces from the heat expanded bracing, The core was warping... I suspect some columns were literally pushed off the column below they rested on and were "loosely" spliced to. No lateral forces were expected for the connections which were 4' or 9' from the bracing elevation.

How much would the end to end joint have to displace for all hell to break loose? If you look at the cross sectional area of those columns... a displacement of as little as perhaps 1" would destroy the bearing area... and the column would experience web and flange crippling. These are meant to be axially aligned to "perform". Was there evidence of web and flange crippling/buckling? I think so... look at some of the pics of the steel debris of the columns of the plane strike zone. What else could cause this? Sagging floor trusses? I have a bridge for sale.

So what happened in the core? In 1 wtc... the north side central areas lost columns and the fire raged in the core (like the fuel had momentum right?) The fires/heat in the core caused the column end connections "adjacent" in plan to the plane destroyed one to be pushed into the space of where the plane had destroyed the columns. So effectively OVER time the column "damage" 1wtc radiated to from the damaged area to the south, SE and SW.... working its way to the center of the core.

When the damage extended into the center of the core.... it was being structurally "hollowed out". But the core perimeter was more or less OK and supporting the floors. In 1wtc when the central columns of the core "failed"... axially to support the columns above...the columns above do what things without support do... they drop. The center of the core "dropped" and they pulled apart the central portion of the hat truss. It HAD been supported on all the core perimeter columns and the 2 central rows in each axis. The hat truss could do what it was designed to do at that point... support the 360 ton concentrated load in the center of the building. But as the hat truss failed it redirected all sorts of forces laterally and multiple core columns displaced from the one below they were bearing on. The antenna collapsed into the tower... the upper block core collapsed pulling with it the floors it supported. The facade lost bracing of the floors... was subject to asymmetrical lateral forces and it DISPLACED enough to drop down. That's what we saw. Floor truss had nothing to do with the top block's collapse. But they were puny and did an unstoppable avalanche to the street level.

2wtc was similar but it lost core support not in the center but in the SE corner... which grew nw until the entire top block was "cantilevered" from the NW core columns... which could hold it up and the "cantilever" failed, the block tipped SE and fell. Floor trusses played no role in this.

This is the "summary version" of what caused the two towers to collapse.
This is not a thread arguing about the WTC collapses but a thread about the the best possible account. Please don't get sidetracked.
 

Jeffrey Orling

Senior Member
I am not interested in writing a book... nor do I have the technical background to write one on a forensic structural collapse. As an architect I wanted to understand how these buildings collapsed. I saw some popular accounts and then the NIST material came out. I was using web sites to learn and form my thinking on the subject. I satisfied my own curiosity, came to my own conclusions/understanding and occasionally share my ideas online with others if they are interested. Some are. Some aren't.
 

Thomas B

Member
The idea of writing a popular structural engineering book focused on the reality of the WTC towers is intriguing.

[...]

WHY has it not been written yet?
WHO should be writing it, or would be capable of writing it?
Is there a MARKET for it?

I suspect the market for this would be tiny...
I'm no longer sure that my contribution is welcome, but since the conversation seems to be continuing, I want to at least acknowledge Oystein's remarks.

It might be useful to compare my imaginary book with with Levy and Salvadori's Why Buildings Fall Down, which was published by the very reputable W.W. Norton in 1992, and presumably sold pretty well. It was reissued in 2002, updated with, among things, a short section on the WTC disaster, where they say, "Other failure scenarios will undoubtably be proposed and debated as investigations into the catastrophe take place over many years. Yet we believe that the basic outline of the failure is clear" (p. 267). It's the sequel to that book, one that follows up on those investigations and debates, that I'm thinking of. Although I'm imagining a book devoted entirely to the WTC, not on building collapses generally, it's hard to imagine that the market for books on collapsing buildings got smaller after 9/11.

Why Buildings Fall Down also tells us WHO might write the book I'm thinking of: an engineer (or two) who have branched out into popular genres. I think a good science journalist could also pull it off, but would have to work closely with an engineer.

The WHY question is puzzling. I'm not persuaded by those of you who say that, after the NIST report, no further writing on the subject is really necessary. When Jeffrey tells me I should just go "look up Euler", he's sort of making my point; it's to avoid having to go through a lengthy process of independent study (and "silly navel gazing") that I'd like a popular book on the subject. Similarly, to answer my questions, Deirdre has suggested I should use Google, or go through the threads here, or even take a structural engineering course! My point is that, since the answer to my questions are known to science, it would be great to have them presented in way that laypeople can access easily and confidently, as in the case of everything from microbes to black holes.

