[W:57: 1585]Evidence that 9/11 was an inside job.

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

The perimeter of the core was 8 + 8 + 4 + 4 = 24 columns The interior therefore had 23.

Perhaps gerrycan subtracted 12 from the total number of columns and got 35 (47-12 = 35). The columns would be under the main truss lines of the hat truss.

In case they are of interest to you, here are the demand/capacity ratios for the core columns at all floors above 70ish. I have the rest of the sheets here for levels below, if you would like them, let me know. They're in the NIST report somewhere. For some reason, I had never noticed them until recently.

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

I think there's a 804A too which brabches from 804, so maybe 35.1/2 would be more accurate.

804A started at the 107th floor, had a temporary support beneath it just below the 107th floor as shown in connection detail 18-6M below, and was it own column. It didn't branch from column 804. It ran up to the roof and connected right below the antenna interface.


804A connection at the 108th floor, connection detail 18-6J.


804A connection at the 109th floor, detail 18-6G.


804A connection at the 110th floor, detail 18-6E.


804A connection at the antenna interface, detail 18-6A (on the left).

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

Rows 01 and 08 were not directly below the truss that supported the antenna interface.

Below is the elevation of column line "01" (1001-501) showing the hat truss steel.


Below is the elevation of column line "500" (501-508) showing the hat truss steel.


Can you explain what characteristics you are using to say that column line "01" was not directly below the truss that supported the antenna interface and column line "500" was?

Thanks.

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

The perimeter of the core was 8 + 8 + 4 + 4 = 24 columns The interior therefore had 23.

Perhaps gerrycan subtracted 12 from the total number of columns and got 35 (47-12 = 35). The columns would be under the main truss lines of the hat truss.

Got it. So the columns under the red lines for 24 columns.

 

[SanderO]

Re: Evidence that 9/11 was an inside job.[W:57]

actually no....

The hat truss main trusses were over the perimeter of the core which is 24 columns. It also had two trusses in the center for each axis. This would add 2 on each side (4x2=8) inside the perimeter... and 3 under the antenna... that makes 11 more for a total of 35 column supporting the trusses of the hat truss. Spme columns supported trusses in each axis.

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

actually no....

The hat truss main trusses were over the perimeter of the core which is 24 columns. It also had two trusses in the center for each axis. This would add 2 on each side (4x2=8) inside the perimeter... and 3 under the antenna... that makes 11 more for a total of 35 column supporting the trusses of the hat truss. Spme columns supported trusses in each axis.

Thank you for explaining.

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

Could you explain gerrycan's quote below? He is attributing the "35 core columns" number to you and that you explained it. I was curious as to what constitutes a column as being "below the truss that supported the antenna interface' and one that is not. Thanks.

I attributed an explanation of it to Sander. I have done all I can to explain it to you. If you don't see it by now, you're probably not going to. The point is that at lower down at floor 96 of tower A CC501 and 508 don't look as if they are descending with the rest initially, meaning that the transfer trusses on the adjacent E and W faces are intact while the columns between 501 and 508 are failing.

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

I attributed an explanation of it to Sander. I have done all I can to explain it to you. If you don't see it by now, you're probably not going to. The point is that at lower down at floor 96 of tower A CC501 and 508 don't look as if they are descending with the rest initially, meaning that the transfer trusses on the adjacent E and W faces are intact while the columns between 501 and 508 are failing.

He explained it.

Thanks.

 

[SanderO]

Re: Evidence that 9/11 was an inside job.[W:57]

So lets move to a discussion of how many core columns down below in the plane crash zone that were supporting the trusses of the hat truss failed? As I have written before I believe that for these trusses to lose support a large portion of their axial support would disappear.. ir be transferred to adjacent columns... This seems like a formula for the failures to progress outward / away from the failed columns. Loads were transferred to adjacent columns which were then pushed past their safe working load and they buckled and the load was move further "outward /away" from the initial plane cause damage finally causing the trusses to have to span distances too far without intermediate support (in their center) and this led to the truss buckling, the antenna drop and slabs collapsing down inside the facade.. pulling free and moving the facade cage from axial alignment.

Yes or no?

