WTC construction manager speaks of the resilience of the twin towers

Originally posted by bsbray11
reply to post by thomk

 

That didn't compromise the stability of the structure, though. The core structure itself didn't have all the open floor space you are talking about, it was more like a conventional steel-framed structure with box columns and beams. The open floor space outside of it may in itself have been easy to bust up, ie the trusses and concrete slabs, but on the other side of these were 100's of closely-meshed perimeter columns and spandrel plates. There was plenty of support. Are you still getting around at pancake theory, esdad?

[edit on 26-12-2009 by bsbray11]

The 'core' of the structure was one part of an intricate design. It had a small solid core that used beams to connect to the outer columns. The building was NOT designed to withstand loads without the support of the outer bearing walls. You know are well aware of this BS.

The only resilience of the building were the 'bolts' that connected the beams to the outer columns. Those columns need to be there to distribute the weight of each floor above it. This is the design and not pancake theory.

Due to the heat of the fires the beams were softened and not able to support the upper floors. They did for a short time which also is by design to allow escape from the building in the event of a catastrophic incident.

Again, I think it is a miracle that both withstand the hits they took.

Originally posted by esdad71
The 'core' of the structure was one part of an intricate design. It had a small solid core that used beams to connect to the outer columns. The building was NOT designed to withstand loads without the support of the outer bearing walls. You know are well aware of this BS.

Yeah but you are basically trying to revert back to pancake theory and saying that the buildings were "hollow tube designs." That crap has been buried in the past by even federal government reports. The core structure was the most robust part of the structure. Without the perimeter structure, the trusses would collapse and the inner core wouldn't be as efficient at handling lateral (wind) loads. Without the inner core structure, though, the whole building would instantly collapse in on itself.

Due to the heat of the fires the beams were softened and not able to support the upper floors.

Beams do not support gravity loads from multiple floors. Columns do.

Sorry, but I am not talking about pancake theory. You can try to apply that and that is ok, but what I am saying, is that this building was built like no other on the planet for it's size. It was, for lack of a better term, an architectural marvel. The building itself however was not as 'stable' as a solid construction building such as the Chrysler Building or the Empire State to name to large skyscrapers in NYC.

It had an inner core which was designed for strength and to incorporate the elevator system in the building, which again, was designed as not to take away precious commercial real estate. However, the inner core was connected to the outer columns. I am not saying hollow, I am stating the design. It was needed to

Here I must correct my previous post and add more information instead of assuming someone of your knowledge would just understand the statement and not try to pick it apart.

The beams weakened which caused the floors to sag at which time the structure basically 'snapped' in a particular section. The building was then however to still stand until the loads could not be distributed properly and they toppled over, not straight down.

We can create another for these points but here ca we agree on one thing ? That is that the resilience of the towers is shown in the fact they withstood the attack in the fashion they did allowing a smaller loss of life.

However, we both know it was not designed to survive the attack on 9/11 but to withstand a smaller plane at a much lower speed.

[edit on 27-12-2009 by esdad71]

Originally posted by esdad71
Sorry, but I am not talking about pancake theory. You can try to apply that and that is ok, but what I am saying, is that this building was built like no other on the planet for it's size.

You could say that for every skyscraper on the face of the Earth. It doesn't mean anything in and of itself, sorry.

The beams weakened which caused the floors to sag at which time the structure basically 'snapped' in a particular section. The building was then however to still stand until the loads could not be distributed properly and they toppled over, not straight down.

There is some really fuzzy thinking going on here. The beams you are talking about were really trusses, and I have no idea why you think their sagging should cause the entire structure to 'snap'. Come on, esdad, FEMA and NIST both are much more articulate and I and many other still have issues with their work not being explicit enough.

However, we both know it was not designed to survive the attack on 9/11 but to withstand a smaller plane at a much lower speed.

No, that is a common misconception. Skilling's engineering team did an analysis that showed the building could withstand a 600 mph impact from a 707. That is not a "much lower speed," it is exactly the same speed, and it is not a much different sized plane. You are thinking of a separate analysis that was carried out by Leslie Robertson's firm. For being here as long as you have, esdad, you should know this by now. At least remember it now for future reference. You could do a Google search for "Skilling impact 600 mph" or some such if you want, or I can post it here myself.

Also the SE Dr. Abolhassan Astaneh-Asl that worked with FEMA claimed all his computer simulations contradicted the idea that the buildings could not have withstood the planes and fires, and actually most skyscrapers in NY could have done as much according to his modeling. The ASCE even came out with an article featuring him accusing the ASCE of "moral corruption" for misleading people for that reason.

