Would the WTC Twin Towers have collapsed from fire alone, without plane impact?

Henkka

Banned
Banned
Your unwitting assumption of theoretical equivalence between the two hypotheses gives too much weight to something that is highly unscientific to start with and wouldn't be considered a plausible rival hypothesis as far as scientific hypotheses go.
Really... Historically, tall buildings had never, ever collapsed from fire before. But tall buildings had collapsed hundreds of times before from other causes, mostly controlled demolition. So when we see a tall building (WTC 7) suddenly fall straight down on 9/11, you think it is "highly unscientific to start with" to consider that it may have been demolished? How come? The entire point of science is that nature seems to stay pretty consistent, and things in the future will behave similarly as they did in the past. But it is NIST and debunkers who claim to have discovered a way for a steel building to fall in a way that exactly resembles a controlled demolition, without actually being a controlled demolition.

You also seem to consider what is or isn't "unscientific" entirely synonymous with whatever is the expert consensus. But of course, we can consider two opposing sides without immediately biasing ourselves by favouring the consensus. Take flat earth vs. globe earth for example. Everyone knows globe earth is the consensus. But you can pretend for a while you didn't know that, and start investigating the issue as if you had never heard about it before. If globe earth is true, then that should come out on top from such an investigation.
 

Thomas B

Active Member
Think of the 10 legs as columns, and the knees as the places where they buckle. If linked, this arrangement is very stable against being pushed from the side, but if you have one helper each push each yellow person from the front, it doesn't matter whether they're linked or not.
Sure. Now we arrange the 20 players in a square (5 per side, facing outwards) with arms linked and shoulders touching.
 

FatPhil

Senior Member.
No.
The outer tube was not designed to stand on its own.

I quoted Fu at you, explaining that the floors are needed to accomodate the deficiency of the framed tube design, in the WTC.

Here is another source:
Overview of the Structural Design of World Trade Center 1, 2, and 7 Buildings

Authors:
Therese P. McAllister, Fahim Sadek, John L. Gross, Jason D. Averill,† Richard G. Gann

The third major structural subsystem was the floors in the tenant spaces between the exterior walls and the core. These floors supported gravity loads, provided lateral stability to the exterior walls, and distributed wind loads among the exterior walls.

In a framed tube system, the floor diaphragms play a key role since they carry lateral forces to the side walls of the building, thereby allowing tube action to take place. In addition, floor diaphragms provide lateral support for the stability of the columns.
Content from External Source
One could also look at the consequences of presuming ThomasB's assertion, what-iffing, and seeing where it leads. For example:

Were the tube strong enough to stand on its own unsupported laterally, then, because it would in reality be supported laterally, it's massively over-engineered. So it could be made with less material, or less strong material. Therefore it could be made more cheaply.

So in order to explain the hypothesis, you don't just need to prove the physics, you now also have to explain the economics.
[SPOILER crappy joke]
The economic footprint's too large!
[/SPOILER]
 

LilWabbit

Senior Member
Really... Historically, tall buildings had never, ever collapsed from fire before.

Historically, tall buildings had also never ever been hit by big passenger jets with tons of jet fuel acting as combustion causing extremely hot fires that were burning for quite a while before the collapse. If the circumstances were comparable, historical precedence would serve as a sound scientific principle. But they weren't.

Me and my wife had recently gotten married (2 years before) and were watching at home on BBC the entire event unfold real time, literally holding onto the edge of our seats. We clearly remember the delay it took from the impact to the collapse during which the towers were burning like two giant candles. When the first collapse started, it took us by a shock. But the first thing that went through our admittedly layman minds wasn't "how uncannily similar it looked to a controlled explosion" but "wow, it seems all that impact and heat weakened the structure", and we were sure the same would happen to the second tower. As it did. And we're not structural engineers even by a long shot. That the official report largely confirmed our impression wasn't a surprise.

You also seem to consider what is or isn't "unscientific" entirely synonymous with whatever is the expert consensus.

No. I said expert, political and even laymen consensus is a plus and shouldn't be ignored. What is unscientific is to cling to a hypothesis that cannot be supported by objective evidence after we deduce all the observables (i.e. predictions of the theory) it must involve such as loud bangs, explosive residue, damage peculiar to particular explosives and multiple credible witness testimonies of tremors coinciding the loud bangs. In science when the theory predicts many observables that aren't present, it's either shelved or fundamentally modified. And I'm not even including the non-parsimonious observables regarding credible leaks, documents and recordings demonstrating a Western military-industrial complex behind the attacks.
 

