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

[jaydeehess]

For a change, I tend to side with Tony on this. Jenga is not a good comparison here. One could additionally argue that removing blocks from a Jenga tower IS CD, even though the purported goal of the game is to not collapse the tower.

In collapse Jenga models little, true.
In load redistribution it demonstrates TSz's error in simple proportional redistribution.
Remove the middle block and yes, the two outside blocks take equal amounts of the load that was on the middle block. Remove a side block though and more load is on the middle block than on the remaining side block.

However, as oz points out when it does collapse it tilts and falls at 'g'.(incidentally, it would achieve over 'g' if it were a connected set of blocks) No squibs visible.

 

[chrismohr]

Your sarcasm well justified but there is an engineering issue which may not be obvious to some members. Tony's error is probably worse than he realises.

The basic issue is that cutting 25% of columns does not automatically mean 25% less load capacity. It could be - almost certainly will be - a lot worse and it will never be better.

Put simply removal of a proportion of columns will almost always weaken the structure by more than the proportion of columns removed.

I invite members to try this little example as a "thought exercise" - it is a worst case scenario to demonstrate the point - a pseudo WTC Tower built with three rows of columns L, C and R.
[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"?
Q 1B Does the Top Block move?

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"?
Q 2B Does the Top Block move?
Q 2C Why (or why not)?

Have fun. Winners get one mini Mars Bar as reward - available for collection from here in Moss Vale. I'll even throw in a beer or three...for those who collect their prize.

OK I'll try and I will almost certainly be wrong. Which is why I ask experts rather than just make proclamations on my own, but here goes:

In the rigid scenario, load R goes to 0, and its load shifts very quickly to L and C. I would guess just about all of it shifts to C. The top block does not move unless C collapses under the new load.

In the flex scenario, once again pretty much all of the load goes to C. In addition, the top block tips to the right, maybe a lot. That's because C is bending under the new load and nothing is holding R up any more. This causes the L columns to take less load, and shifts even more load onto C. This is consistent with the observed fact that all three WTC buildings tilted into their weakest point as they collapsed.

I can't attempt to quantify the extra load of C in both scenarios, but I would strongly guess it would be more than 1/4, probably even more than 1/3, because of the asymmetrical nature of the loss of all the R columns causing other kinds of torquing on the remaining supports. While my understanding of this is very limited, the forces acting on L and C now (whatever they are) are coming in all three dimensions, not just the vertical dimension.

 

[Dave Rogers]

For a change, I tend to side with Tony on this. Jenga is not a good comparison here.

Although I agree it's not a good comparison, Jenga can be used to very trivially debunk the fallacy, repeatedly stated by several truthers, that removing X% of a support structure reduces the load capacity of that structure by X%. The procedure is as follows:

(1) Build a Jenga tower.
(2) On a lower level, remove the left and right blocks. The tower stays upright. The load bearing ability after removing 67% of the supports is sufficient to support the entire tower.
(3) Replace the left block, and remove the centre block.
(4) Note that the load capacity of the structure is not the same as when the centre block was the only one on the level, despite the fact that the same proportion of the structure has been removed.

Dave

 

[Crazy Chainsaw]

This comment is 100% pure inanity and yet another example of the lack of a cohesive argument from those who would deny that the three high rises in NYC came down due to controlled demolition.

I wasn't talking about anything falling over like the unconnected blocks of a Jenga tower.

I was obviously saying that well connected steel framed high rises like the WTC Towers and WTC 7 can't collapse through themselves with no deceleration or at free fall acceleration without controlled demolition being involved.

Would be nice if someone would present a workable theory of CD,
Instead of hand waving assumptions.

 

[AZCat]

Would be nice if someone would present a workable theory of CD,
Instead of hand waving assumptions.

There is a workable theory of CD. You just have to assume quantity of explosives = 0.

 

[Tony Szamboti]

Would be nice if someone would present a workable theory of CD,
Instead of hand waving assumptions.

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.

 

[jay howard]

Possibly:
There WAS a time when many truther comments WERE interesting.

