Debunking resource: Engineers Assess the Truth in AE911Truth (Scott & Hamburger, 2021)

[Oystein]

This White Paper seems to be making its rounds among serious structural engineers - a long-time contact of mine, himself a S.E., forwarded it to me. I have not found it via Google on a publicly accessible resource, but have reasons to assume this is meant for public consumption and spread, so I am posting it here.

The subject, "Engineers Assess the Truth in AE911Truth", refers specifically to the most recent incarnation of the 3-part webinar "9/11: An Architect's Guide" narrated by Richard Gage, formerly President and CEO of AE911Truth (more on that "former" thing below!) and various claims therein, which the authors, Ron Hamburger and David Scott, debunk.

The two authors have probably finer relevant credentials that AE911T's best 20 put together: Eminently qualified and experienced, national and international leaders in organizations of structural engineering and tall building design, and on-hands WTC-disaster experience as part of the SEAoNY (Scott) and FEMA (Hamburger) investigations of the collapses:

David M Scott Hon AIA, FIStructE, FREng, FRSE
Ron Hamburger, PE, SE, MIStuctE.
[...]

About the Authors

David Scott is past chair of the Council on Tall Buildings and Urban Habitat (2006-2009), and a structural engineer who led the design of many tall buildings. He was part of the Structural Engineers Association of New York (SEAoNY) team based at Ground Zero, after the attacks. He is a fellow of the Royal Academy of Engineering.

Ronald Hamburger is a past president of the National Council of Structural Engineering Associations and the Structural Engineers Association of California and of Northern California, and a past chair of the Structural Engineering Certification Board. Since 2011 he has chaired the ASCE 7 Committee on Minimum Design Loads and Associated Criteria for Buildings and Other Structures. He was a lead author for the PEER Tall Building Design Guidelines and served on the FEMA/ASCE Building Performance Assessment Team following the World Trade Center collapse.

As an aside, Ron Hamburger was interviewed by Spike Lee for Lee's recent 4-part documentary on HBO, specifically the 30-minute segment dealing with AE911T's claims of "explosive demolition", which Lee excised following a wave of criticism from previewers (more on that below):

Article:

Ronald Hamburger, who investigated the collapse of the towers for the Federal Emergency Management Agency and also appeared in the original cut of the episode, said in an interview on Thursday that Mr. Lee interviewed him for the series about two months ago. The interview, which Mr. Hamburger said lasted about 10 minutes, revolved around the conspiracy theories about controlled demolition.

Mr. Hamburger, who no longer appears in the episode, said he explained to Mr. Lee that based on his work at the site and hundreds of hours of analysis, he had concluded that the cause was not controlled demolition.

"I did get the understanding in my discussions with him that he wanted to give them credence," Mr. Hamburger said of the conspiracy theories.

Source: https://www.nytimes.com/2021/08/26/arts/television/spike-lee-911-edit.html

Here are the three parts of said webinar (page 17, "References"):

Ref 1 9/11: An Architect's Guide | Part 1: World Trade Center 7 (5/6/21 webinar - R Gage)

Source: https://www.youtube.com/watch?v=9qbi3fokG6U&t


Ref 2 9/11: An Architect's Guide - Part 2 - Twin Towers' Explosive Destruction (8-12-21) Webinar –
Gage)
Source: https://www.youtube.com/watch?v=Q_wqAPk7tOU&t=206s


Ref 3 9/11: An Architect's Guide - Part 3: The Twin Towers and Extreme Heat (3/18/21 Webinar –
R Gage)
Source: https://www.youtube.com/watch?v=FpXGMcohR8A

This section provides a table of content:

How to Read This Paper

The paper is organised around the most common claims and questions that conspiracy theorists use to promote the idea that the WTC buildings were destroyed through intentional controlled demolition. It is designed as a reference document so that each subject can be read separately. Each section addresses a specific conspiracy theory and the authors explain why most architects and engineers do not support the controlled demolition theories:

• Sagging Floor Trusses Can't Pull in Perimeter Columns
• Look at the Explosions
• What about the Massive Dust Cloud?
• A Small Section of Tower Cannot Crush a Larger Section
• Fires Have Never Destroyed a High-Rise Steel-Framed Building
• Towers Cannot Fail Straight Down
• Buildings Have Survived Much Longer in Fire
• What about the Eyewitness Accounts of Explosions?
• Normal Fires Can't Melt Steel
• NIST's Models Don't Look Anything Like the Collapse
• NIST Caught with Their Pants Down
• Thousands of Architects and Engineers Support Ae911truth
• What about the Experts that Support Ae911truth?
• A Question of Integrity
• Do You Support a New Congressional Enquiry?
• Conclusions
• References
Our comments are based on a critique of the three latest Ae911truth educational videos: the 2021 Architect's Guide series. These are essentially the same story that they have told for over a decade. A link to their videos is provided in the references below. We refer to those videos explicitly, e.g. "Ref 2-18:30" refers to Video 2, "An Architect's Guide - Part 2 - Twin Towers" at 18 minutes and 30 seconds.