Henkka

Banned
Banned
Historically, tall buildings had also never ever been hit by big passenger jets with tons of jet fuel acting as combustion causing extremely hot fires that were burning for quite a while before the collapse. If the circumstances were comparable, historical precedence would serve as a sound scientific principle. But they weren't.
I was mostly talking about WTC 7 since that was what instigated my interest in this topic. I edited the post to make it clear, but maybe you didn't see the edit. Just as a word of advice if you're new to 9/11 debates, you don't want to say this. Probably the easiest rhetorical trick a truther can pull in a debate is make their opponent imply that plane impact and tons of jet fuel were very important in collapsing the buildings, and then make them awkwardly backtrack on that when having to explain why WTC 7 collapsed without either of those.

But the first thing that went through our admittedly layman minds wasn't "how uncannily similar it looked to a controlled explosion" but "wow, it seems all that impact and heat weakened the structure", and we were sure the same would happen to the second tower. As it did. And we're not structural engineers even by a long shot.
Well hold on, you were using "layman's logic" as an argument against what I've been saying, but here it seems like you're using "layman's logic" to support what you're saying!

What is unscientific is to cling to a hypothesis that cannot be supported by objective evidence after we deduce all the observables (i.e. predictions of the theory) it must involve such as loud bangs, explosive residue, damage peculiar to particular explosives and multiple credible witness testimonies of tremors coinciding the loud bangs.
All of these things are contested. By that I mean truthers will claim there are recordings and witness testimony of bangs, explosive residue in the dust, sulfidized steel with holes in it, and so on.
 

Mendel

Senior Member.
Historically, tall buildings had never, ever collapsed from fire before. But tall buildings had collapsed hundreds of times before from other causes, mostly controlled demolition. So when we see a tall building (WTC 7) suddenly fall straight down on 9/11,
at that time, 2 other tall buildings had collapsed from fire, hours before

you think it is "highly unscientific to start with" to consider that it may have been demolished?
it's not

but to disregard the body of evidence is unscientific
 

Mendel

Senior Member.
Sure. Now we arrange the 20 players in a square (5 per side, facing outwards) with arms linked and shoulders touching.
yep, which ones are the easiest to push over in that structure?

and how would that change if there was a square table filling the inner space?

(they buckle just the same as the single row btw)
 

Mendel

Senior Member.
Probably the easiest rhetorical trick a truther can pull in a debate is make their opponent imply that plane impact and tons of jet fuel were very important in collapsing the buildings, and then make them awkwardly backtrack on that when having to explain why WTC 7 collapsed without either of those.
that only works on opponents who don't realize the WTC7 was a differently constructed building that failed in a different manner from the towers

and that WTC received substantial damage from WTC debris that started large fires on several levels
that debris was WTC7's plane, so to speak
 

LilWabbit

Senior Member
I was mostly talking about WTC 7 since that was what instigated my interest in this topic. I edited the post to make it clear, but maybe you didn't see the edit. Just as a word of advice if you're new to 9/11 debates, you don't want to say this. Probably the easiest rhetorical trick a truther can pull in a debate is make their opponent imply that plane impact and tons of jet fuel were very important in collapsing the buildings, and then make them awkwardly backtrack on that when having to explain why WTC 7 collapsed without either of those.

We saw that also live and it didn't surprise us "laymen" that the extremely hot debris from the twin towers weakened and heated nearby buildings as well.

Well hold on, you were using "layman's logic" as an argument against what I've been saying, but here it seems like you're using "layman's logic" to support what you're saying!

With the caveat that I was talking about a real-time observation of a long scene which was much more nuanced, messy and complex a process than the after-the-fact analogies on controlled demolitions a truther cites. So I guess for us 'secondary eyewitnesses of the scene through TV' the layperson's mental imagery is in fact more nuanced than the truther's lay logic analogies. Flippantly superimposing these analogies on a far different reality that we observed doesn't just add up. A reality and circumstances that even us laypeople watching it unfold could appreciate as being totally unique and different from what has ever happened to any building before.

All of these things are contested. By that I mean truthers will claim there are recordings and witness testimony of bangs, explosive residue in the dust, sulfidized steel with holes in it, and so on.

Feel free to produce the contesting evidence on new threads unless they have already been discussed. Examining the veracity of specific evidence of that sort is precisely the MO of MB.