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

So lets move to a discussion of how many core columns down below in the plane crash zone that were supporting the trusses of the hat truss failed? As I have written before I believe that for these trusses to lose support a large portion of their axial support would disappear.. ir be transferred to adjacent columns... This seems like a formula for the failures to progress outward / away from the failed columns. Loads were transferred to adjacent columns which were then pushed past their safe working load and they buckled and the load was move further "outward /away" from the initial plane cause damage finally causing the trusses to have to span distances too far without intermediate support (in their center) and this led to the truss buckling, the antenna drop and slabs collapsing down inside the facade.. pulling free and moving the facade cage from axial alignment.

Yes or no?

By the time you have moved down 14 or 15 storeys the columns are all supporting the hat truss.

It would surely make more sense to observe the initial movement of the building, and then insofar as is possible, track how even the downward progress of the top block is using for example the antenna to guage where more or less resistance is being encountered and how even that resistance is. This method would be far more likely to reveal where areas of greater damage may have been present, and presented less resistance.

Also, when you say "slabs" you're talking about the concrete areas of the core, right?

 

[SanderO]

Re: Evidence that 9/11 was an inside job.[W:57]

Also, when you say "slabs" you're talking about the concrete areas of the core, right?

No I was referring to the perimeter rectangular donuts as rigid plates supported in the inside by the belt girder surrounding the core and the angles on the spandrels of the facade panels.

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

By the time you have moved down 14 or 15 storeys the columns are all supporting the hat truss.

It would surely make more sense to observe the initial movement of the building, and then insofar as is possible, track how even the downward progress of the top block is using for example the antenna to guage where more or less resistance is being encountered and how even that resistance is. This method would be far more likely to reveal where areas of greater damage may have been present, and presented less resistance.

Also, when you say "slabs" you're talking about the concrete areas of the core, right?

gerrycan,

would you mind responding to this?:
https://www.debatepolitics.com/cons...-11-inside-job-w-57-a-113.html#post1069608694

This one also:
https://www.debatepolitics.com/cons...-11-inside-job-w-57-a-113.html#post1069607736

And:
https://www.debatepolitics.com/cons...-11-inside-job-w-57-a-117.html#post1069643963

When you have time.

Thanks.

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

Can you explain this comment gerrycan? I thought Leslie Robertson WAS the lead structural engineer of the towers.

Thanks.

It's an understandable misconception to hold given the confusion between the 2 and their respective roles in the structural design of the towers. After all, according to wikipedia they were both the lead structural engineer.




However, John Skilling was the Lead Structural Engineer. It was Skilling who was awarded the contract. It was Skilling who understood the "trick" of this type of building. Try looking at pre 1998 references to the towers, and see who is listed as the lead structural engineer - City in the sky, or The Seattle Times, where Skilling was interviewed about the structures post the 93 bombing. You'll find that Skilling was, as he should have been, credited with being the lead structural engineer.

Take a look through the structural drawing books and note the dates and names on the sheets. Worthington, Skilling, Helle and Jackson was the company. Robertson comes into the fold a little later on, and then eventually starts LERA.

Robertson took a few important decisions for sure, like adding an inch to the C-C perimeters (he originally wanted an additional column to increase the footprint and so the overall stiffness too). He also designed and patented the viscoelastic damping system (though 3M should get some credit there too) and worked a lot on wind data along with Davenport.

Robertson is no doubt a highly capable and skilled engineer, but Skilling was an absolute genius.

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

Based on what I just posted, I am not understanding your two black lines in between the two center column rows in each direction or what they actually represent. Can you please explain? From what I can see, there were fore total column rows with hat truss steel in the center.

701-708
801-807

1004-504
1005-505

Thanks.

They represent the main spans of the truss. You have the drawings there to go look for yourself. The architectural sheets are handy to look at along with the structural books. Or you could go look at the Zaxis model which shows the same thing.

The 2nd link that you asked about is indeed the corner of the building as you can see from the perimeter centre lines on both axis marked clearly. I don't know if I used it by mistake like the other corner rail drawing that I had used before that but for sure it doesn't illustrate whatever point it was we were discussing.