I guess We can open separate threads for any specific debunk that spikes someone's interest - this thread for now is merely to present, and store as a linkable resource, the White Paper as a PDF.

------------

Now for something completely different - twice in the above, I said "more on this below": Richard Gage no longer being CEO/President of AE911Truth, and Lee excising the part on AE911Truth from his film. Both issues are linked.

AE911T had apparently worked with Lee for quite a while, to get their message across in a big mainstream documentary. This documentary first made headlines when HBO provided a preview to members of the press this August, and the NY Times subsequently interviewed Spike Lee about it. It was revealed then that AE911Truth would play center stage on a 30-minutes segment, and that Lee gave them credence. Immediately, several media blasted back and condemned Lee's gullibility - most important among those was, apparently, Jeremy Stahl's piece for Slate, August 24th (my text coloring):

Article:

Spike Lee Has Fallen Down the 9/11 Truther Rabbit Hole

BY JEREMY STAHL
AUG 24, 20214:48 PM
[...]
Lee devotes 30 minutes near the very end of his series to relitigating arguments that have been debunked a thousand times. Specifically, he presents about a dozen conspiracy theorists and members of Gage's group, including Gage himself, in a back-and-forth with three credible scientists who investigated the 9/11 attacks in a teach the controversy–style format that presents the truth behind 9/11 as an open debate between two equally valid sides. In terms of conveying facts, this is a bit like presenting COVID-19 vaccine skeptics in a debate alongside Anthony Fauci...
[...]
But Lee and HBO are offering Gage and his conspiracy theories the biggest and most mainstream platform they've ever had, pointing their viewers directly towards a bog of heinously dangerous ideas: Like other conspiracy theorists, Gage doesn't just stick to 9/11, and if Lee's viewers follow Gage down the rabbit hole, they likely won't, either.

Gage, for instance, considers himself an expert on the COVID-19 pandemic. In the past year, he has said on various podcasts that COVID-19 is a "deep state" "hoax" and "false flag event" that has been perpetrated by an "increasingly restrictive and tyrannical government that has locked us into our own homes, and kept us in isolation from each other with distance and masks, and poisoned us with vaccines that are going to kill us." Gage has also claimed that "Bill Gates is a eugenicist" attempting to "reduce the population" by doing "a good job with the vaccines" because "his father was the head of the whole legal deal for Planned Parenthood." Again, once people dip a toe into the fever swamp of conspiracy theories, they are often sucked all the way in—with all the attendant horrific consequences for society and public health.
[...]
When you listen closely to Gage and attend his events, other alleged criminals start to emerge. Chief among them: Jews. [...]

Source: https://slate.com/news-and-politics/2021/08/spike-lee-hbo-documentary-richard-gage.html

It appears that this article, particularly the bits I marked in dark red, cost AE911Truth their appearance in the limelight of a Lee-docu, and Gage his position and salary at AE, for Gage published this public letter on his new (?) website, richardgage911.org (bolding original, text coloring mine):

Article:

Why I am Going Independent…

Earlier this month AE911Truth issued a press release and e-mail to A&E Members that included this Statement:
"…Richard Gage, organization founder, will no longer serve as the organization's CEO."
As you can imagine, this has raised many questions, which I decided to wait until after the 20th Anniversary to address, in order not to distract from all of the important 9/11 Truth Movement events and activities. This Statement is on my own behalf and not on behalf of AE911Truth. It is my first post which I hope will answer a number of questions.

As you probably know by now we had been working with Spike Lee for months on what was one of the greatest opportunities the 9/11 Truth Movement had ever had to reach a wide mainstream audience, which would have been the final segment of his video documentary that was aired by HBO on Sept. 11th. That 30-minute segment, which included a dozen interviews with Family Members and technical experts, including myself, unfortunately was not broadcast. This action by Spike surely was at least in part due to enormous pressure from the Powers That Be, but my off-topic comments quoted in Slate Magazine's August 24th article, which they had to have made a major effort to find, was most likely a significant contributing factor.