Anyway, good to have you here. And apologies for the occasional loss of patience here. We're all just humans here. Give or take a few aliens lurking in our midst.
 

benthamitemetric

Senior Member
This is a little amusing because debunkers happily suggest we imagine the WTC columns being crushed like pop cans, but anyway...

The point of the 1/10" steel mast example (think of it as a very tall, very strong, pop can if that helps) is that it must be much, much, and indeed "wildly", weaker than a WTC perimeter column. We can measure the aptness of my comparison very easily by calculating the critical length of the lower section of an isolated perimeter column (i.e., consider a column that is prismatic but using the heaviest column dimensions in the WTC perimeter).

What's your estimate of how that calculation comes out? (What I tried to say earlier is that I can't learn from someone who can't, or won't, at least estimate this height.) I'm not hundred percent sure of my calculation, but I think it's at least 400'.

Now, just ask yourself whether a structural system built out of either the masts or columns, which we now know the critical length for individually, would have a longer or shorter critical length than the individual masts or columns.

The textbook example just gives a (ridiculously) extreme lower bound on how tall the perimeters must have been able to stand on their own. That bound is over 200'. I simply believe the engineers designed the shells to stand 7 times taller than that ... under strong wind and seismic loading.
The general principle illustrated by the can is buckling. Mick is illustrating bucking using a common object that does, in fact, buckle and illustrate that principle. Mick is very explicit about what he is illustrating and the limitations of the illustration.

You, however, are trying to illustrate that a complex structural system would withstand a certain, well-defined set of circumstances for which it was not designed. To illustrate that, you point to a graduate-level problem set from a structural engineering course that is presented to you with little context and math you cannot read. But even by what you can read from that page, you should be able to tell that the principle illustrated by the prismatic steel tubular in the problem is inapplicable to the perimeter walls of the towers. The reason you do not realize this is because you skipped the stage of learning that most rational, intellectually curious people would undertake called "learning the basics". If you even just stopped an looked up the term "prismatic" you'd have your first clue that you were way off base, but, if, before diving into a graduate level problem set you spent time reading about when Euler's equation can be applied and what it actually tells you, you'd understand that it cannot solve for a situation where there is nonuniformity in the strength of the column along the axis of its support. This is very basic. This is why columns are braced at their connection points. This is why NIST made a point of reviewing whether columns were severed at their connections versus other failure modes when it analyzed the debris. All of this is completely lost on you. To wit, the critical length for self buckling for a uniform prismatic tubular cannot tell you the "lower bound" for self buckling for a non-prismatic, non-uniform structure, whether of the same or, as is the case here, completely different, dimensions. That is among the least coherent and most lacking-in-critical-thought claims you've ever written here.

You are stuck in a myopia of trying to prove your misguided intuition about how these systems would behave is correct. Even if you just actually read the NIST report at this point you'd at least have some sense for the basic principles you are completely missing. I won't and can't give you an estimate for how high the complex system would stand because I understand that it isn't a matter of intuition or basic principles; it's a very complex engineering problem for which hundreds of pages of calculations or a computer simulation would be necessary. Unlike you, I'm not staring at the problem from a place of only abject ignorance and motivated reasoning. I've fully read the NIST reports, similar technical reports, books like Cities in the Sky and even basic textbooks on structural engineering principles, so I understand that the tower perimeters were designed as the most efficient system possible for their limited role in the building under the assumption that they would be braced by the floors. The towers were so susceptible to windshear and so light compared to other tall buildings that bracing the perimeter was not a trivial project. Its designers spent over a year figuring out that problem alone and even patented new types of truss connections to make it work. But you're going to tell me that all of that work was pointless because the perimeter was so strong it would stand fast regardless. Because, after all, something completely different that is also made of steel can stand by itself for a certain height, so, something something your belief is confirmed! Ok, sure.
 
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Thomas B

Active Member
yep, which ones are the easiest to push over in that structure?
Well, if we assume that the force used isn't enough to break their locked arms, pushing over any one of them would be as hard as pushing all of them over.
and how would that change if there was a square table filling the inner space?
You could also put a straight beam behind each group of players instead of having them lock their arms and then joining the four beams at the corners. That begins to approximate the structure of the perimeter shells. You don't need to fill the space.

The diagram you posted also doesn't identify any forces in the inner space, you'll note. The forces are all transferred along the perimeter.
 

