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

Abdullah

Active Member
Perhaps an even better theory than what @Oystein proposes is the cutting of the channel girders supporting the trusses.
Screenshot_2022-07-30-14-07-03-452_com.microsoft.office.word-01.jpeg
Particularly note where the girder supporting the short span trusses ends just past the corner column. If it is cut here, the girder for the long trusses just may collapse up to the next column row. That could cause 15 trusses to sag in that corner
 

deirdre

Senior Member.
If you wanted to replicate what happened to the Landmark tower on the WTC, I guess you would be cutting the core and perimeter columns near the base.
i hope youre talking about the base of the "block". ( i hate that word, block)

you dont have to wipe out every column or truss or core wall or whatever, you just need to wipe out enough bits to cause the load redistribution safety mechanisms to fail. the building itself will wipe out the core, just like it did in real life.
 

Henkka

Active Member
i hope youre talking about the base of the "block". ( i hate that word, block)

you dont have to wipe out every column or truss or core wall or whatever, you just need to wipe out enough bits to cause the load redistribution safety mechanisms to fail. the building itself will wipe out the core, just like it did in real life.
No, there I meant the base of the entire tower, so it would done the same way as the Landmark tower.

And yeah I agree you wouldn’t have to cut all of them, I think.
 

Thomas B

Active Member
More incredulity, still no argument.
Spurred by @Oystein, inspired by @Henkka, and challenged by @Mendel, I'd like to make the argument for why it's hard to believe that fire alone (or a small amount of explosives at the top) could have brought down the towers.

Imagine two very large box columns, one inside the other. The outer column represents the perimeter shell of the WTC towers, the other represents the core. Make the shell 3" thick at the base (tappering upwards) and the core 6" thick. Make the perimeter a 200' square and the core an 80' square.

Bolt them directly to the bedrock.

These columns will have their own Euler self-buckling limit individually, but they can be strengthened (as the towers were) by connecting the perimeter to the core at regular intervals with trusses. So imagine putting eight trusses every 10' feet, connecting the perimeter to the core, each corner to each corner and each face to each face.

Next, we're going to have to load those floors. Imagine a square donut concrete slab resting on those eight trusses at every story.

What we need, in the first instance, is to determine a height and load (per floor) for this structure that would allow it to stand up in hurricane force winds. (This is not a "scaled down" model; it's just a very simplified one. Its actual dimensions are roughly similar to the WTC towers.)

Next we need to tweak it so that sustained fires (for a few hours) on three floors would cause the trusses to sag sufficiently to pull in the outer shell, initiating collapse.

Finally, we need this to cause the total collapse of the building. I realize this is just a constrainted version of the Hoffman challenge, which has already been dicussed (see this thread), and I'm not asking you to solve it (which would require math that, as I understand it, none of us are capable of doing).

What I'm asking you to understand is that the difficulty you (hopefully) have imagining this structure collapsing totally to the ground by fire (given that it wouldn't collapse by hurricane or earthquake) is the difficulty that I (and, I presume, @Henkka) have understanding how fires alone could have brought down the WTC.

I cannot imagine there's a height / load / connection strength distribution that makes it both strong enough under ordinary circumstances to stand and weak enough when on fire to fail. And I really do believe I'm providing the basic design concept of the WTC towers. This is how it is described by people like Guy Nordenson in a video that I've mentioned before where he talks about the design of the outer shell of the WTC in some detail. The relevant portion is 5 minutes (from where I've cued it up). At 17:56 he says:
In a tube frame the idea is that the entire perimeter of the structure is mobilized so that the front and back faces of the building become like flanges of a box beam.