I think that if a good book, written with the same authority as Levy and Salvadori's, had come out in the years immediately after the NIST report, and the mechanism of total progressive collapse had been patiently explained to the public, the conspiracy theories would have had a much harder time taking hold. After all, the most reasonable adherents to 9/11 conspiracy theories are often the ones that begin with the WTC collapses (rather than, say, stray passports or pet goats). The collapses really are hard to understand. The absence of engineers stepping up, not to spar with conspiracy theorists, but simply to explain the science, leaves an uneasy feeling that the collapses are not as well-understood as we'd like to think. CTs can exploit that uneasiness.
 
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deirdre

Senior Member.
My point is that, since the answer to my questions are known to science, it would be great to have them presented in way that laypeople can access easily and confidently, as in the case of everything from microbes to black holes.
suggestion: ? read some Erik Larson. the author, not the 9/11 conspiracy guy. He wrote Lusitania and Devil in the White City. and other books whose topics you might enjoy.
He tends to write two stories at once, which makes reading more pleasant as it breaks up the 'boring' hardcore stuff a bit. He of course wouldnt get into listing all the various theories (but he might mention some) like you seem to want, but if he can come up with a 2nd complimentary story, i think him writing about how the building was built interspersed with how it came down would draw a large audience. Probably not enough info to please a 9/11 denialist... but if you read some of his books you would be a better judge as you would know what you are looking for.
One book (forget which) was about marconi and wireless communication that seemed educational to me anyway as a laymen.


One problem with thinking a "why the buildings fell down" book from a purely engineering point of view might successful as you hope, is that the whole push is from Architects and Engineers from 9/11 Truth, and people think their authority proves controlled demolition. I think suspicious people would still have a hard time deciding which engineers to believe.
But it would probably help a few people on the fence. Couldnt hurt to write such a book if someone was so inclined.
 

Thomas B

Member
.. read some Erik Larson ...

One problem with thinking a "why the buildings fell down" book from a purely engineering point of view might successful as you hope, is that the whole push is from Architects and Engineers from 9/11 Truth, and people think their authority proves controlled demolition. I think suspicious people would still have a hard time deciding which engineers to believe.
Yes, people like Erik Larson could write this sort of book (although maybe in 50 or 100 years). I haven't read him, but he has a great reputation, and there are many writers like him who, for the sorts of reasons we've been talking about, have decided to stay away from this topic. That's too bad.

As for Architects and Engineers, I think it's worth pointing out that they were founded in 2007, two years after the NIST report. In a sense, the lack of detailed popular science writing on the topic left the field open to alternative explanations. A book now might be too little too late -- that's a good point.
 

Jeffrey Orling

Senior Member
I would "nominate" John McPhee to write such a book.... if it is to be written. He is one on favorite and most readable non fiction writers. Here are his books:

https://www.thriftbooks.com/a/john-...MIzIulsY_h6gIVmZOzCh1s6AwYEAAYAyAAEgJaNvD_BwE

He does write about "science" topics making them accessible to laypersons"

John Angus McPhee (born March 8, 1931) is an American writer, widely considered one of the pioneers of creative nonfiction. He is a four-time finalist for the Pulitzer Prize in the category General Nonfiction, and he won that award on the fourth occasion in 1999 for Annals of the Former World[1] (a collection of five books, including two of his previous Pulitzer finalists). In 2008, he received the George Polk Career Award for his "indelible mark on American journalism during his nearly half-century career".[2]

Since 1974, McPhee has been the Ferris Professor of Journalism at Princeton University.[3]"

++++

Of course a hurdle to do this is what WERE the CAUSES and MECHANISMS in play. As I wrote I believe NIST did not get this correct despite getting some of correct.... So their account for me is NOT authoritative.

I suppose the author might present a few of the various ideas out there... mostly on the www... some more formal and rigorous and others informal such as the explanation I presented which I call "sink hole- top drop" for the twin towers.

7wtc, likewise, has no definitive explanation, in my opinion. There is the most well known... the so called official NIST's column 79 explanation.... Transfer Truss Failure was never taken seriously although the building's engineer Cantor implied the transfers were what did the tower in. The propagation seems it must have involved the transfer trusses regardless of whether they were the location of the "initial failure(s)" as opposed to column 79.

The debate/discussion on the www has lost all its steam perhaps because the take away is that in 7wtc the tower survived long enough to be completely evacuated... so it was deemed a successful design.

The twin's design failures focused on egress path design failure... and that resulted in more robust egress stair enclosures and other fire safety features.

It is telling (to me) that the "design innovations" of the twin towers have not been adapted into the main stream tall building design. hmmmmm
 

benthamitemetric

Senior Member
...

