Is there a legitimate reason to question the official narrative*?

[ozeco41]

How are you defining "irrational"?

Anything which is not rational. I also described your claims as "nonsense" and your post continues the same level of childish nonsense:

Do you think it's possible for the steel in the WTC towers to have gotten as hot as it did in the UL truss system burn tests?

If so, what energy source got them that hot? (We know it's impossible for the office materials to have done so in the towers. This was also confirmed by the UL office burn tests.)

If not, how can steel fail at lower temps for less time? (It can't.)

There is a definite lack of rationality around here, but it doesn't take much analysis to see where it's coming from. If you think NIST is correct and there's no reason to doubt the major claims of the report, then how do you account for the energy gap between what's necessary for the steel to fail and the amount of office material available for fuel?

These are NOT rhetorical questions.

I will not be responding to nonsense no matter how many times you repeat it. Your posts show no understanding of the relevant physics. I understand the physics and can explain it so I'll repeat my offer just this once:

If you decide to get serious I am prepared to explain the relevant physics one issue at a time starting with either:
A) Any rational response from you to one of my reasoned explanations of why each and every column which failed in axial overload was "hot enough" to fail; OR
B) your rational response to my explanation of why load redistribution following a removal of a proportion of columns is always WORSE than the proportion of removed columns.

Both those topics are central aspects needed to comprehend the WTC Twin towers collapses which you clearly do not understand.

I have specifically and rigorously addressed each of those topics with rational argument. I challenge you to respond rationally to my explanations.

Your call. Why not get serious and learn?

 

[BasqueArch]

I have.

For WTC 7
In a model if you were to take down the east penthouse high in the building by removing column 79 above the 40th floor and then remove all 24 core columns between the 14th and 21st floors you will see the collapse occur just like you do on video.

For WTC 1
In a model if you were to remove all 48 core columns at the 98th floor and then between the 99th and 101st floors you will see the collapse initiate just like you do on video. Then keep cutting the corners of the exterior and you will see the collapse propagate just like you do on video.

Sure. And if my aunt had balls she'd be my uncle.

 

[JSanderO]

How are you defining "irrational"?

Do you think it's possible for the steel in the WTC towers to have gotten as hot as it did in the UL truss system burn tests?

If so, what energy source got them that hot? (We know it's impossible for the office materials to have done so in the towers. This was also confirmed by the UL office burn tests.)

If not, how can steel fail at lower temps for less time? (It can't.)

There is a definite lack of rationality around here, but it doesn't take much analysis to see where it's coming from. If you think NIST is correct and there's no reason to doubt the major claims of the report, then how do you account for the energy gap between what's necessary for the steel to fail and the amount of office material available for fuel?

These are NOT rhetorical questions.

You seem to think the word "fail" is ONLY something like fracture or buckle. The ENTIRE frame can fail if, for example steel members expand and push columns out of alignment or shear bolts and fracture welds... leading to loss of axial capacity... load redistribution and so on. The sagging trusses may not have been the straw that broke the camel's back. That was only one theory of NIST.

Ironically the floor system and those wimpy trusses DID play a role in the collapse... progression... but probably not in the initiation of it. As such stone cold trusses and floors "failed" from superimposed massive dynamic loads.

 

[jay howard]

This is really a rather stupid question. As the steel in the WTC towers wasn't protected by fireproofing and was subject to uncontrolled office fires which would have include - for example - plastics, which burn at significantly higher temperatures than wood and paper,...

No they don't. Not according to the people you are defending.

Are you trying to argue that the liquid hydrocarbon they used to start the workspace fires and which they used to heat the trusses up with burn at a lower temperature, less consistently than your magic plastic?

Again, you must presume some ridiculous premise in order to protect the NIST theory of collapse.

 

[DGM]

No they don't. Not according to the people you are defending.

Are you trying to argue that the liquid hydrocarbon they used to start the workspace fires and which they used to heat the trusses up with burn at a lower temperature, less consistently than your magic plastic?

Again, you must presume some ridiculous premise in order to protect the NIST theory of collapse.

The part you're not getting is the temperatures of the trusses doesn't matter in understanding the whole picture. It's one part of a complex equation.

The trusses would pull on the columns but, the heated over-loaded columns would also load the trusses (causing them to sag more).

