WTC7 and the girder walk-off between column 79 and 44

[Tony Szamboti]

It's nice that you ask that.

The "alleged walk-off" triggered the collapse of a floor.

That floor collapse caused the rest of effects that NIST explains well (more floors fell, leaving column 79 unsupported laterally, causing it to buckle, causing the penthouse to fall, and causing a cascade collapse that progressed horizontally until the core gave way, pulling the façade down).

But, the most important point here is that it's irrelevant if NIST got the initiation event wrong. All it took for that chain of events to develop was the collapse of a floor at or around floor 13 by whatever means.

Read that? By whatever means. Floor collapses happen during fires; there is abundant proof in the WTC5 photos from FEMA. NIST elaborated a theory for the mechanism that triggered floor collapse: the girder walk-off. No matter if it's right or wrong, the rest of NIST's theory isn't refuted by disproving their initiation mechanism (the subject of this thread), but by showing that a floor collapse was impossible during the fires.

Good luck with that to those who try.

Finally, it is the columns which need to fail to cause collapse of a building.

Using the AISC criteria for buckling, it is found that column 79 would not buckle unless it was laterally unsupported for at least five floors. So there would need to be a lot of floors and their supporting framework failing around column 79 for a significant number of stories to cause it to become unstable.

The lateral support also only needs to be from two orthogonal sides, and we now know the lateral support from at least one side (provided by the girder to the north of column 79) could not have been removed. So this means all of the connections from the south and west to column 79, for at least five stories, needed to be removed.

 

[Clayton Moore]

Finally, it is the columns which need to fail to cause collapse of a building.

Using the AISC criteria for buckling, it is found that column 79 would not buckle unless it was laterally unsupported for at least five floors. So there would need to be a lot of floors and their supporting framework failing around column 79 for a significant number of stories to cause it to become unstable.

The lateral support also only needs to be from two orthogonal sides, and we now know the lateral support from at least one side (provided by the girder to the north of column 79) could not have been removed. So this means all of the connections from the south and west to column 79, for at least five stories, needed to be removed.

It would seem that 47 X 25 separate core column snaps occurred 25 at a time as each floor collapsed. Quite a core snapping symPHONY.

Begging the core(basic) question

How do the core columns above the 13th floor get the same 25 snaps at a time rhythm as the 25 snaps at a time rhythm of the 13th floor and the 12 floors below?

 

[pgimeno]

The lateral support also only needs to be from two orthogonal sides

I think that that only holds if the connections are in good shape and designed for that purpose. Neither was the case.

and we now know the lateral support from at least one side (provided by the girder to the north of column 79) could not have been removed.

The dynamic load of a floor (or more) falling on a girder can easily make it fall.

 

[pgimeno]

Somewhat off topic, but just imagine what would have happened if this column was column 79.

That's from WTC5 which wasn't struck by a plane, nor had its fireproofing removed, nor was bombed or therm*ted.

ETA: That's just to show how FAR you are from proving that collapse by fire was impossible.

 

[Tony Szamboti]

Somewhat off topic, but just imagine what would have happened if this column was column 79.

[qimg]http://www.formauri.es/personal/pgimeno/xfiles/lordkiri/ch4-021.jpg[/qimg]

That's from WTC5 which wasn't struck by a plane, nor had its fireproofing removed, nor was bombed or therm*ted.

ETA: That's just to show how FAR you are from proving that collapse by fire was impossible.

Column 79 was a quite large built-up column and unlikely to have the above happen to it. It needed at least two of its three girders stripped away for at least five contiguous stories before it would become unstable.

 

[000063]

Yeah like it was possible the huge core columns in all three buildings were going to be individually snapped by a floor's collapse(s).

I think you're confusing cause and effect. The columns breaking from fire and plane impact (mostly fire in WTC7) is what caused the floors to collapse, which lead to more columns breaking, which leads to more floors collapsing, etc. It's called a progressive collapse.

http://www.wtc7.net/collapsecause.html

None of which addresses the fact that beams were knocked out of the buildings in a manner which it was and is physically impossible to predict and no charges of any sort were found on them.

Oh, and 7 collapsed asymmetrically. East Penthouse collapse, and "backward" lean. That website even uses NIST's abandoned diesel fuel theory, and you yourself have admitted that 7 only fell mostly into its footprint (which is false too, but anyway).

 

[000063]

It would seem that 47 X 25 separate core column snaps occurred 25 at a time as each floor collapsed. Quite a core snapping symPHONY.

Begging the core(basic) question

How do the core columns above the 13th floor get the same 25 snaps at a time rhythm as the 25 snaps at a time rhythm of the 13th floor and the 12 floors below?

They didn't. You're strawmanning.

 

[Animal]

Column 79 was a quite large built-up column and unlikely to have the above happen to it. It needed at least two of its three girders stripped away for at least five contiguous stories before it would become unstable.

And once again you make an assumption - that the column would have remained in perfect condition during a collapse.

