I should say up front that the following is in part , my opinion , so as not to be required to provide 'proof' by those who will disagree with it
It is also , in large part , taken from an article from The New York Times , Sept. 8, 2002 , titled "The Height of Ambition" by James Glanz and Eric
My opinion :
It IS possible that the towers collapsed from structural failure due to nothing more than being subjected to the intense fires that resulted from the
ignition of the jet fuel .
Planes did indeed crash into the towers . Whether they were the alleged flights , I can't say with certainity at this time .
Was it possible for aluminum aircraft to penetrate the facade of the towers and cause this type of damage ? Most definitely , YES .
Should the planes have 'crumpled' instead of penetrating the facade ? NO .
Were there secondary explosive devices used to further weaken the structures ? I can't say conclusively , one way or the other .
Did the towers fall as a direct result of successive charges ? In my opinion , NO .
Can the massive dust clouds be explained in a credible way ? YES .
Is it possible that most of the concrete was pulverized ? Most definitely , YES .
Did any steel 'vaporize' ? In my opinion , NO .
Were the towers structurally sound before the impacts , with tried-and-true methods of construction ? NO .
Is it relevant that no other steel high-rises had suffered total collapse , due to fire ? NO , as these towers were not constructed with methods that
were used in any other steel high-rises .
In order to understand how the towers collapsed due to fire alone , would you need to have a cursory understanding of the properties of steel , as
well as knowledge of what types of steel were employed in the construction of the towers ? YES .
The following is taken from the above-mentioned article . Some of it has been paraphrased and I have interjected my thoughts here and there . I will
do my best to use "parenthesis" when quoting directly from the article .
"When they drew up the blueprints for it's construction , they had unwittingly written the script for it's eventual destruction . The project's
architects and engineers used brand new , untested technologies to raise an unprecedented amount of real estate into the sky . They created a pair of
lightweight , almost willowy structures ..."
" Even before they were built , though , critics derided the Buck Rogers quality of the towers noting that new technologies and new architectural
paradigms often bring new vulnerabilities ."
"The trade-center towers could be the start of a new skyscraper age or THE BIGGEST TOMBSTONES IN THE WORLD ." ( Louise Huxtable , architecture
critic , New York Times , 1966 ).
Keep in mind that "ten million square feet of office space represented more rentable office space than existed in all of Houston , Detroit , or
downtown Los Angeles at the time ".
"...the center could endanger thousands in the case of a fire or an explosion ". (Lawrence A. Wien , in a Sept. 1964 letter to Gov. Richard J.
Hughes of New Jersey). Wien would ultimately suggest...that an airplane might someday hit the World Trade Center , with disastrous consequences."
"Now,they had to figure out how to build towers 110 stories into the sky that wouldn't crumble under their own weight."
"Since the first steel-reinforced skyscrapers were built in the latter part of the 19th century,these nature-defying structures had always relied for
their basic support on a kind of three-dimensional cage,or grid. The grid permeated the entire building--massive steel columns interrupting the floor
space every 20 or 30 feet.
The point was structural integrity: if one of the closely spaced steel bones failed, another would be there to take up the slack,avoiding total
"In case of fire,thick sheaths of masonry--brick, stone or terra cotta--around the steel would protect it from the heat, even in out-of-control
"Leslie E. Robertson, the man who designed the guts of the twin towers, had to figure out how the buildings would support themselves, as well as how
to economize wherever possible. He decided that masonry-encased interior columns would be sturdy,but expensive,and this would also eat up tremendous
amounts of rentable floor space. So, Robertson and his team abandoned the traditional way of doing things by doing away with the masonry and used
gypsum (sheetrock) instead, for the interior walls."
(Keep in mind that Yamasaki was commissioned to design the towers,not build them.The 'building' would be the responsibilty of the engineers, namely
Leslie Robertson in this case .)
"Robertson and his team made the decision to incorporate the pinstripe columns of the exterior walls into the main structural elements of the entire
building,to carry almost half the weight of the building,as well as the lateral rigidity that would be needed for resisting the wind.This would erase
the need for interior columns,thereby allowing for more open floor space."
*** "Using exterior columns rather than interior ones for lateral stifness also allowed Robertson to reduce the total amount of structural steel by
at least 30% . The steel in the tightly spaced columns became as THIN AS A QUARTER-INCH toward the top, where it had less load to carry." (emphasis
"Instead of using massive beams or heavy framings for horizontal floor supports, Robertson chose to use bar-joist trusses (thin steel bars and angle
iron,topped with corrugated decking).These trusses would hold up the concrete floors as well as provide lateral support to the exterior
columns,keeping them from buckling under the load they would carry).
"What Robertson failed to take into account was the possibility of an intense,violent fire.The thin bars and angle iron which made up the trusses
would heat up and soften faster than the traditional girders and steel beams."
"While gypsum is extremely resistant to fire,it can't be expected to remain intact in the event of an explosion or violent impact,such as an
airliner crashing into the towers."
"The fire-proofing that the Port Authority chose to use was a newly-invented lightweight,low-cost product called 'mineral wool',which is sprayed
onto the steel.Even during construction,the material showed signs of failing to adhere to the steel.Rain would wash it off.When applied to rusty
steel,it would flake off."
[edit on 27-4-2010 by okbmd]