And by people like Leslie Robertson (I think that's who it is) in this video, who describes the shell as a "box":

Finally, I promised Oystein I would find the place where Uwe Starossek uses a similar thought experiment to present a "design concept" using a massive tube (rather than a system of columns). I believe he used it in the book Progressive Collapse of Structures, but I don't have those pages on hand. Instead, I found it in a journal article he published in Structural Engineering International 18(3), 2008, called "Avoiding Disproportionate Collapse of Tall Buildings". Here's the key passage:
Screenshot 2022-07-30 at 11.24.23.png
Source: https://www.tandfonline.com/doi/abs/10.2749/101686608785096577

I'm not sure it's what you're looking for, but that's the argument for my "incredulity". There are plenty of ways to poke holes in it. And it is my sincere hope that you do poke enough holes in it to make it collapse in a manner that is comparable to ROOSD. I have not been able to do it.

The obvious strategy is to put windows in the shell. But converting the outer shell faces from single plates of 3" (at the base) steel into 60 box columns with 3" walls connected with spandrel plates seems to me to produce a structure of (at least) the same strength (which was, I believe, the point).

I also don't see how just adding more (and weaker) trusses would change anything substantially. And I don't think the problem changes if we imagine the weakening at the top to be brought about by well-placed charges on the initiating floors. But I'm all ears.
 
Last edited:

Abdullah

Active Member
I cannot imagine there's a height / load / connection strength distribution that makes it both strong enough under ordinary circumstances to stand and weak enough when on fire to fail.
When the storm winds blow, they exert an out of plane shear force on the facade that is resisted by compression in the concrete slab which in turn is prevented from sliding backwards by shear in the adjacent walls.

Sagging bends and effectively buckles the slab, m making it useless in compression. So that same out of plane force would cause the columns to bend and perhaps buckle.
 

Thomas B

Active Member
When the storm winds blow, they exert an out of plane shear force on the facade that is resisted by compression in the concrete slab which in turn is prevented from sliding backwards by shear in the adjacent walls.

Sagging bends and effectively buckles the slab, m making it useless in compression. So that same out of plane force would cause the columns to bend and perhaps buckle.
Ah, yes, so as you understand it, the walls would be so thin that, without the floors in place, the outer column would buckle in a light wind. I guess that would also make its walls weak enough to be pulled in by sagging trusses (and indeed to be weakened catastrophically by a few hours of fire.

Is that your view?
 

Abdullah

Active Member
Why was the control needed?
To prevent large portions of the building falling over to the side and hitting another 47 storey building 98 meters away and starting fires which burn for 7 hours causing that building to collapse as well
 
Last edited:

Henkka

Active Member
To prevent large portions of the building falling over to the side and hitting another 47 storey building 98 meters away and starting fires which burn for 7 hours causing that building to collapse as well
So do you think that if the Landmark tower was demolished with the absolute minimum amount of explosives required, so no extra explosives to control the fall, big chunks of the building would hit other buildings? Or would the building itself topple over?
 

Abdullah

Active Member
So do you think that if the Landmark tower was demolished with the absolute minimum amount of explosives required, so no extra explosives to control the fall, big chunks of the building would hit other buildings? Or would the building itself topple over?
Yes.
Remember the core remnant? Imagine what a headache it would have been if that thing hadn't collapsed. The same is true for large sections of the walls stripped of their burden.
 

benthamitemetric

Senior Member
Ah, yes, so as you understand it, the walls would be so thin that, without the floors in place, the outer column would buckle in a light wind. I guess that would also make its walls weak enough to be pulled in by sagging trusses (and indeed to be weakened catastrophically by a few hours of fire.

Is that your view?
Given that it has been clearly documented in the NIST report that the walls of the WTC were, in fact, pulled in by the trusses prior to the global collapse (and that can be easily verified independently via analysis of readily available photographs of the walls), is this your roundabout way of coming to understand that the WTC was not as strong as the cartoon monolith seem to imagine, or is that point flying right over your head at the moment?
 
Last edited:

Henkka

Active Member
And you also believe the building on the left here collapsed in the way that it did, with zero explosives used to either initiate or control the fall? Note that the third comparison in the video happens to actually be the Landmark tower:

Source: https://www.youtube.com/watch?v=D7Rm6ZFROmc

No-click: Video put together by AE911 comparing the fall of WTC 7 to that of three controlled demolitions. The third comparison at 0:12 is the Landmark implosion that has been brought up in this thread.

