Experts: Impact, fire too much for twin towers
©Washington Post,
published September 12, 2001


National Academy of Sciences' Richard Little, who has overseen several studies on how to protect buildings from terrorist attacks.
"We were hopeful at first," added Pennsylvania State University architectural engineer Kevin Parfitt

Hyman Brown, a University of Colorado civil engineering professor
Angus Kress Gillespie, author of the 1999 book Twin Towers: The Life of New York City's World Trade Center
Cesar Pelli, designer of the Petronas Towers in Kuala Lumpur, Malaysia
Information from the Associated Press was used in this report.
http://www.sptimes.com/News/091201/Worldan...act__fire.shtml




Fire, not crashes, caused buildings to collapse, experts say
September 12, 2001

By Sharon L. Crenson
THE ASSOCIATED PRESS
Hyman Brown, a University of Colorado civil engineering professor and the Trade Center's construction manager,
Sanayei said the heat
Both Brown and Saw-teen See, a managing partner in Robertson's engineering firm, said the twin towers originally were designed to sustain a direct hit by a large jetliner, but that such construction couldn't make them fire- or bombproof.

http://www.suburbanchicagonews.com/focus/t.../e12towers.html




Thursday, 13 September, 2001, 12:59 GMT 13:59 UK
How the World Trade Center fell

The steel and concrete structures performed amazingly well, said John Knapton, professor in structural engineering at Newcastle University, UK.
It was the fire that killed the buildings. There's nothing on earth that could survive those temperatures with that amount of fuel burning," said structural engineer Chris Wise.
The buildings' construction manager, Hyman Brown, agreed that nothing could have saved them from the inferno.
http://news.bbc.co.uk/1/hi/world/americas/1540044.stm





2 Planes Hit Twin Towers at the Weakest Spot
http://www.latimes.com/news/local/la-091201collapse.story
http://newsmine.org/archive/9-11/questions...eakest-spot.txt

By USHA LEE McFARLING
Times Staff Writer

September 12, 2001

"It's like hitting someone at the back of the knee," said Nabih Youssef, a structural engineer who heads the Tall Building Council in Los Angeles and is an expert on the design and strength of skyscrapers.
"Whoever took over the plane knew what they were doing," said Greg Fenves, a professor of civil engineering at UC Berkeley.
"They showed some knowledge of physics in the attempt to make the hits as low as possible," said Ron Hamburger, chief structural engineer for ABS Consulting in Oakland and a past president of the Structural Engineers Assn. of California.

"To many who saw the buildings fall on television, the collapse resembled a planned demolition, especially in the way that the twin towers imploded--tumbling in on themselves. But engineering experts discounted the notion that additional explosives had been planted around the base of the buildings to ensure that they came down." - Ron Hamburger...

Instead, the impact of the planes themselves, and the tremendous heat generated by tons of burning jet fuel--upward of 1,000 degrees Fahrenheit--would suffice to destroy the buildings, said Scott Gustafson, owner of Demtech Inc. of Blue Springs, Mo., one of the world's leading demolition experts.

"It was very well thought out," said Hank Koffman, who directs the construction engineering department at USC.
"The technical term is progressive collapse--the slang term is pancaking," said Ron Klemencic, president of Skilling Ward Magnusson Barkshire, the Seattle firm that engineered the World Trade Center.
"Buildings are designed thinking of internally generated heat," added Jon Magnusson, the chairman and chief executive of the Skilling firm.
In most buildings, structural steel supports are 20 to 25 feet apart. In the World Trade Center, the supports are only 39 inches apart, said John Hooper, a structural engineer with the Skilling Ward Magnusson firm.

"Above all, with political turmoil, traffic problems and vast increases in populations and the tremendous impact of the machine, we must have serenity. Man needs a serene architecture to save his sanity in today's world."
Times staff writers Tim Rutten, Thomas H. Maugh II and Kenneth Reich contributed to this story.


USA Today Graphic
September 13, 2001

http://www.usatoday.com/graphics/news/gra/...lapse/frame.htm

Sources & Credits:
William Faschan, Leslie E. Robertson Associates.
Masoud Sanayei, Tufts University.
Franz Josef Ulm, MIT.
www.skyscraper.org

Research:
Joan Murphy
April Umminger
USA Today




Extreme heat, 'pancaking' doom towers into rubble 2,000-degree fire wilts steel; cave-in faster with each floor
By David Lieberman
USA TODAY
http://www.usatoday.com/usatonline/20010913/3627671s.htm

''They rocked back and forth, and then stopped,'' says Masoud Sanayei, professor of civil and environmental engineering at Tufts University in Boston.

