Hardfire: Physics of 9/11

[Tony Szamboti]

In my experience a large proportion of structural engineers can easily become fixated on a minor aspect of design and lose sight of the bigger picture.

The issue currently dominating discussion of Tony's material here is his "Missing Jolt" paper. That paper has lost sight of the bigger picture. It wrongly interprets the actual collapse mechanisms which occurred in similar fashion with the two tower collapses on 9/11.

The critical stages of those collapse mechanisms were:
(1) an initial failure of the impact zone which was a rolling cascade process which quickly but still progressively allowed the "top block" to start to descend.
(2) That descent transitioned into a global collapse which occurred when the falling top block fell inside the outer tube of columns and (mostly) missing or surrounding or partly striking a core which was effectively very much weakened by the manner of load application under failure.
(3) Then pancaking of the floors resulted in a rapid sequential global collapse.

Tony's "missing jolt" is premised on a clear stage of falling top block - after it started to move - meeting a strong resistance. That strong resistance was not there so Tony concludes "no jolt therefore demolition".

Wrong on two parts of the basic premises. Hence my earlier comment that "structural engineers get lost in detail and lose the big picture".

Those two parts which are wrong in time reversed order:

(1)There was no resistance significant to cause any large jolt which would noticeable/measurable by Tony's technique. No outer columns to cause it, few bits of core; AND

(2) There was no free fall of the top block OR fall close to free fall to create the impetus which could crush the columns - but it didn't have to crush columns. The falling mass was more than sufficient to overcome friction and shear the floor joist to column connectors.

The falling impetus was overwhelming for the latter task - overcome floor connectors of one floor at a time plus a bit of residual core strength and some friction of top block on columns.

BUT no matter how large that falling impetus the floor joist connections et al were not strong enough to resist sufficient to show measurable jolt.

So the missing jolt explanation fails like so many in that it does not apply to the mechanism of collapse which actually occurred.

And that is the point where I usually decline to pursue the particular hypothesis further. It does not match the real world of 9/11 so forget it.

(With the thermate claims; -ite; -ate or nano- I don't even bother going that far. There is simply no way that any of the three could cause or contribute to the collapse mechanisms which actually happened WTC 1 or 2 even if we ignore the logistic 99.9% improbability of -ite or -ate being able to be used.)

It would be interesting if you could prove your theory, that the building could collapse with no observation of velocity loss in the upper section, with a model. Even a virtual model. I tend to doubt it can be done.

 

[dafydd]

I design structures for a living

Lego?

 

[9/11 Chewy Defense]

It would be interesting if you could prove your theory, that the building could collapse with no observation of velocity loss in the upper section, with a model. Even a virtual model. I tend to doubt it can be done.

Tony,

Everyone saw the upper section collapse onto the remaining structure with its own mass going at its own velocity.

If you crash your car, what would happen to you if you had no seat belt or airbag?

A: Your body would keep going through the windshield
B: Your body will stop
C: You'll remain in your seat
D: Nothing!

 

[Tony Szamboti]

Tony,

Everyone saw the upper section collapse onto the remaining structure with its own mass going at its own velocity.

If you crash your car, what would happen to you if you had no seat belt or airbag?

A: Your body would keep going through the windshield
B: Your body will stop
C: You'll remain in your seat
D: Nothing!

Of course, this would all depend on the deceleration of the vehicle at the driver's seat, but your body would accelerate at that rate and if there is enough acceleration would hit and possibly even go through the windshield. However, if the windshield could take more force than your static weight then you would have to decelerate and lose velocity while breaking through it. That does not mean you would necessarily stop since that depends on how much energy dissipation would occur and how much your body had at impact.

 

[9/11 Chewy Defense]

Of course, this would all depend on the deceleration of the vehicle at the driver's seat, but your body would accelerate at that rate and if there is enough acceleration would hit and possibly even go through the windshield. However, if the windshield could take more force than your static weight then you would have to decelerate and lose velocity while breaking through it. That does not mean you would necessarily stop since that depends on how much energy dissipation would occur and how much your body had at impact.

Then why are you griping that the top sections of both Towers couldn't have caused themselves to collapse onto the existing sections below them? Since the tops were heavy & couldn't be stopped once the collapses occured.

Can you explain how in the hell could anything be possible that would not result in a total collapse of a structure due to plane damage, fire & gravity? The Towers weren't built like a brick ****house!

 

[Tony Szamboti]

Then why are you griping that the top sections of both Towers couldn't have caused themselves to collapse onto the existing sections below them? Since the tops were heavy & couldn't be stopped once the collapses occured.