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

No I was referring to the perimeter rectangular donuts as rigid plates supported in the inside by the belt girder surrounding the core and the angles on the spandrels of the facade panels.

I am starting to settle on the hypothesis that the initial failure happened with the core, which was then pulling down on the floor trusses as it failed. It doesn't seem to include the core corner columns to start with though, at least not for the North face, which is perplexing. You can see in a slowed down North face initiation video that confinment of the collapse to between CC508 and 501, which might be due to the additional strength and support that the corner cores had. It's not something that I'd wager the whole farm on yet but it is for sure a better bet than NIST's floor truss theory which required the addition of an imaginary force to get the perimeters to pull in.

I think we do agree that the core failed first though, don't we?

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

It's an understandable misconception to hold given the confusion between the 2 and their respective roles in the structural design of the towers. After all, according to wikipedia they were both the lead structural engineer.

View attachment 67250236
View attachment 67250237

However, John Skilling was the Lead Structural Engineer. It was Skilling who was awarded the contract. It was Skilling who understood the "trick" of this type of building. Try looking at pre 1998 references to the towers, and see who is listed as the lead structural engineer - City in the sky, or The Seattle Times, where Skilling was interviewed about the structures post the 93 bombing. You'll find that Skilling was, as he should have been, credited with being the lead structural engineer.

Take a look through the structural drawing books and note the dates and names on the sheets. Worthington, Skilling, Helle and Jackson was the company. Robertson comes into the fold a little later on, and then eventually starts LERA.

Robertson took a few important decisions for sure, like adding an inch to the C-C perimeters (he originally wanted an additional column to increase the footprint and so the overall stiffness too). He also designed and patented the viscoelastic damping system (though 3M should get some credit there too) and worked a lot on wind data along with Davenport.

Robertson is no doubt a highly capable and skilled engineer, but Skilling was an absolute genius.

Note the two portions of your quote in red above. Did you know that it's Leslie Robertson's professional engineering stamp/seal is on almost every drawing (if not EVERY as I have not looked at every drawing individually) in the structural drawing books you have provided thus far? What does Leslie's stamp/seal on all these drawings signify in your opinion?

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

They represent the main spans of the truss. You have the drawings there to go look for yourself. The architectural sheets are handy to look at along with the structural books. Or you could go look at the Zaxis model which shows the same thing.

The 2nd link that you asked about is indeed the corner of the building as you can see from the perimeter centre lines on both axis marked clearly. I don't know if I used it by mistake like the other corner rail drawing that I had used before that but for sure it doesn't illustrate whatever point it was we were discussing.

I have looked for myself which is why I'm questioning you. What you explained in the post below...

Rows 01 and 08 were not directly below the truss that supported the antenna interface. Leaves 47 - 12 cores, I believe Sander already explained this so I won't repeat it.

As for the columns that you highlighted, you should take a closer look at the zaxis model that you posted. You can see the specific core lines and rows involved in the main support. So, which cores are supporting these 2 main spans, pictured below from your own video......
View attachment 67249446

Here's where those main spines would cover as per your diagram.

View attachment 67249447

...is NOT what is shown/explained in the model/drawings.

There are four total spans in the center, not just two as you have described. The four truss spans traverse column rows 701-708, 801-807, 1004-504, and 1005-505. The black lines you have drawn to represent these spans (you show only two) are shown BETWEEN these column rows which is not the case. Below is how the core lines are actually spanned by the truss. Agree or disagree?

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

Note the two portions of your quote in red above. Did you know that it's Leslie Robertson's professional engineering stamp/seal is on almost every drawing (if not EVERY as I have not looked at every drawing individually) in the structural drawing books you have provided thus far? What does Leslie's stamp/seal on all these drawings signify in your opinion?

It signifies that you haven't looked closely enough at enough of the drawings lol

Seriously though, "City in the Sky" p138

"There would be another airplane study performed later, by Leslie E Robertson, a young and talented engineer who would soon set up an office for the Skilling firm in New York" <--- at that time he wasn't a partner.

p159
"When Leslie Robertson, the RISING young engineer in Skilling's firm...." <---still not a partner (My caps added)

p160

"...gave Robertson, bestriding the twin towers in his stocking feet and becoming ever more central to the LATER phases of their engineering design...." presumable he was bestriding the models of the towers.

