Les Robertson's contradictions...

[Blender Head]

A few Truthers have claimed that Robertson contradicted himself pre-9/11 in regards to how the Towers would stand up to airplane impacts. I asked them to name some but only one replied. This Truther linked me here: http://www.jonesreport.com/articles/210207_wtc_designers.html

Some excerpts:

Before 9/11

“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”[2]

(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.’”

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.”

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.[14] 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”.[15] 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.”

Now a lot of the comments made in the site are laughable, such as the "published report by Les that he had seen molten steel" when he had not but what do you guys think of the rest of the article?

 

[MarkyX]

“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”[2]

According to Alex Jones' own source, this is what it said about the analysis:

However, besides this paper, no documents are known detailing how this analysis was made.

So there we go, no math or scientific understanding on how this analysis was made, hence 9/11 deniers will latch onto it.

 

[Reheat]

There is a lengthy discussion here regarding this subject somewhere if you can find it. Beachnut would be your best source on the title of the thread and when it was discussed.

I can tell you right off that the 600 MPH makes absolutely no sense whatsoever because a 707 won't go that fast at low altitude even downhill.

What is more likely is a design to absorb the impact of a lightly fueled 707 lost in the fog. That makes sense.

 

[Blender Head]

What is more likely is a design to absorb the impact of a lightly fueled 707 lost in the fog. That makes sense.

I agree with this conclusion.

How would one address:

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

I've seen the linked .pdf but don't know how to go about it.

 

[Magenta]

How would one address:



I've seen the linked .pdf but don't know how to go about it.

911myths has addressed Robertson's alleged comment:

http://www.911myths.com/html/leslie_robertson.html


The 707 analysis has been discussed ad nauseam eg.

707 Lost in fog and trying to land @ 600 MPH?

 

[Blender Head]

Thanks Mag.

Here is my reply to the Truther:

Ignoring for a second that the study and its methodology is not available what aircraft would fly 600 mph in New York and crash into the buildings, much less the Towers, at that speed? If a plane malfunctioned I certainly hope the pilot would not choose to push the throttle full force.

“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.’”

The use of this quote is great, because it implies an engineer would say "Yup, this building will collapse if it's attacked!" which is ridiculous. Also note "whether the towers would collapse because of a bomb or **a collision with a slow-moving airplane**"

So in reality this is consistent with what he said just before and post-9/11.

The Skilling quote suggests that the designers were worried about the fuel and the resulting fires but doesn't indicate whether tests were done on the survivability of the Towers passed his assertion that the building would remain standing. It's even admitted that the methodology of the study is not available so the reliability of the analysis is in question. In addition, Skilling has the same issue that Les had in the 80s comment: Would an engineer admit his buildings are unsafe?

Frank DeMartini was not on the original design team and died on 9/11. His opinions on the resistance of the Towers are just that: opinion.

This site implies that Les is in on the conspiracy, if that's the case what difference does it make that his firm held reservations before speaking with investigators?

“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.”

And? The article and congressional testimony sourced is five years old at the time of writing, is there an update on this?

Analysis:

The section discusses the 600mph figure and links to another site, which links to then another site, this time the Seattle Times newspaper interview with Skilling, but the story does not include the mention of a 600mph number. The second site links to an Amazon.com page for a book but since it's not available to me I cannot opine on it. Finally, the Terror Timeline (second site linked) provides no information other than a quote that includes the 600mph figure from NIST which states that the paper done on the Towers is not available.

"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."

The author clips Les' quote, and also implies that an engineer would actually admit his buildings would collapse if attacked.

Next, the claim of the jet fuel consideration is addressed:

"This claim is suspicious for two reasons: why would they design the towers to survive plane crashes without considering the jet fuel?"

Various reasons, such as the complexity of the modelling required to determine the jet fuel's effects in the 1960s.

“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.”

This claim is not backed up by the facts. There is no evidence that Les made such comments about steel. Indeed, it could be nothing more than the recollection of the author of the .pdf Jimmy Williams. Les himself has denied making the statement and denies having the experience to determine such:

"I've no recollection of having made any such statements...nor was I in a position to have the required knowledge."

And Williams' notes indicate that Les mentioned molten metal but the context is unclear.

911myths.com/html/leslie_robertson.html

'As well, substantial eye-witness testimony supports observations of Molten Steel'

There are also eye-witness testimony to molten metal; how one can tell steel apart from other metals with low temperatures required for melting is something Arabesque doesn't care to address.

I concur that Robertson was most likely mistaken in saying no tests on the steel had been conducted. However, the NIST is correct as post-collapse effects are irrelevant to how the structures collapsed.