The analysis of the buildings' designed resilience indicated they could survive such an impact and they actually did survive it long enough for the majority of occupants to escape. I guess the issue here is that they did not survive indefinitely and regardless of what mode of failure turned out to be the final straw causing eventual total collapse, there'll never be a concensus on it. The analysis couldn't be tested in reality except for the event actually taking place (high speed large plane strike) which, I hope, no-one was wanting for proof of concept.

In my opinion the buildings were far more extensively damaged by the impacts than was apparent from an external viewpoint and the statement by William Rodriguez is compelling evidence of that.

The stairs were cracking. The sheet rock, when I went up opening the doors, was falling on top of me and on top of the firemen constantly. And the swaying of the building made it easier for that to come off.
I remember listening to the fluorescent lights, the emergency lights that were in the building, cracking up in line; pop, pop, pop, pop, pop all the way to the bottom because of the swiveling.

That's a considerable time after the impacts and the building was swaying, twisting, swivelling enough to distort the stairwells sufficiently to break flourescent tubes in the stairwell emergency lights and still dislodging sheetrock panels. I could presume that the distortions were actually at a maximum and building up then because the lights had remained intact up till that stage.

Maybe it's purely conjecture but it's possible that the building's spine was extensively fractured by the impacts (bolts and welded joints broken) leaving only the outer columns keeping the core sections in vertical alignment. We won't reach any sort of agreement on the exact mode of failure in my lifetime or even my grandchildren's lifetimes so I don't see the point of arguing about it - it happened & it was tragic.


[edit on 27/12/2009 by Pilgrum]

Regardless, an impact from a large plane vs a small plane is not going to make the different between no collapse and a complete global collapse.

A complete global collapse, as happened to 3 buildings that day, is the MOST extreme outcome of any effect on those buildings.

The silly 'debunker' arguments and irrelevant details pretty much amounts to nothing in the grand scheme of those extreme outcomes, from not so extreme events.

Saying the building was only designed for a small aircraft impact, or the collapse times were not exactly at free-fall speed, or the buildings were unique, does not amount to the extreme outcome you're trying to explain away. They're just empty arguments that offer nothing to the debate other than giving 'truthers' the opportunity to school you...

reply to post by Pilgrum


Even if all that was true it still doesn't explain the way the buildings, all 3, collapsed globally, symmetrically, with no sign of slowing of the collapse wave (resistance). There is no way that the damage could have been so extensive as to take away ALL the resistance of lower floors.

Look at WTC2 and the top tilt, that should be enough to see that something was going on other than office fires, the top did not do what it should have done according to known physics, unless something removed all the resistance of the lower building. Office fires and damage to upper floors could not do that. Something removed the path of most resistance, or the top would have continued it's path which was twisting and tilting, not dropping. If it was it's weight it would still have kept it's path while possibly taking some of the building with it. But to suddenly take a completely symmetrical vertical path from all that chaos is highly unlikely. Nature is never that neat and tidy.

[edit on 12/27/2009 by ANOK]

Originally posted by Pilgrum
In my opinion the buildings were far more extensively damaged by the impacts than was apparent from an external viewpoint and the statement by William Rodriguez is compelling evidence of that.

Rodriguez said there was an explosion in the basement levels seconds before the plane even struck. There are many more testimonies of basement explosions. It was reported live on TV that day that FBI officials had said they suspected a vehicle had exploded in the underground parking garage to coincide with the plane impacts. Another journalist said their subway car filled with smoke as it approached the WTC. A 300 lb steel and concrete door was destroyed, the windows in the lobby were blown out, and NYPD Lt. William Walsh said in testimony that the elevators servicing the basements and lower floors were blown out of their hinges, NOT the elevators servicing the upper floors, and he was very clear about this.

Construction worker Philip Morelli and engineer Mike Pecoraro also reported blasts in the basement, and various government agencies couldn't even decide on the impact times for either plane, even though the 2nd one was broadcast on live TV, because the seismic signals for the "impacts" came seconds before the actual planes struck the buildings, even after adjustment for delays.

All in all, yes, there was much more extensive damage than was apparent from the impacts, but that's because it was unrelated to the impacts.

[edit on 27-12-2009 by bsbray11]

reply to post by ANOK


We have been over it all quite a few times and I still see nothing remarkable about symmetrical structures exhibiting symmetry even in total failure, particularly in this case of top-down failure. The arrested tilting of WTC2 has been a large bone of contention but, even in that, I can see conventional explanations.

