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Title: Why the towers fell: Two theories [by a civil engineer]
Source: [None]
URL Source: http://www.vermontguardian.com/commentary/032007/TwinTowers.shtml
Published: Mar 1, 2007
Author: William Rice
Post Date: 2007-04-17 16:30:39 by honway
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Views: 11247
Comments: 196

Why the towers fell: Two theories
By William Rice
William Rice, P.E., is a registered professional civil engineer who worked on structural steel (and concrete) buildings in Boston, New York, and Philadelphia. He was also a professor at Vermont Technical College where he taught engineering materials, structures lab, and other building related courses,
Posted March 1, 2007
Having worked on structural steel buildings as a civil engineer in the era when the Twin Towers were designed and constructed, I found some disturbing discrepancies and omissions concerning their collapse on 9/11.
I was particularly interested in the two PBS documentaries that explained the prevailing theories as determined by two government agencies, FEMA and NIST (National Institute of Science and Technology). The first (2002) PBS documentary, Why the Towers Fell, discussed how the floor truss connectors failed and caused a “progressive pancake collapse.”
The subsequent 2006 repackaged documentary Building on Ground Zero explained that the connectors held, but that the columns failed, which is also unlikely. Without mentioning the word “concrete,” the latter documentary compared the three-second collapse of the concrete Oklahoma City Murrah Federal Building with that of the Twin Towers that were of structural steel. The collapse of a concrete-framed building cannot be compared with that of a structural steel-framed building.
Since neither documentary addressed many of the pertinent facts, I took the time to review available material, combine it with scientific and historic facts, and submit the following two theories for consideration.
The prevailing theory
The prevailing theory for the collapse of the 110-story, award-winning Twin Towers is that when jetliners flew into the 95th and 80th floors of the North and South Towers respectively, they severed several of each building’s columns and weakened other columns with the burning of jet fuel/kerosene (and office combustibles).
However, unlike concrete buildings, structural steel buildings redistribute the stress when several columns are removed and the undamaged structural framework acts as a truss network to bridge over the missing columns.
After the 1993 car bomb explosion destroyed columns in the North Tower, John Skilling, the head structural engineer for the Twin Towers, was asked about an airplane strike. He explained that the Twin Towers were originally designed to withstand the impact of a Boeing 707 (similar in size to the Boeing 767). He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.”
The 10,000 gallons of jet fuel (half capacity) in each jetliner did cause horrendous fires over several floors, but it would not cause the steel members to melt or even lose sufficient strength to cause a collapse. This is because the short-duration jet fuel fires and office combustible fires cannot create (or transmit to the steel) temperatures hot enough. If a structural steel building could collapse because of fire, it would do so slowly as the various steel members gradually relinquished their structural strength. However, in the 100-year history of structural-steel framed buildings, there is no evidence of any structural steel framed building having collapsed because of fire.
Let’s assume the unlikelihood that these fires could weaken all of the columns to the same degree of heat intensity and thus remove their structural strength equally over the entire floor, or floors, in order to cause the top 30-floor building segment (South Tower WTC #2) to drop vertically and evenly onto the supporting 79th floor. The 30 floors from above would then combine with the 79th floor and fall onto the next level down (78th floor) crushing its columns evenly and so on down into the seven levels below the street level.
The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds at nearly free-fall speed. This violates Newton’s Law of Conservation of Momentum that would require that as the stationary inertia of each floor is overcome by being hit, the mass (weight) increases and the free-fall speed decreases.
Even if Newton’s Law is ignored, the prevailing theory would have us believe that each of the Twin Towers inexplicably collapsed upon itself crushing all 287 massive columns on each floor while maintaining a free-fall speed as if the 100,000, or more, tons of supporting structural-steel framework underneath didn’t exist.
The politically unthinkable theory
Controlled demolition is so politically unthinkable that the media not only demeans the messenger but also ridicules and “debunks” the message rather than provide investigative reporting. Curiously, it took 441 days for the president’s 9/11 Commission to start an “investigation” into a tragedy where more than 2,500 WTC lives were taken. The Commission’s investigation also didn’t include the possibility of controlled-demolition, nor did it include an investigation into the “unusual and unprecedented” manner in which WTC Building #7 collapsed.
The media has basically kept the collapse of WTC Building #7 hidden from public view. However, instead of the Twin Towers, let’s consider this building now. Building #7 was a 47-story structural steel World Trade Center Building that also collapsed onto itself at free-fall speed on 9/11. This structural steel building was not hit by a jetliner, and collapsed seven hours after the Twin Towers collapsed and five hours after the firemen had been ordered to vacate the building and a collapse safety zone had been cordoned off. Both of the landmark buildings on either side received relatively little structural damage and both continue in use today.
Contrary to the sudden collapse of the Twin Towers and Building #7, the four other smaller World Trade Center buildings #3, #4, #5, and #6, which were severely damaged and engulfed in flames on 9/11, still remained standing. There were no reports of multiple explosions. The buildings had no pools of molten metal (a byproduct of explosives) at the base of their elevator shafts. They created no huge caustic concrete/cement and asbestos dust clouds (only explosives will pulverize concrete into a fine dust cloud), and they propelled no heavy steel beams horizontally for three hundred feet or more.
The collapse of WTC building #7, which housed the offices of the CIA, the Secret Service, and the Department of Defense, among others, was omitted from the government’s 9/11 Commission Report, and its collapse has yet to be investigated. Perhaps it is time for these and other unanswered questions surrounding 9/11 to be thoroughly investigated. Let’s start by contacting our congressional delegation.
William Rice, P.E., is a registered professional civil engineer who worked on structural steel (and concrete) buildings in Boston, New York, and Philadelphia. He was also a professor at Vermont Technical College where he taught engineering materials, structures lab, and other building related courses. Subscribe to *9-11*
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#1. To: honway, ALL (#0)
After the 1993 car bomb explosion destroyed columns in the North Tower, John Skilling, the head structural engineer for the Twin Towers, was asked about an airplane strike. He explained that the Twin Towers were originally designed to withstand the impact of a Boeing 707 (similar in size to the Boeing 767).

First of all John Skilling was NOT the head structural engineer for the WTC towers. Leslie Robertson is the head structural engineer of record. He was the one who moved to New York to do the design. Mr Skilling remained in Seattle. Second, did Mr Rice fail to note the difference in the speed of the planes assumed in the design and the ones that hit the towers? That difference corresponds to a factor of 7 (or more) difference in the impact energy of the planes.

He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.”

There was NO consideration of fire after the plane impact in the design. Leslie Robertson stated that fire resulting from a plane impact was NOT considered in the design. If Mr Rice thinks otherwise, he is wrong.

The 10,000 gallons of jet fuel (half capacity) in each jetliner did cause horrendous fires over several floors, but it would not cause the steel members to melt or even lose sufficient strength to cause a collapse.

Melting of steel is not the theory of NIST.

This is because the short-duration jet fuel fires and office combustible fires cannot create (or transmit to the steel) temperatures hot enough.

Wrong again. First, the fires were NOT of short duration (didn't he read the NIST report like he claimed?) and second how hot does he think the temperatures have to get to weaken steel? The fires in the Windsor Tower in Madrid reached 1400 F and that was without jet fuel to start it. There are plenty of examples of temperatures in fires in ordinary office building reaching those temperatures or even higher. Or does Mr Rice actually think steel strength is unaffected at these temperatures? If so, then I question his credentials. Also, does he think the numerous engineers who did analysis with codes that are generally agreed to be the state of the art in fire engineering are incompetent or wrong when they concluded temperatures in the towers reached nearly 2000 F?

If a structural steel building could collapse because of fire, it would do so slowly as the various steel members gradually relinquished their structural strength.

Apparently Mr Rice overlooked the likelihood that fireproofing in the towers was extensively damaged by the impacts? And how fast does Mr Rice think unprotected steel strength responds to temperatures of ... say ... 1400 F or higher?

However, in the 100-year history of structural-steel framed buildings, there is no evidence of any structural steel framed building having collapsed because of fire.

This is the silliest statement yet. If that were the case, then why are there fire codes on steel structures? Why is there so much effort (and cost) to protect steel members from fire? The fact is that steel framed building HAVE collapsed due to fire. Mr Rice is simply WRONG.

Let’s assume the unlikelihood that these fires could weaken all of the columns to the same degree of heat intensity and thus remove their structural strength equally over the entire floor,

Again, we find Mr Rice claiming a theory that NIST does not promote. What Mr Rice is doing is putting forth a STRAWMAN ... something false to knock down. In fact, if Mr Rice had done as much research of the matter as he claims, he'd know that the theory is that sagging floors broke sections of the outer wall columns and THAT is what led to the collapse. Obviously, he didn't.

The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds at nearly free-fall speed.

ROTFLOL! Where has this guy been the last 5 years? How can he claim the towers collapsed in ten seconds if he read the NIST reports as he claimed? If he looked at ANY non-conspiracy website he'd see the towers took 15 seconds or so to collapse. Videos and photos prove this. Even some conspiracy leaning websites admit this. And he should know this IF he's done ANY research besides visiting the more extreme conspiracy websites. This alone is good reason to doubt this individuals competence or opinion.

Contrary to the sudden collapse of the Twin Towers and Building #7

The collapse of WTC 7 was not sudden. Firemen have said they knew it was going to collapse hours before it did because they could see it deforming.

The buildings had no pools of molten metal (a byproduct of explosives) at the base of their elevator shafts.

This is more conspiracy nonsense. NO ONE who was an eyewitness has said they found POOLS of molten metal at the base of the elevator shafts.

only explosives will pulverize concrete into a fine dust cloud

If this is so, why hasn't ONE demolition expert in the entire world come forward to say it? Afterall, it should be so obvious when someone like Mr Rice even knows it. Does Mr Rice think they are all part of the conspiracy? ROTFLOL!