Early you mentioned gravity as the only other force outside of heat. This is still wrong.

 

[Dave Rogers]

No they don't. Not according to the people you are defending.

Are you trying to argue that the liquid hydrocarbon they used to start the workspace fires and which they used to heat the trusses up with burn at a lower temperature, less consistently than your magic plastic?

Again, you must presume some ridiculous premise in order to protect the NIST theory of collapse.

Your view of the nature of controlled testing appears to be roughly on the level of a three-year old. You seem to think that NIST said, "Hey, let's get some floor trusses as hot as we possibly can, then see if they collapse!" and then had to make excuses when they didn't. In reality, the heating applied by NIST followed a precisely controlled temperature profile to match the testing applied to any other assembly needing a fire rating, and not to match the temperature of any specific set of fires. In particular, it was never intended to match the temperatures attained by the floor assemblies in the actual WTC fires; rather, it was intended to compare their performance with other assemblies, for which the temperature profile needs always to be the same.

Seriously, do you not understand the concept of a standardised test?

Dave

 

[ozeco41]

Sure. And if my aunt had balls she'd be my uncle.

 

[JayUtah]

...the people you are defending.

You insist on framing the discussion in these terms. No one is here because they intend to defend NIST or any other organization. Everyone here is an independent, private citizen disputing your claims according to their own reasons.

Despite your frantic plea for relevancy, that's all you get. You need to warm up to the reality that your conspiracy theories fly very, very far under the radar of the relevant fields of study and professional practice. Despite your desire to "do battle" with NIST, we are not their proxies or designates.

 

[BasqueArch]

Can everyone see how Chainsaw feels the need to insert ludicrous statements in order to keep from revising the NIST theory?

I know you're not familiar with this test, because if you read the time/temp curves you would clearly see they are measuring at various places on the steel itself.

For anyone keeping score, he's claiming that the UL scientists responsible for measuring heat at the surface of the steel decided instead to measure the air temperature in the insulation layer around the steel. So, the 800C STEEL temperature (for about an hour) I keep referring to, Chainsaw is saying that's the temps of the air in the insulation. Which of course, is not true. But it serves a purpose:

That keeps him from digesting the fact that the steel did not fail even after almost an hour at 800C. Now we all know that they weren't referring to SFRM temperatures, but the structure of these conversations is such that "debunkers" get to claim any crazy ******** they want in order to keep from making any corrections to the official narrative.

But because Chainsaw knows that these tests disconfirm any kind of heat-induced collapse theory, so he's playing defense as best he can.

And 20 seconds on el Google produces this from NCSTAR 1-5B:



So, either you are unable to read or unwilling. Or you are perpetuating a purposeful misunderstanding. Any way you cut it, you are flat wrong. Maybe they did measure the temperature of the SFRM, but the temperatures I'm talking about were STEEL temps: 800C for about an hour. Loaded to the maximum psf. No failure modes. No way around it.

Stop protecting a bunk theory. If you're a "debunker", this would be a good time to start doing some debunking of the bunk theory in your back pocket.

It's laudable that you are trying to find evidence to justify your conspiracist opinions, but good intentions are not enough. You are out of your depth here, not having an engineering education and experience. This has been studied and quantified by a number of leading experts.

Either Usmani or Arup or both showed that the insulation would have made little difference in the joists' failure but for the time. The joists failed not in bending but in buckling. Usmani showed it was a function of both temperature and number of adjacent floors involved, even discounting for the planes' damage. Higher temperature, fewer floors, lower temperature more floors. The perimeter columns progressively lost bracing and bent over time and then failed.

What engineering professionals consider worth listening to, learning from is totally different from the seat of the pants opinions you express here.
The 3 towers failed due to fires not a CD conspiracy.

 

[ozeco41]

And the Gish Galloping AKA "Whack-a-Mole" continues.

By now even jay howard must realise that we know he is wrong - no matter how many times he repeats the errors.

I have - true to my preferred style - taken the alternate path of explaining what is right. i.e. explaining what really happened. Same result with jay howard as with Tony Szamboti - both of them run away. jh with more Gish Galloping.

The true explanation of the cascade failure initiation depends on a number of "building blocks" of applied physics.