Henkka

Banned
Banned
We saw that also live and it didn't surprise us "laymen" that the extremely hot debris from the twin towers weakened and heated nearby buildings as well.
How do you figure it was "extremely hot"? The North Tower collapsed 102 minutes after impact, and the jet fuel burned off in less than ten minutes, as has been discussed in this thread. So the temperature of whatever debris was impacting WTC 7 should have been no more than a normal office fire. Also, earlier you said this:
If the circumstances were comparable, historical precedence would serve as a sound scientific principle. But they weren't.
Do you agree or disagree that there have been fires that were similar to those that occurred in WTC 7?
 

benthamitemetric

Senior Member
How do you figure it was "extremely hot"? The North Tower collapsed 102 minutes after impact, and the jet fuel burned off in less than ten minutes, as has been discussed in this thread. So the temperature of whatever debris was impacting WTC 7 should have been no more than a normal office fire. Also, earlier you said this:

Do you agree or disagree that there have been fires that were similar to those that occurred in WTC 7?
NIST made a fulsome fire model to estimate the temperatures in a rigorous way based on known principles so you don't have to just guess.
 

LilWabbit

Senior Member
How do you figure it was "extremely hot"? The North Tower collapsed 102 minutes after impact, and the jet fuel burned off in less than ten minutes, as has been discussed in this thread. So the temperature of whatever debris was impacting WTC 7 should have been no more than a normal office fire.

I'll let the experts interject. But the longer the fire, the hotter the steel beams get. It was clear even for us watching the smoke lasting a long time and getting thicker that the fire was getting hotter. I could easily imagine extremely hot steel beams remaining hot for a long time, and indeed they were still putting out fires in the rubble the following day.

Also, earlier you said this:

Do you agree or disagree that there have been fires that were similar to those that occurred in WTC 7?

Disagree based on the highly differing circumstances involving a collapsing and burning skyscraper impacting WTC7.
 

Henkka

Banned
Banned
I could easily imagine extremely hot steel beams remaining hot for a long time, and indeed they were still putting out fires in the rubble the following day.
Uhh actually, they were putting out fires for three months afterwards, not just the following day. But that's a story for another time, as they say. (Source: https://en.wikipedia.org/wiki/Collapse_of_the_World_Trade_Center#Cleanup )

Disagree based on the highly differing circumstances involving a collapsing and burning skyscraper impacting WTC7.
Probably another thing you don't want to say, because a savvy truther can just quote these parts from NIST at you:
8. What caused the fires in WTC 7?
Debris from the collapse of WTC 1, which was 370 feet to the south, ignited fires on at least 10 floors in the building at its south and west faces. However, only the fires on some of the lower floors—7 through 9 and 11 through 13—burned out of control. These lower-floor fires—which spread and grew because the water supply to the automatic sprinkler system for these floors had failed—were similar to building fires experienced in other tall buildings. The primary and backup water supply to the sprinkler systems for the lower floors relied on the city's water supply, whose lines were damaged by the collapse of WTC 1 and WTC 2. These uncontrolled lower-floor fires eventually spread to the northeast part of WTC 7, where the building's collapse began.

And:
16. Did debris from the collapse of WTC 1 cause damage to WTC 7's structure in a way that contributed to the building's collapse?
The debris from WTC 1 caused structural damage to the southwest region of WTC 7—severing seven exterior columns—but this structural damage did not initiate the collapse. The fires initiated by the debris, rather than the structural damage that resulted from the impacts, initiated the building's collapse after the fires grew and spread to the northeast region after several hours. The debris impact caused no damage to the spray-applied fire-resistive material that was applied to the steel columns, girders and beams except in the immediate vicinity of the severed columns. The debris impact damage did play a secondary role in the last stages of the collapse sequence, where the exterior façade buckled at the lower floors where the impact damage was located. A separate analysis showed that even without the structural damage due to debris impact, WTC 7 would have collapsed in fires similar to those that occurred on Sept. 11, 2001. None of the large pieces of debris from WTC 2 hit WTC 7 because of the large distance between the two buildings.
https://www.nist.gov/world-trade-center-investigation/study-faqs/wtc-7-investigation

So the fires initiated the collapse, the building would have collapsed solely from those fires without debris impact, and the fires were similar to those experienced in other tall buildings. Now I don't mean any offense, but I feel like you're not super experienced in these conversations. A savvy debunker wouldn't answer "disagree" to that question, because they would anticipate that the truther would then just quote NIST at them, and put them into an awkward position of seemingly disagreeing with NIST.
 