Can you explain how in the hell could anything be possible that would not result in a total collapse of a structure due to plane damage, fire & gravity? The Towers weren't built like a brick ****house!

The lower sections of the buildings were designed to handle several times the load above them. The upper section load would have to be amplified to break the lower section and that requires deceleration greater than 1g. That means velocity loss. There is no velocity loss at any time in the measured fall of the upper section of WTC 1.

 

[9/11 Chewy Defense]

The lower sections of the buildings were designed to handle several times the load above them. The load would have to be amplified to break the lower section and that requires deceleration greater than 1g. That means velocity loss. There is no velocity loss at any time in the measured fall of the upper section of WTC 1.

The WTC designs were constructed to work together. That means the outter columns that were connected to the floors which in turn were connected to the inner columns. You comprimise any section by plane damage & fire that structure isn't going to last long. Plus the Towers were tube within a tube design, the first ever design for large buildings.

Until you come up with a CGI model that shows you're thermite/explosive theory then I'll accept anything you throw at. You're a mechanical engineer for crying out loud, get off your ass & do something to prove what you say is true!

 

[ozeco41]

It would be interesting if you could prove your theory, that the building could collapse with no observation of velocity loss in the upper section, with a model. Even a virtual model. I tend to doubt it can be done.

Tony I did not say, in the possibly ambiguous terms you use, that there was either:

(1) "no observation of velocity loss in the upper section" - which depends on how large the velocity loss was. Note specifically I did not say "no observable velocity loss in the upper section", which depends on how small you can observe; NOR

(2) did I suggest/agree to what could be inferred as a single step velocity loss. The contact of top block to lower stub tower was more akin to two wire baskets sequentialy impacting element after element. The nature of the impact was multiple little jolts from multiple element on element contacts overlapped and sequenced in a complex mess.

I am aware that my use of the wire basket example was taken out of context and misused by another member - ignore that.

By its nature the top block on lower stub impact was "soft edged" therefore no need, rather no basis to form a "big jolt" unless explosive removal of supports is presumed - and that surely gets a bit circular.

The central point of my post, and several others on similar point made previously, is that the premise of your model is wrong. It does not fit what actually happened.

You have suggested that I support my explanation/hypothesis/theory. I am quite prepared to do just that at an appropriate time, or reference the other forum where it is all laid out.

So far all I have attempted in this thread is to point out the misfit with your model. I don't want to commit the discourtesy of "mind reading" by pointing out where I incline to believe your thinking may have gone astray.

However there are two possible starting points to explaining the "initial collapse". Both require sufficient weakening of the impact zone to a stage where it will not support the top block. Those two, broadly stated are:

1) The initial damage and ongoing weakening processes reach a "cascade" point where weakening causing transfer of loads reaches the point where there is not sufficient reserve strength to transfer load to. Such a process progresses at exponential increasing speed.

2) Given that the progressive weakening referred to above was progressing to some stage, the second starting point is that explosive or pyrotechnic devices were used to assist those processes. Yes the explosive etc stuff could have been of sufficient capacity to succeed without the initial and fire damage.

Those are the two broad possibilities.

They lead to two significantly different scenarios.

A) The "cascade" process either without explosive assistance or with just sufficient assistance to ensure failure leads immediately into a soft transition to the global collapse. There is no "space/time" for your jolt scenario to arise.

B) If a "sufficient by itself" demolition scenario existed it could lead to your scenario but it would have to be explosive for "instant" effect. There is no evidence of such explosives usage AND (The area where truthers resist debate) it is a logistic near impossibility to install same.

And naturally use of thermate etc as the "Sufficient by itself" incendiary overwhelmer presents timing problems which puts it back into my scenario of a "soft transition - no jolt".

Through both of these scenarios a key factor is that from the initial collapse the outer tube columns were effectively "out of the game" because the "top block" fell inside the outer tube. And the core must also have been disabled but to a lesser extent and not directly observable.

The natural processes cascade failure ensured that there was not sufficient column strength resistance to cause the 'big jolt".

 

[DGM]

The lower sections of the buildings were designed to handle several times the load above them. The upper section load would have to be amplified to break the lower section and that requires deceleration greater than 1g. That means velocity loss. There is no velocity loss at any time in the measured fall of the upper section of WTC 1.

There would have to be, If not the building would have fallen at "free-fall". Something slowed it down. Unless I misunderstand what your implying.

 

[Tony Szamboti]

There would have to be, If not the building would have fallen at "free-fall". Something slowed it down. Unless I misunderstand what your implying.