I've already recently repeated my first level reasoned explanations for two of those building blocks which are:
A) An outline explanation of why each and every column which failed in axial overload was "hot enough" to fail;
B) A thought experiment to explain why load redistribution following a removal of a proportion of columns is always WORSE than the proportion of removed columns.

DGM has identified another aspect - inward bowing and joist pull in - where the key issue of misunderstanding is failure to realise that joist sag DOES NOT need to cause all the pull in which was observed. Once inward bowing passes a critical point ("p delta") the bowing will continue "under its own steam".

There are two other obvious building block issues to explain:
A) Where and how in 3D the processes of load redistribution progress; AND
B) Why "cut columns" mixed in among those failing in axial overload do not change the overall logic.

AND cut columns includes BOTH those cut by aircraft and those which (may have been) cut by CD. The silly ruddy building is not smart enough to tell the difference* - if they were cut they were cut. CD or aircraft is irrelevant.

So all you members who are thinking through this issue - are there any other building blocks of logic which are needed? Top level issues not details?



* I cannot resist the "aside".
Have any of you noticed how many truther claims impute cognitive intelligence to the collapsing building.

They claim that CD collapses are different to "natural" ones? Without realising that the silly building lacks the brains to decide to collapse differently when CDed to how it has to collapse "natural".

Building thinks: "I'm collapsing...mmmm...I was started by CD....now let's remember how am I supposed to collapse from CD? Aha! "Hey - Column 75 - your turn comes after beam 902. And remember you have to fall at free fall speed - its CD not natural"

 

[Redwood]

Thanks to NoahFence, Oystein and ChrisMohr for attempting the thought exercise.

This was the exercise - a simplified model resembling the WTC Twin Towers situation - and I will overlay << the answers:
[qimg]http://conleys.com.au/webjref/3colsmodela.jpg[/qimg]
So just three rows of columns.
They are carrying loads of L=100, C= 200 and R=100.

Step #1
The Top Block we assume rigid. Cut out all of row "R"
Q 1A What happens to the loads in "L" and "C"? << L becomes ZERO C becomes 400
Q 1B Does the Top Block move? << No. It balances (precariously) on "C"

Step #2
The Top block is really slightly flexible as with any steel framed structure.
Again remove row "R"
Q 2A What happens to the loads in "L" and "C"? << As previously L becomes ZERO C becomes 400 fora brief instant then
Q 2B Does the Top Block move? << It topples to the right
Q 2C Why (or why not)? << Because the Top Block "sags" over the pivot C causing the CoG to drift slighty right of C >> topple.

I will obtain 3 mini Mars Bars and hold the prizes for collection next time any of you three are down this way.

OK mark your own papers. I didn't overlay the issue with disclaimers about near enough. So Oystein did a good job of identifying what he sees as the second order issues.

I disagree slightly. I think he has picked the third order ones and skipped over second. Oystein - not making a big issue of it but my engineer’s gut feeling is that the (near enough) static explanation of elastic sagging would dominate over your dynamic interpretations. Second order over third order. The elastic nature of the top structure and the supports not sufficient to allow the movements and velocities you identify to have sufficiently large effects. I agree with your qualitative assessments but suggest they are quantitatively too small. Similarly your 600 IMO too optimistic.

However the exercise demonstrates clearly the points I wanted everyone to grasp.

Removal of a proportion of columns will almost always weaken the structure by more than the proportion of columns removed.

Removal of 25% of the overall load capacity has a 100% increase in load on the most affected columns. Obviously the sort of effect that would be critical in a cascading failure scenario.

Repeat it with 100-100-100 initial loads and the C load becomes 300.

Sure both of the examples are worst case scenarios BUT the point is the same. Removal of a proportion of columns does not have a proportional effect on load redistribution.

It indirectly proves my secondary points - the real effect will NEVER be less than proportional and with one unlikely exception ALWAYS worse.

Now the challenge is to get Tony Szamboti, jay howard et al accepting that building block fact of physics as part of the overall real event.

And the next stage is to overlay heat effects and once again show why the columns which collapsed from axial overload all got "hot enough" to buckle/fail.

Or, to put it in simple terms which Joe Average already understands intuitively, there's a heckuva difference between removing 20% of a building's support on just one side, and 20% of the support spread evenly around the building. Which is why Joe Average just yawns when a Truther tries to make this argument to him.