 

[ergo]

Yes, because any time a floor collapses in any building where the floors below it are weakened by fire making the floors collapse in cascade, leaving a column unsupported laterally, where that column holds most of the rest of the building, the building plummets to the ground. Structural steel is useless in unfought long-duration fire. Buildings where that has happened crash have historically crashed to the ground. In fact, this is so true now that the demolition industry has been in steady decline since 2001. That's because the secret's out: just collapse a floor and the entire structural framework will fail. That's what buildings are designed to do now. It makes them easier to collapse when they're no longer needed. if there was a way to control the effect of fires it would be a good demolition method for steel buildings, but unfortunately fires are quite unpredictable, and they're hard to fight afterwards, making debris removal much more complicated than with explosives.

Saved for posterity.

I'm very much looking forward to pgimeno backing up his claims.

1. Column 79 holds "most of the rest of the building."

2. "Structural steel is useless in unfought, long-duration fire."

3. "Buildings where that has happened have historically crashed to the ground."

4. "In fact, if there was a way to control the effect of fires it would be a good demolition method for steel buildings."


Yes, indeed. Very much looking forward to this.

 

[pgimeno]

Saved for posterity.

I'm very much looking forward to pgimeno backing up his claims.

1. Column 79 holds "most of the rest of the building."

Clarification: I meant only in the vertical direction, i.e. the amount of floors that column 79 held at the point of failure which was "most of the building" as in "much more above the point of failure than below" vs the amount of floors that the bent column in WTC5 held (it was in the 8th floor of a 9 floor building).

 

[Tony Szamboti]

And once again you make an assumption - that the column would have remained in perfect condition during a collapse.

Column 79 was an enormous built-up W14 x 730 structural steel member. It weighed over 7 tons per story. Just what kind of damage do you think a collapsing 5 inch thick concrete floor with relatively light beams and girders could have done to it?

The only thing that could have truly affected column 79 was to cause it to be left laterally unsupported for at least five stories with its vertical load still on it. That is what NIST is trying to say happened. Their problem is that it isn't that easy to show the floors would have collapsed and their theory for the collapse of the girder and floor to the north of the column has been shown to be in error on this thread.

It is incredible that some here think they can just wave a magic wand and make the right floors collapse in the right places, with the only basis given being their belief that anything can happen in a fire.

 

[triforcharity]

Column 79 was an enormous built-up W14 x 730 structural steel member. It weighed over 7 tons per story. Just what kind of damage do you think a collapsing 5 inch thick concrete floor with relatively light beams and girders could have done to it?

Loss of lateral support is fatal to a huge column.

Simple test for you Tony.

Take 5 2x4x8's and nail them together. Any way is fine really. Now, stand it up, and hold it tight. It stands up relatively easily, right? Right.

Now, make sure you've got your hard hat on, so that you don't get hurt.

Let go of the wooden column. What happens?

Tell me what you think will happen.

If I need to, I can make a video of what will happen. I know you and the other duped truthers love their YouTube videos, so if that's what I need to do, I will.

You just let me know.

 

[ergo]

Column 79 was an enormous built-up W14 x 730 structural steel member. It weighed over 7 tons per story. Just what kind of damage do you think a collapsing 5 inch thick concrete floor with relatively light beams and girders could have done to it?

The only thing that could have truly affected column 79 was to cause it to be left laterally unsupported for at least five stories with its vertical load still on it. That is what NIST is trying to say happened. Their problem is that it isn't that easy to show the floors would have collapsed and their theory for the collapse of the girder and floor to the north of the column has been shown to be in error on this thread.

Not to mention the fact that the building is not going to curl up and die because one column fails in one area, if it was to at all. Right, Tony? Let's please not forget the bigger picture here. The whole concept is ridiculous, and arguing about what happened to column 79 - although I understand why it needs to be soundly refuted - imo, nevertheless legitimizes the silliness.

 

[Clayton Moore]

Not to mention the fact that the building is not going to curl up and die because one column fails in one area, if it was to at all. Right, Tony? Let's please not forget the bigger picture here. The whole concept is ridiculous, and arguing about what happened to column 79 - although I understand why it needs to be soundly refuted - imo, nevertheless legitimizes the silliness.

Evidence that the building would not curl up?

 

[Tony Szamboti]

Not to mention the fact that the building is not going to curl up and die because one column fails in one area, if it was to at all. Right, Tony? Let's please not forget the bigger picture here. The whole concept is ridiculous, and arguing about what happened to column 79 - although I understand why it needs to be soundly refuted - imo, nevertheless legitimizes the silliness.

Given that some believe the entire NIST explanation for the collapse of WTC 7 is silly, the process that they allege to have caused WTC 7 to collapse completely to the ground needs to be scrutinized in a step by step fashion.

This thread was about the alleged initiating event of a girder walk-off failure, which has now been shown to have clearly been impossible.