7wtc, likewise, has no definitive explanation, in my opinion. There is the most well known... the so called official NIST's column 79 explanation.... Transfer Truss Failure was never taken seriously although the building's engineer Cantor implied the transfers were what did the tower in. The propagation seems it must have involved the transfer trusses regardless of whether they were the location of the "initial failure(s)" as opposed to column 79.
....
There is no evidence that the role of transfer trusses was "never taken seriously". In fact, it is very clear that NIST specifically analyzed the transfer truss system and its possible role in the collapse. We've been over this before. And before. And before.
 

Thomas B

Member
Of course a hurdle to do this is what WERE the CAUSES and MECHANISMS in play. As I wrote I believe NIST did not get this correct despite getting some of correct.... So their account for me is NOT authoritative.

I suppose the author might present a few of the various ideas out there... mostly on the www... some more formal and rigorous and others informal such as the explanation I presented which I call "sink hole- top drop" for the twin towers.

7wtc, likewise, has no definitive explanation, in my opinion.
Maybe I've been naive to assume that we'd all agree that the collapse mechanisms are "known to science". If the science of the collapses is to be popularized it must obviously exist as science first. So maybe we need start with a different question: Besides the NIST reports, what are the three best (most detailed) statements (in the technical literature) of how the towers collapsed (plus another three for WTC7)? Who are the leading experts (who wrote those papers)? After all, it's their accounts that would need to be popularized, and any disagreement between them would be part of the "narrative non-fiction" account we've been imagining.

In so far as the claim that "the collapses have been explained by science" is part of the debunking of conspiracy theories, I think the debunker should know these sources and their status in the engineering disciplines.
 

benthamitemetric

Senior Member
And briefly.... what does NIST write about the role of the transfers? Which ones?
I addressed that directly in the links (which go to three separate other places on the metabunk forums where that exact issue has been, and could continue to be, discussed). I don't see a reason to have a fourth discussion on the point in this thread. Not only would it be redundant, but it would further the transformation of this thread into an open discussion of all 9-11 issues (which transformation I think has arguably already begun). And that transformation wouldn't really helpful to the OP or anyone else.
 

deirdre

Senior Member.
In so far as the claim that "the collapses have been explained by science" is part of the debunking of conspiracy theories, I think the debunker should know these sources and their status in the engineering disciplines
You dont seem very familiar with Metabunk. or it's content.

Metabunk examines individual specific claims of evidence, (from denialists AND from NIST etc) so debunkers dont have to just dismiss whole conspiracy theories by "the collapses have been explained by so and so". Those would just be 'appeals to authority'.

None of which has anything to do with your book idea. Laymen people on the fence might believe your book, although i think there are plenty of non-technical articles and documentaries already for them. but hard core people who want to believe the government blew up the buildings (mostly because they watch Youtube videos) would still need MB type analyses of individual, very specific claims.

which brings us back to 'who exactly would be the target audience'. Engineering students can read NIST, Bazant and the insurance report guys (forget their names) for themselves. They wouldnt need a book.
 

Jeffrey Orling

Senior Member
Maybe I've been naive to assume that we'd all agree that the collapse mechanisms are "known to science". If the science of the collapses is to be popularized it must obviously exist as science first. So maybe we need start with a different question: Besides the NIST reports, what are the three best (most detailed) statements (in the technical literature) of how the towers collapsed (plus another three for WTC7)? Who are the leading experts (who wrote those papers)? After all, it's their accounts that would need to be popularized, and any disagreement between them would be part of the "narrative non-fiction" account we've been imagining.

In so far as the claim that "the collapses have been explained by science" is part of the debunking of conspiracy theories, I think the debunker should know these sources and their status in the engineering disciplines.
Clearly there was one ONE thing... like a bomb which explodes to destroy something. Even a CD is complex... explosive damage and often push columns out of alignment... or they made damage the load path so much that it buckles and without support... what it was holding collapses because of gravity. Structures "resist" gravity. Compromised ones can do it at or or very well.

But there are many axial load paths in a high rise... so loss of one means what IT supported will fall. But to get the entire building to fall there has to be a load redistribution from the area without support to the areas which have "intact" support. If the loads can be re distributed such that the columns which acquire new loads... the building can remain standing. But the re distributed loads could and often do overwhelm the columns which they find their way to. The that column fails and there could another redistribution. If there is local failure without re-distribution... the building remains standing with a "column bay" missing. Column bays CAN isolate failures.

The WTC towers did not have column bays outside the core. They were long span column free outside the core. The perimeter columns of the core and the columns of the exterior support the weight of the floors and contents outside the core. Open column free floor plans would tend to NOT arrest local failure/collapses. WTC... guilty.

The cores usually don't have much floor in them.. They are elevator, stair shafts, and mechanical shafts. Cores are robustly braced... and aside from the perimeter columns the load is mostly the core steel itself.

