What the World Trade Center Building Designers Said: Before and After 9/11
What the World Trade Center Building Designers Said: Before and After 9/11
An analysis of contradictions in statements by Building Designer Leslie Robertson
Another Quotation from John Skilling added about the possibility of controlled demolition destroying the World Trade Center buildings in 1993.
“A previous analysis [by WTC building designers], carried out early in 1964, calculated that the towers would handle the impact of a 707 traveling at 600 mph without collapsing”
(Between Early 1984 and October 1985):
“However, O’Sullivan consults ‘one of the trade center’s original structural engineers, Les Robertson, on whether the towers would collapse because of a bomb or a collision with a slow-moving airplane.’ He is told there is ‘little likelihood of a collapse no matter how the building was attacked.’”
“[Building designer] John Skilling recounts his people having carried out an analysis which found the twin towers could withstand the impact of a Boeing 707. Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed.” But, he says, “The building structure would still be there.”
“The analysis Skilling is referring to is likely one done in early 1964, during the design phase of the towers. A three-page white paper, dated February 3, 1964, described its findings: “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.” However, besides this paper, no documents are known detailing how this analysis was made.”
“Skilling - a recognized expert in tall buildings - doesn't think a single 200-pound car bomb would topple or do major structural damage to a Trade Center tower. The supporting columns are closely spaced and even if several were disabled, the others would carry the load. ‘However,’ he added, ‘I'm not saying that properly applied explosives - shaped explosives - of that magnitude could not do a tremendous amount of damage.’ Although Skilling is not an explosives expert, he says there are people who do know enough about building demolition to bring a structure like the Trade Center down. ‘I would imagine that if you took the top expert in that type of work and gave him the assignment of bringing these buildings down with explosives, I would bet that he could do it.’”
“Leslie Robertson, one of the two original structural engineers for the World Trade Center, is asked at a conference in Frankfurt, Germany what he had done to protect the twin towers from terrorist attacks. He replies, ‘I designed it for a 707 to smash into it,’ though does not elaborate further.”
[Leslie Robertson:] “The twin towers were in fact the first structures outside the military and nuclear industries designed to resist the impact of a jet airplane.”
[Frank A. Demartini:] “The building was designed to have a fully loaded 707 crash into it. That was the largest plane at the time. I believe that the building probably could sustain multiple impacts of jetliners because this structure is like the mosquito netting on your screen door -- this intense grid -- and the jet plane is just a pencil puncturing that screen netting. It really does nothing to the screen netting.” Frank A. Demartini, on-site construction manager for the World Trade Center, spoke of the resilience of the towers in an interview recorded on January 25, 2001.
Sept 3-7, 2001—just before 9/11
“The Boeing 707 was the largest in use when the towers were designed. [Leslie] Robertson conducted a study in late 1964, to calculate the effect of a 707 weighing 263,000 pounds and traveling at 180 mph crashing into one of the towers. [Robertson] concluded that the tower would remain standing. However, no official report of his study has ever surfaced publicly.”
“The engineer who said after the 1993 bombing that the towers could withstand a Boeing 707, Leslie Robertson, was not available for comment yesterday, a partner at his Manhattan firm said. ‘We're going to hold off on speaking to the media,’ said the partner, Rick Zottola, at Leslie E. Robertson Associates. ‘We'd like to reserve our first comments to our national security systems, F.B.I. and so on.’”
“The building owners, designers and insurers, prevented independent researchers from gaining access—and delayed the BPAT team in gaining access—to pertinent building documents largely because of liability concerns.”
“[The] National Institute of Standards and Technology (NIST), in 2005 state that it has been ‘unable to locate any evidence to indicate consideration of the extent of impact-induced structural damage or the size of a fire that could be created by thousands of gallons of jet fuel.’”
“In 2002, Leslie Robertson wrote: “To the best of our knowledge, little was known about the effects of a fire from such an aircraft, and no designs were prepared for that circumstance.”
“[Leslie Robertson:] I support the general conclusions of the NIST report… The [WTC] was designed for the impact of a low flying slow flying Boeing 707. We envisioned it [to be like] the aircraft that struck the Empire State building [during] WW II. It was not designed for a high speed impact from the jets that actually hit it… Yes there was a red hot metal seen [in the WTC rubble] by engineers. Molten—Molten means flowing—I’ve never run across anyone who has said that they had in fact seen molten metal, or by the way if they had seen it, if they had performed some kind of an analysis to determine what that metal was.” Steven Jones in discussion With Leslie Robertson [MP3] by KGNU Radio, Denver, CO, Oct 26, 2006
Robertson has made some glaring contradictions in his statements.