I'm not rejecting any possibilities out of hand however. Just waiting for something new to lead us in the right direction because your, mine or anyone elses assessment based on observation only really isn't going to solve the unkowns to anyone's satisfaction. It'll take something far more solid than pure conjecture to sort it all out and I'm losing hope that it will ever be forthcoming.

reply to post by Pilgrum


A structure falling symmetrically is not dependent upon the structure itself being symmetrical. It requires the actual failures and forces involved to be symmetrical, which is a completely different ball game. The damage to those buildings was NOT symmetrical.

In chaotic systems, like a building collapsing, according to chaos theory, even a tiny asymmetry (manifested in a falling building as a lean/tilt) becomes amplified as the system progresses. Not self-correcting. That is a sign of intelligent control.

reply to post by bsbray11


That basement explosion troubles me too and the possibility of a car bomb or something along those lines can't be ruled out. There was a lot of damage reported down there but it was essentially superficial in terms of what it did to the structure supporting the tower.

I have trouble reconciling the reported 'white vapour' and strong smell of kerosene down there with a car bomb though unless the the bomb was associated with a large supply of kerosene to make it smell like jet fuel was the cause (sounds like excessive attention to detail?). I have issues with Rodriguez's split-second timing of the explosion with the impact as well because there's no way he could determine that sort of timing detail from his basement office. The difference in sound propagation through steel and concrete compared to air can explain what he heard and felt as separate events.

I still need a lot more to be confident of what really happened down there.

Originally posted by Pilgrum
There was a lot of damage reported down there but it was essentially superficial in terms of what it did to the structure supporting the tower.

I'm not sure how we would be able to determine what exact damage was actually done.

I have trouble reconciling the reported 'white vapour' and strong smell of kerosene down there with a car bomb though unless the the bomb was associated with a large supply of kerosene to make it smell like jet fuel was the cause (sounds like excessive attention to detail?).

There was an entire parking lot down there. If all the reports of basement explosions, including what was said of the FBI suspecting such a thing happening again, then all of the cars blown up/damaged by that would be an obvious source for that smell. It was certainly a hell of a lot closer than where the planes hit. I also never got how a blast wave could supposedly travel such a distance down drywall shafts without blowing through the drywall itself and dissipating that way, rather than traveling 1000 feet through such shafts and then causing so much destruction in the lobby and basement levels, or why upper-level servicing elevators would not also be blown off their hinges if this actually happened.

I have issues with Rodriguez's split-second timing of the explosion with the impact as well because there's no way he could determine that sort of timing detail from his basement office. The difference in sound propagation through steel and concrete compared to air can explain what he heard and felt as separate events.

I've never heard that one before but at least it is a better attempt at explaining Rodriguez's testimony than just saying he was lying, as a lot of others have resorted to claiming.


According to Wikipedia, sound travels through steel at 6000 m/s for longitudinal waves (P-waves) and 3200 m/s for shear waves (S-waves).

Sound travels at 343 m/s through dry air at 20 C.

en.wikipedia.org...

So at least theoretically it makes sense, since the sound would travel through the air much slower than it would through the steel, but it doesn't explain all the actual physical damage that was caused in the basements and lobby. Rodriguez also said the first sound he heard seemed to have come from below him.


A rough estimate here, there was about 1000 ft. or 300m between the impacts and where Rodriguez would have been. It would have taken the air approximately 0.87s to bring the sound to Rodriguez, and the steel 0.05s-0.09s. So they would have arrived within a second of one another through the different mediums. Any bigger of a difference than that and you'd have to have a different reason. Again, I think the difference between the seismic signals and the 2nd plane's impact witnessed in live TV is worth considering because there is a much greater difference between those times, for example, than this would account for. Similar for the 1st plane between different sources, though it wasn't caught on live TV.

There is no fuzzy thinking here. Trusses then,not beams...whatever you want to call them...they failed. Plain and simple. However, there is a part of the design that is rarely looked at and that would be the viscoelastic dampers that were used in the design. I find it odd that it is not referenced much more in these forums but maybe that is because it could have had a part in the collapse.

ALso, Leslie Robertson was the person who originally stated that an impact of a 707 'lost' if it hit the WTC would allow the building to still stand and allow evacuation if the 707 was travelling 200 mph. However, most non OS posters will only speak of Mr. Skilling who 'recalls' a study but has no proof. There was supposed to be an analysis of a 600 mph strike but no outcome to reference or view just a memory. He stated that the biggest issue would be fires but that the building would survive the initial impact.

This would mean the design did accomplish what it was designed for. It withstood a major impact, stood long enough for evacuation but no where in ANY of these documents does it state it would not collapse.

Stick to the OP Bray and stop pontificating.

Originally posted by esdad71
However, most non OS posters will only speak of Mr. Skilling who 'recalls' a study but has no proof.