William Rice, P.E., is a registered professional civil engineer who worked on structural steel (and concrete) buildings in Boston, New York, and Philadelphia. He was also a professor at Vermont Technical College where he taught engineering materials, structures lab, and other building related courses.

honway, can you provide proof that any of this is true? Can you perhaps point me to a resume or a university where he got his degree? And who did he work for while working on those structures? Pardon me if I'm now a little skeptical. Let's see what the Vermont Technical College website says. His name isn't listed as faculty or staff: http://catalog.vtc.edu/content.php?catoid=12&navoid=225 . Why is that? In fact, a search of their website doesn't turn up the name William Rice anywhere. Why is that?
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Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-17 16:54:40 ET Reply Trace Private Reply
#2. To: BeAChooser (#1)
Are you on another rampage?

Bunch of internet bums ... grand jury --- opium den ! ~ byeltsin
Minerva posted on 2007-04-17 17:10:27 ET Reply Trace Private Reply
#3. To: honway (#0)
The official story is so ludricrous that its acceptance is an indication one is completely brainwashed and incapable of free, rational thought, or guilty as sin and protecting the perps.

Paul Revere posted on 2007-04-17 17:16:00 ET Reply Trace Private Reply
#4. To: All (#0)
The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds at nearly free-fall speed.

http://www.pbs.org/wgbh/nova/wtc/
In the link above,you can click on the link to 9/11 Conspiracy Theories and hear Dr. Shyam Sunder of the NIST explain Tower 1 collapsed in 11 seconds and Tower 2 collapsed in 9 seconds.

honway posted on 2007-04-17 17:30:42 ET Reply Trace Private Reply
#5. To: All (#4)
Dr. Shyam Sunder of the NIST explain Tower 1 collapsed in 11 seconds and Tower 2 collapsed in 9 seconds.

Dr. Shyam Sunder was the Lead Investigator Building and Fire Safety Investigation of WTC Disaster

honway posted on 2007-04-17 17:32:11 ET Reply Trace Private Reply
#6. To: All (#0)
Contrary to the sudden collapse of the Twin Towers and Building #7, the four other smaller World Trade Center buildings #3, #4, #5, and #6, which were severely damaged and engulfed in flames on 9/11, still remained standing. There were no reports of multiple explosions. The buildings had no pools of molten metal (a byproduct of explosives) at the base of their elevator shafts. They created no huge caustic concrete/cement and asbestos dust clouds (only explosives will pulverize concrete into a fine dust cloud), and they propelled no heavy steel beams horizontally for three hundred feet or more.

honway posted on 2007-04-17 17:35:45 ET (1 image) Reply Trace Private Reply
#7. To: All (#6)
http://www.vermontguardian.com/commentary/032007/Mar23Letters.shtml
Author responds to 9/11 critics
This is in response to Jeremy Young’s letter posted in the Vermont Guardian (March 9) questioning my knowledge of basic physics.
It would seem that politics often supersedes science when one tries to determine what really happened on 9/11.
From my perspective as an engineer, the following statements can only be explained by the use of explosives. However, these facts seem to be either “debunked” or ignored by those who would have us avoid questioning the safer, more comfortable, and less thought-provoking official crash-and-burn theory.
I would like to question the prevailing theory by asking Young, or anyone, for reasonable alternative explanations to the following statements:
• Only explosives could have caused the pulverization of the WTC buildings’ concrete into dust. • Only high temperature explosives could create the molten metal that lingered for several weeks under the debris of those three WTC buildings. These documented temperatures of the molten metal were much hotter (by over several hundred degrees Fahrenheit) than any temperatures that could possibly be provided by the 9/11 jet fuel/kerosene fires. • Only explosives could propel heavy steel beams/columns more than 300 feet away from the Twin Towers. According to basic projectile physics, this is well beyond the range that can be accomplished by the prevailing crash-and-burn theory.
Finally, I reaffirm my knowledge of physics and of Newton’s Law of Conservation of Momentum. Overcoming the stationary inertia would slow down the collapse.
Moreover, Newton’s Law is immaterial when compared to the resistance provided by the massive supporting structural steel framework of each Tower. Each of the Twin Towers’ collapses would have had to compress and destroy about 100,000 tons of structural steel framing and do it in a collapse duration of only ten seconds. Without explosives this is impossible and has never happened in the 100-year history of structural steel buildings.
William Rice, P.E.
William Rice is a former professor at the Vermont Technical College in Randolph, and wrote a piece in the Feb. 28 issue of Vermont Guardian.

honway posted on 2007-04-17 17:40:22 ET Reply Trace Private Reply
#8. To: honway (#6)
The debunkers cannot deal with the molten steel, so they deny it.

Paul Revere posted on 2007-04-17 17:40:50 ET Reply Trace Private Reply
#9. To: honway (#0)
Curiously, it took 441 days for the president’s 9/11 Commission to start an “investigation” into a tragedy where more than 2,500 WTC lives were taken. The Commission’s investigation also didn’t include the possibility of controlled-demolition, nor did it include an investigation into the “unusual and unprecedented” manner in which WTC Building #7 collapsed.

All engineering analysis aside, the above alone presents some disturbing questions.
"The penalty good men pay for indifference to public affairs is to be ruled by evil men" Plato
tom007 posted on 2007-04-17 18:10:48 ET Reply Trace Private Reply
#10. To: honway, ALL (#4)
In the link above,you can click on the link to 9/11 Conspiracy Theories and hear Dr. Shyam Sunder of the NIST explain Tower 1 collapsed in 11 seconds and Tower 2 collapsed in 9 seconds.

NIST's official statement is that "the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2."
It really doesn't matter what Sunder said in an interview when photos and videos taken that day prove the collapse took about 15 seconds for each tower. You are the one always posting images and videos, honway. Why don't you believe what they are telling you in this case?
Here is a CNN live video clip that shows it took about ten seconds for the bottom of the mushrooming dust cloud to reach the ground, and another seven or so for the top to reach the ground.
Here is an image that shows free-fallings panels well in front of the collapsing level

Here is a link to time indexed frames from a video that clearly shows the collapse taking about 15 seconds:
http://911research.wtc7.net/wtc/evidence/videos/ntc_frames.html
The following is a link to a photo that http://911research.wtc7.net says was taken 11 seconds into the collapse.
http://911research.wtc7.net/wtc/evidence/photos/docs/trade17.jpg
Look at that photo, honway. There is a lot of tower still standing.
Now unless you want to claim that all of the above are fabricated or lies, why would you persist in this nonsense? Doing so will only end up discrediting the whole *Truth* movement and make it harder to get the valid questions about 9/11 answered.
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Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-17 18:42:27 ET (1 image) Reply Trace Private Reply
#11. To: beachooser, nolu_chan, Robin, Minerva, Christine, Brian S, Honway, Aristeides, Red Jones, Diana, Kamala, All (#1)
The collapse of WTC 7 was not sudden. Firemen have said they knew it was going to collapse hours before it did because they could see it deforming.

There you go again, you treasonous queer!
How many seconds did it take from the start of the collapse to ground contact?
Was that not "sudden?" That's the context of the issue.
Or, would you confirm that the firemen knew that the controlled demolition was going to take place - as in the abrupt (sudden) collapse of the building?
BAC, your queerthink is as disgusting, as you are!

SKYDRIFTER posted on 2007-04-17 18:43:07 ET Reply Trace Private Reply
#12. To: honway, ALL (#7)

Only explosives could have caused the pulverization of the WTC buildings’ concrete into dust.

Wrong. Here's another, more sane, explanation:
http://www.911myths.com/WTCONC1.pdf "The Pulverization of Concrete in WTC 1 During the Collapse Events of 9-11"

Only high temperature explosives could create the molten metal that lingered for several weeks under the debris of those three WTC buildings.

Wrong. Here's another, more sane, explanation:
http://www.911myths.com/WTCTHERM.pdf "Aluminum and the World Trade Center Disaster"

These documented temperatures of the molten metal were much hotter (by over several hundred degrees Fahrenheit) than any temperatures that could possibly be provided by the 9/11 jet fuel/kerosene fires.

But jet fuel only initiated the fire. Many other things burned in the towers and the rubble later on. Plastics burn very hot (http://911myths.com/html/wtc_molten_steel.html). And as Dr Greening points out in the linked articles at the beginning of this post, there were even hotter chemical reactions possible given the materials and boundary conditions in the towers and rubble.

Only explosives could propel heavy steel beams/columns more than 300 feet away from the Twin Towers. According to basic projectile physics, this is well beyond the range that can be accomplished by the prevailing crash-and-burn theory.

Wrong. Here's another, more sane, explanation (at the end of the article):
http://www.911myths.com/html/explosive_force.html

Finally, I reaffirm my knowledge of physics and of Newton’s Law of Conservation of Momentum. Overcoming the stationary inertia would slow down the collapse.

Slow it down, from what to what? Odd that Rice is the ONLY structural engineer in the world claiming that the two towers collapsed too fast, Mr. Rice. Maybe it's because the rest of the engineering community actually understands the tremendous loads created when 30 floors of structure fall one floor onto the floor below. I suppose he thinks the collapse should have stopped at that point. ROTFLOL!

Moreover, Newton’s Law is immaterial when compared to the resistance provided by the massive supporting structural steel framework of each Tower.

These towers were 95 percent air. Here's a photo that proves it.
http://www.abovetopsecret.com/forum/staff/agentsmith/wtccoreshilouette.jpg

Each of the Twin Towers’ collapses would have had to compress and destroy about 100,000 tons of structural steel framing and do it in a collapse duration of only ten seconds.

