How were WTC core columns separated at the weld planes?

Max Photon

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How were WTC core columns separated at the weld planes?

by: Max-to-the-Core Photon


If one examines the high-resolution photos at the FEMA Photo Library of Disaster #1391 - New York Terror Attacks - one sees that the vast majority of core columns are separated into 3-story lengths, and that the separations are at the weld planes.

I believe MColombo is the eagle-eyed engineer who clearly articulated this.


The purpose of this thread is to generate a list of reasonable explanations for how the core columns were separated at the weld planes, and then attempt to rank the list of explanations.


(For those unencumbered by intelligence, please leave the humor to Max, okay?)


Here is a quick list to get us started...


WTC core columns were separated at the weld planes by:
  • Dynamic loads experienced during collapse, caused heat-stressed steel by the welds to fail;
  • Explosives of some type -whether high-explosives, nano-thermites, or other - placed just above of below the weld planes - generated a lateral concussive force that caused the heat-stressed steel near the welds to fail;
  • Pressure built up inside core box columns (from heating);
  • High-explosive linear-shaped-charges (LSCs);
  • Thermite cutter charges;
  • Mini-nukes;
  • DEWs;

The last four find zero support in the FEMA photos.

Also, because the core box columns are an open system, we can probably exclude pressure buildup.


That now leaves:

  • Dynamic loads experienced during collapse caused the heat-stressed steel by the welds to fail;
  • Explosives of some type -whether high-explosives, nanothermites (if they can generate sufficient detonation velocities), or other explosives - placed just above of below the weld planes - generated a lateral concussive force that caused the heat-stressed steel near the welds to fail.

Comments?


Max

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Last edited:
Comments? Sure.

Aircraft at high velocity, impacts, with subsequent explosions, fire, with subsequent weakened support, aided by gravity = collapse. More or less.

Why is this so very difficult to understand?
 
Bell's experience with Deja Vu

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Max Photon, didn't you just made such a thread?

Or did you?

Bell

***
 
Max Photon said:
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That now leaves:
  • Dynamic loads experienced during collapse caused the heat-stressed steel by the welds to fail;
  • Explosives of some type -whether high-explosives, nanothermites (if they can generate sufficient detonation velocities), or other explosives - placed just above of below the weld planes - generated a lateral concussive force that caused the heat-stressed steel near the welds to fail.
Comments?


Max

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Click to expand...

There is substantial evidence for explanation number one (See NIST report), and there is ZERO evidence for explanation number two. There's your answer. (For example there is not a single audio clip of an explosive being detonated)
 
Dynamic loads

Hi Max,

When I consider the probability of co-axial collisions of columns once the collapse starts (which is extremely low), I am forced to look at the other possibility which is floors and horizontal members impacting each other due to horizontal displacement. The result would be unshored columns which are much easier to break and which would break at the weakest points (i.e. the welds). My opinion is that the only columns failing in compression mode would be at the onset of collapse. Still there is alot of energy that gets spent in the process.
 
Sciencey, with Max Photon

Bell said:
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Max Photon, didn't you just made such a thread?

Or did you?

Bell

***
Click to expand...


I did, but it was misperceived as humor, and moved.

Moderators suggested I try again, and this time, to try and act more sciencey.


Max Serious


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Was heat from thermite used to effectively unshore the core columns?

GregoryUrich said:
Hi Max,

When I consider the probability of co-axial collisions of columns once the collapse starts (which is extremely low), I am forced to look at the other possibility which is floors and horizontal members impacting each other due to horizontal displacement. The result would be unshored columns which are much easier to break and which would break at the weakest points (i.e. the welds). My opinion is that the only columns failing in compression mode would be at the onset of collapse. Still there is alot of energy that gets spent in the process.
Click to expand...


Hi Greg,

An idea I have posited in MAX-MIHOP is that thermite was placed at the seats of core columns (where horizontal members connect), not to cut, melt, or slice the steel, but to heat-weaken the connections, and hence reduce the strength of horizontal bracing.

I believe that the evidence of thermite planted at core column seats is the heavy, continuous oxidation layers at the seats.

Note that NIST discusses such oxidation in NCSTAR 1-3C/chapter 6.

Basically, the thermite was used to heat the seats to just below 625C (to avoid detection by tests that check for spheroidization of pearlite and cementite). This heating caused noticeable parabolic oxidation.


So, is it possible that heat from thermite was used to effectively unshore the core columns?


Max

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Max Photon said:
Hi Greg,

An idea I have posited in MAX-MIHOP is that thermite was placed at the seats of core columns (where horizontal members connect), not to cut, melt, or slice the steel, but to heat-weaken the connections, and hence reduce the strength of horizontal bracing.

I believe that the evidence of thermite planted at core column seats is the heavy, continuous oxidation layers at the seats.

Note that NIST discusses such oxidation in NCSTAR 1-3C/chapter 6.