 

[bio]

Robertson behavior is very suspicious indeed, because he did not say the truth! This white paper from 1964 and testimonies of other engineers debunks Robertson "claim":

"Robertson took the time to calculate how well his towers would handle the
impact from a Boeing 707, the largest jetliner in service at the time. He
says that his calculations assumed a plane lost in a fog while searching
for an airport at relatively low speed, like the B-25 bomber. He concluded
that the towers would remain standing despite the force of the impact and
the hole it would punch out. The new technologies he had installed after
the motion experiments and wind-tunnel work had created a structure more
than strong enough to withstand such a blow.
Exactly how Robertson performed these calculations is apparently lost -- he says he cannot find a copy of the report. Several engineers who worked with him at the time, including the director of his computer department, say they have no recollection of ever seeing the study. But the Port Authority, eager to mount a counterattack against Wien, seized on the results -- and may in fact have exaggerated them. One architect working for the Port Authority issued a statement to the press, covered in a prominent article in The Times, explaining that Robertson's study proved that the towers could withstand the impact of a jetliner moving at 600 miles an hour.
That was perhaps three times the speed that Robertson had considered.
If Robertson saw the article in the paper, he never spoke up about the discrepancy. No one else issued a correction, and the question was answered in many people's minds: the towers were as safe as could be expected, even in the most cataclysmic of circumstances.
NYT, 9/08/2002

In the end even NIST does not believe Robertson anymore and wrote:

"NIST did find a three page White Paper, dated February 3, 1964, summarizing a 21,000-page study of the effects of a Boeing 707 carrying 23,000 US gallons (87 m³) of fuel hitting the buildings at 600 mph (1,000 km/h). The study found that the buildings would not collapse in the event of aircraft impact."

 

[DC]

Robertson is kinda suspect....

 

[leftysergeant]

Robertson is not acting suspiciously. He seems, at worst, not to have fact-checked an article somebody wrote about what he had concluded. Why would he be expected to?

The 600MPH figure is an absurdity. There would be no reason for anyone to even calculate what would happen in the case of an impact at that speed. It was less likely to happen than that King Kong would step on the towers.

707 aint that fast.

 

[DC]

Robertson is not acting suspiciously. He seems, at worst, not to have fact-checked an article somebody wrote about what he had concluded. Why would he be expected to?

The 600MPH figure is an absurdity. There would be no reason for anyone to even calculate what would happen in the case of an impact at that speed. It was less likely to happen than that King Kong would step on the towers.

707 aint that fast.

oc 600 MPH is the 707 top speed according to boeing.
and they just used the biggest plane at the highest speed. just like the papers from 1964 said, like robertson said before he started to lie about it, also what deMartini said and so on.

it comes in very handy to not find the calculations from then

 

[bio]

Robertson is not acting suspiciously. He seems, at worst, not to have fact-checked an article somebody wrote about what he had concluded. Why would he be expected to?

The 600MPH figure is an absurdity. There would be no reason for anyone to even calculate what would happen in the case of an impact at that speed. It was less likely to happen than that King Kong would step on the towers.

707 aint that fast.

What would you have said, if Dr. Jones had said something similar?

This was something important, what Robertson had to remember correctly. Why not? We are not talking about a photo, which Dr. Jones interpreted incorrectly.

 

[Dave Rogers]

This whole question is a ridiculous non-issue. Robertson claimed to have done three pages of longhand calculations in 1964 which indicated that the towers would survive the impact. NIST did state-of-the-art finite element model simulations which ran for weeks on high-end workstations forty years later which showed that Robertson's simple longhand calculation was wrong. A better calculation produces more accurate results; what's surprising about that?

Dave

 

[DC]

This whole question is a ridiculous non-issue. Robertson claimed to have done three pages of longhand calculations in 1964 which indicated that the towers would survive the impact. NIST did state-of-the-art finite element model simulations which ran for weeks on high-end workstations forty years later which showed that Robertson's simple longhand calculation was wrong. A better calculation produces more accurate results; what's surprising about that?

Dave

FE sim of the collapse? or just the impact damage?
workstations? dont you mean a cluster server?

 

[R.Mackey]

And, as has been remarked here countless times, the original calculation only appeared to have treated the impact.

The Towers did survive the impacts. There is absolutely no reason to suspect the rough calculation, carried out before the Towers were even built, said anything about the fire.

This particular straw has been grasped at for years.

 

[beachnut]

oc 600 MPH is the 707 top speed according to boeing.
and they just used the biggest plane at the highest speed. just like the papers from 1964 said, like robertson said before he started to lie about it, also what deMartini said and so on.

it comes in very handy to not find the calculations from then

A 707 does not do 600 mph at 700 feet. DeMartini has nothing to do with the design of the WTC, and your citing him proves you lack the basic knowledge to make a rationale conclusion on this issue!

The only speed a 707 would be doing at 700 feet is 180 mph, landing.

It is sad you are not knowledgeable to make a rational statement on 9/11 issues. You need to do extensive study on flying, your 600 mph is so ridiculous it makes you appear totally clueless on this subject.

The study Robertson did was correct, he used 180 mph speed for impact, the WTC would survive, most the plane would fall down the building! There would be parts that looked like a plane, more so than 9/11.

The fact is Robertson did do a study for a 187 pound TNT kinetic energy impact; the WTC would survive.
The 600 mph speed appears in a White Paper by the Port Authority with no real explanation of why a 707 would be going 600 mph at 700 feet, an illegal act, and over the top speed of 350 KCAS! So the truth movement is brain dead when they bring up the 600 mph impact study that has no basis in reality.