Now I think I'm gonna be accused of going off-topic again for bringing up WTC 7, but I would argue that I'm not, because this all flows from the initial question of the thread. So you would have to believe the following:

The WTC Twin Towers collapsed because of plane impact and (mostly) the subsequent fires.

-->

From this, it logically follows that a collapse could have been initiated with a relatively small amount of explosives, such as 75 pounds, used to attack the trusses.

-->

A much smaller, 30-story steel building was demolished using 364 pounds of explosives. But the reason why it required so much more explosives was only because it had to be brought down in a controlled fashion, whereas the proposed 75 pounds of explosive could only accomplish an "uncontrolled" demolition of the WTC towers.

-->

But also, WTC 7 went down in an eerily "controlled" fashion despite zero explosives being used to initiate or control the fall.

So does it take lots of explosives to bring a building down like that, or possibly none at all? It can't be both. I'm not an engineer or physicist, so I can't do any calculations on this stuff. I'm just pointing out that it seems like the starting belief, "WTC towers collapsed because of plane impact and fires", has a number of logically necessary implications that lead you into a messy tangle of contradictions and absurdities. That shouldn't be the case if the starting belief is true.
 

Thomas B

Active Member
When the storm winds blow, they exert an out of plane shear force on the facade that is resisted by compression in the concrete slab which in turn is prevented from sliding backwards by shear in the adjacent walls.

Sagging bends and effectively buckles the slab, m making it useless in compression. So that same out of plane force would cause the columns to bend and perhaps buckle.
Ah, yes, so as you understand it, the walls would be so thin that, without the floors in place, the outer column would buckle in a light wind. I guess that would also make its walls weak enough to be pulled in by sagging trusses (and indeed to be weakened catastrophically by a few hours of fire).
What is your estimate of how tall a 200' x 200' box column made of 3" steel plates welded at the corners would have to be before it would buckle in a light wind?

Do we agree intuitively that a 20' high steel enclosure like this would be very stable -- even in a hurricane? At what height does bracing it latterally to a core column become necessary?
 
Last edited:

Thomas B

Active Member
is this your roundabout way of coming to understand that the WTC was not as strong as the cartoon monolith seem to imagine, or is that point flying right over your head at the moment?
No, I don't understand how/why the towers would not be as strong as my cartoon monolith. That's how their strength is normally described. That was the point of my post.

@Abdullah's solution to the cognitive dissonance seems to be to think of the monolith as itself quite weak. But, as I've just noted in a reply to him, that weakness must necessarily arise only at some critical height (if the outer wall is short enough, it will be very, very strong). I can't imagine why one would build something that is weaker even higher than this.
 
Last edited:

benthamitemetric

Senior Member
So over the head it is.
No, I don't understand how/why the towers would not be as strong as my cartoon monolith. That's how their strength is normally described.
Well, I hope you put this on a poster or T-shirt for your next truther rally. It seems to sum up the essence of your thought process quite nicely.

Why were the walls pulled inward during the fires?
 

LilWabbit

Senior Member
Let me attempt to address your argument in less technical language than the experts on the thread but based on what they've tried to explain to you while losing patience in the process:

Now I think I'm gonna be accused of going off-topic again for bringing up WTC 7, but I would argue that I'm not, because this all flows from the initial question of the thread. So you would have to believe the following:

The WTC Twin Towers collapsed because of plane impact and (mostly) the subsequent fires.

Yes.

-->

From this, it logically follows that a collapse could have been initiated with a relatively small amount of explosives, such as 75 pounds, used to attack the trusses.

A collapse, but not the exact same collapse that occurred. A demolition with 75 pounds of explosives you're referring to would also imply other observables, both audial, visual and residual, that haven't been observed.

-->

A much smaller, 30-story steel building was demolished using 364 pounds of explosives.