ROTFLOL! He doesn't even have the correct collapse time ... even after all this time to gather the facts. One begins to doubt Mr Rice's competence.
And again, I ask for PROOF that Mr Rice is who he says. The Vermont Technical College does not mention his name ANYWHERE on their website nor can I find any mention of this individual anywhere but in these letters he writes. What is his education, where did he work and on what did he work, honway?
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Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-17 19:17:28 ET Reply Trace Private Reply
#13. To: BeAChooser, Christine, Zipporah (#12)
Who raised your post limit? She should be spanked!
A new truth movement friendly digg type site: Zlonk it!
Critter posted on 2007-04-17 19:22:05 ET Reply Trace Private Reply
#14. To: All (#5)
http://www.pbs.org/wgbh/nova/wtc/
Click on 9/11 Conspiracy Therories at the above link for the source of the quote below.
Dr. Shyam Sunder- Lead Investigator- Building and Fire Safety Investigation of WTC Disaster:
"The measurements have indicated that Tower One collapsed in about 11 seconds and Tower Two collapsed in about 9 seconds."

"...the building is 70% just air in volume."

honway posted on 2007-04-17 19:47:27 ET Reply Trace Private Reply
#15. To: BeAChooser, Minerva, Paul Revere, tom007, SKYDRIFTER, Critter (#1)
[BAC] First of all John Skilling was NOT the head structural engineer for the WTC towers. Leslie Robertson is the head structural engineer of record. He was the one who moved to New York to do the design. Mr Skilling remained in Seattle.
As usual, BAC's source is missing. My source is not.
NIST Report, Chapter 1, page 1, paragraph 1.1, reads in relevant part:

To fulfill all the functional, aesthetic, and economic desires for this concent, innovative archetecture was needed, In 1962, the firm of Minoru Yamasaki & Associates was hired to perform the architectural desighn which was first unveiled in 1964. The team also involved Emory Roth & Sons, P.C., as the architect of record. The structural engineering was by Worthington, Skilling, Helle and Christiansen. (Some time after completion of the construction, Skilling, Helle, Christiansen, and Robertson, and then Leslie E. Robertson Associates (LERA) assumed that role.)

NIST Report, Chapter 1, page 6, reads in relevant part:

Skilling and his team rose to the challenge of providing the required load capacity within Yamasaki's design concept. They incorporated an innovative framed-tube concept for the structural system.

-------
[BAC] did Mr Rice fail to note the difference in the speed of the planes assumed in the design and the ones that hit the towers? That difference corresponds to a factor of 7 (or more) difference in the impact energy of the planes.
BAC, exactly how much in excess of 600 mph did you determine that the planes were moving when they struck 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.”

According to the NIST Report, Chapter 2, page 20, paragraph 2-3, WTC-1 was hit by a plane "[m]oving at about 440 mph..."
According to the NIST Report, Chapter 3, page 38, paragraph 3-2, WTC-2 was hit by a plane moving "540 mph...."
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[BAC] He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.”
There was NO consideration of fire after the plane impact in the design. Leslie Robertson stated that fire resulting from a plane impact was NOT considered in the design. If Mr Rice thinks otherwise, he is wrong.

In the wake of the WTC bombing, the Seattle Times interviews John Skilling who was one of the two structural engineers responsible for designing the Trade Center. Skilling recounts his people having carried out an analysis which found the Twin Towers could withstand the impact of a Boeing 707. He says, “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.” [Seattle Times, 2/27/1993]

Do recall that, "(Some time after completion of the construction, Skilling, Helle, Christiansen, and Robertson, and then Leslie E. Robertson Associates (LERA) assumed that role. [structural engineer])"
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[BAC] The 10,000 gallons of jet fuel (half capacity) in each jetliner did cause horrendous fires over several floors, but it would not cause the steel members to melt or even lose sufficient strength to cause a collapse.
Melting of steel is not the theory of NIST.
Melting steel happened. Relevant theories attempt to explain how it happened.
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nolu_chan posted on 2007-04-18 5:14:04 ET Reply Trace Private Reply
#16. To: honway (#14)
http://www.911blogger.com/node/6040

What the World Trade Center Building Designers Said: Before and After 9/11 Submitted by Arabesque on Wed, 02/07/2007 - 7:55pm. Leslie Robertson What the World Trade Center Building Designers Said: Before and After 9/11
An analysis of contradictions in statements by Building Designer Leslie Robertson
By Arabesque[1]
Update: 03/12/2007
Another Quotation from John Skilling added about the possibility of controlled demolition destroying the World Trade Center buildings in 1993.
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.’”[3]
1993
“[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.”[4]
“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.”[5]
“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.’”[6]
2001
“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.”[7]
[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.”[8]
[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. [9]
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.”[10]
After 9/11
“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.’”[11]
“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.”[12]
“[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.’”[13]
“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.”[14]
“[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
Analysis:
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.[15] 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”.[16] 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.”[17]
· 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.[18] 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.”[19]
· 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.”[20]. As well, substantial eye-witness testimony supports observations of Molten Steel.[21]
· 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.[22] However, NIST did not even mention the molten steel and called it “irrelevant to [their] investigation.”[23] 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.

----------------------------------------------- ---------------------------------
[1] http: //www.911blogger.com/blog/877
[2] Paul Thompson’s Complete 9/11 Timeline: (see February 27, 1993)
[3] http://www.cooperativeresearch.org/entit y.jsp? entity=leslie_robertson
See here: [Glanz and Lipton, 2004, pp. 227; New York County Supreme Court, 1/20/2004]
[4] [Seattle Times, 2/27/1993]
[5] [Glanz and Lipton, 2004, pp. 131-132; Lew, Bukowski, and Carino, 10/2005, pp. 70-71]
[6] [Seattle Times, 2/27/1993]
[7] [Chicago Tribune, 9/12/2001; Knight Ridder, 9/12/2001]
[8] [Robertson, 3/2002; Federal Emergency Management Agency, 5/1/2002, pp. 1-17]
[9] http://www.prisonplanet.com/articles/no vember20 04/141104designedtotake.htm
[10] [Glanz and Lipton, 2004, pp. 138-139, 366]
[11] “Believed to Be Safe, the Towers Proved Vulnerable to Jet Fuel Fire”
By JAMES GLANZ
http://www.punjabilok.com/america_under _attack/ believed_tobe_safe.htm
[12] [US Congress, 3/6/2002; Associated Press, 3/7/2002]
[13] [National Institute of Standards and Technology, 9/2005, pp. 13]
[14] [Robertson, 3/2002]
[15] [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”.
[16] Complete 9/11 Timeline: (see February 27, 1993)]
[17] http://www.cooperativeresearch.org/entit y.jsp? entity=leslie_robertson
See here: [Glanz and Lipton, 2004, pp. 227; New York County Supreme Court, 1/20/2004]
[18] [Seattle Times, 2/27/1993]
[19] [Seattle Times, 2/27/1993]
[20] [SEAU News, 10/2001] This fact was observed by David Ray Griffin and Paul Thompson’s Complete 9/11 Timeline.
[21] http://georgewashington.blogspot.com/20 05/12/wh y-was-there-molten-metal-under.html
[22] See here for pictures and comments in FEMA’s report mentioning the melted steel: http://www.911research.wtc7.net/wtc/evi dence/me tallurgy/index.html
“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.
[23] See here: http://911research.wtc7.net/reviews/nis t/WTC_FA Q_reply.html#13
Mark
"I was real close to Building 7 when it fell down... That didn't sound like just a building falling down to me while I was running away from it. There's a lot of eyewitness testimony down there of hearing explosions. [..] and the whole time you're hearing "boom, boom, boom, boom, boom." I think I know an explosion when I hear it... — Former NYC Police Officer and 9/11 Rescue Worker Craig Bartmer
Kamala posted on 2007-04-18 5:18:34 ET Reply Trace Private Reply
#17. To: Kamala (#16)
“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]

Thanks for the information.

honway posted on 2007-04-18 9:13:14 ET Reply Trace Private Reply
#18. To: nolu_chan, ALL (#15)
[BAC] First of all John Skilling was NOT the head structural engineer for the WTC towers. Leslie Robertson is the head structural engineer of record. He was the one who moved to New York to do the design. Mr Skilling remained in Seattle.

As usual, BAC's source is missing. My source is not.

Rather than dishonest and snide remarks, you should pay more attention to the facts and what's been posted on this forum. I've provided links to back my assertion up over and over in previous threads here at 4um (not to mention uncounted times at LP). If you weren't paying attention, NC, that's your problem. You didn't even use your browser because if you had you would know I was right. The fact is Leslie Robertson was the LEAD STRUCTURAL ENGINEER. Skillings ran the company and was not even in NYC where the design was done.
http://www.nae.edu/nae/bridgecom.nsf/weblinks/CGOZ-58NLCB?OpenDocument "Reflections on the World Trade Center, Leslie E. Robertson, ... snip ... The lead structural engineer reflects on the rise and fall of the World Trade Center towers."
http://web.mit.edu/civenv/wtc/PDFfiles/Chapter%20I%20History.pdf "Robertson was the most influential engineer on the project and assumed the position of lead structural designer of the towers. Robertson had as much influence on the form of the building as anyone apart from Yamasaki himself."
http://www.asce.org/pressroom/news/display_press.cfm?uid=1349 "Leslie E. Robertson, lead structural engineer for the World Trade Center Towers, will be honored with a 2003 Outstanding Projects and Leaders (OPAL) award for lifetime contributions in design. The award will be presented on Thursday, May 1, at the American Society of Civil Engineers' (ASCE) fourth annual OPAL awards gala at the Omni Shoreham Hotel in Washington, D.C.
http://www.pbs.org/wgbh/nova/wtc/about.html ""Building on Ground Zero" features candid interviews with leading construction and safety experts, investigators, architects, and engineers—including Leslie Robertson, lead structural engineer of the original World Trade Center and Shanghai's new World Financial Center, and Jake Pauls, occupants advocate and evacuation specialist.
And there are dozens more where that came from.

NIST Report, Chapter 1, page 1, paragraph 1.1, reads in relevant part:

NIST Report, Chapter 1, page 6, reads in relevant part:

Does NOT say that Shillings was the lead structural engineer. Skilling got mentioned because he owned the company. It was Robertson and those under him who were responsible for 99% of the actual design.