Mendel

Senior Member.
Well, if we assume that the force used isn't enough to break their locked arms, pushing over any one of them would be as hard as pushing all of them over.
Would you concede that the ones in the middle are more movable?
and that pushing on them adds strain all the way to the corner, while pushing on a corner person adds very little strain towards the middle?
You could also put a straight beam behind each group of players instead of having them lock their arms and then joining the four beams at the corners. That begins to approximate the structure of the perimeter shells. You don't need to fill the space.
Show me a picture (or drawing) of that beam for the WTC.

I "don't need" to fill that space, but if I do, I can achieve the same rigidity with less steel. (your beam also bends). That's how the WTC was designed.
The diagram you posted also doesn't identify any forces in the inner space, you'll note. The forces are all transferred along the perimeter.
Yes. Because that diagram is of a framed tube that has no lateral support, like the players with linked arms in my first example.

Adding lateral support (the table) directs lateral forces into the inner space, and away from the corners. The players' arms (esp. near the corners) don't need to resist as much pull when the table is there.
 

Thomas B

Active Member
If you even just stopped an looked up the term "prismatic" you'd have your first clue that you were way off base...
I'm pretty sure you're wrong about this. Of course, I know what "prismatic" means, and it is my impression that the columns were prismatic in sections (they didn't taper continuously, because they were made by welding steel plate together). Remember, I said:
We can measure the aptness of my comparison very easily by calculating the critical length of the lower section of an isolated perimeter column (i.e., consider a column that is prismatic but using the heaviest column dimensions in the WTC perimeter).
In any case, as the textbook goes on to make clear, tapered columns would just be able to go taller using the same amount of steel. So we could use that calculation only as an idealized approximation of the actual columns, which were better understood as prismatic tubes of decreasing thickness extended end-to-end.

I can easily imagine extending the textbook mast downwards with increasingly thicker walls (and, if need be, a wider radius). There'll be some limit, of course, which I don't know how to calculate. But 10 cm x 65 m is obviously not the tallest free standing steel column that is physically possible.
 

LilWabbit

Senior Member
Uhh actually, they were putting out fires for three months afterwards, not just the following day. But that's a story for another time, as they say. (Source: https://en.wikipedia.org/wiki/Collapse_of_the_World_Trade_Center#Cleanup )


Probably another thing you don't want to say, because a savvy truther can just quote these parts from NIST at you:


And:

https://www.nist.gov/world-trade-center-investigation/study-faqs/wtc-7-investigation

So the fires initiated the collapse, the building would have collapsed solely from those fires without debris impact, and the fires were similar to those experienced in other tall buildings.

Where does it say the building would have collapsed in the exact way it did and when it did solely due to fire without debris impact? How is that a logically necessary conclusion from anything written in the NIST? Please demonstrate using sound logical inference rules and not just sloppy reading and thinking (no disrespect intended either). Your citation explicitly reads the impact from the debris "played a secondary role" rather than 'no role'. It stands to reason the exact nature and timing of the collapse would have been different without the debris impact even if there had been a solely fire-initiated collapse without any impact.

Now I don't mean any offense, but I feel like you're not super experienced in these conversations.

Maybe not, but I'm quite experienced in logic and scientific analysis. No offense taken.
 

benthamitemetric

Senior Member
I'm pretty sure you're wrong about this. Of course, I know what "prismatic" means, and it is my impression that the columns were prismatic in sections (they didn't taper continuously, because they were made by welding steel plate together). Remember, I said:

In any case, as the textbook goes on to make clear, tapered columns would just be able to go taller using the same amount of steel. So we could use that calculation only as an idealized approximation of the actual columns, which were better understood as prismatic tubes of decreasing thickness extended end-to-end.

I can easily imagine extending the textbook mast downwards with increasingly thicker walls (and, if need be, a wider radius). There'll be some limit, of course, which I don't know how to calculate. But 10 cm x 65 m is obviously not the tallest free standing steel column that is physically possible.
You think the perimeter walls of the towers are prismatic? Want to take another guess? Way to completely miss the point. Compared to your tubular at scale, the perimeter walls are a very thin mesh that is periodically weakened at the column and beam connections. And you of course have nothing to say about missing the column connections, which blow the whole comparison up as well.
 
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benthamitemetric

Senior Member
You are literally not reading my posts, right?

I said that each discrete section of the perimeter columns are in fact prismatic because they are made of uniform plates of steel.
And those columns are each three stories tall and connected together into a mesh that forms the structure you are trying to describe, which structure is not prismatic. Any chance you get it now?
 