The 3 towers at the WTC had the open office floors collapse BEFORE the core. The cores of the twins came down because the floor collapses destroyed the core lateral bracing. Without bracing the cores cannot stand.

WTC7 was for sure and unusual column design... because they column on the office tower could not go directly to the foundations... the sub station was in the way. So the columns were supported on "beams" and the beams on two columns. Those "beams" were massive 3 story trusses in some cases. Some were 9' high steel girders cantilevers. Much of the perimeter moment frame columns were supported on a 3 story belt truss at floors 5-7.

Essentially the "design strategy" was to put the "eggs" (column loads) in a few very strong "baskets" (huge columns and massive trusses)

All of this is "known" engineering. It's like a row of standing dominoes... knock the first and all will come down.... even if each successive one is a larger domino then the previous one. Falling adds the energy to knock a slghtly bigger domino over.

WTC collapses were run away chain reaction of structural failures.

What were the first dominos? That is one question. And what was the sequence. Clearly there was not a unique sequence of failures... but many.

Engineering explains why a core without bracing collapses.

How does the bracing fail? Most likely collapsed from being overloaded from falling floor debris and massive equipment.

I suppose one could work backwards from the end... the last things to fail to the beginning... the first things to fail. But there may be more than one cause for a failure.

This is why the MOVEMENT of parts of the building is a HUGE tell. They tell us what is failing / where it's failing and suggests what caused it to fail.

Accurate observation and the technical knowledge to understand what you observe is the KEY TO UNDERSTANDING.
 

Jeffrey Orling

Senior Member
I addressed that directly in the links (which go to three separate other places on the metabunk forums where that exact issue has been, and could continue to be, discussed). I don't see a reason to have a fourth discussion on the point in this thread. Not only would it be redundant, but it would further the transformation of this thread into an open discussion of all 9-11 issues (which transformation I think has arguably already begun). And that transformation wouldn't really helpful to the OP or anyone else.
Well yes and no. In order to write a summary... the key point must be established. I don't think they have been. For example I don't think sagging floor trusses have been established as the cause of the antenna collapse... the core collapse... or even the peeling of the facade.

I don't recall how NIST explains the collapse of the region around column 79 led to a global collapse or even the loss of support of the entire moment frame.
 

Thomas B

Member
You dont seem very familiar with Metabunk. or it's content.
I am indeed new here. And I did actually withdraw from this conversation for the reasons you stated (which were also communicated to me privately). But then the conversation just continued anyway, with people who've been here for a while, dealing with exactly the subjects that I was trying to raise. I understand that you don't find it interesting, but I don't see what harm I'm doing or what rules I'm breaking.

For example, this thread seems relevant to some of the goals of Metabunk:
  • To develop and promote efficient methods of finding, exposing, and preventing bunk
  • To create re-usable debunkings (antibunk)
  • To help people escape the rabbit hole, either directly, or by giving tools to their friends
Also, it seems to fall squarely under the "meta exemption". It's an attempt to understand "why people believe, why they are resistant to debunking, why bunk spreads, how best to address it."
 

Jeffrey Orling

Senior Member
You dont seem very familiar with Metabunk. or it's content.

Metabunk examines individual specific claims of evidence, (from denialists AND from NIST etc) so debunkers dont have to just dismiss whole conspiracy theories by "the collapses have been explained by so and so". Those would just be 'appeals to authority'.

None of which has anything to do with your book idea. Laymen people on the fence might believe your book, although i think there are plenty of non-technical articles and documentaries already for them. but hard core people who want to believe the government blew up the buildings (mostly because they watch Youtube videos) would still need MB type analyses of individual, very specific claims.

which brings us back to 'who exactly would be the target audience'. Engineering students can read NIST, Bazant and the insurance report guys (forget their names) for themselves. They wouldnt need a book.
Hypotheses are not scientific claims, but rely on science and engineering. Evidence usually can support the hypothesis. So there was a hypothesis that the shuttle exploded because an o ring failed. It was based on science. There is no physical evidence of a failed o ring... only temperature data a launch. It was a good hypothesis and likely it true. A better one has not been advanced.

In the case of the wtc collapses... the hypotheses are... in my opinion... not sufficiently supported by "evidence"... especially when there was an opportunity to examine all the debris. The accepted explanations appear to me to be poorly supported hypotheses. For me the jury is still out. No one seems concerned though.
 

Jeffrey Orling

Senior Member
Maybe I've been naive to assume that we'd all agree that the collapse mechanisms are "known to science". If the science of the collapses is to be popularized it must obviously exist as science first. So maybe we need start with a different question: Besides the NIST reports, what are the three best (most detailed) statements (in the technical literature) of how the towers collapsed (plus another three for WTC7)? Who are the leading experts (who wrote those papers)? After all, it's their accounts that would need to be popularized, and any disagreement between them would be part of the "narrative non-fiction" account we've been imagining.