 

[Jango]

Making the same claim time and again after being repeatedly shown how wrong you are.



Insulated steel vs uninsulated steel....on;y a troofer would think it would not.


Personal incredulity and ignorance does not make your fantasy a reality.

Of course it can......the test was not about real world condition......something you continuously hand wave away.


You said that looking in a mirror I expect.



There is no gap......your personal incredulity does not make your fantasy come true.

Did NIST have any physical evidence that the fireproofing was dislodged or was it just a theory?

 

[BasqueArch]

Did NIST have any physical evidence that the fireproofing was dislodged or was it just a theory?

You meant to say hypothesis. A theory is a proven hypothesis.

 

[Crazy Chainsaw]

Did NIST have any physical evidence that the fireproofing was dislodged or was it just a theory?

They had photos of lose fireproofing,
And did impact testing with buck shot.

 

[Grizzly Bear]

JayH, kudos to at least stating a position on it. TS has been asked a similar question and has not commented in several years of having it directed at him. Not surprisingly I have some critique of it, but you have some added respect for not dodging it.

What difference does it make? Does the intention change the fact that the steel got to 800C for about an hour?

The problem is you believe a standardized test using base line parameters as part of the standardized testing should have been replicated by reality which had nothing to do with the reason nor the parameters under which the NIST testing was done. The fact that the test assemblies didn't collapse completely or at all is not an indication of whether or not the damaged structure and fire proofing would provide the same as-built performance, and this much is obvious from the fact that the towers were seriously damaged. The tests were done only to establish what rating the towers had in their as-built condition to create a baseline model and assist with their other work

In other words, you're outrage is with a red herring. Not only that,; In your own words, "what difference does it make"... Since you obviously do not register the difference and do not care about it anyway then I see little need to say any further. Your position speaks loudly for itself.

Facts don't care what your intentions are.

They really don't care about your false outrage that much either. I'm all open to discuss further if you are able to move forward on this, but I think you've answered for everyone the degree of skepticism you hold - which is to say - negligible.

 

[beachnut]

Did NIST have any physical evidence that the fireproofing was dislodged or was it just a theory?

Someone failed to read NIST, and failed to understand how easy it was to dislodge fire-protection below the floors, and that the core was covered with 3 inches of wallboard; did you ever punch a hole in wallboard?


It is fact - the fire proofing was dislodged

Wow, it removed some cladding too.

The impacts of 11 and 175 were equal in kinetic energy to 1300 and 2093 pounds of TNT. Not theory, fact.

You could calculate how much insulation was removed by the impact with modeling, and the available energy. Also, people who were in the stairs saw wallboard displaced.

Did you figure out your smoke "reason" was bogus?

You say there is a legitimate reason to question the official narrative, but fail to provide the reason. Did you answer your poll wrong?

 

[Animal]

No they don't. Not according to the people you are defending.

Are you trying to argue that the liquid hydrocarbon they used to start the workspace fires and which they used to heat the trusses up with burn at a lower temperature, less consistently than your magic plastic?

Again, you must presume some ridiculous premise in order to protect the NIST theory of collapse.

<sigh> I have 35 year old text books that show real world fire temperatures that far exceed the ASTM testing standard.

Your ignorance of the subject is vast.

 

[Animal]

They had photos of lose fireproofing,
And did impact testing with buck shot.

Not to mention real world experience. I designed a large office building a few years ago.....it required spray-on on the underside of the roof deck. They did it before a lot of the roof work was completed......then they had to do it again because so much had been dislodged simply because people were walking around on the roof.

 

[jaydeehess]

People, keep in mind that floor failure in the continuing collapse was due to massive overloading.

 

[Animal]

You insist on framing the discussion in these terms. No one is here because they intend to defend NIST or any other organization. Everyone here is an independent, private citizen disputing your claims according to their own reasons.

Despite your frantic plea for relevancy, that's all you get. You need to warm up to the reality that your conspiracy theories fly very, very far under the radar of the relevant fields of study and professional practice. Despite your desire to "do battle" with NIST, we are not their proxies or designates.

In years past, debunking troofer claims was a brain exercise, (as well as an exercise in internet research) the last couple of years it was entertainment, watch the newest troofer roll out the retread claims. Now it is like trying by a car wreck on the interstate with only the tow trucks left hauling away the debris.