[BAC] did Mr Rice fail to note the difference in the speed of the planes assumed in the design and the ones that hit the towers? That difference corresponds to a factor of 7 (or more) difference in the impact energy of the planes.

BAC, exactly how much in excess of 600 mph did you determine that the planes were moving when they struck 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.

This was a back of the envelope calculation done AFTER the design was complete. Robertson is on the record stating that the towers were DESIGNED for an impact in fog at low speed (180 mph).
http://www.nae.edu/nae/bridgecom.nsf/weblinks/CGOZ-58NLCB?OpenDocument "Reflections on the World Trade Center, Leslie E. Robertson, ... snip ... The lead structural engineer reflects on the rise and fall of the World Trade Center towers. ... snip ... It was assumed that the jetliner would be lost in the fog, seeking to land at JFK or at Newark. 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. Indeed, at that time, no fireproofing systems were available to control the effects of such fires."
You might want to read the history of what went on back then before sticking your foot further in your mouth: http://scott-juris.blogspot.com/The%20Height%20of%20Ambition%20Part%20Four.pdf "The Height of Ambition: Part Four September 8, 2002 By JAMES GLANZ and ERIC LIPTON ... snip ... But Robertson still had one more set of structural calculations to perform. Lawrence Wien, who was continuing his fight against the towers, had begun to remind New Yorkers publicly of a Saturday morning in July 1945, when a B-25 bomber, lost in the fog, barreled into the 79th floor of the Empire State Building. Most of the 14 people who died were incinerated by a fireball created when the plane's fuel ignited, even though the fire was quickly contained. The following year,another plane crashed into the 72-story skyscraper at 40 Wall Street, and yet another one narrowly missed the Empire State Building, terrifying sightseers on the observation deck. Wien and his committee charged that the twin towers, with their broader and higher tops, would represent an even greater risk of mid air collision. They ran a nearly full-page ad in The Times with an artist's rendition of a commercial airliner about to ram one of the towers. ''Unfortunately, we rarely recognize how serious these problems are until it's too late to do anything,'' the caption said. The Port Authority was already trying to line up the thousands of tenants it would need to fill the acres of office space in the towers. Such a frightful vision could not be left unchallenged. Robertson says that he never saw the ad and was ignorant of the political battle behind it. Still, he recalls that he addressed the question of an airplane collision, if only to satisfy his engineer's curiosity. For whatever reason, 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 counter attack 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. There were only two problems. The first, of course, was that no study of the impact of a 600-mile-an-hour plane ever existed. ''That's got nothing to do with the reality of what we did,'' Robertson snapped when shown the Port Authority architect's statement more than three decades later."

[BAC] He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.”

First of all, BAC did not say that. That was a quote from the thread's article to which I responded.

There was NO consideration of fire after the plane impact in the design. Leslie Robertson stated that fire resulting from a plane impact was NOT considered in the design. If Mr Rice thinks otherwise, he is wrong.

THIS was my response.

He says, “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.” [Seattle Times, 2/27/1993]

All of which is true. After the plane impacts (even at close to 600 mph) the building structure was still there. It was the fuel induced FIRE that caused the problem. It was "horrendous". It did kill a lot of people. And it ultimately collapsed the damaged structure. Skilling NEVER said that they analyzed what that fire would do to the towers or whether they would survive that fire. Indeed, at that time they did the design of the towers, they did not have the tools to determine that.

[BAC] The 10,000 gallons of jet fuel (half capacity) in each jetliner did cause horrendous fires over several floors, but it would not cause the steel members to melt or even lose sufficient strength to cause a collapse.

Again, I did not say that. I was quoting an assertion in the article.

Melting of steel is not the theory of NIST.

That is true. NISTs theory for the collapse of the towers does not require melting steel.

Melting steel happened.

Perhaps. Likely. But when did it melt? And what caused that melting. The odd thing is that not one expert in fire or steel anywhere in the world has come forward to express the impossibility of ORDINARY fires in the rubble melting that steel.
And I'm still waiting to hear your theory for what kept that steel molten for 6 weeks or more. Because it sure wasn't the thermite bombs you seem to believe went off on 9/11. Thermite bombs don't work that way.
---------------------------------------------------------
Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-18 22:29:01 ET Reply Trace Private Reply
#19. To: BeAChooser (#18)
And I'm still waiting to hear your theory for what kept that steel molten for 6 weeks or more.

I'm still waiting to learn why you're so apparently sanguine about the govt's efforts to prevent any meaningful investigation.

HOUNDDAWG posted on 2007-04-18 23:09:21 ET Reply Trace Private Reply
#20. To: Kamala, honway, nolu_chan, ALL (#16)
http://www.911blogger.com/node/6040

Where are all those who jumped on me for using blogs as sources? ROTFLOL!

“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]

The source for this is Paul Thompson’s Complete 9/11 Timeline. ROTFLOL! This is false. The calculation was done by Skilling (and only Skilling) and he was not one of the principle designers of the Towers. Nevertheless, and for the record, the towers did handle the impact of a 707 sized plane travelling almost that fast.

“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.’”[3]

Let's see. The towers did in fact survive the 1993 bomb attack. And they would probably have survived a "slow-moving airplane". The rest of that statement can be attributed to designers' pride.

“[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.”[4]

Read this http://archives.seattletimes.nwsource.com/cgi-bin/texis.cgi/web/vortex/display?slug=1687698&date=19930227 (the actual 2/27/1993 article from the Seattle Times) and see how the author has dishonestly added a complete sentence to the Seattle Times article. And Skillings was right about the building surviving the impact, as I just pointed out to nolu_chan.

“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 author does not understand the difference between an analysis and design. A white paper is a back of the envelope stab at an answer to something. It is not part of the design. There is a reason it is called a "white paper". So it's a stretch to imply this white paper was done as part of the design process.

“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.

That's not true. All Skillings concluded is that the structure would still be standing AFTER THE IMPACT. He expressed concern about what the fires would do. But designers in those days didn't have the means to determine what that would be.

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.”

It's worth noting that designers also didn't have the computers and computer tools necessary to determine this with any certainty either. And Skillings said "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." THE BIGGEST PROBLEM. And it was basically unaddressed because the tools to address it simply didn't exist in those days.
By the way, I hope folks can see the irony in this. Mark is putting forth this article and Skillings white paper as proof that the towers were designed to survive and should have survived. At the same time Mark completely dismisses the use of modern computers and computer codes to analyze the response of the structure and the fires. The tools Skilliing had were like the tools of cavemen compared to what engineers have available today. But Mark trusts the old tools and doesn't trust the more modern ones. That deserves a laugh. ROTFLOL!

“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.

And it looks like he was right as the 1993 van bomb attack proved.

‘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.’”[6]

And that's probably true too. So what? This doesn't in any way prove that bombs brought down the towers. For one thing, NOT ONE structural engineer or demolition expert in the world is on record saying they believe bombs brought down the WTC towers. NOT ONE. That might mean something...

“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.”[7]

True, he did design for a 707 hitting the towers. BUT AT LOW SPEED.

[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,

First of all, readers should know that Demartini degree was in architecture, not structures. There is a difference. Second, in that statement, he completely overlooked the importance of velocity in the impact. It was NOT "designed" for a high speed impact. And it was not designed for multiple impacts. Third, Demartini was not the construction manager during the construction of the towers. He was 14 when construction began. So I doubt he was all that familiar with their "design". On the other hand, Leslie Robertson was very familiar with it.

“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.”[10]

As I said, the design was for a plane impacting at 180 mph, not 400, not 500, not 600.

“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.’”[11]

A prudent course of action given the power of lawyers in this country.

“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.”[12]

Can you name any that are now complaining? And as I said, lawyers are likely to blame for those documents not being released. Not Bush's cabal.

“[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.’”[13]

Well if they weren't considered, where's that leave the conspiracy crowd? Suddenly the towers were not designed for a plane crash and fire?

“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.”[14]

Which makes sense given that the computers and computer codes needed to accurately model such effects weren't invented until after the WTC was built.

“[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…

Thank you for confirming what I've already stated. And this statement is completely consistent with everything he had stated previously.

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

Well, there certainly was some molten metal (maybe not the "pools" that the CT community claims). And certainly no one appears to have done an actual analysis to determine what the metal was. But I'm willing to assume some of it was steel.

Robertson has made some glaring contradictions in his statements.

No he hasn't.

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.[15]

So is that proof he too was part of the conspiracy? What's it like knowing that virtually everyone out there was part of the conspiracy ... but not you? ROTFLOL!

A quote by Building Designer Skilling

Notice how the author of the article the blog quotes deceptively adds the words "building designer" before Skilling ... just like he dishonestly inserted it (and a complete sentence) into a quote from one of the sources he referenced?

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.

No it wouldn't be reasonable. Otherwise all buildings would be designed to consider the maximum speed that a plane could hit it. Any plane. What the designers REASONABLY did is take care of the situation that came up when a plane hit the Empire State building. It was flying in fog. Which is why it hit the building in the first place. That could happen today, perhaps. But in clear weather designers back in the 1960's would have considered it UNLIKELY that a commercial jet would hit the largest buildings in the world. And in fog at low altitude a commercial jet would not likely be going anywhere near its maximum velocity. In fact, the REASONABLE thing to assume is that the plane would be at low altitude because it was preparing to land and it got lost in the fog. And if its preparing to land it isn't travelling at maximum speed. So the statement by the author of the article you quote is simply nonsense.

Is it possible that Robertson was asked to leak this “deliberately misleading information” just before 9/11? However, this is just speculation.

ROTFLOL! Like I said, how many people do the CT community think were part of the plot? Everyone but them because it seems they now have everyone either part of it or actively threatened to keep quiet. Which is completely ridiculous.

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?

Well first of all, a plane that was landing and lost in the fog would probably be relatively low on fuel. Second, they didn't because they simply didn't have the tools to do it.