In so far as the claim that "the collapses have been explained by science" is part of the debunking of conspiracy theories, I think the debunker should know these sources and their status in the engineering disciplines.
Well Professor Bezant wrote factual engineering papers which has nothing to do with why the towers collapsed!
 

Thomas B

Member
The accepted explanations appear to me to be poorly supported hypotheses. For me the jury is still out. No one seems concerned though.
I'm not sure this is true, but I understand why some people might get that impression. In a strange way, the lack of concern can itself become a source of concern for conspiracy-minded people. On the face of it, the idea that a whole building can collapse because a single column fails is "concerning". But professional engineers seem to accept it as a result of standard design principles. The conspiracy theorist now imagines that engineers know full well that skyscrapers aren't that fragile and that only a lot of explosives (on many columns) could do the trick. But they stay silent -- "unconcerned" -- out of concern for their careers. The only way to correct this impression is to lay out the case and the verdict in terms that make sense to the lay reader. Explaining why it is actually acceptable for buildings to collapse in this way under these circumstances.
 

Thomas B

Member
Well Professor Bezant wrote factual engineering papers which has nothing to do with why the towers collapsed!
Yes, like I say, those papers -- their status in the discipline -- need to be explained (away?). Interestingly, when Europhysics News published a rebuttal to the AE911T paper they published in 2016, Bazant was co-author. A good book on this would figure out what role that "simple analysis" plays and how it relates to the complexities of the actual collapses. What do engineers use Bazant's analysis for? (I think NIST mentions it in passing when they explain why they didn't analyze the progressive collapse. But I haven't been able to find it again for a while.)
 

Jeffrey Orling

Senior Member
I'm not sure this is true, but I understand why some people might get that impression. In a strange way, the lack of concern can itself become a source of concern for conspiracy-minded people. On the face of it, the idea that a whole building can collapse because a single column fails is "concerning". But professional engineers seem to accept it as a result of standard design principles. The conspiracy theorist now imagines that engineers know full well that skyscrapers aren't that fragile and that only a lot of explosives (on many columns) could do the trick. But they stay silent -- "unconcerned" -- out of concern for their careers. The only way to correct this impression is to lay out the case and the verdict in terms that make sense to the lay reader. Explaining why it is actually acceptable for buildings to collapse in this way under these circumstances.
I say "poorly supported" because there is both a dearth of real time data... and a rather incomplete inventory and study of debris. You recall how steel in the pile was quickly gathered and sold... I suspect some imported clues left on those ships.

I am not sure how many engineers accept that a single column failure could lead to the collapse of an entire building.
 

Thomas B

Member
All of this is "known" engineering. It's like a row of standing dominoes... knock the first and all will come down.... even if each successive one is a larger domino then the previous one. Falling adds the energy to knock a slghtly bigger domino over.
I'm uncomfortable with this image. A stack row of dominoes feels too much like a house of cards. One would think engineers deliberately design buildings to be more robust than that.

I like to think of a skyscraper as "a machine for holding things (like floors) up". Under the right (i.e., terribly wrong) circumstances the same structures become machines for letting things fall (in particular ways). Their de-struction is "mechanical" in that things happen in a sequence. Since the structures are wholly known to science (before collapse) it is possible to describe a ca. 15-second process that destroyed them.

I agree with Jeffrey that such collapse models can only be hypothesized and tested against quite superficial evidence (videos) today. But from the point of view of debunking the claim that the collapses were "physically impossible" (without demolition) only one or two plausible sequences (after initiation) need to be described. To date, this has only been done in a hand-waving way, with what looks to a layperson like a back-of-the-envelope calculation (e.g., as quoted by Keith). What is needed is something more like James Cameron's second-by-second sinking of the Titanic.
 

deirdre

Senior Member.
I am indeed new here. And I did actually withdraw from this conversation for the reasons you stated (which were also communicated to me privately). But then the conversation just continued anyway, with people who've been here for a while, dealing with exactly the subjects that I was trying to raise. I understand that you don't find it interesting, but I don't see what harm I'm doing or what rules I'm breaking.

For example, this thread seems relevant to some of the goals of Metabunk:
  • To develop and promote efficient methods of finding, exposing, and preventing bunk
  • To create re-usable debunkings (antibunk)
  • To help people escape the rabbit hole, either directly, or by giving tools to their friends
Also, it seems to fall squarely under the "meta exemption". It's an attempt to understand "why people believe, why they are resistant to debunking, why bunk spreads, how best to address it."
I was mostly talking about you not knowing already who the 3 main engineering papers are.

and how you seem to be defining debunkers. I know that is how 'debunkers' on Youtube and Facebook are, but i'm pointing out that your audience here isn't the same as Youtube or Facebook. I also dont want outside readers, reading this thread, to think Metabunk is like Youtube or Facebook.