"Recalls" has nothing to do with it.

The buildings have been investigated and found to be safe in an assumed collision with a large jet airliner (Boeing 707—DC 8) traveling at 600 miles per hour. Analysis indicates that such collision would result in only local damage which could not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact. 4

911research.wtc7.net...

Original source for this website, "City in the Sky, Times Books, Henry Hold and Company, LLC, 2003, page 131."

According to the book this information was released February 1964, while the buildings were still being designed.

It withstood a major impact, stood long enough for evacuation but no where in ANY of these documents does it state it would not collapse.

Nowhere does it say they would, either. I hope I don't have to remind you that these "collapses" were completely unprecedented, meaning nothing like this had ever happened to a skyscraper in the history of mankind and therefore no science could possibly predict it. The failure mechanisms NIST asserted were responsible were also firsts for steel skyscrapers.

Stick to the OP Bray and stop pontificating.

I don't see how we are very far off topic at all.


I'd be interested to hear why you think the dampers would have contributed to collapse too, considering they were installed to increase building performance in high winds and simply consisted of what were essentially springs between the trusses and exterior columns.

Originally posted by bsbray11

I'm not sure how we would be able to determine what exact damage was actually done.

That's exactly the problem but we can place it between two extreme limits at least. It was more than 'nothing' and less than sufficient to cause immediate failure of the superstructure as the building didn't collapse straight away. A large high explosive detonation in an enclosed area like the basement floors would create an intense overpressure pulse but Rodriguez and his co-workers didn't suffer any classic symptoms of that like ruptured eardrums, eye damage etc. and the initial story was they felt a 'rumble' like someone moving heavy furniture and those rumbles have been putting on weight every time he tells the story. I never got the impression of him lying, but I do see some progressive embellishment going on

I have a good idea of what they're describing as I've been in a large building during an earth tremor myself and the best way I could describe it is like a heavy truck passing on a rough road - the floor vibrates. Explosions are distinctly different to that.

reply to post by Pilgrum


I don't believe conventional explosives were used, either, but at the same time, something going off on floors below isn't necessarily going to cause eardrum ruptures above. Military teams often strap conventional HE's on a door and stand only a few feet away, around a corner, and wait for it to detonate before charging into the room immediately afterward. We would probably be talking about larger amounts but an inverse square law is still going to be at work.

Originally posted by Pilgrum
The arrested tilting of WTC2 has been a large bone of contention but, even in that, I can see conventional explanations.

And yet after all these years no one has been able to present this 'conventional explanation'. I posted a thread not that long ago asking for this. The thread was strangely empty of de-bunkers but for a couple who gave it a shot but quickly gave up.

There simply isn't one, or else it would be in the NIST report, wouldn't it?

And we know the NIST report does not explain the global collapse, only their hypothesis on what initiated the collapse. Their claim is that global collapse was inevitable once initiated, which doesn't take an engineer to tell you is a lie. There is no precedence to base such a claim on. (That should raise a red flag with anyone with half a brain).
It's just very convenient because the initiation of the collapse is the easy part to explain away, trying to explain away how the collapses were global is the problem, let alone trying to explain the tilt of WTC2 and it's subsequent global symmetrical collapse through the path of most resistance.

The only thing the de-bunkers have ever come up with is Greenings paper which we showed years ago was a bunch of garbage based on nothing but assumptions, like the NIST report.

[edit on 12/28/2009 by ANOK]

reply to post by ANOK


You're onto something there that defines the whole problem and the arguments related to it

Without some extensive data acquisition from inside the buildings to indicate what failed, when & how, every explanation is just a theory with little to back it up and adding a political bias just makes things harder to resolve. I don't see a way out of that circle of incredulity based on available information.

Originally posted by Pilgrum
We have been over it all quite a few times and I still see nothing remarkable about symmetrical structures exhibiting symmetry even in total failure,

WTC 7 wasn't symmetrical.

particularly in this case of top-down failure.

WTC 7 wasn't top-down failure. The lower floors had the fires according to NIST.

I'm not rejecting any possibilities out of hand however. Just waiting for something new to lead us in the right direction because your, mine or anyone elses assessment based on observation only really isn't going to solve the unkowns to anyone's satisfaction. It'll take something far more solid than pure conjecture to sort it all out and I'm losing hope that it will ever be forthcoming.

A more thorough, independent ivestigation might help. Correct?

[edit on 28-12-2009 by Nutter]

reply to post by Nutter


As this thread deals with the 'twin towers', WTC7 really doesn't fit the topic here 'WTC construction manager speaks of the resilience of the twin towers'. Yes it's quite a different event in many ways but let's not get them all mixed up.