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Henkka

Banned
Banned
Where does it say the building would have collapsed in the exact way it did and when it did solely due to fire without debris impact? How is that a logically necessary conclusion from anything written in the NIST? Please demonstrate using sound logical inference rules and not just sloppy reading and thinking (no disrespect intended either). Your citation explicitly reads the impact from the debris "played a secondary role" rather than 'no role'. It stands to reason the exact nature and timing of the collapse would have been different without the debris impact even if there had been a solely fire-initiated collapse without any impact.
Where did I claim it would collapse the exact same way? Yeah according to NIST, the building would have collapsed in a different way without debris impact damage, but it would have still collapsed. You can find all the simulations NIST did here: https://drive.google.com/drive/folders/1y9ww7NXEnqaZUWNjkH1E7yMq9b6nO8-2

Under "WTC7_Structural response" you can find the three different scenarios they tried, "Debris impact damage", "No debris impact damage" and "Column 79 sudden failure".

But the point is, according to NIST, WTC 7 would have collapsed solely from fires, even though the fires were similar to those experienced in other buildings (that did not collapse obviously). So it fits what you laid out here:

If the circumstances were comparable, historical precedence would serve as a sound scientific principle. But they weren't.
The historical precedence is that tall buildings don't collapse from fire.
 

LilWabbit

Senior Member
Where did I claim it would collapse the exact same way? Yeah according to NIST, the building would have collapsed in a different way without debris impact damage, but it would have still collapsed. You can find all the simulations NIST did here: https://drive.google.com/drive/folders/1y9ww7NXEnqaZUWNjkH1E7yMq9b6nO8-2

Under "WTC7_Structural response" you can find the three different scenarios they tried, "Debris impact damage", "No debris impact damage" and "Column 79 sudden failure".

But the point is, according to NIST, WTC 7 would have collapsed solely from fires, even though the fires were similar to those experienced in other buildings (that did not collapse obviously). So it fits what you laid out here:


The historical precedence is that tall buildings don't collapse from fire.

Like I said, there's no historical precedence for the type of fire caused by passenger jets with jet fuel crashing into tall buildings, including secondary fires on surrounding buildings caused by the initially collapsed burning buildings. You cannot separate the two events in order to prove a point. So no, your argument on historical precedence is sloppy and unsound. That is to say, even if the NIST claims fires alone would have caused a collapse. In scientific analysis (or genuine attempts at being scientific) you simply cannot ignore what exactly happened and instead argue by appeal to analogies involving different circumstances.

I believe this has been repeatedly pointed out to you on this thread.

So yes, you're free to analyze the way you do, but to claim it has any scientific rigour would be a mistake.
 
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benthamitemetric

Senior Member
I will as soon as you tell me the critical height (without the floor bracing) of this structure that you claim to understand so well.
Nice retreat. Tell me more about the prismatic perimeter walls, Thomas B. As I said earlier:
I won't and can't give you an estimate for how high the complex system would stand because I understand that it isn't a matter of intuition or basic principles; it's a very complex engineering problem for which hundreds of pages of calculations or a computer simulation would be necessary. Unlike you, I'm not staring at the problem from a place of only abject ignorance and motivated reasoning. I've fully read the NIST reports, similar technical reports, books like Cities in the Sky and even basic textbooks on structural engineering principles, so I understand that the tower perimeters were designed as the most efficient system possible for their limited role in the building under the assumption that they would be braced by the floors. The towers were so susceptible to windshear and so light compared to other tall buildings that bracing the perimeter was not a trivial project. Its designers spent over a year figuring out that problem alone and even patented new types of truss connections to make it work. But you're going to tell me that all of that work was pointless because the perimeter was so strong it would stand fast regardless. Because, after all, something completely different that is also made of steel can stand by itself for a certain height, so, something something your belief is confirmed! Ok, sure.
 

Henkka

Banned
Banned
Like I said, there's no historical precedence for the type of fire caused by the planes with jet fuel crashing into tall buildings, including secondary fires on surrounding buildings caused by the initially collapsed burning buildings.
Um, how does this make sense... The fire's properties aren't changed if they're ignited by the collapse of a nearby building. What was burning in the building was office furnishings, so they burned similarly as other buildings with office fires had. This is all admitted by NIST in their own FAQ in the parts I quoted for you. All the jet fuel was long gone when the building collapsed, so I don't understand why you would even bring it up.

That is to say, even if the NIST claims fires alone would have caused the collapse which I didn't read anywhere.
Okay, let's just put it like this...