I used to be a moderator here. Your implications in some of your wording will obviously cause members to post a bit off topic as they will want to respond (just like i wanted to respond to what i perceived you were implying), but that happens often with new members. This thread can be moved to Open Discussion if it becomes (i think it has ) a gish gallop.

I wasn't commenting on your thread following rules.
 

Thomas B

Member
I was mostly talking about you not knowing already who the 3 main engineering papers are.
I have offered some suggestions, actually. Until I talked to Mick, I thought Bazant was uncontroversially a key figure. I still think he must be somewhat important (for the reason I stated above). I've also mentioned Uwe Starossek as a possible expert (though it's a book). Both Bazant and Starossek take it for granted that the primary mechanism was the buckling of columns. I'm curious to know what papers the rest of you see as central -- i.e., where you are getting the floor-failure model from.
 

Jeffrey Orling

Senior Member
I say "poorly supported" because there is both a dearth of real time data... and a rather incomplete inventory and study of debris. You recall how steel in the pile was quickly gathered and sold... I suspect some imported clues left on those ships.

I am not sure how many engineers accept that a single column failure could lead to the collapse of an entire building.
I'm uncomfortable with this image. A stack row of dominoes feels too much like a house of cards. One would think engineers deliberately design buildings to be more robust than that.

I like to think of a skyscraper as "a machine for holding things (like floors) up". Under the right (i.e., terribly wrong) circumstances the same structures become machines for letting things fall (in particular ways). Their de-struction is "mechanical" in that things happen in a sequence. Since the structures are wholly known to science (before collapse) it is possible to describe a ca. 15-second process that destroyed them.
......
The domino is basically a metaphor... but it has a basis in mechanics/physics. Structures are much more robust than dominoes or jenga blocks... but when structural elements fail... loads HAVE to relocate.

Stand on two feet and each one is supporting half your weight. Lift up one foot and the other leg and foot have to support your entire body weight. What if you have a bad knee... say it can only support 80% of your body weight? OK if you have both feet on ground when you stand or walk.... but some walking requires ALL your body weight on one leg for even an instant... stair decent. Your knee might collapse walking down the stairs... but not standing with both feet on the ground.

Structures and connections within them are designed within a margin of safety... it's already inside the load tables. A 12WF45 can replaced by a 12WF40 in some situations.... but it has less factor of safety.

Developers are looking to save money. Materials/weight is a huge part of the cost and so making then lean and mean is what the engineer is asked to do... redundancy and safety factors are shaved/skimped on. Why would someone build a stronger building (more expensive) than they have to?

These buildings were not "fortresses" by any means. I would argue that the floors had a fair bit more flex than other buildings.

As was mentioned above... a typical WTC office floor was designed for something like 52#/SF super imposed live load (don't recall the actual number). But what I DO recall, the engineers requested a live load compliance reduction from the code dictated 100#/SF. They argued that 100#/SF was too high and they received the floor load reduction.

But whatever that # / SF was.... it was way lower than the weight of the floor above on it... and the furniture and people etc. Once the floors began to break apart and fall... there was not enough strength in the office floors to stop arrest the collapse there. Imagine placing an 8'x8'x8' cube of lead on one of the floors. It would crash right through and continue all the way to the ground.

No one expected sections of several floors to collapse... but when they did the floors below barely slowed them down. The collapse was something like 60mph. And because there were no bays.. the collapse migrated around the floor involving the entire doughnut foot print.
 

Jeffrey Orling

Senior Member
I was mostly talking about you not knowing already who the 3 main engineering papers are.

and how you seem to be defining debunkers. I know that is how 'debunkers' on Youtube and Facebook are, but i'm pointing out that your audience here isn't the same as Youtube or Facebook. I also dont want outside readers, reading this thread, to think Metabunk is like Youtube or Facebook.

I used to be a moderator here. Your implications in some of your wording will obviously cause members to post a bit off topic as they will want to respond (just like i wanted to respond to what i perceived you were implying), but that happens often with new members. This thread can be moved to Open Discussion if it becomes (i think it has ) a gish gallop.