Spike may well have been upset to see my comments quoted in the article, which was on his interview with the magazine, as the first two segments of his mini-series "Epicenter" focused on the devastation, particularly by Covid-19 in NYC, in which he makes clear that he agrees with the official narrative on that subject.

This was of course a great disappointment—for A&E, for all of us in the 9/11 Truth Movement and for me personally—to have worked so hard to reach that historic moment only for it not to happen. In those moments of speaking off-topic I failed to remember that I represent 3,500 architects and engineers who have signed our AE911Truth Petition which is only about the destruction of the Twin Towers and Building 7 on September 11th, 2001—and nothing else. Any opinions that I hold about Covid-19 issues or any other off-mission topic based on research that I do on my own time have absolutely no place in any interview I give on behalf of AE911Truth.
[...]
Our board met and deliberated for hours in what was a very difficult debate for us all. In the end the majority felt that the PR problem regarding my off-mission comments could continue to undermine future efforts to break into mainstream media and made the very tough decision to ask for my resignation as CEO. The resulting board resolution effectively removed me as CEO along with my employment with AE911Truth.

Source: https://richardgage911.org/why-im-going-independent/

So in summary, Gage cites the quotes found in the Slate article, that he made about his belief in Covid-19 CTs, as a main reason why Lee pulled the segment and the Board kicked him out.

-----

Cutting back to my original topic, the Scott+Hamburger White Paper: I have little doubt that Spike Lee has been a recipient of this White Paper after the interview he did with Hamburger (and probably other actual experts), and that the authors made sure to amass some of their heavy-weight structural engineering colleagues behind it. This, too, may have been a contributing factor to Lee's decision to excise the AE911T nonsense.

 

[Jeffrey Orling]

I read this paper and it was not impressive and used the old appeal to authority argument. Their authorities do seem to have credibility whereas truth movement's experts do not. The paper lacked details of technical explanations and they promote the idea that floor trusses led to column buckling of the facade.
The problem I have always had with this... whether they trusses push or pull... is that there would have to be almost all the trusses involved on all 4 sides of the core as well as in the 4 corners... and more or less doing "whatever" in the same time frame. While the flames were extensive, I do not see evidence to support that trusses all around the core were failing in the same time frame... leading to facade column buckling.
And then there's the fact the the antenna descends before the upper block moved down. And there is no mention or accounting of the fact that the upper block appears to have translated... moved laterally mis aligning the perimeter columns.
Frankly I found the discussions on 911FF about the collapse of all three towers more robust and compelling.
While these engineers have impressive resumes the paper is little more than an appeal to authority.... not a convincing set of technical arguments.
++++
Of course Spike Lee was in way over his head and had to trust/rely on experts he felt he could trust. He was apparently hoodwinked by Gage and understandable so (kinda). I hate quoting Regan but Spike Lee failed to... trust but VERIFY. And since he was not competent to verify... he was easily led astray.

Again I am struck by the fact that curious persons don't find sites like JREF, 911FF, Metabunk... but find all the crazy conspiracy YTs of David Chandler, Dylan Avery and Richard Gage et al.

 

[Oystein]

...The paper lacked details of technical explanations....

I find that to be rather a strength than a weakness of this White Paper. It doesn't get lost on the 7th leave on the 3rd branch of the 48th tree of the forest - it understands the forest.

 

[porkpie]

While these engineers have impressive resumes the paper is little more than an appeal to authority....

Am I misunderstanding what an appeal to authority is? At no stage do I remember the authors backing up their assertions with their credentials.

not a convincing set of technical arguments.

That doesn't appear to be their aim. I would suggest that technical arguments about this or that tiny aspect of the collapses are unnecessary if the main points can be explained in simple language.

 

[Mick West]

Richard Gage no longer being CEO/President of AE911Truth

That's a pretty seismic shift in the whole 911 Truth movement. I wasn't anticipating that at all. Possibly a fatal blow to AE911. I also doubt that Gage is going to do very well on his own. Without the "3000 architects and engineers" behind him, he's going to slide quickly towards the more extreme end of the conspiracy spectrum.