And more importantly, John Skilling claimed in 1993 that they did consider the jet fuel when they designed the buildings.[18]

No, he did not. He said that fuel induced fires were the big problem. That is all he said. He did not say the towers would survive those fires. Just that it would be standing after the impact. And keep in mind that his firm was designing the building so the last thing he would want to do is cause potential occupants to think the building unsafe. He wrote the white paper to reassure folks. As such he wouldn't emphasize any deficiencies in their ability to do an accurate analysis. Like their inability to analyze what fire would do to a structure like that. An inability caused by the fact that the computers and codes needed to do that with any degree of confidence simply did not exist back them.

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.”[20].

This is highly deceptive reporting. Reference 20 provides the following source to back up their statement. http://www.seau.org/SEAUNews-2001-10.pdf That source has article written by James M. Williams, SEAU president in which HE presumably describes the contents of a speech by Robertson. He writes "As of 21 days after the attack, the fires were still burning and molten steel was still running." And that statement does not say that Robertson himself saw molten steel. It doesn't say that anywhere in the linked source.

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.[22]

More dishonesty. They did not perform analysis on anything identified as molten steel. They performed it on intact steel samples. In fact, the source that is linked to this claim only states that they found "evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure. A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel." This is not melting in the sense postulated by the CT community. This is something that would actually lower the melting point of the steel. They went on to say that "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." Because a "eutectic mixture" is one that has a lower than normal melting point, and because this might have been caused in the years prior to the collapse or in the rubble when the steel was exposed to sulfer and other chemicals, this might actually be yet another explanation why molten steel was found in the rubble.

However, NIST did not even mention the molten steel and called it “irrelevant to [their] investigation.”[23]

Because their charter was to explain the collapse, not explain why some molten steel was found in the rubble.

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?

Is the author a KOOK who thinks that tens of thousands are part of the conspiracy or helping to cover it up? Does THAT make any sense in this day and age?

No clear explanation for the source of the sulfur has been identified.

Read Dr Greening paper on the sulfer at the WTC. I think that's clear enough.
---------------------------------------------------------
Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-19 0:47:25 ET Reply Trace Private Reply
#21. To: BeAChooser AKA Our resident creepy korean guy (#20) (Edited)
Who is going to read that kooky spam you just posted? You imaginary girlfriend?

Bunch of internet bums ... grand jury --- opium den ! ~ byeltsin
Minerva posted on 2007-04-19 0:55:10 ET Reply Trace Private Reply
#22. To: BeAChooser (#20)
I would be careful about posting kooky, hostile writings. The authorities have their hackles up about guys like you.

Bunch of internet bums ... grand jury --- opium den ! ~ byeltsin
Minerva posted on 2007-04-19 0:58:56 ET Reply Trace Private Reply
#23. To: BeAChooser (#20)
Don't say anything about that McBeef guy either.

Bunch of internet bums ... grand jury --- opium den ! ~ byeltsin
Minerva posted on 2007-04-19 0:59:55 ET Reply Trace Private Reply
#24. To: BeAChooser (#18)
[From BAC #18] http://www.nae.edu/nae/bridgecom.nsf/weblinks/CGOZ-58NLCB?OpenDocument "Reflections on the World Trade Center, Leslie E. Robertson, ... snip ... The lead structural engineer reflects on the rise and fall of the World Trade Center towers."
[The same NAE source quoting Robertson] Yes, no doubt I could have made the towers braver, more stalwart. Indeed, the power to do so rested almost solely with me.
Robertson was not even a partner in Skilling's firm. Robertson was an employee. The power to take an action, or to not take an action, rested with Skilling's firm. Should the partners of the firm have decided that something Robertson wanted to do would not be done, Robertson would have had three choices: (1) do as his employer wanted; (2) quit; (3) get fired.
It is unrealistic for the employee to assert that the power to act rested almost solely with the employee. The power rests with the employer.

nolu_chan posted on 2007-04-20 3:22:26 ET Reply Trace Private Reply
#25. To: BeAChooser, Kamala, honway (#20)
[BAC #18 quoting] ... no study of the impact of a 600-mile-an-hour plane ever existed.
[BAC #20] The source for this is Paul Thompson’s Complete 9/11 Timeline. ROTFLOL! This is false. The calculation was done by Skilling (and only Skilling) and he was not one of the principle designers of the Towers. Nevertheless, and for the record, the towers did handle the impact of a 707 sized plane travelling almost that fast.

http://wtc.nist.gov/media/Public%20Transcript%20021204%20Final1_withlinks.pdf
Transcript of NIST Public Meeting in New York City – February 12, 2004
Table of Contents
Jim Hill, National Institute of Standards and Technology ......... 1
Shyam Sunder, National Institute of Standards and Technology ..... 2
Public Comment Session I ........................................ 12
Sally Regenhard, Skyscraper Safety Campaign ..................... 12
Patricia Lancaster, New York City Department of Buildings ....... 15
Jim Tidwell, International Code Council ..........................17
Robert Solomon, National Fire Protection Association ............ 18
Jack Murphy, New York City Fire Safety Directors Association .... 19
Bill Bowen ...................................................... 21
James Quintiere, University of Maryland ......................... 23
Abolhassan Astaneh-Asl, University of California, Berkeley ...... 25
Lawrence Shapiro, W.R. Grace & Company .......................... 27
Tim Vellrath, Vellrath Engineering .............................. 29
* * *
Dr. Sunder: Good morning. Jim has already introduced me as the lead investigator for the federal building and fire safety investigation of the World Trade Center disaster, and I will take this time this morning to explain to you our overall goals, our objectives, and where we are in terms of status and progress on the investigation.
* * *
I want to start first by talking about data collection because this is a very, very important aspect of what we're trying to do. We've collected a very large amount of data and information from a whole host of organizations: The building owners, the designers, the City of New York, both the fire department, the police department, and numerous other organizations that support this, including suppliers of materials, such as fireproofing.
We have a few requests for materials that are lost, currently pending, or not yet located. We are making every effort to recreate that information, since much of it was lost when the buildings collapsed, especially those that deal with the buildings themselves. We, at this point, believe that we have received all of the essential information for us to do a credible investigation. And we have said that for the past three months, while we continue to work the problem of the few
Page 5
Transcript of NIST Public Meeting in New York City - February 12, 2004 4
pieces of information that we still seek. And in doing so, we've received considerable cooperation from a whole host of organizations, including survivors and victim's families. I'm going to touch on a number of aspects of our investigation which I think it’s worth for the public to know at this point in time. First of all the issue with regard to the safety of the towers in an aircraft collision. Buildings are not designed to withstand the impacts of fuel laden commercial airliners. However, in the case of the World Trade Center, it was a consideration. The structural safety of the towers in an aircraft collision was considered in the original design.
We have some documents from 1964 that suggest that.
The impact scenario that was considered is a Boeing 707 traveling at 600 miles an hour. There's another document a month later that considers an aircraft impact at the 80th floor of one of the towers. When you put those two together, the events of September 11th look strikingly similar.
The analysis that was reported from that time indicated that such collision would result in only local damage which could not cause collapse or substantial damage to the buildings. We now know that the buildings withstood the initial impact of the aircraft. The loss of life would have been far greater had the buildings collapsed upon impact. The large size of the buildings, the 208 x 208 feet floor plan area, and the dense exterior grid of columns, enabled the buildings to withstand the initial impact of the airplanes. But when you go beyond the initial impact to look at fire safety and life safety, we find that there are some contradictory views.
There are two views on whether or not the effect of jet fuel and the subsequent - and the aircraft contents with regard to fire safety was considered or not. One view suggested that the fuel would dump into the building and there would be a horrendous fire. The second view suggested that possibly the fuel load and the fire damage may not have been considered.
These are the opinions of people who should know what was done at that time.
With regard to life safety, there are two views, again, on what would be the effect on occupant life safety. One view, which considered the fires, suggested that - one view which did not consider the fire suggested that the aircraft impact would not have endangered the lives and safety of occupants not in the immediate area of impact. Another view, which considered the fires, which took that into account, recognized that a lot of people would be killed, even though the building structure would still stand.
We are still hopeful that we'll have further information available from wherever it resides, from the public, from people who know, to help us to better understand these different perspectives. And if we can get documents, that would be even better.
* * *

nolu_chan posted on 2007-04-20 3:46:34 ET Reply Trace Private Reply
#26. To: BeAChooser, Kamala, honway (#20)
[BAC #20] The source for this is Paul Thompson’s Complete 9/11 Timeline. ROTFLOL! This is false. The calculation was done by Skilling (and only Skilling) and he was not one of the principle designers of the Towers. Nevertheless, and for the record, the towers did handle the impact of a 707 sized plane travelling almost that fast.