'A bigger building requires more explosives' is layman's logic that doesn't agree with the physics of scale.

But the reason why it required so much more explosives was only because it had to be brought down in a controlled fashion, whereas the proposed 75 pounds of explosive could only accomplish an "uncontrolled" demolition of the WTC towers.

By and large, yes. With the caveat that layman's logic still doesn't agree with the physics of scale. It may not require more than 365 pounds of explosives to bring down the WTC Twin Towers in a controlled fashion if done intelligently. Experts, feel free to pitch in?

-->

But also, WTC 7 went down in an eerily "controlled" fashion despite zero explosives being used to initiate or control the fall.

Only the final cascading looked similar to a "controlled" demolition to us laymen. But the 7 hours of fires on the 10th floor damaging and weakening the building hardly bespeaks of control. Nor the damage on the Fiterman Hall. Plus, like with the WTC Twin Towers, a controlled demolition would also imply other observables, both audial, visual and residual, that haven't been observed.

So does it take lots of explosives to bring a building down like that, or possibly none at all? It can't be both.

It doesn't really matter since the audial, visual and residual evidence of explosives being used is entirely absent.

I'm not an engineer or physicist, so I can't do any calculations on this stuff.

You don't need to in order to appreciate the basics outlined in the above.

I'm just pointing out that it seems like the starting belief, "WTC towers collapsed because of plane impact and fires", has a number of logically necessary implications that lead you into a messy tangle of contradictions and absurdities.

Not logically necessary as demonstrated in the foregoing.

That shouldn't be the case if the starting belief is true.

Yes.
 

benthamitemetric

Senior Member
I don't know. Do you also think the monolith's walls would be susceptible to it?
No one cares about your cartoon. We've told you why the walls were pulled in. If the cartoon that exists only in your head would behave differently, that just means that cartoon isn't telling you anything useful about the towers. This reminds me of the "Homer Thompson" gag from the Simpsons. "When I step on your foot and tell you that your cartoon is irrelevant and that you need to understand the building we are actually discussing, you smile and nod."
 

Henkka

Active Member
Not controlled enough for whoever owned this building across the street (the link title is self descriptive)
https://en.m.wikipedia.org/wiki/File:Fiterman_hall_damage.jpg
So do you think the collapse of a building can be considered "controlled" only if it lands 100% in its own footprint? 90% won't do?

Also, you seem to be implying that to make a building collapse so that it won't damage nearby buildings, you need lots of "control", meaning explosives. The flipside of that is that a building collapsing with no "control" at all could fall largely outside of its footprint, massively damaging nearby buildings. But often in these debates, people will argue skyscrapers will fall straight down all by themselves, because gravity pulls that way. So again, which is it... Did the Landmark tower require lots and lots of explosives to fall like it did, and then WTC 7 fell in an eerily similar fashion with zero explosives?

None of this is even applicable to the conspiracy debate tbh... Because if the WTC towers were demolished as a part of a criminal conspiracy, obviously the perpetrators had zero qualms about WTC 7 damaging other buildings, as if they were doing a legal and professional demolition lol.
 

Thomas B

Active Member
No one cares about your cartoon. We've told you why the walls were pulled in. If the cartoon that exists only in your head would behave differently, that just means that cartoon isn't telling you anything useful about the towers. This reminds me of the "Homer Thompson" gag from the Simpsons. "When I step on your foot and tell you that your cartoon is irrelevant and that you need to understand the building we are actually discussing, you smile and nod."
Weird. OK. Just stop engaging with my postings, maybe?
 

Henkka

Active Member
No one cares about your cartoon. We've told you why the walls were pulled in. If the cartoon that exists only in your head would behave differently, that just means that cartoon isn't telling you anything useful about the towers.
This is, again, the "begging the question" fallacy.

"If your analogy for the towers doesn't collapse from fire, then it's not a good analogy, because the towers collapsed from fire."