 

[Jeffrey Orling]

I suppose engineers can do approach the AE911T materials in one of two ways... One is to demonstrate that all Gage's technical points are false... and the other is to present the technical explanations to explain the 3 collapses. NIST of course presented the sagging floor truss theory for the twins, and the girder and beam drop from column 79 in 7wtc. These explanations are technically correct and logically consistent. However, I would assert that there are other explanations which would produce the collapses and the same visuals and evidence. This is because these were complex structures and it's are to "pin down" the sequence of the runway structural failures. Hulsey asserts without proof that fire cannot destroy a steel frame high rise. As far as I can tell all engineers accept the same cause... heat from unfought fires.
So... what made columns fail to support their design loads? NIST tells us trusses pushed or pulled the perimeter columns and caused them to buckle. Other theories posit that the heat caused the beam braces inside the core to cause the core columns to misalign and buckle, the hat truss and upper floors collapsed and that mass "avalanched" the floors from top to bottom... all the columns below the plane strikes failed when they lost bracing as the floors collapsed down.
NIST sort of "punts' and calls the post imitation... a global collapse. Granted it was chaotic and complex... and not possible to precisely detail the sequence.... but the mechanisms are all understood by the engineering community.

So with no attempt to provide more details... I find the explanations unsatisfying.

++++

I will say this.... the CD concept is something that the average person can understand... bombs destroy. That makes CD and easy sell for Gage
Progressive runaway structural and systems failure too esoteric for the public and so we saw a complex process distilled to falling pancakes... The heat driven explanations are a hard sell.

 

[NoParty]

...I hate quoting Regan but Spike Lee failed to... trust but VERIFY....

No worries...you're quoting an old Russian proverb.
(Reagan was famously taught it by Suzanne Massie in the '80s)
https://en.wikipedia.org/wiki/Trust,_but_verify

 

[Bruce Lansberg]

And then there's the fact the the antenna descends before the upper block moved down.

I'm not sure about that. In the video below the initiating part of the collapse of the north tower was filmed from the Hudson. We are given a nice view on the west facade of the tower. We can see the top fall to the right, so southward. I believe most video's were taken from the north. The antenna thus is falling away from us from that point of view, where the north roofline stays in place for a short moment.


Source: https://youtu.be/3HbD_Q6kmh8?t=101

 

[Jeffrey Orling]

I'm not sure about that. In the video below the initiating part of the collapse of the north tower was filmed from the Hudson. We are given a nice view on the west facade of the tower. We can see the top fall to the right, so southward. I believe most video's were taken from the north. The antenna thus is falling away from us from that point of view, where the north roofline stays in place for a short moment.


Source: https://youtu.be/3HbD_Q6kmh8?t=101

My hunch is that the hat truss lost axial support in the core... antenna collapsed and all the floor loads were then moved to the perimeter which translated and buckled at the level of the plane impact where significant parts of the core was destroyed.
I find the floor trusses pulling or pushing at the perimeter all around the perimeter including the corner quadrants makes less sense. (NIST)

 

[Bruce Lansberg]

My hunch is that the hat truss lost axial support in the core.

But why? The video linked above suggest no such thing. Roof and antenna remain relative positions.

I find the floor trusses pulling or pushing at the perimeter all around the perimeter including the corner quadrants makes less sense.

From the executive summary, page xxxviii, in the NCSTAR 1 report:

In WTC 1 , the fires weakened the core columns and caused the floors on the south side of the building to sag. The floors pulled the heated south perimeter columns inward...

https://nvlpubs.nist.gov/nistpubs/Legacy/NCSTAR/ncstar1.pdf

I don't see how NIST claims "trusses pulling or pushing at the perimeter all around the perimeter". The video confirms NIST's claim.

 

[Jeffrey Orling]

But why? The video linked above suggest no such thing. Roof and antenna remain relative positions.



From the executive summary, page xxxviii, in the NCSTAR 1 report:


https://nvlpubs.nist.gov/nistpubs/Legacy/NCSTAR/ncstar1.pdf

I don't see how NIST claims "trusses pulling or pushing at the perimeter all around the perimeter". The video confirms NIST's claim.

Could you explain how weakened core columns would cause the floors on the South side to "sag".

 

[Bruce Lansberg]

Could you explain how weakened core columns would cause the floors on the South side to "sag".

Pretty sure we shouldn't have this discussion in this thread, Therefor I'll be as brief as possible. NIST doesn't say anything about the core columns in the earlier quote but that they weakened because of the fires. They say the fires caused the floors on the south side of the building to sag.

"The fires" is the grammatical subject of the sentence. Since I'm not a native English speaker, I might be wrong (but I'm not).

 

[Jeffrey Orling]

Pretty sure we shouldn't have this discussion in this thread, Therefor I'll be as brief as possible. NIST doesn't say anything about the core columns in the aerlier quote but that they weakened because of the fires. They say the fires caused the floors on the south side of the building to sag.

"The fires" is the grammatical subject of the sentence. Since I'm not a native English speaker, I might be wrong (but I'm not).