You are misunderstanding and since this question has been asked dozens of times and answered about that many times, I hope you don't mind if I ask you to go back and review those earlier posts on the several threads where this issue has been discussed.

 

[beachnut]

The lower sections of the buildings were designed to handle several times the load above them. The upper section load would have to be amplified to break the lower section and that requires deceleration greater than 1g. That means velocity loss. There is no velocity loss at any time in the measured fall of the upper section of WTC 1.

This is classic no physics stuff. Sampling theory and the fact that the real world is not a model make your claim of no velocity loss bogus. With a simple model of momentum transfer we see the WTC collapse times matched for the floors failing. You want reality to be like a model.

Gravity and physics are not used in your rarefied world of paranoid delusions where the big bad government does all the conspiracy theories in your delusions on 911.

Physics shows the gravity collapse of each WTC tower released over 130 tons of TNT kinetic energy. Is that enough amplification? Yep

The realcddeal, is a preconceived delusion based on some unknown bias of yours and the other engineers who have failed ideas on 911.

 

[ozeco41]

...... You want reality to be like a model....

Which is precisely the point I made and explained in some detail a few posts back.

 

[ozeco41]

The lower sections of the buildings were designed to handle several times the load above them. The upper section load would have to be amplified to break the lower section and that requires deceleration greater than 1g. That means velocity loss. There is no velocity loss at any time in the measured fall of the upper section of WTC 1.

Here your false premise assumption is out in the open protected only by a bit of ambiguity. We only need to insert a couple of the words you omit to make your false starting premise obvious.

The COLUMNS OF THE lower sections of the buildings were designed to handle several times the load above them. <<<STOP RIGHT THERE

(My emphasis and comment added.) The top block did not fall onto the outer tube columns of the lower tower AND the core of the top block could not have landed on the lower core with anywhere near full original load capacity of the core columns.

Given that your starting point is wrong the following conclusion is also wrong.

...The upper section load would have to be amplified to break the lower section <<<STOP AGAIN

(My comment again)... rethink here Tony. What "lower section" had to break?
This, by inference seems to mean the strength of the intact lower section - essentially the columns for vertical load bearing. WRONG!!!

The "Top Blocks" fell inside the outer tube. All that had to break was the floor joist to column connectors designed to hold the static and dynamic loading of ONE FLOOR only. (Yes I can explain the core but lets get the easy bits out of the way first.)

And the rest falls to one side as irrelevant and unsupported....

... and that requires deceleration greater than 1g. That means velocity loss. There is no velocity loss at any time in the measured fall of the upper section of WTC 1.

 

[Tony Szamboti]

Here your false premise assumption is out in the open protected only by a bit of ambiguity. We only need to insert a couple of the words you omit to make your false starting premise obvious.

(My emphasis and comment added.) The top block did not fall onto the outer tube columns of the lower tower AND the core of the top block could not have landed on the lower core with anywhere near full original load capacity of the core columns.

Given that your starting point is wrong the following conclusion is also wrong. (My comment again)... rethink here Tony. What "lower section" had to break?
This, by inference seems to mean the strength of the intact lower section - essentially the columns for vertical load bearing. WRONG!!!

The "Top Blocks" fell inside the outer tube. All that had to break was the floor joist to column connectors designed to hold the static and dynamic loading of ONE FLOOR only. (Yes I can explain the core but lets get the easy bits out of the way first.)

And the rest falls to one side as irrelevant and unsupported....

You keep saying the perimeter of the upper section fell inside of the perimeter of the lower section as though it is a given. There is no proof of this in the initial fall of the upper section.

In reality what happened is the first several floors at the bottom of the upper section broke apart. How does that factor into your thinking?

 

[R.Mackey]

... and yet another thread has been dragged off-topic.

This is not a thread to discuss Tony's monomaniacal fixation on his mythical "missing jolt." Discussions of the impact and first-principles models are on topic, but his pet belief is not.

Although I appreciate Tony's comment that he agrees with the estimates of impact damage. See? Some common ground.

 

[ozeco41]

... and yet another thread has been dragged off-topic.

This is not a thread to discuss Tony's monomaniacal fixation on his mythical "missing jolt." Discussions of the impact and first-principles models are on topic, but his pet belief is not.

Although I appreciate Tony's comment that he agrees with the estimates of impact damage. See? Some common ground.

I understand the concern however the concept that a model should match the prototype, that a model should be analogous to reality, that a model of the twin towers collapse should model how those towers actually collapsed is surely "first principles".