You can't just say that when whether or not the buildings collapsed from fire is the entire dispute.
 

benthamitemetric

Senior Member
Weird. OK. Just stop engaging with my postings, maybe?
No, I'll continue to point out how it makes no sense to focus on a cartoon in your head while ignoring the actual building, while you keep doing what you do best by trolling this forum with your nonsense. If you actually wanted to understand what happened to the towers, you'd now go try to fill in the gigantic gap in your knowledge about why the walls were pulled in, but this is just another instance where you demonstrate by your actions that you are not here to learn anything (or else you are so epistemologically crippled that you cannot).
 

benthamitemetric

Senior Member
This is, again, the "begging the question" fallacy.

"If your analogy for the towers doesn't collapse from fire, then it's not a good analogy, because the towers collapsed from fire."

You can't just say that when whether or not the buildings collapsed from fire is the entire dispute.
Why do you think the walls were pulled in, then? Do you have a better response for us after all this time than "I don't know"?
 

Abdullah

Active Member
What is your estimate of how tall a 200' x 200' box column made of 3" steel plates welded at the corners would have to be before it would buckle in a light wind?
35ft

Euler's buckling equation is

Critical load × area moment of inertia² × boundary condition² = π² × elastic modulus

From which can be derived

Length² × boundary condition² × critical stress = π² × elastic modulus × gyradius²

For a very large 3 inch steel plate:
- elastic modulus us 30,000ksi
-gyradius is 1 inch
-stress from gravity load is between 7 and 20 ksi depending on steel grade
-boundary condition for s fixed fixed column is 0.5

Therefore the length is a minimum of 414" with no wind at all. That means around 35ft.

But this 3" tube is not realistic. The correct thickness is around 1ft. At that thickness, the critical height is 140ft, which is comparable to the plate width, so Euler's equation is useless, and the answer becomes more time consuming
 

Abdullah

Active Member
So do you think the collapse of a building can be considered "controlled" only if it lands 100% in its own footprint? 90% won't do
Kind of. Clearly it wouldn't do for the neighbors.

But often in these debates, people will argue skyscrapers will fall straight down all by themselves, because gravity pulls that way.
Yes, skyscrapers will fall largely straight down by themselves. But not fully, and certainly not enough.
So again, which is it... Did the Landmark tower require lots and lots of explosives to fall like it did, and then WTC 7 fell in an eerily similar fashion with zero explosives?
False choice. It has already been explained how the collapses were dissimilar.
 

Henkka

Active Member
Why do you think the walls were pulled in, then? Do you have a better response for us after all this time than "I don't know"?
Afaik, this is the best clip of the walls being pulled in... Just posting it here for reference:

Source: https://www.youtube.com/watch?v=XvGY6Ann1mY

No-click: Up-close shot of the perimeter columns of WTC 2 being pulled in, and then the collapse

It looks to like the walls are already somewhat pulled in during the first second of the video, and then they're pulled in quite a bit more and they snap as the collapse begins. I think for one, that both things could be true... That the trusses were pulling on the perimeter due to the heat, but also that this did not then cause the subsequent total destruction.
 

benthamitemetric

Senior Member
Afaik, this is the best clip of the walls being pulled in... Just posting it here for reference:

[video omitted]

No-click: Up-close shot of the perimeter columns of WTC 2 being pulled in, and then the collapse

It looks to like the walls are already somewhat pulled in during the first second of the video, and then they're pulled in quite a bit more and they snap as the collapse begins. I think for one, that both things could be true... That the trusses were pulling on the perimeter due to the heat, but also that this did not then cause the subsequent total destruction.
Great. Maybe try explaining the trusses pulling the walls in to our friend Thomas "I don't understand how/why the towers would not be as strong as my cartoon monolith" B. He still doesn't get it. And so it seems with you at least we are just back to the start with you not believing the plane impacts + fires would cause enough damage to initiate the total collapse, but, once that collapse initiated, you understand why it would progress to the ground through all the floors at least. It's been a long time since a truther came around thinking that the collapse initiation, which we can all see clearly happened on floors that were damaged and fully involved in fires, needed some alternative explanation.