Until after the construction of the WTC was completed, Leslie Robertson had not yet risen to the level of junior partner in he engineering firm of John Skilling. Robertson was an employee, not a partner. Robertson eventually became a partner, but that did not happen until after construction was completed.
A series of articles from Engineering News Record from 1964 to 1971, refer to either John Skilling or Leslie Robertson. I have boldfaced each name in each instance and have left no instance unquoted from the linked source. Robertson did not receive a mention until 1971. Prior to that there are repeated references to John Skilling, but nary a mention of Robertson.
http://911research.wtc7.net/mirrors/guardian2/wtc/eng-news-record.htm
SOME ARTICLES FROM ENGINEERING NEWS RECORD.
-----
Architects are Minoru Yamasaki & Associates of Birmingham, Mich., and Emery Roth & Sons, of New York City. Structural engineers are Worthington, Skilling, Helle & Jackson, of Seattle.
July 9, 1964
-----
The concept was explained to the New York Architectural League by John Skilling, a partner in Worthington, Skilling, Helle and Jackson, of Seattle, consulting structural engineers on the World Trade Center (see p. 124).
April 2, 1964
-----
Walls resist wind. In designing the record-height towers against wind, Worthington, Skilling, Helle and Jackson adopted a scheme that does not rely on the core at all to take wind. Each tower will act as a vertical, cantilevered hollow tube. The giant Vierendeel trusses forming the loadbearing exterior walls will provide the required rigidity and strength to resist wind. All the horizontal shear will be resisted by the sides of the building parallel to the wind, and most of the overturning moment will be taken by the exterior walls normal to the wind. For economy in resisting the stresses, the wall columns will be made of high-strength steels, as indicated in the diagram above.
April 2, 1964
-----
Minoru Yamasaki and Associates, Birmingham, Mich., and Emery Roth & Sons, New York City, are the Architects. Worthington, Skilling, Helle and Jackson, of Seattle, are, the consulting structural engineers; Jaros, Baum and Bowles, of New York City, the consulting mechanical engineers; and Joseph R. Loring and Associates, New York City, the consulting electrical' engineers. These firms were assisted in the design by the World Trade Center Planning Division under the direction of Malcolm P. Levy, and the PNYA engineering department, John M. Kyle,' chief engineer.
January 23, 1964
-----
Fig . World Trade Center's towers will rise 1,350 ft in New York
Fig . Proposed skyscrapers will dominate the skyline of downtown Manhattan.
Fig . Floorbeams will span from exterior columns to elevator-core walls.
Fig . Structural consultant John Skilling.
Fig . Architects Richard (left) and Julian Roth and Minoru Yamasaki.
January 23, 1964
-----
To maintain uniform column and spandrel dimensions, structural engineers Worthington, Skilling, Helle & Jackson, of Seattle, specified a variety of steel strengths and sections to resist varying stresses throughout the frame.
February 2, 1967
-----
Monti on management. Monti operates from the 10th floor of a building overlooking the WTC site. Although he concentrates most of his attention in areas where things go wrong, he maintains constant communication with the main contractors, with the architects and with the engineering consultants, Skilling, Helle, Christiansen, Robertson, Seattle, on structural design; Joseph Loring & Associates, New York City, on electrical work, and Jaros, Baum & Bolles, New York City, on mechanical.
February 11, 1971
-----
==============
http://www.skyscrapersafety.org/html/article_11092001.html
-----
In 1963, the firm entered a competition held by the Port Authority of New York and New Jersey to build in New York City what would be the tallest buildings ever constructed-the two towers of the World Trade Center. It was one of eight engineering firms-most of them large partnerships in New York-asked to submit proposals. Although the firm's tallest building up to that point was the twenty-story I. B.M. Building in Seattle, the architect of that building was Minoru Yamasaki-the same architect the Port Authority had selected for the World Trade Center. At a meeting to present the firm's proposal to the architect and developers, John Skilling, one of the four partners, used only a drawing pad, an easel, and some markers to make his pitch.
-----
What Skilling proposed was a pure tube structure. His design was consistent with the general principles at work in the new generation of high-rises, but he carried the concept of the tube building farther than it had ever been taken before. (Or since: the Sears Tower, in Chicago, which replaced the World Trade towers as the world's tallest building in 1973, is also a tube building, but it is actually a cluster of nine smaller tubes.) The Twin Towers would be perforated steel boxes surrounding a hollow steel core. The outer box would be two hundred and eight feet on each side, and made of fourteen-inch-wide steel columns that were spaced on forty-inch centers-much closer than the fifteen-to-thirty-foot spaces that separate most supporting columns in a building. Like the cast-iron buildings of the previous century, the exterior walls would be load-bearing; unlike most skyscrapers, which hide their supporting columns, the Twin Towers would proudly wear their structure on their sleeves. Because there were so many load-bearing columns around the perimeter of each building, the engineers could completely eliminate all columns within the office space. Joining the outside tube to the inner core were state-of-the-art lightweight floor trusses that spanned sixty feet from core to exterior walls on two sides, and thirty-five feet on the other two sides. Yamasaki liked the design because it reminded him of a bamboo tube, an important totem for him. The Port Authority liked the design because, among other things, the towers would offer the single largest expanse of column-free office space in Manhattan-a realtor's dream.
Skilling's firm got the commission, and Robertson, then thirty-five, moved to New York to open a new office, and to supervise the structural aspects of the building's construction. In 1983, the Seattle office and the New York office split, becoming two separate firms. Skilling (who died in 1998) and Robertson later argued about who was more responsible for the structure of the towers. "These are guys with big egos, and things got a little testy between them regarding who was ultimately responsible for the design," says Jon Magnusson, the chairman and C.E.O. of the Seattle-based firm, which is now called Skilling Ward Magnusson Barkshire. "Skilling said, 'It was me,' Robertson said, 'It was me,' but I think the truth is that both of them made a significant contribution."
-----
http://911research.wtc7.net/wtc/analysis/design.html
John Skilling
John Skilling was the head structural engineer for the World Trade Center. In a 1993 interview, Skilling stated that the Towers were designed to withstand the impact and fires resulting from the collision of a large jetliner such as Boeing 707 or McDonald Douglas DC-8.
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, ... The building structure would still be there.
A white paper released on February 3, 1964 states that the Towers could have withstood impacts of jetliners travelling 600 mph -- a speed greater than the impact speed of either jetliner used on 9/11/01. 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.
-----
Frank Demartini's Statement
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.
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.
Demartini, who had an office on the 88th floor of the North Tower, has been missing since the 9/11/01 attack, having remained in the North Tower to assist in the evacuation. 6 Demartini had first worked at World Trade Center when Leslie E. Robertson Associates hired him to assess damage from the truck bombing in 1993.
Like All Skyscrapers, the Twin Towers Were Over-Engineered
One aspect of engineering that is not widely understood is that structures are over-engineered as a matter of standard practice. Steel structures like bridges and buildings are typically designed to withstand five times anticipated static loads and 3 times anticipated dynamic loads. The anticipated loads are the largest ones expected during the life of the structure, like the worst hurricane or earthquake occurring while the floors are packed with standing-room-only crowds. Given that September 11th was not a windy day, and that there were not throngs of people in the upper floors, the critical load ratio was probably well over 10, meaning that more than nine-tenths of the columns at the same level would have to fail before the weight of the top could have overcome the support capacity of the remaining columns.
There is evidence that the Twin Towers were designed with an even greater measure of reserve strength than typical large buildings. According to the calculations of engineers who worked on the Towers' design, all the columns on one side of a Tower could be cut, as well as the two corners and some of the columns on each adjacent side, and the building would still be strong enough to withstand a 100-mile-per-hour wind. 7 Also, John Skilling is cited by the Engineering News Record for the claim that "live loads on these [perimeter] columns can be increased more than 2000% before failure occurs."
-----
The WTC’s structural engineer, Skilling Helle Christiansen Robertson, called the member a floor truss on the drawings. "All sizes of all members of all trusses were provided in the drawings," says Robertson, currently LERA’s director of design.

==============

http://www.baltimoresun.com/news/custom/attack/bal-te.architect13sep13,0,4261351.story?coll=bal-attack-utility
Engineers blame collapses on fires
Burning jet fuel's heat softened steel supports of WTC towers, they say; Sprinklers disabled, outmatched
By Edward Gunts
Sun Architecture Critic
Originally published September 13, 2001
...
Worthington, Skilling, Helle and Jackson - the predecessor to Hooper's firm - was the structural engineer for the World Trade Center. Minoru Yamasaki was the lead architect.
Engineers from the firm said eight years ago that the World Trade Center was designed to withstand the impact of a Boeing 707 crash, because they knew a smaller plane had crashed into the Empire State Building. But even then, they warned that it wouldn't be safe from a subsequent fire.
"Our analysis indicated that the biggest problem would be the fact that all the fuel [from the jet] would dump into the building," lead structural engineer John Skilling told The Seattle Times in 1993. "There would be a horrendous fire. A lot of people would be killed.
Skilling's scenario proved to be remarkably prescient.
-----

nolu_chan posted on 2007-04-20 3:51:38 ET Reply Trace Private Reply
#27. To: BeAChooser (#18)
[From BAC #18] http://www.nae.edu/nae/bridgecom.nsf/weblinks/CGOZ-58NLCB?OpenDocument "Reflections on the World Trade Center, Leslie E. Robertson, ... snip ... The lead structural engineer reflects on the rise and fall of the World Trade Center towers. ... snip ... It was assumed that the jetliner would be lost in the fog, seeking to land at JFK or at Newark. 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. Indeed, at that time, no fireproofing systems were available to control the effects of such fires."

What would a jetliner be doing trying to land in Manhattan???
It has no place to land in New York county, Richmond county, Kings county, or Bronx county. It would have to be seeking to land in Queens county on Long Island (JFK nee Idlewild, or LaGuardia), or over in Newark in New Jersey.
The plane that hit the Empire State building got lost in the fog during WW2, and before all the jetliners had radar and could fly in the fog using instruments. There is not much chance of a jetliner getting lost and trying to land at Penn Station, Port Authority Bus Terminal, or on top of Madison Square Garden.
Maybe there is a Bermuda Triangle formed by the train station, the bus station, and the garden. Even so, there is not much chance for a jetliner to get caught between Penn Station and MSG.
It seems someone forgot about the invention of radar.

nolu_chan posted on 2007-04-20 4:17:12 ET Reply Trace Private Reply
#28. To: BeAChooser (#18)
This was a back of the envelope calculation done AFTER the design was complete.