I wasn't commenting on your thread following rules.
I think you should head over to the 911FreeForum and read up on why the towers collapsed and the are critiques of Bazant etc.

https://www.tapatalk.com/groups/the...o45oADC4SAaTXaZePi0ei2yNsrC0q77cDS4ge-2iiLt90
 

deirdre

Senior Member.
I think you should head over to the 911FreeForum and read up on why the towers collapsed and the are critiques of Bazant etc.

https://www.tapatalk.com/groups/the...o45oADC4SAaTXaZePi0ei2yNsrC0q77cDS4ge-2iiLt90
the topic is this book he wants written. And bazant is one of the big names he would want included in the book. i did remember something called ARUP.. is that bigger than Bazant? if so you can change my Bazant to ARUP.


He was saying he wants all the theories presented and outlined in the book.

@Thomas B the other name i couldnt remember is Weidlinger. (the silverstein insurance report).
 

benthamitemetric

Senior Member
Weidlinger, ARUP, LZA Technologies and Thornton-Tomasseti (all among the top engineering firms in the world) have each also done substantial independent modeling work concerning the twin towers' failures, as per this note from 2003. I recall seeing this note a few years back and discovering that there were expert reports related to these analyses submitted in federal court at some point during the many insurance litigations concerning the damage to the complex and its surrounds. As the twin tower collapse mechanics never much interested me given the air plane damage's contribution to the failure initiations and how simple energy equations can explain the rest, however, I didn't go any further in researching the subject. But an enterprising researcher could likely find a very detailed reports and exchanges concerning all facets of engineering considerations concerning the collapse of the twin towers if they searched the dockets of the major 9/11 insurance litigations via Pacer, as I previously did to pull the Aegis Insurance materials re WTC7.

I've beaten this horse often in the past, but maybe it's not quite dead yet so I'll note it again for the OP: conspiracy theorists often act like these buildings existed in a bubble and that they could be taken out by a conspiracy without tens of thousands of unrelated third parties being affected. Obviously, that's not the case. And, as a result of the widespread effects of the collapses, there were thousands of related litigations brought to federal court that pertained to as many serious claims re what actually happened on 9/11, many of which implicated hundreds of millions or even billions of dollars of claims. In the course of those litigations, many of the best lawyers in the world, with subpoena powers at their disposal, doubtlessly spent hundreds of thousands of hours, collectively, pouring over all of the evidence and arguments with the help of the best expert witnesses in the world. The idea that the occurrence of something like a controlled demolition, which would immediately change the course of billions of dollars of claims, somehow escaped their discovery is farcical.

Relating this back to the OP's post, I am sure that he could find everything he needed for his book and more in those dockets.
 
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Keith Beachy

Senior Member
... To date, this has only been done in a hand-waving way, with what looks to a layperson like a back-of-the-envelope calculation (e.g., as quoted by Keith). What is needed is something more like James Cameron's second-by-second sinking of the Titanic.
Hand Waving, as NIST engineers studied the connections of the floor to the shell and core - simple science results, and they come up with 29,000,000 pounds, floor fails. Science and engineering, not hand waving.

After initiation, more than 29,000,000 pounds of mass, or equal force come to play, the collapse can't stop based on the structure of the WTC towers studied in depth, not hand waving... Read NIST (lateral support was from the Shell. The WTC was built as a system, we can see it in photos as the shell core and floors were assembled floors at time, bottom up. The shell would have stopped a aircraft going 200 mph (there was a study, engineering study showing the speed they calculated).

As for the energy involved, energy released stored as E=mgh, not hand waving, basic physics.

The collapse progression is the easiest to understand, and can be seen on video.

If you want a CGI presentation of the collapse progression, it can be done, but it may not be engineering. Engineering modes often have no visual presentation. A simple model of the time to collapse is based on momentum... it has no visual, but comes up with time similar to the collapse time.

Like a wing on the 777, things break when overloaded... Source: https://www.youtube.com/watch?v=Ai2HmvAXcU0


Sad to say, no matter how simple and layperson like an explanation is, there will always be conspiracy theories
 

Thomas B

Member
Hand Waving, as NIST engineers studied the connections of the floor to the shell and core - simple science results, and they come up with 29,000,000 pounds, floor fails. Science and engineering, not hand waving.

[...]

As for the energy involved, energy released stored as E=mgh, not hand waving, basic physics.
But this is exactly what I mean by "hand waving" and "back of the envelope". The alternative is to carefully describe the changing states of the upper block and the lower section, along with the mechanism that connects them. Diagrams could be drawn up that begin with structures at the stages where we can compare them with video, but continue to the bottom, even when the dust clouds obscure the view.

I appreciate that you don't think it's necessary. But what you're saying is that you don't need anything more than (what I'm calling) "hand waving".
 

Thomas B

Member
The idea that the occurrence of something like a controlled demolition, which would immediately change the course of billions of dollars of claims, somehow escaped their discovery is farcical.
I'm largely in agreement with this statement. It's a good reason not to believe in demolition. But not believing in demolition is not the same thing as understanding what actually happened. I think that understanding should emerge from the engineering literature, not the legal proceedings.