Bruce... discussing this sort of thing is not on topic.... so a separate thread would be required.
My point... and Econ makes a similar one... is that being an expert... like NIST does not mean you are correct. In fact work I have read about the WTC in online forums by highly educated analytical people makes sense and might be a better/more accurate description of the WTC collapses. NIST's may claim for the twin towers was that sagging trussed led to the top blocks collapsing down. Maybe and maybe not. I assert that there are other valid "scenarios" which could produce the visuals seen in the public record.

There's not much interest in this anymore because... I think... everyone except the "truthers" accepts that fire was the cause of the undoing. It was not the plane impacts alone... it was not CD...

So what will be gained by having several plausible explanations?

 

[Bruce Lansberg]

I read this paper and it was not impressive and used the old appeal to authority argument.

In fact work I have read about the WTC in online forums by highly educated analytical people makes sense

?

So what will be gained by having several plausible explanations?

It all starts with observation Jeffrey. You still have a hunch the axial support was lost and as a result, the antenna dropped first. Even after I posted the video that was shot from the west in which we can observe such a thing did not occur. I don't believe there is any sense in finding a plausible explanation for an event that never happened.

 

[Jeffrey Orling]

?


It all starts with observation Jeffrey. You still have a hunch the axial support was lost and as a result, the antenna dropped first. Even after I posted the video that was shot from the west in which we can observe such a thing did not occur. I don't believe there is any sense in finding a plausible explanation for an event that never happened.

Are you saying the antenna did not tilt and drop INTO the roof of 1WTC?

 

[Oystein]

Are you saying the antenna did not tilt and drop INTO the roof of 1WTC?

Yes, I think that's what he is saying. That the impression that the antenna drops before the roofline does is an artifact of most cameras being somewhere to the North, while the top tilts towards South, such that the North roofline drops less than the center of the roof / antenna (which in turn would drop less than than the South roofline).

 

[Bruce Lansberg]

Are you saying the antenna did not tilt and drop INTO the roof of 1WTC?

Most definitely I'm saying that (again ). Well, it did tilt, together with the full roof.

We are given a nice view on the west facade of the tower. We can see the top fall to the right, so southward. I believe most video's were taken from the north. The antenna thus is falling away from us from that point of view, where the north roofline stays in place for a short moment.

Please watch the video in post #8 again.

 

[Jeffrey Orling]

I watched it. Hard to determine what is happening.
I had thought that the top of 1WTC did not tip much. I would have to look at other vids. But the angle of the antenna is pretty far off vertical.... as it falls and / or drops. For the top not to tip as much the antenna would have had to break fee of the roof... move independently... And I suppose that is possible, I simple can't draw that conclusion for the video in Post #8.
I am pretty sure that the antenna structure was integrated into the hat truss... not simply planted on top of the roof. If true there's a good chance it dropped and tilted. And it if dropped perhaps it lost axial support below it from failed core columns.

 

[Bruce Lansberg]

Just found a thread specificaly about the claim the antenna is dropping first. Joe Hill has taken the effort to compare 4 stills from the video above and compare them using guiding lines.

https://www.metabunk.org/threads/false-narrative-north-tower-antenna-dropped-before-roof-line.10819/

The antenna didn't drop, contrary to what Gage was trying to tell us.

 

[Jeffrey Orling]

Just found a thread specificaly about the claim the antenna is dropping first. Joe Hill has taken the effort to compare 4 stills from the video above and compare them using guiding lines.

https://www.metabunk.org/threads/false-narrative-north-tower-antenna-dropped-before-roof-line.10819/

The antenna didn't drop, contrary to what Gage was trying to tell us.

Again this is veering off topic.
So if the top block came down at first pretty much intact to do so...
the core columns would have to "fail"
or
the entire top would have to move laterally
or
enough of the core columns would have to have failed leaving too few with inadequate capacity to keep it up. If it tips south intuition tells me that the north side was stronger. Hence NIST makes the claim that the floor trusses on the south side caused the south perimeter columns to buckle.

Do "they" tell use what floor's columns buckled? The columns were staggered and 3 stories tall.

This is confusing.

Experts speak up!

 

[econ41]

This is confusing.

Not really. Just arrange the known facts in correct sequence and don't be distracted by side trails.

So if the top block came down at first pretty much intact to do so..

