Indications of intrernal structural instability of both towers prior to collapse?

[torgos_pizza]

I have read a number of survivor accounts suggesting both towers had indications of severe structural instability prior to the collpase....
In a way it reminded me of how the Titanic broke in half right before sinking- It wasn't a sudden, out of the blue breakup, but early in the sinking, survivors heard gradual popping and cracking sounds..I think perhaps it was the same with the towers..
In your opinions(s), were there any indications within the WTC that the towers were highly unstable and about to fall, or did they by all counts appear structurally sound (aside from the impact damage)?

[AZCat]

1. The NIST documented bowing of the perimeter columns...

prior to collapse. I forget where in the report (my copy is at home) but they show several images that clearly demonstrate the bowing.

[petgoat]

2. No indication in the south tower. Of course, if NIST would release the 6000 photos and 6000 videos

they're keeping out of public hands, maybe we could see for ourselves.

That hero janitor feller claimed there was a partial collapse from floor
65 to floor 43 "boom! boom! boom! boom! boom! boom!" He also claimed on
Rupert Murdoch-controlled Sky TV in the UK recently that the fire-exit
doors from the office floors to the stairwells were jammed in their
frames.

[MNReformer]

3. This is interesting--from someone who worked at the design firm.

http://exoptica.typepad.com/blogoptica/2008/07/why-the-world-trade-center-tower-floors-could-not-pancake-collapse-as-we-have-been-told.html

Why the World Trade Center Tower's floors could not 'pancake' collapse as we have been told.
The typical floor structural configuration for the World Trade Center Towers spanned from the exterior wall columns to where the inner columns and a welded cage of steel formed support for the elevator shafts, stair towers, air shafts and mechanical systems, as well as, transferring floor and roof loads to the reinforced concrete foundation/footing structure sitting on bedrock some 70' below grade. Leasable floor areas typically terminated at the service core, where individual floor sections began again according to the floor plan layout. Yes, the individual floors acted as a unified structural 'diaphragm' to stiffen the structure laterally, but the steel composition of each floor was constructed in smaller units of open web trusses spanning between steel reinforced concrete�beams and topped with a steel deck and lightweight concrete. Thus, each floor was NOT a monolithic slab and structural system spanning across each tower from one exterior wall to the other three, as we are led to believe.

Each floor, in fact, terminating at the contiguous inner structural service core, resembled a square 'donut', with the core area being the 'donut hole', so to speak. Failure of floor structural support in any quadrant of the building plan, or even in any half, thus, would have failed asymmetrically. And at the time of failure would not, could not, have 'pancaked' symmetrically as the misleading NIST and commission reports indicate (diagrams shown in these reports are graphically out of scale, and do not accurately represent the building's massive, in fact, over designed, internal structure).

Original WTC Construction Drawings: http://911research.wtc7.net/wtc/evidence/plans/table.html

Floor Plan, 35th to 40th Floors (click the link for this)

Building Sections (again, click the link for this)

How do I know this? What is my personal technical reference? From 1970 to 1972 I was a young design development draftsman for the firm of Minoru Yamasaki Associates, the design architectural firm for the WTC. I was part of the team that detailed the complex aluminum cladding fenestration details for similar building and also worked, in part, on detailing the WTC Executive Floor interior paneling and updating the WTC plans to reflect various 'as-built' construction changes. Based on actual project experience, I was, and am, quite familiar with the structural system at work on the towers, both at a technical and intuitive level.

From many videos it is clear that the initial devastating floor overloading was uneven, and then, suddenly, floor by floor, the destruction became uniform as the buildings seemingly demolished themselves. I would have expected a random destructive overload to cause only a portion of the building floors to fail at a time. This did not happen. The failure, thus, appears controlled and suspicious.

For the floors to 'pancake' uniformly, the first floor to fail would require all perimeter connections to fail almost simultaneously on each floor. The towers could not possibly have collapsed in this way as we have been told in the official reports. One floor, coincident, on top of another to start a demolition-like sequence, without powerful external forces at work, forces other than the plane crash--and the relatively low temperature jet fuel fires which burned away quickly--would not lead to a symmetrical, uniform collapse of all the floors. What other external forces could there be? Explosives? It is my view, knowing what I know, that the WTC towers were intentionally demolished.

R H Nigl July 18, 2008

[e-mail]

N.B. Where are the structural drawings? They still have not surfaced available for public review. I know they are available, there must be many copies in archives. Certainly the Port Authority, the City of New York, the architects and the steel shop fabricator's have copies.

[AZCat]

4. The structural drawings (or any of the building plans, for that matter)...

are not public domain. Nor would they be kept by anyone other than the building owner/operators for very long (although the consultants may keep copies of their own work for reference). This isn't a small plan set, you know - it's something like seventeen volumes.

[petgoat]

5. Peter Lance says a mole in the FDNY, Ahmed Amin Refai. obtained the the WTC plans

Lance reports that a colleague said Refai had dug the blueprints out of a dumpster.
Lance says he was told Refai also had the blueprints to the bridges and tunnels.

1000 Years for Revenge is the book.

http://www.writerswrite.com/journal/oct03/lance4.htm


Another interesting thing about Refai. Lance says he lied to get a second copy of
his electronic pass to "Metrotech, which is the city's most secure building, the FDNY's
new headquarters".

Now I'm wondering if the same pass for Metrotech might get one into Giuliani's secret
command bunker in WTC7?

[AZCat]

6. He might have gotten them that way.

We do throw them away after a while, and if nobody thinks it's a security issue we just dump them in the trash (the secure plans we don't usually get copies of). Nowadays with electronic copies of everything it's easier to get rid of the paper/mylar/vellum copies (although some institutions still keep hard copies of everything).

[PatrickSMcNally]

7. "failure would not, could not, have 'pancaked' symmetrically as the misleading NIST"

One should better distinguish the issue of "symmetric pancaking" at the onset of collapse from "symmetric pancaking" once the collapse was in motion. The collapse probably did not begin with symmetric pancaking. But once the first few floors have crashed then one may expect that the full volume of the collapsing building will exert a sufficiently uniform force to revert to a symmetric pancaking form while the collapse is in motion.

[MNReformer]

8. Oh, one would, would one?

How about writing to the author of the post--who clearly disagrees with your notion?

To quote: "From many videos it is clear that the initial devastating floor overloading was uneven, and then, suddenly, floor by floor, the destruction became uniform as the buildings seemingly demolished themselves. I would have expected a random destructive overload to cause only a portion of the building floors to fail at a time. This did not happen. The failure, thus, appears controlled and suspicious.

For the floors to 'pancake' uniformly, the first floor to fail would require all perimeter connections to fail almost simultaneously on each floor. The towers could not possibly have collapsed in this way as we have been told in the official reports. One floor, coincident, on top of another to start a demolition-like sequence, without powerful external forces at work, forces other than the plane crash--and the relatively low temperature jet fuel fires which burned away quickly--would not lead to a symmetrical, uniform collapse of all the floors. What other external forces could there be? Explosives? It is my view, knowing what I know, that the WTC towers were intentionally demolished."

He clearly discounts the possibility you propose. He is quite clear in saying that even after the collapse initiation the buildings would not have collapsed uniformly.

[AZCat]

9. Who give a shit what he claims?

He doesn't provide sufficient backup for it to merit consideration. He makes the same claim as many here - that the collapses could not have been as "symmetrical" as they appeared to be. The problem is that they weren't really symmetrical, and the issue is an ignoratio elenchi.