1) Do you agree that according to NIST, the fires in WTC 7 were similar to those experienced in other tall buildings? Yes/No
2) Do you agree that according to NIST, WTC 7 would have collapsed from those fires even without any structural damage from debris? Yes/No
3) Do you agree that prior to the collapse of WTC 7, there was no historical precedent of a tall building collapsing from such fires? Yes/No
 

benthamitemetric

Senior Member
You retreat into complexity, and I, into simplicity. The symmetry is nice. See you around.
More like, because you don't understand what you are talking about, you made an obviously inapt comparison between a simple system and a complex one and drew from that comparison conclusions that obviously do not follow, and I pointed that out. And now you realize how off the mark the comparison was but can't own up to it.
 

LilWabbit

Senior Member
Um, how does this make sense... The fire's properties aren't changed if they're ignited by the collapse of a nearby building.

The enormous heat of burning steel beams generated during the first fire which (burning steel debris falling into another building) is surely going to affect the unique and unprecedented nature of the secondary fires on WTC7 which, together with the debris impact, caused the collapse.

Historical analogies of fires in tall buildings (and even less in low-standing ones) just won't capture these circumstances well enough to disprove the mainstream account of what exactly happened.

What was burning in the building was office furnishings, so they burned similarly as other buildings with office fires had. This is all admitted by NIST in their own FAQ in the parts I quoted for you. All the jet fuel was long gone when the building collapsed, so I don't understand why you would even bring it up.


Okay, let's just put it like this...

1) Do you agree that according to NIST, the fires in WTC 7 were similar to those experienced in other tall buildings? Yes/No

No. As shown above.

2) Do you agree that according to NIST, WTC 7 would have collapsed from those fires even without any structural damage from debris? Yes/No

Not in the manner and speed it actually collapsed. Yes or no answer cannot capture this nuance. I'm pretty sure (a totally non-expert opinion) most tall buildings would collapse if a fire raged there long enough. But without the impact from debris it would just take much longer. Why we haven't seen that is because either the fires have been put out or they have naturally died out before reaching critical heat or cause critical enough damage to initiate a collapse.

3) Do you agree that prior to the collapse of WTC 7, there was no historical precedent of a tall building collapsing from such fires? Yes/No

There has never been even a remotely similar fire in a tall building as explained in the above and therefore there's been no collapse. Yes or no answer cannot capture this nuance.

Nuances and exactness matter. Leastways if we are trying to be scientific.
 

Thomas B

Active Member
More like, because you don't understand what you are talking about, you made an obviously inapt comparison between a simple system and a complex one and drew from that comparison conclusions that obviously do not follow, and I pointed that out. And now you realize how off the mark the comparison was but can't own up to it.
This is probably something should go on the psychoanalysis thread, but it seems very important to you that you're smarter than me. I'm happy to grant the possibility, but so far you're not helping me understand.

You seem to be saying that the "complex system" of the perimeter shell was built to be weaker under lateral loading than the "simple system" of the mast in the textbook. That is, the conclusion you seem to want me to draw from your sophisticated reading of reading of the literature is that it's critical height, without the floors in place, would be lower than 200'.

After all, the only claim I'm making is that it must, surely, have been stronger, even without the the floors in place.
 

Mendel

Senior Member.
And now you realize how off the mark the comparison was but can't own up to it.
He doesn't. He thinks his comparison is valid, and that we don't understand it.

He thinks a column that is "prismatic in sections" is still prismatic.
He's not looking for knowledge, he's looking for confirmation of answers he already believes in.
 

Henkka

Banned
Banned
There has never been even a remotely similar fire in a tall building
NIST:
These lower-floor fires—which spread and grew because the water supply to the automatic sprinkler system for these floors had failed—were similar to building fires experienced in other tall buildings.
This is an irreconcilable contradiction between you and NIST. If you want to argue independent from NIST, that's fine I guess, but just say that then. Econ41 for example has said repeatedly he does not just take whatever NIST or Bazant say as absolute fact. But we should probably stop here, I figured this could maybe be 2-3 posts of back and forth regarding your original question of why I was distrustful of the official explanations, but it turned into an entire page of an off-topic argument lol. But if you disagree with NIST, at least we're in the same boat of being distrustful of the official explanation.
 

LilWabbit

Senior Member
NIST:

This is an irreconcilable contradiction between you and NIST.

No it's not and this is a very easy one where you have gotten caught up with a particular wording out of its context and employing that wording to argue your own point (btw, many Evangelical Christians do the same with the way they read the Bible). NIST is not claiming the WTC7 fires had historical precedents, especially when you take into account the way the WTC7 fire started and the impact from the debris as a secondary component in causing the collapse the way it did (explicitly regarded by the NIST as a contributing factor to the collapse but not the primary initiator).