There is no "if" about it. When the "Top Block" started to move bodily downwards the levels above the impact and fire failure zone were still structurally intact. Note that step in the sequence..

the core columns would have to "fail"

Self evident by definition. The "Top Block" is moving downwards THEREFORE all columns have failed to support vertical loads.

or
the entire top would have to move laterally

It is "AND" not "OR". Plus it is a necessary fact of reasoned logic that each column that failed due to buckling would AT LEAST move horizontally to the extent needed for the top half of column to bypass the bottom. Add a couple of extra steps of logic to prove that any columns which were failed by clear cutting (i.e. those cut by aircraft impact (and any cut by CD if anyone ever proves that detail)) will also end up top part missing bottom part THEREFORE some horizontal movement. AND there was gross horizontal movement - extent depending on exactly what time in the collapse you identify. Here is the most extreme example of the four views.

The other three had less horizontal movement but still enough to prove top section of column ends were missing their bottom sections.

or
enough of the core columns would have to have failed leaving too few with inadequate capacity to keep it up. If it tips south intuition tells me that the north side was stronger. Hence NIST makes the claim that the floor trusses on the south side caused the south perimeter columns to buckle.

It is NOT "OR". And you have regressed to an earlier stage. Remember your comments STARTED with Top Block moving downwards. All three of your sub-comments revert to that earlier stage. You started by accepting "Top Block moving down". If you want to go back to explain that do so. Otherwise you are denying your own premise.

Do "they" tell use what floor's columns buckled? The columns were staggered and 3 stories tall.

Both comments irrelevant to the discussion

This is confusing.

Experts speak up!

Shouldn't be AND I have. Whether I'm "expert" or not.

 

[Jeffrey Orling]

views.
View attachment 47050

You diagram is concept.... but there was no clean break at one level as you depict. It was a sawtooth

Did we see this:

My quickie sawtooth is not precise... but the point is made... the "break" would be two saw tooth edges of the "chex" column/panels.. corner conditions not even shown in this sketch

Note your depiction... shows clean break at a single floor. Does that make sense? Why this confuses me...
The trusses were of two lengths X and +/- 2x
Expansion for the same heat exposure would be different X and +/- 2x
The corners quadrants ...NOT opposite the core were "less restrained" than the trusses which were restrained by the stiff belt girder around the core. (not shown)
++++
So for even a saw tooth fracture... the failure would have to be over 3 story heights and almost uniform around the perimeter.
BUT perhaps there IS a core column failure "sequence" which would preserve most of the structural integrity of the top block so some how it failed at the weakest points at the perimeter panel connection to panel and produced a saw tooth form of break???

We can't see the break line... but we can "assume" that it wasn't a straight on at one floor level.

 

[Mendel]

Note your depiction... shows clean break at a single floor. Does that make sense?

yes, but that's not relevant to his point regarding lateral movement.

 

[Jeffrey Orling]

yes, but that's not relevant to his point regarding lateral movement.

Perhaps... My understanding of the NIST experts was that there was pull in on one floor level leading to bucking on the south side... and how does that become the entire block translating and breaking at one floor level?

 

[Jeffrey Orling]

Really what I am trying to get at.... is that when we try to depict the collapse graphically with "cartoons" we run the risk of so much over simplification that the diagram becomes too far detached from what really happen. It looks good, makes sense but is too far off.

Again... NIST showed a single area on the SE facade of inward bowing of the facade.

Take a huge leap to get to Econ's clean separated blocks with the top one tilted 10-20 degrees with clean breaks dropping and "missing" the columns below,

In 2WTC the tilt was more intuitive because it seems related to the plane damage of the SE.
Yes the damage in 1WTC on the north becomes discounted and we need to consider some
south side" heating mechanism.

Sure it could be different collection of mechanism in each tower. But no experts seem to be making that claim.

 

[Jeffrey Orling]

Finally... we did see some crazy bent core columns. I presume they were from 2 WTC's core where it was able to stay "connected" one side and loose so much support that it bent the core columns trying to support the entire upper mass. Still it's hard to imagine how that exactly that happened.. and to how many columns??? But that sort of tilting would mean lots of column end connections were broken to allow separation and lateral and vertical movement. I can't begin to imagine how the axial forces were being moved laterally. I am sure they were... but it is not intuitive.
++++
And note:
All core column tops were at the same level. Only 1/3 of the perimeter panel tops were at that level.. because the perimeter panels "chex" were staggered. Floor attachments at the perimeter were at the spandrels. So there was not a uniform height for the floor attachments to the columns. All this suggests to me that a "clean break" was not likely.
It did not matter.

 

[econ41]

yes, but that's not relevant to his point regarding lateral movement.

Horses, proximity to water, motivation to imbibe.....

Some times I'm astonished by my patience.

 

[Jeffrey Orling]

Horses, proximity to water, motivation to imbibe.....