Because it was the era of "Genuine Truthers" who were seeking "truth" as in veracity - correctness- being right. Long before the word "truth" became meaningless or damaged.

We do not see Genuine Truthers these days. Hard line denialists don't count.

Oh please. No one here seems the least bit concerned that the NIST approach has produced neither forensic corroboration (of any kind) nor laboratory confirmation that this "Fire-Driven Cascade Miracle" was even possible.

You make it sound like you have one tiny bit of curiosity about the anomalies surrounding the collapses. If you do, it certainly doesn't imply NIST being wrong about their overall theory.

In fact, it seems that no matter what objections are brought in front of the NIST description of events, the theory doesn't change. Not because it's airtight. Far from it. The maximum possible temperature/time curves do not allow for the kinds of failures (FDCM) that we witnessed.

We all know NIST built 4 truss systems and heated them far beyond any conditions possible with office materials as fuel. More fuel than was possible in the towers, (more consistent heating), plus more time than the towers stood, and they survived just fine.

If building a scale version of the floor trusses, loading them to their max rated limits, and burning them in an oven at higher temperatures for longer than was possible does not produce this "cascade" miracle, then what reason do you have to believe it?

It's looking more and more like a non-falsifiable theory. Surprise, surprise.

Of course as a "skeptic", this revelation shocks you, right?

 

[ozeco41]

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:

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.

 

[ozeco41]

Oh please. No one here seems the least bit concerned that the NIST approach has produced neither forensic corroboration (of any kind) nor laboratory confirmation that this "Fire-Driven Cascade Miracle" was even possible.

You make it sound like you have one tiny bit of curiosity about the anomalies surrounding the collapses. If you do, it certainly doesn't imply NIST being wrong about their overall theory.

In fact, it seems that no matter what objections are brought in front of the NIST description of events, the theory doesn't change. Not because it's airtight. Far from it. The maximum possible temperature/time curves do not allow for the kinds of failures (FDCM) that we witnessed.

We all know NIST built 4 truss systems and heated them far beyond any conditions possible with office materials as fuel. More fuel than was possible in the towers, (more consistent heating), plus more time than the towers stood, and they survived just fine.

If building a scale version of the floor trusses, loading them to their max rated limits, and burning them in an oven at higher temperatures for longer than was possible does not produce this "cascade" miracle, then what reason do you have to believe it?

It's looking more and more like a non-falsifiable theory. Surprise, surprise.

Of course as a "skeptic", this revelation shocks you, right?

Your continued posting of irrational nonsense noted jay howard.

I understand the physics and can explain it - in fact I could also coach you in logic but let's stay with physics for now. I'll repeat my offer:

If you EVER decide to get serious either:
A) respond to my repeated reasoned explanations of why each and every column which failed in axial overload was "hot enough" to fail; OR
B) Respond to my just posted explanation of why load redistribution following a removal of a proportion of columns is always WORSE than the proportion of removed columns.

 

[Grizzly Bear]

Oh please. No one here seems the least bit concerned that the NIST approach has produced neither forensic corroboration (of any kind) nor laboratory confirmation that this "Fire-Driven Cascade Miracle" was even possible.

You make it sound like you have one tiny bit of curiosity about the anomalies surrounding the collapses. If you do, it certainly doesn't imply NIST being wrong about their overall theory.

In fact, it seems that no matter what objections are brought in front of the NIST description of events, the theory doesn't change. Not because it's airtight. Far from it. The maximum possible temperature/time curves do not allow for the kinds of failures (FDCM) that we witnessed.

We all know NIST built 4 truss systems and heated them far beyond any conditions possible with office materials as fuel. More fuel than was possible in the towers, (more consistent heating), plus more time than the towers stood, and they survived just fine.

If building a scale version of the floor trusses, loading them to their max rated limits, and burning them in an oven at higher temperatures for longer than was possible does not produce this "cascade" miracle, then what reason do you have to believe it?

It's looking more and more like a non-falsifiable theory. Surprise, surprise.

Of course as a "skeptic", this revelation shocks you, right?

Base line model to establish as built fire rating vs real world events.