The NIST is merely pointing out that fires spreading due to sprinkler failure in lower floors are not new. For you to claim this is proof of NIST thinking the WTC7 fire as a whole has historical precedents is an over-reach.
 
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benthamitemetric

Senior Member
This is probably something should go on the psychoanalysis thread, but it seems very important to you that you're smarter than me. I'm happy to grant the possibility, but so far you're not helping me understand.

You seem to be saying that the "complex system" of the perimeter shell was built to be weaker under lateral loading than the "simple system" of the mast in the textbook. That is, the conclusion you seem to want me to draw from your sophisticated reading of reading of the literature is that it's critical height, without the floors in place, would be lower than 200'.

After all, the only claim I'm making is that it must, surely, have been stronger, even without the the floors in place.
You haven't demonstrated once that you are trying in good faith to learn here. You demonstrate the opposite by refusing to read and familiarize yourself with the basic sources upon which these conversations are premised, cherry picking the points to which you respond so as superficially further your argument but not your understanding, and misrepresenting your beliefs to an extent that is almost comical (hey everyone-we found the first person who argued against truthers for years while believing the tower collapses cannot be explained without demolition devices!) while you string the conversations along with nonsense. And you lack the self awareness to realize that, even if you wanted to, you can't learn from jumping from no knowledge to graduate-level problem sets. So I'm not trying to teach you. I'm just pointing out the errors of your "reasoning" so that others who are starting to look at these topics from a similar perspective as yours do not find metabunk hosting a collection of unchallenged rubbish. Whether you learn something or not is up to you.

And you even suggesting that I am asking you to draw any conclusion about whether 200' is the correct height or not for the perimeter to buckle under self-loading just shows all of that. You'd rather attack some stupid strawman than deal with the fact that the methodology you dug up from a graduate text that you do not understand does not work to describe a series of columns that are bolted together into a structure. Those columns were each three stories tall. The height of the structure was obtained by connecting them together. When you introduce those connections, you drastically weaken the structure as compared to a uniform, prismatic structure of the same dimensions. To figure out by how much is a very complicated calculation that I am not equipped to undertake, and I don't pretend to be, but you are not even equipped to recognize that such a calculation is needed while at the same time you purport to draw conclusions as if such a calculation had been completed.

And to drive the above points home even more, this entire misbegotten thread about whether the perimeters would buckle or not comes from a complete strawman as no one is claiming that the perimeters failing by self-buckling was a significant aspect of the collapse, let alone one necessary to understand it.
 
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Henkka

Banned
Banned
No it's not and this is a very easy one where you have gotten caught up with a particular wording out of its context and employing that wording to argue your own point (btw, many Evangelical Christians do the same with the way they read the Bible). NIST is not claiming the WTC7 fires had historical precedents, especially when you take into account the way the WTC7 fire started and the impact from the debris as a secondary component in causing the collapse the way it did (explicitly regarded by the NIST as a contributing factor to the collapse but not the primary initiator).

The NIST is merely pointing out that fires spreading due to sprinkler failure in lower floors are not new. For you to claim this is proof of NIST thinking the WTC7 fire as a whole has historical precedents is an over-reach.
Here's Shyam Sunder of NIST:
Sprinklers in building 7 did not function for much of the bottom half of the building. Nevertheless, other tall buildings have burned for as long or longer in similar fires without collapsing when sprinklers either did not function or were not existing. We knew that what understanding what happened to the building would be difficult. It did not fit any textbook examples that you could point to and say, yes, that is why the building fell.
https://www.c-span.org/video/?280569-1/investigation-world-trade-center-building-7 3 minutes in.

I feel like you're battling some cognitive dissonance here... But I get what you're arguing. You're grasping onto that there must be some key difference in the fires that WTC 7 experienced compared to fires in other buildings, because otherwise, why did it collapse and those other buildings didn't? Now, NIST's take on it is, very explicitly, that there was no massive difference, only that the fires happened to cause a very rare, "extraordinary event" as they put it in the FAQ. And you're arguing the difference was that the fires were set in a very unique way, that being debris impact from a building collapsing nearby. But think about it... Once the fires are ignited, what's the difference? It's just office furnishings burning. All the fire proofing in WTC 7 was still intact, and we know steel frames hold up in those sorts of temperatures just fine from examples like One Meridian.
 
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