It is a White Paper from 1964. Groundbreaking occurred two years later in 1966.
http://wtc.nist.gov/media/Public%20Transcript%20021204%20Final1_withlinks.pdf
Transcript of NIST Public Meeting in New York City - February 12, 2004
Shyam Sunder, National Institute of Standards and Technology the lead investigator for the federal building and fire safety investigation of the World Trade Center disaster:
Buildings are not designed to withstand the impacts of fuel laden commercial airliners. However, in the case of the World Trade Center, it was a consideration. The structural safety of the towers in an aircraft collision was considered in the original design.
We have some documents from 1964 that suggest that.
The impact scenario that was considered is a Boeing 707 traveling at 600 miles an hour. There's another document a month later that considers an aircraft impact at the 80th floor of one of the towers.

http://en.wikipedia.org/wiki/World_Trade_Center
Construction
Groundbreaking for the construction of the World Trade Center was on August 5, 1966.
In 1970, construction was completed on One World Trade Center, with its first tenants moving into the building in December, 1970. Tenants first moved into Two World Trade Center in January 1972.
http://en.wikipedia.org/wiki/White_paper
A white paper is an authoritative report. White papers are used to educate customers, collect leads for a company or help people make decisions. They can also be a government report outlining policy.

nolu_chan posted on 2007-04-20 4:35:18 ET Reply Trace Private Reply
#29. To: BeAChooser (#18)
I've provided links to back my assertion up over and over in previous threads here at 4um (not to mention uncounted times at LP). If you weren't paying attention, NC, that's your problem.

I am not responsible to look for your Hormel samples on other threads or sites.
The only things to be learned from researching your spam at other sites is to learn your Bozo count or why you were banned.
It does seem that you have a fan club over at FU.
http://www.freedomunderground.org/view.php?v=3&t=3&l=24&aid=23539#7
[Dakmar #7] ok, everyone wants BeAChooser to post here say Aye!
[continental op #8] Absolutely. BRing him over I'll murder the bastard. ect,ect ect...
[continental op #21] I always got time for bealooser. Drag the rat over here. I'll annihilate him.

nolu_chan posted on 2007-04-20 4:48:48 ET Reply Trace Private Reply
#30. To: nolu_chan (#28)
Leslie Robertson was the coffee and donut boy for the real players, Skilling & Co. They sent him to NY to slop around in the mud, while in Seattle, they got the awards and had dinner.
He is the only one alive from that time, I believe. He is jealous, vindictive that he never got the acclaim the others did. I think he eventually left to start his own company.
Robertson now is only protecting what matters most, himself, money and his so called reputation.
Mark
"I was real close to Building 7 when it fell down... That didn't sound like just a building falling down to me while I was running away from it. There's a lot of eyewitness testimony down there of hearing explosions. [..] and the whole time you're hearing "boom, boom, boom, boom, boom." I think I know an explosion when I hear it... — Former NYC Police Officer and 9/11 Rescue Worker Craig Bartmer
Kamala posted on 2007-04-20 6:36:56 ET Reply Trace Private Reply
#31. To: Kamala, BeAChooser (#30)
Leslie Robertson was the coffee and donut boy for the real players, Skilling & Co. They sent him to NY to slop around in the mud, while in Seattle, they got the awards and had dinner.

To be fair, Engineering News Record said, "Leslie E. Robertson, was the WTC's project manager."
In the world of reality TV, on The Apprentice WTC, Skilling would have been Donald Trump and Robertson would have been the Project Manager.

nolu_chan posted on 2007-04-20 16:47:56 ET Reply Trace Private Reply
#32. To: nolu_chan, ALL (#25)
Buildings are not designed to withstand the impacts of fuel laden commercial airliners. However, in the case of the World Trade Center, it was a consideration. The structural safety of the towers in an aircraft collision was considered in the original design. We have some documents from 1964 that suggest that. The impact scenario that was considered is a Boeing 707 traveling at 600 miles an hour.

I can't help that Sunder occasionally is unclear when he speaks. He said the towers collapsed in 9 and 11 seconds and that is demonstrably FALSE. What he meant is that the first pieces of material were observed to strike the ground 9 and 11 seconds after the collapse began. And the ONLY document they have does not say that the towers were DESIGNED for a 600 mph impact. It was a WHITE PAPER, not a design document, that only says the tower would survive a 600 mph impact. Which is not surprising, if it was DESIGNED to survive a 180 mph impact ... given the safety factors used by designers of buildings in those days and the dearth of tools with which they could model impacts in those days.
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Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-20 17:07:05 ET Reply Trace Private Reply
#33. To: nolu_chan, ALL (#26)
Until after the construction of the WTC was completed, Leslie Robertson had not yet risen to the level of junior partner in he engineering firm of John Skilling. Robertson was an employee, not a partner. Robertson eventually became a partner, but that did not happen until after construction was completed.

Being a partner versus being the lead structural engineer on a project is more a matter of having the MONEY to become a partner, not whether one controls the detailed design of a given project. You are just throwing out a red herring, because I proved by posting numerous credible sources that state unequivocally that Robertson, not Skilling, was the lead structural engineer on the project and indeed one of the most influential members of the design team.
It is a FACT that Robertson lived and worked in NYC which is where the design team was located. Skillings was still in Seattle and could not possibly have led the design team effectively. He may have conceptualize the design he wanted at the beginning, but it was Robertson and his team which made it a reality. And it would be Robertson, not Skilling, who would know the details of the design. Skilling was probably out marketing for new work for his company while his man worked the problem. That's what the CEOs of most firms do, by the way.
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Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-20 17:16:21 ET Reply Trace Private Reply
#34. To: nolu_chan, ALL (#28)
"This was a back of the envelope calculation done AFTER the design was complete."

It is a White Paper from 1964. Groundbreaking occurred two years later in 1966.

http://en.wikipedia.org/wiki/Design_and_construction_of_the_World_Trade_Center "On September 20, 1962, the Port Authority announced the selection of Minoru Yamasaki as lead architect, and Emery Roth & Sons as associate architects.[26] Yamasaki came up with the idea of twin towers. To meet the Port Authority's requirement to build 10 million square feet of office space, the towers would each be 110-stories tall. Yamasaki remarked that the "obvious alternative, a group of several large buildings, would have looked like a housing project".[27] Yamasaki's design for the World Trade Center was unveiled to the public on January 18, 1964, with an eight-foot model.[27]
So there is NO POSSIBLE WAY that any White Paper from 1964 affected the DESIGN.
You don't know what you are talking about nolu_chan.
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Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-20 17:27:23 ET Reply Trace Private Reply
#35. To: BeAChooser (#33)
Being a partner versus being the lead structural engineer on a project is more a matter of having the MONEY to become a partner, not whether one controls the detailed design of a given project.

The employee receives a salary.
The partners in the company split the corporate profits.
The partners decide what the corporate employees do or refrain from doing. If the employee does not like their decision he can quit or be fired.
More BAC nonsense.

nolu_chan posted on 2007-04-20 18:08:15 ET Reply Trace Private Reply
#36. To: BeAChooser (#34)
Yamasaki's design for the World Trade Center was unveiled to the public on January 18, 1964, with an eight-foot model.[27]
So there is NO POSSIBLE WAY that any White Paper from 1964 affected the DESIGN.

Yamasaki was the architect. He did not do the engineering.
The design of the building did not end with the display of an 8-foot model.
But if you say so...
After the design was BAC-complete, engineering concepts were explained to the New York Architectural League by the Big Boss Structural Engineer, John Skilling, a partner in Worthington, Skilling, Helle and Jackson.

http://911research.wtc7.net/mirrors/guardian2/wtc/eng-news-record.htm
From Engineering News Record
The concept was explained to the New York Architectural League by John Skilling, a partner in Worthington, Skilling, Helle and Jackson, of Seattle, consulting structural engineers on the World Trade Center (see p. 124).
April 2, 1964

nolu_chan posted on 2007-04-20 19:19:06 ET Reply Trace Private Reply
#37. To: BeAChooser (#33)
It is a FACT that Robertson lived and worked in NYC which is where the design team was located. Skillings was still in Seattle and could not possibly have led the design team effectively. He may have conceptualize the design he wanted at the beginning, but it was Robertson and his team which made it a reality.

Right. Demolition of the buildings on the site did not even begin until 1966. Looking at all those old buildings is what enabled the engineers to do their work. ~rme~ Robertson was an employee of Skilling and company. The architect conceptualizes the design of the building.
The building contractors and all those construction workers made it a reality.
http://www.greatbuildings.com/buildings/World_Trade_Center_History.html
On March 25, 1966, four years after the enactment of the authorizing legislation, demolition finally began on 26 vacant buildings on the World Trade Center site.

nolu_chan posted on 2007-04-20 19:30:02 ET Reply Trace Private Reply
#38. To: nolu_chan, ALL (#36)
"Yamasaki's design for the World Trade Center was unveiled to the public on January 18, 1964, with an eight-foot model.[27]"

[BAC] - So there is NO POSSIBLE WAY that any White Paper from 1964 affected the DESIGN.

Yamasaki was the architect. He did not do the engineering.

The design of the building did not end with the display of an 8-foot model.

And you think they wait to determine what the underlying major structure is until AFTER the Architect unveils the DESIGN to the public? ROTFLOL!
Here are some signs from the same article that the design was well underway much earlier than 1964.
"The exterior walls will comprise giant Vierendeel trusses, designed to act like huge cantilevered hollow tubes. They will be pre-assembled in units two stories high and about 10 ft wide, spliced at mid-height of the columns and midspan of the deep spandrel beams. The closely spaced columns will consist of 14-inch-sq hollow box sections, providing high torsional and bending resistance. ... snip ... July 9, 1964" Well clearly the design was well underway by July 1964.
"Four New York City construction companies will independently review construction techniques planned for the two 110-story towers at the World Trade Center ... snip ... April 16, 1964" Gee, in April 1964 they are already awarding bids to construction folks to REVIEW construction techniques. So they must know what they were going to build.
"The Port of New York Authority will. pay architects Minoru Yamasaki & Associates and Emery Roth & Sons an extra $800,000 over the initial $1.5-million fee for designing the World Trade Center in New York City. The new contract covers further design refinements for the superstructure of the twin 110-story towers, studies of integration of the PATH railroad station into the project. October 15, 1964" Hmmm ... in October 1964, they were already awarding more money for REFINEMENTS of the design.
"HOW COLUMNS WILL BE DESIGNED FOR 110-STORY BUILDINGS ... snip ... April 2, 1964" Gosh, according to that article in April 1964 they already have all the major dimensions that we know about the structure ... the size of its members ... the response to loads ... the variations in steel strength over the height. So what did Skillling really do?
"NEW YORK'S 110-STORY TOWERS ... Most local designers and builders want to know more about the New York World Trade Center and its sky-shattering heights (ENR Jan. 23, p. 33), but they generally like what they've seen so far. ... snip ... James Ruderman, consulting structural engineer "The structural design of the tower buildings shows a commendable job of rethinking, where ideas were given a lot of thought and not just treated routinely." ... snip ... January 30, 1964." Oh my gosh ... in January of 1964 a structural engineer is commenting on the structural design. He must have had something to comment on.