Some times I'm astonished by my patience.

Sure... we all agree heat did it.... but that doesn't tell us much...

 

[econ41]

Perhaps... My understanding of the NIST experts was that there was pull in on one floor level leading to bucking on the south side... and how does that become the entire block translating and breaking at one floor level?

Why not read and comprehend what I have said several dozen times.

The "initiation stage" for both "Twin Towers" collapses resulted because all columns failed to carry vertical downwards loads. The mechnaism of failure was a sequenced cascading failure. Similar to toppling dominoes in that the first coluimn to fail led to load transferring to other columns. So the second failed then the third then the fourth. Grasp the CONCEPT. Don't look for detailed nit picks. Once you "get" the concept I will tell you the reasons it isn't as simple as toppling dominoes BUT the priciples are valid.

If you seriously need to consider the physics look at a very simplified model as per this diagram.

... ask "if columns "A" and "B" weaken because they get too hot what happens to the weight they were carrying as load? Can you see that extra load will go onto column "C"? << That much should be easy. Can you see that the extra load going onto "C" will be MORE than what was previously carried by "A" plus "B"? And that is a lot harder. So if you cannot "see" it - ask and I wlll [try to] explain... And it is a true principle totally unrelated to the reasons perimeter columns of WTC1 & 2 could fail with serrated ends because of the way the columns were pre-fabricated....

 

[Jeffrey Orling]

Why not read and comprehend what I have said several dozen times.

The "initiation stage" for both "Twin Towers" collapses resulted because all columns failed to carry vertical downwards loads. The mechnaism of failure was a sequenced cascading failure. Similar to toppling dominoes in that the first coluimn to fail led to load transferring to other columns. So the second failed then the third then the fourth. Grasp the CONCEPT. Don't look for detailed nit picks. Once you "get" the concept I will tell you the reasons it isn't as simple as toppling dominoes BUT the priciples are valid.

If you seriously need to consider the physics look at a very simplified model as per this diagram.

View attachment 47058... ask "if columns "A" and "B" weaken because they get too hot what happens to the weight they were carrying as load? Can you see that extra load will go onto column "C"? << That much should be easy. Can you see that the extra load going onto "C" will be MORE than what was previously carried by "A" plus "B"? And that is a lot harder. So if you cannot "see" it - ask and I wlll [try to] explain... And it is a true principle totally unrelated to the reasons perimeter columns of WTC1 & 2 could fail with serrated ends because of the way the columns were pre-fabricated....

Econ... I understand perfectly that a failed column's loads go one of two ways.... vertically down... and laterally to near columns.
BUT was failure mode do you suggest?
Lost capacity from heat?
Lost capacity when the column ends mis aligned.... lateral translation?
Partial or total loss of capacity?

I am sorry that you think my trying to "grasp" column failure is a nit pick.

++++

Just a guess.... I think loss of capacity from heating would be gradual and not the mechanism. I don't think enough area, or heat was present. Just a hunch.
Heat rises and fires generally are over a "large" area... we're not talking the heat localized like a welding torch. So..... in my tiny mind.... heat MOSTLY acted on slabs, and the beams which supported the slabs. THAT WAS THE MECHANISM WHICH NIST TOLD US LED TO COL 79 FAILURE IN 7WTC. Col 79 was not a core column and it was not a part of the moment frame. It caused a "local floor collapse" and that somehow involved adjacent columns ... pulled them???? and this rapidly repeated and spread throughout the floor plan... the entire inside collapsed which left the moment frame unsupported laterally and axially. THAT sequence is not that hard to follow and doesn't need details... no column C D E and so on.

BUT the column failure is simply not well articulated... by you or anyone that I can tell...other than some sort side buckling of perimeter columns at a single floor on the south facade's east side.

 

[Jeffrey Orling]

You pivot/fulcrum is not accurate either.
What is more accurate would be that C location would be where the parts to above A and B... left side would break off. But I don't understand the force vectors... so I say.... I am confused.
C looks like a crush location not a fulcrum

 

[Oystein]

All you guys have completely forgotten what thread you are in, and you just go on and on and on and on and on and on with a private conversation that you had having circling round and round in many places elsewhere. I reported an early post, way up-thread, earlier today.

However, here is one argument against some versions of "CD" claims that the Scott/Hamburger white paper also makes. First, Jeffrey's version:

You diagram is concept.... but there was no clean break at one level as you depict. It was a sawtooth

Did we see this:
View attachment 47055
My quickie sawtooth is not precise... but the point is made... the "break" would be two saw tooth edges of the "chex" column/panels.. corner conditions not even shown in this sketch
...