Cores - Drawing book 3 - look through it, look at the dates, and look at the names of Skilling's firm. Robertson's name is there on some but not the earlier sheets.

Whatever the make up of partners in the firm was, Skilling's name was first, because it was Skilling who owned and controlled the business. What does the fact that Robertson's name doesn't appear on the earlier drawings, but does on the later ones suggest to you ?

What does the fact that Skilling's name is always the first name suggest to you ?



^^ (that's a useful one to keep)



See the name of the firm in the top left of each ?

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

I have looked for myself which is why I'm questioning you. What you explained in the post below...


...is NOT what is shown/explained in the model/drawings.

There are four total spans in the center, not just two as you have described. The four truss spans traverse column rows 701-708, 801-807, 1004-504, and 1005-505. The black lines you have drawn to represent these spans (you show only two) are shown BETWEEN these column rows which is not the case. Below is how the core lines are actually spanned by the truss. Agree or disagree?
View attachment 67250243

Yeah, the main truss lines go from centre to centre E-W and N-S. As for drawing one line Vs two, what of it ? If you were going to draw more than an indicator, then why not draw 4 or 6 aswell as it approaches the centre.

I'm not sure what the point is you're trying to make, and I'm not sure you are either tbh


ADD - I added this to the previous post by mistake, but try using it to make your point. Some of the features may apply to tower B



It's colour coded, so you can refer clearly to exactly what bit you are talking about.

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

Now, on your point re 2 lines Vs 1, If you were going to express the main lines on this, which I put on the thread over a week ago....


.... with just one simple line, in order to illustrate each of the main truss lines, what would you draw ?

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

It signifies that you haven't looked closely enough at enough of the drawings lol

gerrycan, please answer the question.

What does an engineer's stamp on drawings signify?

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

gerrycan, please answer the question.

What does an engineer's stamp on drawings signify?

No. Skilling was the lead structural engineer for the twin towers. Not disputable. Not debatable.

Ends.

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

No. Skilling was the lead structural engineer for the twin towers. Not disputable. Not debatable.

Ends.

Sorry gerrycan, I'm afraid it doesn't "end".

Robertson was made partner in 1967 and the firm became known as Skilling, Helle, Christiansen, Robertson. His name was even incorporated into the drawing headers. See the top of the header below.


It used to read:


So not only was a partner in the firm working on the design of the towers, he stamped/sealed the drawings.

 

[gamolon]

Re: Evidence that 9/11 was an inside job.[W:57]

No. Skilling was the lead structural engineer for the twin towers. Not disputable. Not debatable.

Why didn't he stamp/seal the drawings then?

 

[gerrycan]

Re: Evidence that 9/11 was an inside job.[W:57]

Sorry gerrycan, I'm afraid it doesn't "end".

Robertson was made partner in 1967 and the firm became known as Skilling, Helle, Christiansen, Robertson. His name was even incorporated into the drawing headers. See the top of the header below.
View attachment 67250253

It used to read:
View attachment 67250254

So not only was a partner in the firm working on the design of the towers, he stamped/sealed the drawings.

Engineering News Record, April 1964
"Skilling :- Architect's engineer plans the biggest" <-- With Skilling on the front cover.

Seattle Times, 1993
"We looked at every possible thing we could think of that could happen to the buildings, even to the extent of an airplane hitting the side," said John Skilling, head structural engineer. "However, back in those days people didn't think about terrorists very much."

Skilling, based in Seattle, is among the world's top structural engineers. He is responsible for much of Seattle's downtown skyline and for several of the world's tallest structures, including the Trade Center."

So now what you need to do is find me something from earlier than 1998 that refers to Les Robertson as the lead structural engineer of the twin towers. You won't, because he wasn't.

Robertson worked for Skilling, and after Skilling gained the contract he sent Robertson to NY to open his office there in 1964. Robertson didn't like him. They eventually fell out, and having been made a partner in 67, Robertson split off and formed LERA, I think in the 80s. Most of the design was done by 1967.

Get back to me when you find that reference to Robertson being the lead.