Wednesday, April 09, 2008

Numerous Structural Engineers Now Publicly Challenge Government's Explanation for Destruction of the World Trade Center

Numerous structural engineers now publicly challenge the government's account of the destruction of the Trade Centers on 9/11, including:

Two professors of structural engineering at a prestigious Swiss university (Dr. Joerg Schneider and Dr. Hugo Bachmann) said that, on 9/11, World Trade Center 7 was brought down by controlled demolition (translation here)

Kamal S. Obeid, structural engineer, with a masters degree in Engineering from UC Berkeley, of Fremont, California, says:
"Photos of the steel, evidence about how the buildings collapsed, the unexplainable collapse of WTC 7, evidence of thermite in the debris as well as several other red flags, are quite troubling indications of well planned and controlled demolition"
Ronald H. Brookman, structural engineer, with a masters degree in Engineering from UC Davis, of Novato California, writes:
"Why would all 110 stories drop straight down to the ground in about 10 seconds, pulverizing the contents into dust and ash - twice. Why would all 47 stories of WTC 7 fall straight down to the ground in about seven seconds the same day? It was not struck by any aircraft or engulfed in any fire. An independent investigation is justified for all three collapses including the surviving steel samples and the composition of the dust."
Graham John Inman, structural engineer, of London, England, points out:
"WTC 7 Building could not have collapsed as a result of internal fire and external debris. NO plane hit this building. This is the only case of a steel frame building collapsing through fire in the world. The fire on this building was small & localized therefore what is the cause?"
Paul W. Mason, structural engineer, of Melbourne, Australia, argues:
"In my view, the chances of the three buildings collapsing symmetrically into their own footprint, at freefall speed, by any other means than by controlled demolition, are so remote that there is no other plausible explanation!"
David Scott, Structural Engineer, of Scotland, argues:
"Near-freefall collapse violates laws of physics. Fire induced collapse is not consistent with observed collapse mode . . . ."
Nathan Lomba, Structural Engineer, of Eureka, California, states
"I began having doubts about, so called, official explanations for the collapse of the WTC towers soon after the explanations surfaced. The gnawing question that lingers in my mind is: How did the structures collapse in near symmetrical fashion when the apparent precipitating causes were asymmetrical loading? The collapses defies common logic from an elementary structural engineering perspective. “If” you accept the argument that fire protection covering was damaged to such an extent that structural members in the vicinity of the aircraft impacts were exposed to abnormally high temperatures, and “if” you accept the argument that the temperatures were high enough to weaken the structural framing, that still does not explain the relatively concentric nature of the failures.

Neither of the official precipitating sources for the collapses, namely the burning aircraft, were centered within the floor plan of either tower; both aircraft were off-center when they finally came to rest within the respective buildings. This means that, given the foregoing assumptions, heating and weakening of the structural framing would have been constrained to the immediate vicinity of the burning aircraft. Heat transmission (diffusion) through the steel members would have been irregular owing to differing sizes of the individual members; and, the temperature in the members would have dropped off precipitously the further away the steel was from the flames—just as the handle on a frying pan doesn't get hot at the same rate as the pan on the burner of the stove. These factors would have resulted in the structural framing furthest from the flames remaining intact and possessing its full structural integrity, i.e., strength and stiffness.

Structural steel is highly ductile, when subjected to compression and bending it buckles and bends long before reaching its tensile or shear capacity. Under the given assumptions, “if” the structure in the vicinity of either burning aircraft started to weaken, the superstructure above would begin to lean in the direction of the burning side. The opposite, intact, side of the building would resist toppling until the ultimate capacity of the structure was reached, at which point, a weak-link failure would undoubtedly occur. Nevertheless, the ultimate failure mode would have been a toppling of the upper floors to one side—much like the topping of a tall redwood tree—not a concentric, vertical collapse.

For this reason alone, I rejected the official explanation for the collapse of the WTC towers out of hand. Subsequent evidence supporting controlled, explosive demolition of the two buildings are more in keeping with the observed collapse modalities and only serve to validate my initial misgivings as to the causes for the structural failures."
Edward E. Knesl, civil and structural engineer, of Phoenix, Arizona, writes:
"We design and analyze buildings for the overturning stability to resist the lateral loads with the combination of the gravity loads. Any tall structure failure mode would be a fall over to its side. It is impossible that heavy steel columns could collapse at the fraction of the second within each story and subsequently at each floor below.

We do not know the phenomenon of the high rise building to disintegrate internally faster than the free fall of the debris coming down from the top.

The engineering science and the law of physics simply doesn't know such possibility. Only very sophisticated controlled demolition can achieve such result, eliminating the natural dampening effect of the structural framing huge mass that should normally stop the partial collapse. The pancake theory is a fallacy, telling us that more and more energy would be generated to accelerate the collapse. Where would such energy would be coming from ?"
David Topete, civil and structural engineer, San Francisco, California

Charles Pegelow, structural engineer, of Houston, Texas (and see this)

Dennis Kollar, structural engineer, of West Bend, Wisconsin

Doyle Winterton, structural engineer (retired)

Michael T. Donly, P.E., structural engineer

William Rice, P.E., structural engineer, former professor of Vermont Technical College

See this website and this website for further additions.