Same error that plagues the missing jolt, different claim, different source model. Same hardline stance to ignore the difference

 

[NoahFence]

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.

Interestingly, it seems if you collapse a 110 story building and have huge chunks of it slam into a 47 story building, starting fires that will not be fought over multiple floors for 7 hours, that building will collapse.

That theory, unlike yours, contains irrefutable evidence.

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.

In a reality, if you slam one of the largest planes in the world as fast as you can into the side of a building 110 stories high, eventually it can collapse due to the subsequent fires.

That theory, unlike yours, contains irrefutable evidence - AND a precedent!

 

[JayUtah]

Oh please. No one here seems the least bit concerned that the NIST approach has produced neither forensic corroboration (of any kind) nor laboratory confirmation that this "Fire-Driven Cascade Miracle" was even possible.

Actually, no one anywhere is interested in what you think that should be. Because you're clearly not a scientist and you can't go beyond vague handwaving.

 

[Crazy Chainsaw]

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 and7 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.

That is not a workable theory.of CD, you have to
Provide more information than that to have a
Workable functioning theory of CD.

 

[ozeco41]

That is not a workable theory.of CD, you have to
Provide more information than that to have a
Workable functioning theory of CD.

The "more information" - just a working outline - a précis of his arguments - and supported to at least prima facie standard...
...THEN there will be something to respond to.

Put very simply - he has to say HOW.

 

[Crazy Chainsaw]

Base line model to establish as built fire rating vs real world events.

Same error that plagues the missing jolt, different claim, different source model. Same hardline stance to ignore the difference

Yes the model and fire test
Basicly showed it was the loss of
Fireproofing that lead to.the collapses.

 

[Crazy Chainsaw]

The "more information" - just a working outline - a précis of his arguments - and supported to at least prima facie standard...
...THEN there will be something to respond to.

Put very simply - he has to say HOW.

Yes exactly Steven E. Jones tried to come up with
a workable theory and failed.
Dr. Frank Greening got the closest to a workable
Theory with his AP. Theory but it would also
Have tremendous problems.

 

[ozeco41]

... Dr. Frank Greening got the closest to a workable Theory with his AP. Theory but it would also
Have tremendous problems.

Agreed. I also think he was playing "tongue in cheek".

 

[jaydeehess]

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.

Congratulations on having created one liner technical descriptions of your theory. Perhaps an FEA demonstrating to the same or better degree as NIST's, that it would work as you advertise it would, is warranted.

However, unlike the NIST probable theories that have obvious drivers of destruction vis a vis aircraft impact and fires, yours lacks a niggling issue in that you cannot demonstrate the existence of explosives, you only infer their existence due to an interpretation of the way dust expels from the structures and the fact that they do collapse. Nor do you have a workable theory of how and when and who placed these explosives, certainly not a provable or even one with any evidence beyond pure imagination derived fictions. Which BTW is one major reason why you cannot convince skeptics that your fictions have any basis in reality.

 

[Crazy Chainsaw]

Agreed. I also think he was playing "tongue in cheek".

I know.he was, of course the obvious flaw in the theories is
There was no need to Do CD. At all just weaken
The buildings and allow for a natural fire collapse.
Remove fire proofing, and do some damage to
The structure hide it under fake fire proofing,
Using steel wool as the fiber material in the
Fake fire proofing.
Crash the planes the buildings come down,
no evidence of explosives or explosions just
Natural collapses.
Thanks to Cters, Truthers work though,
We know it was CD, and a natural engineered
Collapse could not have occured.
Good thing too, I doubt a naturally engineered
Collapse could have ever been debunked.

 

[ozeco41]

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.

Congratulations on having created one liner technical descriptions of your theory...

If he was writing a technical paper he has little more than the title. Plus the first sentence of the Abstract - except that the conditional "if you were to" puts that in doubt - there is no explanation of "How" which is the bit which counts. No substance to the paper and no substance to his alleged "workable theory".

A workable theory has to demonstrate that it is workable.

It fails to get to first base as a "workable theory" and as a paper it would fail peer review. Have to go to Bentham....err...