· Robertson claims that the building was designed to only survive plane crashes at speeds of 180 mph. Interestingly he made this claim only a few days before 9/11. A quote by Building Designer Skilling indicates that “A previous analysis, carried out early in 1964, calculated that the towers would handle the impact of a 707 traveling at 600 mph without collapsing”. Robertson must resolve this apparent contradiction. It is a very suspicious statement given the fact that it would be reasonable to consider the maximum speed of a plane flying into the Twin Towers. Is it possible that Robertson was asked to leak this “deliberately misleading information” just before 9/11? However, this is just speculation. Also suspicious is the fact that he said in 1984-5 that there was “little likelihood of a collapse no matter how the building was attacked.”
· Robertson says that the building was not designed to survive jet fuel fires: “To the best of our knowledge, little was known about the effects of a fire”. This claim is suspicious for two reasons: why would they design the towers to survive plane crashes without considering the jet fuel? And more importantly, John Skilling claimed in 1993 that they did consider the jet fuel when they designed the buildings. Given this fact, which statement is more likely to be correct about jet fuel fires being considered?
· NIST is also contradicted when they claim that there was no “evidence to indicate consideration of… thousands of gallons of jet fuel”. This statement is clearly false. See John Skilling’s statement: “Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire… The building structure would still be there.”
· In interview with Steven Jones, Robertson claims that he had “never run across anyone who has said that they had in fact seen molten metal.” This statement is extremely suspicious considering the fact that Robertson himself claimed to have seen it in a published news report! This contradicts his own statement about seeing molten metal: “Leslie Robertson, the structural engineer responsible for the design of the WTC, describes fires still burning and molten steel still running 21 days after the attacks.”. As well, substantial eye-witness testimony supports observations of Molten Steel.
· Robertson is also incorrect when he says that “if they had seen [Molten Steel, they had not] performed some kind of an analysis to determine what that metal was. This statement is false. FEMA analyzed samples of the molten steel. However, NIST did not even mention the molten steel and called it “irrelevant to [their] investigation.” This could have simply been a mistake by Robertson.
Is Robertson being pressured to lie and make false statements? Was he asked to leak a false statement just before 9/11 about the speed of the planes having an impact on their destruction? Are these contradictions by accident or mistake?
A news report stated that he wanted to give his opinion to the FBI before making his comments public. This in itself is not overly suspicious—but his contradictions are. No clear answers to these and similar questions can be obtained through speculation alone—Leslie Robertson must account for these himself. If another 9/11 investigation is obtained, it is clear that Leslie Robertson will have to answer these and other relevant questions.
 “Believed to Be Safe, the Towers Proved Vulnerable to Jet Fuel Fire”
By JAMES GLANZ
 [Chicago Tribune, 9/12/2001; Knight Ridder, 9/12/2001] These articles the day after 9/11 make clear the fact that this statement was made before 9/11: “Les Robertson, the Trade Center's structural engineer, spoke last week at a conference on tall buildings in Frankfurt, Germany”.
 See here for pictures and comments in FEMA’s report mentioning the melted steel:
“Although virtually all of the structural steel from the Twin Towers and Building 7 was removed and destroyed, preventing forensic analysis, FEMA's volunteer investigators did manage to perform "limited metallurgical examination" of some of the steel before it was recycled. Their observations, including numerous micrographs, are recorded in Appendix C of the WTC Building Performance Study. Prior to the release of FEMA's report, a fire protection engineer and two science professors published a brief report in JOM disclosing some of this evidence.” 1
“The results of the examination are striking. They reveal a phenomenon never before observed in building fires: eutectic reactions, which caused "intergranular melting capable of turning a solid steel girder into Swiss cheese." The New York Times described this as "perhaps the deepest mystery uncovered in the investigation."2 WPI provides a graphic summary of the phenomenon.”
“The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified. The rate of corrosion is also unknown. It is possible that this is the result of long-term heating in the ground following the collapse of the buildings. It is also possible that the phenomenon started prior to collapse and accelerated the weakening of the steel structure. A detailed study into the mechanisms of this phenomenon is needed to determine what risk, if any, is presented to existing steel structures exposed to severe and long-burning fires.”
Evidence of evaporated steel as reported by the New York Times:
“Engineers have been trying to figure out exactly what happened… ‘Fire and the structural damage… would not explain steel members in the debris pile that appear to have been partly evaporated’” from:
Glanz, James (2001). “Engineers are baffled over the collapse of 7 WTC; Steel members have been partly evaporated,” New York Times, November 29. 2001.