Basically, the thermite was used to heat the seats to just below 625C (to avoid detection by tests that check for spheroidization of pearlite and cementite). This heating cause noticeable parabolic oxidation.


So, is it possible that heat from thermite was used to effectively unshore the core columns?


Max
Was heat from thermite used to effectively unshore the core columns?
Click to expand...

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Click to expand...
NO
 
Last edited:
Max Photon said:
Hi Greg,

An idea I have posited in MAX-MIHOP is that thermite was placed at the seats of core columns (where horizontal members connect), not to cut, melt, or slice the steel, but to heat-weaken the connections, and hence reduce the strength of horizontal bracing.

I believe that the evidence of thermite planted at core column seats is the heavy, continuous oxidation layers at the seats.

Note that NIST discusses such oxidation in NCSTAR 1-3C/chapter 6.

Basically, the thermite was used to heat the seats to just below 625C (to avoid detection by tests that check for spheroidization of pearlite and cementite). This heating cause noticeable parabolic oxidation.


So, is it possible that heat from thermite was used to effectively unshore the core columns?


Max

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Click to expand...

Max you have provided no evidence for your claims here, only speculation. COuld you please try again but with relevant evidence? Thanks.
 
Were core columns heat stressed not only from welding, but from thermite?

DGM said:
If you mean "heat stressed steel" as from the welding process itself.
Click to expand...


DGM,

I meant "heat-stressed steel" as a multi-valued function.

First, we would expect the steel neighboring the welds to be heat-stressed from the welding process itself.

Second, I have put forth the notion that the weld regions could have been heat-stressed above-and-beyond that caused by the welding processes, say by thermite placed at core columns seats, or at or near the weld planes.


Max

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Max Photon said:
DGM,

I meant "heat-stressed steel" as a multi-valued function.

First, we would expect the steel neighboring the welds to be heat-stressed from the welding process itself.

Second, I have put forth the notion that the weld regions could have been heat-stressed above-and-beyond that caused by the welding processes, say by thermite placed at core columns seats, or at or near the weld planes.


Max

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Click to expand...

Yes yes... theories are nice and all, but where is your EVIDENCE that thermite was used? That is kind of important to support your claim.
 
Max was indeed told to start another thread and make it more science-y. So, this thread is legit. Please stick to the topic and keep the humourous responses to the Humour section.
Replying to this modbox in thread will be off topic  Posted By: Lisa Simpson
 
Hi Max!

The obvious question to ask is:

What was the strength of the welds?

I have seen claims that they were very strong... and claims that they were very weak!
 
There are very few instances where connections are designed to be stronger than the elements the connections are connecting. The main reason is that it is prohibitively expensive to do this, and it is much simpler and cost-effective to design the connections to resist the applied loads. It is fairly safe to assume that the column-splices at the WTC did not develop the entire strength of the column at the connection in all axes.

The interior columns would be subject to minimal (really zero) lateral forces or tension. As the load on the columns is almost a pure compression element, the only welding required would really be for stability and strength during construction. It makes perfect sense that interior columns would fail at connections.

Exterior columns are a WEE bit different. I imagine the connection to be something like:

column+splice.JPG

http://bp2.blogger.com/_-e0bzNzFdXc/RxlNd5AwItI/AAAAAAAAAKc/NlfoIE9ROvc/s1600-h/column+splice.JPG

I apologize for the truely horrendous detail drawn in paint. I don't have autocad on this machine. As seen, the weld in one axis could be legitimately stronger in the strong axis of the moment frame and weaker out-of-plane.
 
A-Dynamic loads experienced during collapse caused the heat-stressed steel by the welds to fail;
B-Explosives of some type -whether high-explosives, nanothermites (if they can generate sufficient detonation velocities), or other explosives - placed just above of below the weld planes - generated a lateral concussive force that caused the heat-stressed steel near the welds to fail.
Click to expand...

As there was no residual trace of det-cord, blasting caps, nitrates, phosphates or any other foreign explosive or pyrotechnic chemicals, and since placing of such devices immediately below the points of impact immediately after impact was impossible due to the condition of the buildings, and since ingressing into said areas to plant such devices would be all but impossible and certainly fatal, I think the only logical analysis could be based on A

(Bolding and A,B letter designations mine)
 
Apollo20 said:
Hi Max!

The obvious question to ask is:

What was the strength of the welds?

I have seen claims that they were very strong... and claims that they were very weak!
Click to expand...

I do not have experience with buildings, but I have plenty of experience around equipment. So, I would think (yes, just an opinion) that you would have a mixed bag. All iron workers are not created equal, so you would have some who were excellent welders and some not so much.
 
OldTigerCub:

You claim that there was no residual trace of nitrates, phosphates or any other foreign explosive or pyrotechnic chemicals, but where is your evidence for this?

I believe the FBI AND NIST did not look for explosive or pyrotechnic residues.

However, other analysese, by other labs, found plenty of nitrates....
 
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