Scott & Hamburger make the same point, but about each level of collapse progression, not initiation. The point is valid for both. Here is their take:

Tall buildings are never demolished with explosives at every level; why would they do it here? With thousands of explosives, surely there would be a high risk of one picture of a cutter charge. But there is a much simpler form of evidence that shows there was no line of explosives and that is the damage to the perimeter wall. The connections are much weaker than the columns and the wall failed at the connections. The connections are staggered in three-storey segments. So, there was no lines of damage. The segments are seen in the debris and in the collapse videos. The connections were studied extensively Ref 7.

So, they contrast the staggered wall segments post-collapse with the apparent "explosions" seen to shoot out of one floor after another - which would produce a horizontally linear cut through the walls (and leave lots and lots of wall panels cut in thirds).

 

[Jeffrey Orling]

All you guys have completely forgotten what thread you are in, and you just go on and on and on and on and on and on with a private conversation that you had having circling round and round in many places elsewhere. I reported an early post, way up-thread, earlier today.

However, here is one argument against some versions of "CD" claims that the Scott/Hamburger white paper also makes. First, Jeffrey's version:



Scott & Hamburger make the same point, but about each level of collapse progression, not initiation. The point is valid for both. Here is their take:



So, they contrast the staggered wall segments post-collapse with the apparent "explosions" seen to shoot out of one floor after another - which would produce a horizontally linear cut through the walls (and leave lots and lots of wall panels cut in thirds).

We are off topic....
The floor by floor collapses had nothing to do with columns... caused by or impacted.

 

[econ41]

All you guys have completely forgotten what thread you are in, and you just go on and on and on and on and on and on with a private conversation that you had having circling round and round in many places elsewhere.

Maybe - and certainly from your perspective mea culpa. The refocusing to the topic actually occurred in the first responding posts I didn't "buy in" until later. The OP goal was to bring attention to the Ron Hamburger and David Scott white paper which is a debunk of specific claims by AE911. It is therefore limited to what is necessary to debunk those AE911 claims. And not a comprehensive engineering explanation of what actually happened.

We should probably have followed your OP suggestion.

I guess We can open separate threads for any specific debunk that spikes someone's interest - this thread for now is merely to present, and store as a linkable resource, the White Paper as a PDF.

 

[Jeffrey Orling]

Still OT.... My understanding is that MetaBunk is not the sort of forum to discuss but more to "debunk" something that's out there.
So... It's hard to debunk the truss joists pull in because truss joists do expand... more on the long span and half as much on the short span... assuming the same amount of heating. Does NIST assert that the pushing of the trusses were only on the south side of 1WTC? They only show one location and its inward bowing... It's sagging pulling not expanding pushing... with the core supporting half the outside the core floor loads... wouldn't there be core failure involved? Again... I get heat caused the frame to go kittywhampus... but I don't get it. Tops won't drop with adequate support... and that means buckled/weakened columns or displace column ends with insufficient bearing.

 

[econ41]

Still OT....

I don't think these latest questions are BUT if you and Oystein as OP think it is why don't you OP a new thread?

... My understanding is that MetaBunk is not the sort of forum to discuss but more to "debunk" something that's out there.

Correct. And, if interpreted strictly, "debunking" is limited to identifying and correcting errors in the "bunk". When my preference is always to explain what really happened. Which can be far more efficient than responding within the limitations of the "bunk". But usually requires putting the narrow issue of "bunk" in the correct but broader setting. And thereby risking going "off topic".

Your call. Some of your questions are not off the actual OP topic. BUT go against the OP's stated preference for detailed discusion to go to separate threads. So why not OP a thread?

 

[Jeffrey Orling]

I don't think these latest questions are BUT if you and Oystein as OP think it is why don't you OP a new thread?


Correct. And, if interpreted strictly, "debunking" is limited to identifying and correcting errors in the "bunk". When my preference is always to explain what really happened. Which can be far more efficient than responding within the limitations of the "bunk". But usually requires putting the narrow issue of "bunk" in the correct but broader setting. And thereby risking going "off topic".

Your call. Some of your questions are not off the actual OP topic. BUT go against the OP's stated preference for detailed discusion to go to separate threads. So why not OP a thread?

I get the notion of debunking... The subject/target is "truther" false claims... the target audience is truthers with an open mind who can be disabused or truther "junk science"....Maybe some people who are not in the rabbit hole might benefit from debunking... doubt it. For that demographic.... the 9/11 4 Dummies that Thomas wants to see is the way to go... or "private lessons" from someone like Econ...