What's your theory for what initiated the collapse?
 

Henkka

Active Member
And so it seems with you at least we are just back to the start with you not believing the plane impacts + fires would cause enough damage to initiate the total collapse, but, once that collapse initiated, you understand why it would progress to the ground through all the floors at least.
This seems to be a misunderstanding from when you asked me what would happen if the entire mass of the one of the top blocks was applied to a single floor. I said yeah, it would collapse, because the floors were just designed to hold up people and furniture, not an entire 12 or 28-story building. The thing is I don't believe that this is at all what happened, or could ever happen, because the core is in the way.
 

benthamitemetric

Senior Member
This seems to be a misunderstanding from when you asked me what would happen if the entire mass of the one of the top blocks was applied to a single floor. I said yeah, it would collapse, because the floors were just designed to hold up people and furniture, not an entire 12 or 28-story building. The thing is I don't believe that this is at all what happened, or could ever happen, because the core is in the way.
In the way of what? The initiation or the progression?
 

Henkka

Active Member
In the way of what? The initiation or the progression?
In the way of the "entire mass" of a top block being applied only to a floor. In my mind, the core would catch a ton of that weight if the top block started coming down somehow, causing a clear deceleration if not totally arresting the collapse.
 

Abdullah

Active Member
In the way of the "entire mass" of a top block being applied only to a floor. In my mind, the core would catch a ton of that weight if the top block started coming down somehow, causing a clear deceleration if not totally arresting the collapse.

Instead of
1-giving way through the same floor failure mechanism
2- Not catching a ton of that weight because the top block fell apart and crashed through the office floors?
 

benthamitemetric

Senior Member
In the way of the "entire mass" of a top block being applied only to a floor. In my mind, the core would catch a ton of that weight if the top block started coming down somehow, causing a clear deceleration if not totally arresting the collapse.
The entire weight of the top block didn't need to be applied to the next floor to fail the next floor. NIST's very conservative calculation only included the weight of the floor systems in the top block. They excluded the weight of all of the columns in the top block. And they excluded the momentum of the top block. So only a fraction of the weight of the top block would be needed to fail the floors, and there is no reason to think that fraction of weight would not ultimately come into contact with those floors after the initiation. Anyway, you're obviously not going to come around on this point any time soon if you still haven't wrapped your head around what weight we are actually talking about.

So what is your theory for what initiated the collapse?
 

Henkka

Active Member
The entire weight of the top block didn't need to be applied to the next floor to fail the next floor. NIST's very conservative calculation only included the weight of the floor systems in the top block. They excluded the weight of all of the columns in the top block. And they excluded the momentum of the top block. So only a fraction of the weight of the top block would be needed to fail the floors, and there is no reason to think that fraction of weight would not ultimately come into contact with those floors after the initiation.
I could grant you all that for the sake of the argument, but I still think you're describing an entirely different event than what we saw happen. To me, it sounds like you're describing the floors being sort of stripped off of the core. You've implied that after the core columns lost lateral support of the floors, they would fail also, but I don't think you cited anything to back that up. The core columns were laterally braced between themselves. So chronologically, you seem to be saying the floors failed first, and then the core. But according to FEMA, this did not happen, and the collapse began in the core:


https://www.fema.gov/pdf/library/fema403_ch2.pdf Page 27

So the first visible downward movement was that of the transmission tower, which sat on the hat truss, which sat on the core columns. How does that fit into your theory of the core columns failing only after they lost lateral support from the floors?
 

Thomas B

Active Member
35ft

Euler's buckling equation is

Critical load × area moment of inertia² × boundary condition² = π² × elastic modulus

From which can be derived

Length² × boundary condition² × critical stress = π² × elastic modulus × gyradius²

For a very large 3 inch steel plate:
- elastic modulus us 30,000ksi
-gyradius is 1 inch
-stress from gravity load is between 7 and 20 ksi depending on steel grade
-boundary condition for s fixed fixed column is 0.5

Therefore the length is a minimum of 414" with no wind at all. That means around 35ft.