To be clear, I think much of the power of conspiracy theories comes from the unnecessarily long time people spend in the state of "wanting to believe" but simply not understanding the progressive collapse explanation. They would be helped greatly by the book I'm proposing.
 

Thomas B

Member
The domino is basically a metaphor... but it has a basis in mechanics/physics. Structures are much more robust than dominoes or jenga blocks... but when structural elements fail... loads HAVE to relocate.

Stand on two feet and each one is supporting half your weight. Lift up one foot and the other leg and foot have to support your entire body weight. What if you have a bad knee... say it can only support 80% of your body weight? OK if you have both feet on ground when you stand or walk.... but some walking requires ALL your body weight on one leg for even an instant... stair decent. Your knee might collapse walking down the stairs... but not standing with both feet on the ground.

Structures and connections within them are designed within a margin of safety... it's already inside the load tables. A 12WF45 can replaced by a 12WF40 in some situations.... but it has less factor of safety.

Developers are looking to save money. Materials/weight is a huge part of the cost and so making then lean and mean is what the engineer is asked to do... redundancy and safety factors are shaved/skimped on. Why would someone build a stronger building (more expensive) than they have to?

These buildings were not "fortresses" by any means. I would argue that the floors had a fair bit more flex than other buildings.

As was mentioned above... a typical WTC office floor was designed for something like 52#/SF super imposed live load (don't recall the actual number). But what I DO recall, the engineers requested a live load compliance reduction from the code dictated 100#/SF. They argued that 100#/SF was too high and they received the floor load reduction.

But whatever that # / SF was.... it was way lower than the weight of the floor above on it... and the furniture and people etc. Once the floors began to break apart and fall... there was not enough strength in the office floors to stop arrest the collapse there. Imagine placing an 8'x8'x8' cube of lead on one of the floors. It would crash right through and continue all the way to the ground.

No one expected sections of several floors to collapse... but when they did the floors below barely slowed them down. The collapse was something like 60mph. And because there were no bays.. the collapse migrated around the floor involving the entire doughnut foot print.
I'm sorry if I missed it, but who would you say is the most authoritative proponent of your view of the collapses? What's the best presentation of it in writing? You present it here as the result of your own research, but what I'm suggesting is that this shouldn't be necessary any longer. It's been almost 20 years.
 

Jeffrey Orling

Senior Member
I'm sorry if I missed it, but who would you say is the most authoritative proponent of your view of the collapses? What's the best presentation of it in writing? You present it here as the result of your own research, but what I'm suggesting is that this shouldn't be necessary any longer. It's been almost 20 years.
The problem with the twin is what was the sequence / cause which caused the static building to "move downward"... collapse. The collapse mechanism is pretty well described as "ROOSD" - runaway open office space destruction. This is a term I believe Tom (http://www.sharpprintinginc.com/911/) originated over at the 911 Free Forum. There were many "contributors" to the "details" including Ozeco, OneWhiteEye, femr2 (https://femr2.ucoz.com/) and others.
The 9-11-01 History Archive published by Tom (though now old) has IMO the best resources for all things technical about the WTC including links and references and critiques of all the major work on the topic including discussion of the sociological and psychological factors in play.

Rather than ask members here their opinions... go to Tom's site... virtually everything is there. Tom's work was not embraced by all because he did not subscribe to the NIST accounts as authoritative.

The site is rich for reading, learning and understanding the events (collapse of the buildings) and investigations after the fact. There are days and days of materials to read.
 

benthamitemetric

Senior Member
I'm largely in agreement with this statement. It's a good reason not to believe in demolition. But not believing in demolition is not the same thing as understanding what actually happened. I think that understanding should emerge from the engineering literature, not the legal proceedings.

To be clear, I think much of the power of conspiracy theories comes from the unnecessarily long time people spend in the state of "wanting to believe" but simply not understanding the progressive collapse explanation. They would be helped greatly by the book I'm proposing.
You misunderstand the significance of the legal cases. In the course of the litigations at issue, many engineers, doubtlessly chosen from the best and brightest in the world as the note I shared indicates and as was the case with the Aegis experts, were tasked with creating complex engineering reports, which were then submitted the courts as evidence, subject to very strict rules. As with the Aegis reports re WTC7, those reports pertaining to the twin towers likely rival the NIST report in terms of scope and sophistication of analysis. And, because the engineers writing them were engaged in the adversarial process of the litigations, for each report, there will likely be a response from an equally qualified engineer or group of engineers. There is thus going to be a very robust engineering discussion in the court records. I suspect that there is no where in the world where you will find a similarly exhaustive discussion of these specific engineering topics, actually.
 
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