There are many other structural engineers who have questioned the government's account in private. We support them and wish them courage to discuss these vital issues publicly.

See also this.




8 Comments:

Blogger Mike M C said...

The truth needs to come out. Building pulverization is a fact, not fiction, and certainly not a theory.

7:47 PM  
Blogger 911 Treason Was Terrorism said...

300+ Architects and Engineers at http://www.ae911truth.org speak publicly about the controlled demolition that took place on 911.

A year ago there were less than 200.

Check out what's happening on truthaction.org. It's fantastic!

9:48 PM  
Blogger alythcott1 said...

Thanks for posting this George. It's historic and lends the Truth followers and Leaders greater credence, being able to point to actual structural engineers for validity of their skepticism. The OCT croud has long said that people like Dr Jones didnt write peer reviewed papers, or that structural engineers sneer at 911Truth.

No More!

1:42 AM  
Blogger moth said...

This implies that the buildings were previously set up with professional demolition charges/wiring. That is usually a lot of dangerous work done by skilled professionals. So instead of just interviewing structural engineers, how about seeking out and interviewing some people in the demolition trade. See what they say. Could all that preparation work be done without someone noticing? Could they suggest any clues/evidence specific to demolition.

9:02 AM  
Blogger boog said...

were creeping closer to the truth, one tiny step at a time. Bush and his crooked cronies will pay fro what they did.

9:25 AM  
Blogger acacia72 said...

I've been wondering if perhaps the federal gov't or the NY state gov't pre-wired the Twin Towers sometime after the first WTC bombing in case they were bombed again and needed to be brought down for safety's sake. Maybe someone in the gov't was actually on top of things and figured a controlled demolition might some day be necessary rather than have the towers collapse uncontrollably sideways, thereby doing a LOT of collateral damage. Ok, that's possible, and I can even see that it might be better to "lay low" rather than to admit to it. Ok, so far so good. Now, here's the rub; why bring down bldg #7? It was absolutely NOT necessary and Larry Silverstein was caught on camera telling the NYFD to "pull it" inre to destroying bldg #7. To have been able to do this, bldg #7 MUST have been pre-wired; why would that be? There are simply too many unanswered questions and things that make sense when you look at them one way, but then make NO sense whatsoever when looked at from another angle, and also some things that make absolutely NO sense no matter HOW you look at them.

I fear America has been BETRAYED.

4:45 PM  
Blogger Justin said...

The killing of Marvin Bush's housekeeper (Bertha Champagne) killed in Marvin Bush's front yard and how that was hidden by the news media should be a red flag to most sane Americans. Add to that his unquestioned and un-investigated role on the Board of Directors of Securacom which provided security for the World Trade Center, Dulles Airport and United Airlines and his role at HCC Insurance, which provided insurance coverage on the WTC, seems the U.S. is indeed part of the New World Order Dubya and Marvin's poppa promised America. Problem is, the New World Order's agenda is to fulfill the mission of the U.N.'s founding fathers. But the President was supposed to uphold the U.S. Constitution. At least that's what he took an Oath of Office to do. Strange how Bush and kin have gotten away with high treason with no resistance by our government.

9:31 PM  
Blogger michael said...

Probably each of the Twin Towers could have sustained 10 strikes by aircraft rather than just the one each, woozy, but still standing.

Pock marked, for sure, but the core column mass relatively unaffected.

Assume two masses, one, the WTC weighs 500,000~ tons, the other, the Boeing, weighs 300~ tons.

This is a mass ratio of 1 : 1650~ .

Also too - half of this mass is soft stuff, like people, and fuel, and luggage, and seating and other furniture.

The fuel went whoosh ! mostly to the outside of the Sth Tower, the people mass were squished horribly and had no effect on the structural integrity, nor would their suitcases with clothing have any effect.

So that removes half the mass from consideration, which means we now have a mass ratio of 1 : 3,300~ .

Plausible to suggest that a mass ration of 1 : 100 would knock a building over by Boeing, but not plausible at all to suggest that a mass ratio of 1 : 3,300~ would do it.

Consider too, that this aircraft mass is travelling at perhaps 300m/s, speed of sound is 330m/s, and it's really a pedestrian affair as far as disruptive kinetic energy delivery to the core columns is concerned, as it is only the engines and landing gear which have enough solidity and resistance to disintegration to make much of an impact.

But, by the time they have traversed the distance from the outer skin of the building to the many structural steel core members, considerable kinetic energy would have been lost.

Did that happen with the Sth Tower as it was dealt a glancing blow ? So, why did it fall first, and straight down and not lean over ?

So, consider that the engines and landing gear might well have been travelling by then at 100 m/s as they come up against the steel core members.

How fast is that ? A racing car travelling at 360kph or 223mph.

Imagine 36 structural steel members bunched together vertically, with appropiate spacing, and a racing car crashes directly into the bunch at 223mph, which just happens to be Indy 500 speed.

Would anyone say that the engine of the car will do anything much to any of the steel members, let alone rupture enough of them ?

Maybe deform one, and its energy is gone.

That is another way of saying that this whole thing was a controlled demolition job with pre-placed charges - hundreds of them.

2:20 PM  

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