But this 3" tube is not realistic. The correct thickness is around 1ft. At that thickness, the critical height is 140ft, which is comparable to the plate width, so Euler's equation is useless, and the answer becomes more time consuming
That seems very short to me. Is this because the faces are so wide (200'), and you're treating each of them just as freestanding sheets of steel? (I don't see where the crosssectional area of the entire 200'x200' box column enters your calculation.)

I mean, suppose they were only 2' squares, then they'd surely be able to go taller than than the 213' in the textbook example?

mastexample.JPG
Source: https://ocw.mit.edu/courses/2-080j-structural-mechanics-fall-2013/resources/mit2_080jf13_lecture10/
 

benthamitemetric

Senior Member
I could grant you all that for the sake of the argument, but I still think you're describing an entirely different event than what we saw happen. To me, it sounds like you're describing the floors being sort of stripped off of the core. You've implied that after the core columns lost lateral support of the floors, they would fail also, but I don't think you cited anything to back that up. The core columns were laterally braced between themselves. So chronologically, you seem to be saying the floors failed first, and then the core. But according to FEMA, this did not happen, and the collapse began in the core:


https://www.fema.gov/pdf/library/fema403_ch2.pdf Page 27

So the first visible downward movement was that of the transmission tower, which sat on the hat truss, which sat on the core columns. How does that fit into your theory of the core columns failing only after they lost lateral support from the floors?
You keep conflating initiation and progression in a way that is not helpful. And I'm at a loss for why you are going back to FEMA's preliminary report, but whatever.

Are you talking about why the core failed at the initiation or why the rest of the core failed after the floors failed during the progression? Do you even understand that we are talking about two different types of failures at two distinct points in time in the collapse?

And, I repeat, because I know you are dodging: What is your theory for what initiated the collapse?
 

Henkka

Active Member
And I'm at a loss for why you are going back to FEMA's preliminary report, but whatever.
The observation that the transmission tower started coming down first is still valid, even if much of the report is now outdated. I'm unaware if NIST ever addressed this observation.
Are you talking about why the core failed at the initiation or why the rest of the core failed after the floors failed during the progression?
Both are puzzling to me. No, I don't understand why the core failed initially. But if we just ignore that for a moment and make the top block of the core start coming down magically, I think that would be followed up by a significant impact and deceleration, which was not observed.
And, I repeat, because I know you are dodging: What is your theory for what initiated the collapse?
Well, rather than a theory, I would say that my approach is that we "eliminate the impossible", and what remains after that must be what happened.
 

benthamitemetric

Senior Member
The observation that the transmission tower started coming down first is still valid, even if much of the report is now outdated. I'm unaware if NIST ever addressed this observation.

Both are puzzling to me. No, I don't understand why the core failed initially. But if we just ignore that for a moment and make the top block of the core start coming down magically, I think that would be followed up by a significant impact and deceleration, which was not observed.

Well, rather than a theory, I would say that my approach is that we "eliminate the impossible", and what remains after that must be what happened.

Well, when you can show that the building could withstand the impacts + subsequent fires, please let us know. NIST modeled them out in excruciating detail and demonstrated that they were the likely cause of the collapse. You have not presented any actual reason, whether technical or logical, that the buildings could survive those scenarios. You've just been reduced to going in circles about completely hypothetical and irrelevant explosive scenarios, to which your only contribution is "nuh-uh, I don't believe 'em."

And you haven't offered any reason for us to believe that the lower block could arrest the upper block once it started moving. You just imagine somehow that the lower columns were going to reach out and grab the top block and re-connect it in midair and then hold it tight, even after it slipped past the initial columns that failed and even though it is now abundantly clear to you that none of the floor systems could go anything to stop the falling mass.

You thus haven't eliminated anything.
 
Last edited:
Top