The concept was explained to the New York Architectural League by John Skilling, a partner in Worthington, Skilling, Helle and Jackson, of Seattle, consulting structural engineers on the World Trade Center (see p. 124).

April 2, 1964

Here's a real puzzler for you, NC. The White Paper written by Skilling that you are making such a big deal about was released February 3, 1964. So if the concept was just being explained to Skilling in APRIL of that year, how did he manage to do a detailed analysis to show that the structure could survive a 600 mph commercial jet impact back in February? Hmmmmmmm???? I anticipate that question will go just as unanswered as my question about what kept the molten steel molten 6 weeks after the collapse ... or my question about whether that photo of debris proves Steven Jones is a liar. ROTFLOL!
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Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
BeAChooser posted on 2007-04-20 21:27:57 ET Reply Trace Private Reply
#39. To: BeAChooser (#38)
[BAC #38] And you think they wait to determine what the underlying major structure is until AFTER the Architect unveils the DESIGN to the public? ROTFLOL!
No moron. You said at #34, "So there is NO POSSIBLE WAY that any White Paper from 1964 affected the DESIGN."
A whole bunch of things could, and most certainly did, change in the design after 1964. What I said at #36 was, "The design of the building did not end with the display of an 8-foot model."
In your idiocy, you asserted that prior to the White Paper in 1964, the design had been COMPLETED. Now in a bait and switch, in order to try to extract your sorry butt from your display of gross public dumb, you assert, "some signs from the same article that the design was well underway much earlier than 1964."
Referring to the White Paper of February 3, 1964, you blathered at #18, "This was a back of the envelope calculation done AFTER the design was complete."
That the design was UNDERWAY prior to 1964 would in no way support your prior claim that "there is NO POSSIBLE WAY that any White Paper from 1964 affected the DESIGN."
Also, at #18, you did not say the design was UNDERWAY prior to the White Paper, you explicitly stated the White Paper was "done AFTER the design was complete." [BAC upper case emphasis.]
AFTER 1964, Robertson's original engineering design plan had to be scrapped because tests in 1965 showed the buildings would sway beyond the limits of human tolerance. As Glanz and Lipton wrote in the New York Times, "Even today, Robertson has no trouble conjuring what two towers full of seasick office workers would have meant: 'A billion dollars right down the tube.' So he went back to work."

http://tinyurl.com/2vm8fu
The Height of Ambition: Part Four
The New York Times, Sunday Edition
September 8, 2002
The Height of Ambition: Part Four
By JAMES GLANZ and ERIC LIPTON
* * *
Using exterior columns rather than interior ones for lateral stiffness not only increased the building's floor space; it also let Robertson reduce the total amount of structural steel in the building by at least 30 percent. The steel in the tightly spaced columns became as thin as a quarter-inch toward the top, where it had less load to carry. Robertson had succeeded in achieving his main goals for these exotic steel trees. But in designing what would become the feathery branches of those trees -- the floors -- he pushed even further toward lightweightness and cost savings. Rather than the massive beams or heavy framings that serve as horizontal floor supports in virtually every large steel office tower, Robertson chose bar-joist trusses -- airy, weblike networks of thin steel bars and angle irons topped with corrugated decking. Those trusses, which spanned as much as 60 feet, had two critical roles: they held up the concrete floors, and they provided lateral support to the exterior columns, keeping them from buckling under the load they carried.
According to Robertson's figures, the trusses worked as well as heavy traditional girders and beams in performing those roles under ordinary circumstances. What he did not take into account was the extraordinary conditions of an intense, violent fire. Girders and beams would be far superior under those circumstances. Thin steel elements heat up and soften faster than thick ones. But in recent conversations, Robertson has said that architects generally handle anything dealing with fire in building projects, not engineers, so he did not think about this reduction in safety.
Robertson and the Port Authority made another choice that proved fateful decades later. They chose not to use thick masonry or cement to encase the three escape stairways in each tower but rather light sheets of gypsum. Although the gypsum was extremely resistant to fire, and less likely than masonry to crack when the building swayed in the wind, it would work only if it remained intact -- and it was much more susceptible to being shaken loose or damaged by an explosion or any other kind of unexpected impact. There was another factor that Robertson had to take into account: the swaying motion of his buildings. The lightweight steel skeletons would not only put people unnaturally high in the air, as all skyscrapers do. They would let the buildings sway back and forth in the wind, like the biggest, leafiest trees ever planted. Heavy masonry-clad high-rises like the Empire State Building had never had to deal with this problem. For that reason, engineers had never measured how much swaying motion humans could stand before they became dizzy, seasick, frightened or disoriented.
To answer that question, Robertson turned to an expert in human perception in Eugene, Ore. -- a spot as far removed from the New York press as he could find. Paul Hoffman, a psychologist, agreed to perform a secret series of experiments to find out just how much swaying motion was too much. Hoffman purchased a small office building in downtown Eugene and in the summer of 1965 put an ad in the local paper offering free eye checkups at a ''vision research center.'' But it was actually an elaborate ruse: the optometrist who conducted the eye exams was one of Hoffman's employees, Paul R. Eskildsen. And as each patient stared at triangles projected on the wall, a hidden technician would trigger a giant set of hydraulics underneath the room that heaved it back and forth like a big saltshaker.
''This is a strange room,'' one patient said, according to Eskildsen's detailed notes. ''I suppose it's because I don't have my glasses on. Is it rigged or something? It really feels funny.''
Patient after patient reacted the same way -- becoming dizzy and confused soon after the eye exam began. Humans, Hoffman discovered, were much more sensitive to motion than anyone had realized. A few inches of sway over 5 or 10 seconds set off psychophysical alarm bells.
''The people who were most surprised of all were the engineering firm and the Port Authority,'' Hoffman says. First, Port Authority officials trooped out to Eugene. Old photos show them milling around the little optometrist's office, looking flummoxed. Then they insisted on redoing the experiments by swinging a makeshift office on cables inside one of the Lincoln Tunnel's ventilation towers on Manhattan's West Side. ''It was a big packing crate, is what it was, that they had dolled up to look like an office,'' says Eskildsen, who traveled to New York for the new round. ''I had two guys outside who pushed the room. It was hilarious.'' About 40 Port Authority officials rode in the contraption. The results were the same.
Wind-tunnel experiments in Fort Collins, Colo., confirmed that Robertson's initial design would sway far beyond those human tolerances, says Jack Cermak, then a professor of civil engineering and the director of the wind-tunnel laboratory at Colorado State University. Even today, Robertson has no trouble conjuring what two towers full of seasick office workers would have meant: ''A billion dollars right down the tube.'' So he went back to work.
* * *
But Robertson still had one more set of structural calculations to perform. Lawrence Wien, who was continuing his fight against the towers, had begun to remind New Yorkers publicly of a Saturday morning in July 1945, when a B-25 bomber, lost in the fog, barreled into the 79th floor of the Empire State Building. Most of the 14 people who died were incinerated by a fireball created when the plane's fuel ignited, even though the fire was quickly contained. The following year, another plane crashed into the 72-story skyscraper at 40 Wall Street, and yet another one narrowly missed the Empire State Building, terrifying sightseers on the observation deck. Wien and his committee charged that the twin towers, with their broader and higher tops, would represent an even greater risk of midair collision.
They ran a nearly full-page ad in The Times with an artist's rendition of a commercial airliner about to ram one of the towers. ''Unfortunately, we rarely recognize how serious these problems are until it's too late to do anything,'' the caption said.
The Port Authority was already trying to line up the thousands of tenants it would need to fill the acres of office space in the towers. Such a frightful vision could not be left unchallenged. Robertson says that he never saw the ad and was ignorant of the political battle behind it.
Still, he recalls that he addressed the question of an airplane collision, if only to satisfy his engineer's curiosity. For whatever reason, 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.
There were only two problems. The first, of course, was that no study of the impact of a 600-mile-an-hour plane ever existed. ''That's got nothing to do with the reality of what we did,'' Robertson snapped when shown the Port Authority architect's statement more than three decades later. The second problem was that no one thought to take into account the fires that would inevitably break out when the jetliner's fuel exploded, exactly as the B-25's had. And if Wien was the trade center's Cassandra, fire protection would become its Achilles' heel.
* * *
[nc - there are at least a few more problems. Robertson's assertion of being unaware of the Wein ad and the political battle is not credible. Perhaps Robertson performed only an imaginary study consisting of nothing more than some propaganda released to the press, or he blew smoke at the architect. A prominent article in the New York Times explained that Robertson's study proved that the towers could withstand the impact of a jetliner moving at 600 miles an hour. There can be no credible assertion of unawareness by all concerned in the building of the WTC and no correction was issued. Robertson's three decades late assertion that he considered only a plane going 180 mph is not credible.]
Compare with BAC drivel at #18

nolu_chan posted on 2007-04-21 2:34:41 ET Reply Trace Private Reply
#40. To: all (#0) (Edited)
I have concluded that the only purpose BAC has here is to derail all 9-11 discussions with spam filled posts and outrageous claims. He's the Donald Segretti showing up to sabotage an open forum and make it his agenda.
I put him on Bozo, but his impact on these threads is still seen, as he sucks out the oxygen from the conversation.
I tend to skip any thread in which he participates actively, and I suspect that is one of his objectives, since disruption is his primary goal.

Paul Revere posted on 2007-04-21 5:18:25 ET Reply Trace Private Reply

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