Tony has shown more understanding than you acknowledge in your focus on denigrating his "pet belief". The more important common ground IMHO is that he counters my bold assertion that the "top block" fell inside the outer tube with his own equally bold assertion that:

...In reality what happened is the first several floors at the bottom of the upper section broke apart. How does that factor into your thinking?

The reality was that the bulk of the falling top block fell inside the outer tube whether it was broken into pieces or still as intact floors. At what point it actually fully fell apart matters little. The critical fact is that the falling mass impacted on the floors below and was not resisted significantly by column strength other than the strength to hold the floor joists enough to fracture the joist to column connectors.

And the most important aspect of Tony's counter bold assertion is that he recognises that breaking of the top block was part of the mechanism of transition from "initial collapse" to "global collapse".

The reality here is that my statements so far have avoided specifying at which stage the top block disintegrated. Tony's claims that the floors fell apart early may be true. I suspect the reality is a more complex mix with disintegration somewhat later than he claims. But it makes no difference to the overall collapse mechanisms and Tony's own bold assertion denies his "big jolt" although he possibly does not realise it at this stage.

So Tony's form of "breaking up" is inimical to his jolt theory because it is an element by element process. It does not have the "column on column impact invoking near full column strength" which is essential to the "big jolt theory"

So surely that "one small step" in assisting Tony to unravel his thinking is worth a minor deviation of topic.

PS And I am aware of several "loose ends" that the above explanation glosses over in the interests of brevity. My purpose is to get the broad outline on the table and engage Tony in discussion rather than continue the tirades of abuse directed at him.

 

[R.Mackey]

Tony has shown more understanding than you acknowledge in your focus on denigrating his "pet belief". The more important common ground IMHO is that he counters my bold assertion that the "top block" fell inside the outer tube with his own equally bold assertion that: [...]

So surely that "one small step" in assisting Tony to unravel his thinking is worth a minor deviation of topic.

No, it's not. Absolutely not. There are several other threads and 50+ pages of discussion that cover precisely these points. I debated him and brought these up live on Hardfire. All of this has no effect, as it always doesn't where the Truth Movement is concerned. Get it out of this thread.

 

[ozeco41]

No, it's not. Absolutely not. There are several other threads and 50+ pages of discussion that cover precisely these points. I debated him and brought these up live on Hardfire. All of this has no effect, as it always doesn't where the Truth Movement is concerned. Get it out of this thread.

I recognise your "earned right" as one of the established leaders of debate on this forum. And I also understand that your prediction as to the waste of effort in debate with Tony is probably correct.

That does not excuse your rudeness towards me as another member nor any presumption that you are the only one who understands WTC collapse on 9/11.

However I will leave your personal thread for the OP.

Just muse on this point. Why did you choose to attack me out of all those who have posted off topic?

Eric C

 

[R.Mackey]

Just muse on this point. Why did you choose to attack me out of all those who have posted off topic?

And now we have a derail on derails themselves...

You neglect to note that my original reminder didn't single out anyone, but was a broad-spectrum request. I singled you out after you argued with that request. And if you had any idea how many derails I report, you wouldn't ask such a silly question in the first place. Finally, if asking you to follow the rules strikes you as rude, that's your problem.

Next time, I'll just go straight to the mods, if that's how you like it.

 

[Furcifer]

I recognise your "earned right" as one of the established leaders of debate on this forum. And I also understand that your prediction as to the waste of effort in debate with Tony is probably correct.

That does not excuse your rudeness towards me as another member nor any presumption that you are the only one who understands WTC collapse on 9/11.

However I will leave your personal thread for the OP.

Just muse on this point. Why did you choose to attack me out of all those who have posted off topic?

Eric C

oz- just an aside. I've derailed my fair share of Ryan's threads. You see a topic, you click on it, you read about 20 posts, and the actual OT is usually so far gone you stand very little chance of accidentally hitting upon it.

This has no bearing on you, your post or your intention. Not even close.

What I recently discovered is that some people take their threads very seriously. They put extra effort into responding to posts, making very detailed analysis or observations.

Trying to maintain that under the best of circumstances is difficult. You come back to a thread with 100 off topic posts you have to sift through and evaluate in order to keep some focus on your original topic.

Anyhoo, I'm not sure if you get this. I didn't really until late. I thought Ryan was kinda being a dick. What I didn't consider is the time and effort he actually puts into responding to the things he actually wants to talk about. Maybe not what he "wants" to talk about, but what he's willing to focus in any given thread.

I say he's a sucker for even trying, but hey, that's what he wants so I respect it. (plus you have to pity him, he has a very weak palette, he probably prefers whites to reds but isn't willing to admit it)