Thank you for explaining.Originally Posted by SanderO
Thank you for explaining.
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.
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?
Nothing is as it appears.
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?
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.
Nothing is as it appears.
gerrycan,
would you mind responding to this?:
https://www.debatepolitics.com/consp...post1069608694 (Evidence that 9/11 was an inside job.[W:57])
This one also:
https://www.debatepolitics.com/consp...post1069607736 (Evidence that 9/11 was an inside job.[W:57])
And:
https://www.debatepolitics.com/consp...post1069643963 (Evidence that 9/11 was an inside job.[W:57])
When you have time.
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.
Leslie E Robertson - Wikipedia.jpg
John Skilling - Wikipedia.jpg
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.
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 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?
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