''The momentum was too much to handle,'' says William Faschan, a partner at Leslie E. Robertson Associates, the towers' structural engineers.
''It was like a doughnut with this core element providing vertical support,'' says Tod Rittenhouse, principal of Weidlinger Associates.
But the towers were ''built to withstand the largest hurricane that could be envisioned,'' Faschan says.
The simplicity of the design helped. ''It was such a box,'' says Mysore Ravindra, president of LeMessurier Consultants, the firm that engineered New York's Citicorp building.
''Nobody could afford it,'' Ravindra says. ''It's almost unthinkable. There is no lesson to be learned. There was nothing in the building that was flawed.''
Rittenhouse agrees. ''There isn't much you can do'' about a fire like the ones ignited by the exploding jets, he says.



Inferno Heat, Not Impact, Brought Down Towers, Experts Say
Bijal P. Trivedi
for National Geographic Today
September 17, 2001
At temperatures above 500 degrees Celsius, steel loses its strength and "turns to Play-doh," said engineer Ted Krauthammer, of Penn State University in University Park, Pennsylvania.

"I was surprised and horrified to see them collapse," said Brooklyn-born physicist Frank Moscatelli of Swarthmore College in Pennsylvania. ," Moscatelli did some calculations. He estimated that the combined amount of energy released from the impact of the planes hitting the towers, the jet fuel explosions, and the collapse of both buildings was roughly equivalent to exploding 200 tons of TNT—about 2 percent to 4 percent of the explosive energy of the bomb detonated at Hiroshima. "Basically, the aircraft and the fire destroyed the top 20 stories and gravity destroyed the rest," he said.
The architectural design of the older building also has greater "redundancy" in column supports, said engineer Marc Hoit of the University of Florida in Gainesville.


Gravity Helped Terrorists Destroy Twin Towers
By Robert Roy Britt
Senior Science Writer
posted: 07:00 am ET
19 September 2001

Ultimately it was gravity," said Jon Magnusson, chairman and chief executive of Skilling Ward Magnusson Barkshire, a Seattle firmed that did the original structural engineering work on the towers.
"The airplanes destroyed the upper 20 floors," Moscatelli told SPACE.com. "Gravity did the rest."
If there was no fire, in my opinion the buildings would be standing today," Magnusson said in a telephone interview. "And they would stand until there was a significant wind storm."
Mir Ali, a professor of architecture at the University of Illinois, disagreed.
Another scientist suggested that the building might have had other structural damage, something that might never be determined from the rubble of the disaster.

He described the potential vibration as akin to a ringing bell. The initial ringing would have damped out quickly. But if large enough, it could have left permanent damage. In such a scenario, the steel support beams would behave like plastic, Lerner-Lam explained: Bend them a little, they spring back. Bend them further, they stay bent. Bend them enough, they break.
Both Magnusson and Ali said they doubted this scenario.
Engineers aren't sure if the central columns were compromised in the fires.
http://space.com/scienceastronomy/generals...nce_010919.html

The following list of stories demonstrates that the US had an immediate agenda to claim that the collapses were fire-induced. A bias was entered into the mainstream media services and this is something that can be traced back to particular individuals and groups...

Within 24 hours the story of the collapse of the WTC goes from bewilderment, to defying the history of high-rise buildings and fire within the US...

This was either well prepared beforehand...or was fabricated in an attempt to eliminate questions of an inside job...


http://www.icivilengineer.com/News/WTC/background.php

The height above street level and the trajectory of the impact tells the whole story, arthurs, regardless of your constant spam in attempts to refute the irrefutable.

The Amazing Flying Columns at both Bankers Trust and WFC 3 did NOT slide to their locations on top of an avalanche of debris. They were blown to these locations through thin air over 350 feet laterally from their point of origins, and given their entrance trajectories were blown laterally for those distances from very high in the towers before beginning their free-fall. Your obfuscating photo from a ground view far distant from WFC 3 means nothing at all... all it does is to hide the actual trajectory from viewers from THAT distant perspective.

hmmmmm....Let me see....

If the plane impacts done no real damage...