Please great one, tell me how a plane limited to 350 KCAS (whose wings actually start to peal off above 350 KCAS at 700 feet) can go 600 mph? Go ahead tell me how a plane who would be going 180 mph at 700 feet, would be going 600 mph?

600 mph at 700 feet is dumb! Who ever repeats it as fact is stupid.

The top speed of a 707 is not 600 mph at 700 feet. At least your signature is correct. And you still blindly repeat junk you look up on the internet, even from Boeing.

 

[roundhead]

The well known DeMartini quote is very telling regarding 9/11. He said the planes would do virtually nothing, and wasnt the least bit bashfull about that statement.

Before somebody tries to belittle his status as an expert, lets not forget, Robertson hired him as a troubleshooter after the 1993 bombing. So obviously the guy is an expert regarding tower makeup, and building performance issues.


Let me repeat, Robertson hired DeMartini to look into building performance and make recommendations after the 1993 bombing. That says a lot about the guys professional reputation.

And he said the planes flat out WOULDNT DO SQUAT.

News flash, he didnt all the sudden get stupid.

Another news flash, the only guy who got stupid( Robertson)is still alive and HAVE to slurp the official lie.He only became stupid 5 minutes after 9/11.Having to slurp the official lie.

 

[Newtons Bit]

The study Robertson did was correct

How can you say that the study they did was correct if the documentation doesn't exist and no one can remember was was actually analyzed?

 

[Loss Leader]

Just wanted to add (although it's been said before) that there was absolutely no way to model the behavior of jet fuel or the resulting fires back in the 1960's. All they could do was calculate the force of the plane itself against the strength of the columns.

Thus, whatever calculation anybody did do back then would have been woefully inadequate.

And, of course, there was no reason to suspect in the 1960s that anybody would fly a huge passenger jet into a building at full speed. For that matter, there was almost no reason to suspect in on September 10, 2001.

 

[beachnut]

How can you say that the study they did was correct if the documentation doesn't exist and no one can remember was was actually analyzed?

Roberton's study is. A 707 impact at 180 mph would cause 7 to 11 times less damage, and the WTC towers would survive.

The damage would be local, fire would steam down the building side, most the fuel would be in the wings. The wings would fall off and fall to the ground, watch out. Zero significant core damage, no severed core columns. Three possible breaches in the Shell.

Take a 187 pounds of TNT kinetic energy event in the shape of a plane and do the calculations. What do you get? Does the WTC tower survive or what? I say Robertson was correct, his design would survive a 707 strike at 180 mph. After seeing the impacts on 9/11 and studying the damage from both, I have zero reservations the WTC would survive and I would back up my idea by standing on the top! Unlike Ross! My own calculations I find zero core columns cut when using Robertson's design scenario, and only local damage to the impact area. Fire can be fought, no major systems in the WTC destroyed. What do you get?

 

[beachnut]

The well known DeMartini quote is very telling regarding 9/11. He said the planes would do virtually nothing, and wasnt the least bit bashfull about that statement.

DeMartini was right (except for the fully loaded part), the design impact could take a 707, and possible multiple impacts. But see, energy is equal to one half mass times velocity squared, and I doubt if you understand velocity squared based on your blind allegiance to false information and lies of 9/11 truth. The design speed for an aircraft impact of a 707 was 180 mph. 9/11 jets were not going 180 mph. you lost this round.

Before somebody tries to belittle his status as an expert, lets not forget, Robertson hired him as a troubleshooter after the 1993 bombing. So obviously the guy is an expert regarding tower makeup, and building performance issues.

Darn he is not an expert. What speed did DeMartini think the design was for. What was DeMartini again. He was a WTC construction manager. Oops not an expert on this topic. Failure is yours again.

Let me repeat, Robertson hired DeMartini to look into building performance and make recommendations after the 1993 bombing. That says a lot about the guys professional reputation.

Wrong again. He was hired by the structural engineering firm Leslie E. Robertson Associates to help with the repairs of the 1993 terrorist bombing at the World Trade Center. Do you get anything close to right about 9/11?

And he said the planes flat out WOULDNT DO SQUAT.

Oops, 9/11 planes were speeding, darn, the design was out the window, and DeMartini was not wrong, he died in the WTC, not because he was wrong, but due to terrorist killing him. You must of missed the on purpose part of 9/11, and not that DeMartini was talking about an accidental aircraft impact.

News flash, he didnt all the sudden get stupid.

Another news flash, the only guy who got stupid( Robertson)is still alive and HAVE to slurp the official lie.He only became stupid 5 minutes after 9/11.Having to slurp the official lie.

Robertson takes responsibility for his building falling. But he did design it for an impact of a 707 at 180 mph, he said so, and it makes sense he picked the speed a 707 would be doing at 1000 feet. No one got stupid, the WTC was designed for an impact of a 707, you have no clue what energy is, or how to apply rational thought to 9/11. You grab a quote from DeMartini, with no parameters, and use his quote out of context to support your inability to form rational conclusion on 9/11.