Given that there are other ways posited that some of the lateral support for column 79 could be removed, however improbable, it needs to be discussed to see how likely or unlikely it was and whether it would be sufficient to cause it to buckle and fall.

Of course, one could skip the column 79 issue if one of the later parts of the theory is shown to be impossible regardless of the condition of column 79.

 

[GlennB]

Using the AISC criteria for buckling, it is found that column 79 would not buckle unless it was laterally unsupported for at least five floors.

These criteria relate to single unit columns, do they not?

Col 79 had spliced connections every 2 floors.

Source: NCSTAR 1-9 (ii) pdf p.562, and fig 12-30

I don't know if you're unaware of this or whether your reference to AISC criteria is pure sophism.

 

[Tony Szamboti]

These criteria relate to single unit columns, do they not?

Col 79 had spliced connections every 2 floors.

Source: NCSTAR 1-9 (ii) pdf p.562, and fig 12-30

I don't know if you're unaware of this or whether your reference to AISC criteria is pure sophism.

I am aware of the spliced connections, and also the fact that they are designed to generate a minimum moment of inertia and radius of gyration sufficient to mantain the buckling strength of the column as though it were a single continuous member. The AISC criteria can thus be used on a spliced column.

 

[Animal]

Column 79 was an enormous built-up W14 x 730 structural steel member.

A sure sign a a troofer......over stating (with words like "enormous" "robust" etc) of subject matter that is important to their claim.

It weighed over 7 tons per story. Just what kind of damage do you think a collapsing 5 inch thick concrete floor with relatively light beams and girders could have done to it?

Second sign of a troofer.....the under stating of that which could hurt their claim ("relatively light")

The only thing that could have truly affected column 79 was to cause it to be left laterally unsupported for at least five stories with its vertical load still on it. That is what NIST is trying to say happened.

For someone that claims engineering knowledge.......you have a strange habit of trying to limit possibilities to just what you believe cannot happen in order to maintain your claim. Or maybe that is just your religious troofer beliefs that make you do that.......cults can do strange things to otherwise educated people. The fact is you have no knowledge of what damage may have occurred to the column during the interior structural failures. Your constant claims of "only this" and "only that" prove your agenda.

Their problem is that it isn't that easy to show the floors would have collapsed and their theory for the collapse of the girder and floor to the north of the column has been shown to be in error on this thread.

Your problem is you keep insisting you have proved something that you haven't.

It is incredible that some here think they can just wave a magic wand and make the right floors collapse in the right places, with the only basis given being their belief that anything can happen in a fire.

It is incredible that some here think they can just wave a magic wand and believe that demolition charges or magic thermite collapsed the building with the only basis given being their belief the government is out to get them.

 

[000063]

Saved for posterity.

I'm very much looking forward to pgimeno backing up his claims. ...

Are you even capable of recognizing your own hypocrisy?

I love how you have to strawman his post wildly to make your "points". I've already shown several times in this forum why CD is physically and logically impossible. You, personally, have been remarkably loath to address such logic, even before you put me on ignore. In fact, you don't like to admit when you're wrong about anything, no matter how ludicrous, such as the famous "moon-sized rubble field".

Not to mention the fact that the building is not going to curl up and die because one column fails in one area, if it was to at all. Right, Tony? Let's please not forget the bigger picture here. The whole concept is ridiculous, and arguing about what happened to column 79 - although I understand why it needs to be soundly refuted - imo, nevertheless legitimizes the silliness.

Unbacked claims, incredulity, straw man. This claim is backed up by a multi-year investigation, which is used to teach architecture. Hundreds of thousands of people every year are learning about the NIST report, and most have no problem with it.

 

[Tony Szamboti]

A sure sign a a troofer......over stating (with words like "enormous" "robust" etc) of subject matter that is important to their claim.



Second sign of a troofer.....the under stating of that which could hurt their claim ("relatively light")




For someone that claims engineering knowledge.......you have a strange habit of trying to limit possibilities to just what you believe cannot happen in order to maintain your claim. Or maybe that is just your religious troofer beliefs that make you do that.......cults can do strange things to otherwise educated people. The fact is you have no knowledge of what damage may have occurred to the column during the interior structural failures. Your constant claims of "only this" and "only that" prove your agenda.



Your problem is you keep insisting you have proved something that you haven't.



It is incredible that some here think they can just wave a magic wand and believe that demolition charges or magic thermite collapsed the building with the only basis given being their belief the government is out to get them.

With the way you talk here it sounds like you might have sure signs to look for to tell if someone is a boogieman also.

Sorry if you don't like my choice of words used to decribe the physical nature of the structural members in question, but I think it is safe to say that most people would consider a 1,100 lbs./ft. column to be "enormous" and 55 lbs./ft. beams and 130 lbs./ft. girders to be "relatively light" when compared to it.

My only agenda is reality, and due to the controversy which has arisen around it, giving a fair hearing to the NIST report on WTC 7, to determine its possibility, is a reality based objective.