Why did the World Trade Center towers collapse?
The towers of the World Trade Center were designed to withstand as a whole the horizontal impact of a large commercial aircraft. So why did a total collapse occur?
The reason is the dynamic consequence of the prolonged heating of the steel columns to very high temperature.
The heating caused creep buckling of the columns of the framed tube along the perimeter of the structure, which transmits the vertical load to the ground.
The likely scenario of failure may be explained as follows…
- FULL TEXT (7 pages, 145k pdf)
- FIGURES (4 pages, 96k pdf)
- ONLINE VERSION (University of Illinois, Department of Theoretical and Applied Mechanics)
- PUBLISHED VERSIONS
- SIAM News, Vol. 34, No. 8, October 13, 2001
- Journal of Engineering Mechanics, Vol. 28, No. 1, pp. 2-6, January 2002
- and many more in different languages.
Note: After September 13, 2001 this press release was circulated around the world by email and over the web, and there soon appeared similar versions of the same basic analysis. For example, E. Kausel of MIT, in spite of his attempts to acknowledge the priority of this article, has been quoted several times (MIT Tech Talk 9/26/01, Scientific American 10/9/01) regarding the predictions of the “two simple models” above.
My father is an expert on structural stability and collapse.
Although he has analyzed the collapse of many buildings in the past, he could never have imagined the gruesome cause and mode of failure of the World Trade Center towers in New York City in the terrorist attacks of September 11, 2001.
Following the initial impacts by hijacked passenger airplanes, thousands of victims within the towers and hundreds of brave rescue workers who rushed to their aid were surprised, and senselessly murdered, by the sudden and complete collapse of both 110 story towers.
The brief article above, written by my father for a press release shortly after the disaster, gives a probable physical explanation for the collapse of these apparently very well designed buildings.
Of course, there is no acceptable explanation for the intent of the terrorists, and their sponsors, to kill so many innocent and peaceful men, women, and children.
See more here math.mit.edu
Header image: Los Angeles Times
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Tom
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Like the JKF murder, we will never know the truth.
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NecktopPC
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Because it would not have been financially feasible for the owner to have all of the asbestos removed from the buildings to have them renovated – and the insurance payout of $3 Billion odd dollars may have been very enticing.
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Herb Rose
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Hi NecktopPC,
Do you really think that the muslim radicals who flew the airplanes into the buildings did so to benefit the jewish owner of the buildings?
Herb
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Size
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You mean the ‘muslim radicals’ who couldn’t even fly light aircraft properly? Those ‘muslim radicals’?
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Howdy
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Last I heard a long time ago, they used M$ flight simulator to become acquainted with controls and procedures.
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Size
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Even experienced pilots couldn’t have controlled jets flying at that elevation and speed. It’s stretching credulity to breaking point to suggest a flight simulator could have equipped novices with the necessary skills.
Howdy
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Odd that pilots have controlled jets at not much greater than take-off speed, and with an engine down at only several hundred feet.
The two jets were apparently traveling at 500 knots plus for one, and 400 knots plus for the other, though of course, that is also contested. Regardless, the aircraft would fly.
“It’s stretching credulity to breaking point to suggest a flight simulator could have equipped novices with the necessary skills.”
I do not believe so.
Howdy
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Airplane Flying Handbook (FAA-H-8083-3B) Chapter 4
https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/airplane_handbook/media/06_afh_ch4.pdf
It’s a pdf that includes slow flying.
Herb Rose
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Hi Size,
The Smithsonian channel has a show called “Air Disasters” where they show te forensic investigation done after airplane accidents. They did one on the plane attack on the Pentagon where the black boxes data showed the pilots put the airplane on autopilot to fly to the area then took control to crash the plane into the building. You don’t need great piloting skill to crash a plane.
Herb
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Size
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Who’s talking about crashing an aeroplane? Of course, that would be as easy as falling off a bicycle. And as easy as erecting a straw man argument. But hey, if you don’t want to address issues, that’s just fine Herb.
Howdy
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The whole thread is about crashing planes, Size.
Above, you said the planes wouldn’t fly, even with an experienced pilot, yet they were crashed. So make your mind up and address what you are actually going on about, because at the moment, your comments are in conflict. Address that please.
Herb Rose
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Hi Size,
There are tens of thousands of people who witnessed the planes striking the buildings,. There are multiple videos from different perspectives showing the planes flying into the buildings. There are thousands of people who lost relatives that were on the planes or in the buildings. Your denials are based on what evidence? You don’t accept evidence and believe what you want to believe denying anything that would show you to be wrong. The world is full of idiots like you that are completely convinced of their infallibility..
Herb
denis dombas
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Herb Rose, so you buy fake government narrative ?Those buildings are brought down by
US government with explosives like thermite and used occasion to invade Iraq and Afganistan, so basically inside job.
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Herb Rose
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Hi Dennis,
I will agree that bldg 7 was demolished by the CIA after the planes hit. They had offices in the building allowing them to install demolition charges and needed a way to destroy the evidence of what they did, if there was an emergency evacuation that left the building unsecured. Do you think that it was the government that crashed the plane into the Pentagon and planned to destroy the capital bldg? Four planes crashed that day, not a coincidence. The plot involved all four planes, not just the ones that struck the towers.. The plane that crashed into the ground was part of the plot but was foiled by the passengers, not the government. People keep coming up with scenarios for different parts of the plot ignoring the entirety.
Herb
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Neil
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I am really surprised that you have chosen to print this article.
The heat produced by aviation fuel and office fires is not sufficient to buckle steel girders.
The collapse of the 3 towers was preplanned controlled demolition, and probably a false flag operation to justify America’s ‘War on Terror’ , and military intervention in the Middle East.
Watch this brief video to see how absurd the official narrative is:
https://odysee.com/@deehinja:5/Corbett911:5
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James
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Steel frame buildings, if they have a steel truss roof, will always collapse even with a small fire, because the hot smoke stays under the roof and the yield strength of the steel drops to below the loads. I’ve seen it happen several times. Usually during construction or maintenance, because a welder starts a fire in the polystyrene insulation, yet to be installed. Something similar happened at Notre Dame in Paris, as cause, but no steel there, just wood. Fire is terrible once it gets going; so buildings must designed so that everyone can get out before collapse. Sooner or later, a fire will start; and it’s not certain that it can be put out. In NY, maybe no one had imagined that type of attack; tons of avker and hot engines, all at once; more than enough to cause collapse.
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Howdy
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Since I haven’t seen anything to the contrary, I have to wonder why the claim that burning fuel was running down the building, didn’t cause fire to appear lower down.
https://www.kxxv.com/news/timeline-of-events-on-september-11
The twin towers were built to withstand a 707 collision, they were hit by, depending where you look, two 757, or a 757 and a 767. 707 has four engines.
https://www.aviatorjoe.net/go/compare/707-320B/757-200/
The main difference between the two aircraft is one is a narrowbody twin-engine aircraft (757) and the other is a wide-body twin-aisle twin-engine jet (767).
https://simpleflying.com/boeing-757-vs-boeing-767/
https://www.airlinerspotter.com/boeing-airliner-spotting.htm
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Herb Rose
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Hi Howdy,
If you look at the image after the impact you can see the outline of thevwings as they penetrated the facade of the towers. Since there was a full load of fuel stored in those wings and forward momentum you would expect the fuel to be inside the building, not running down the exterior.
Herb
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Howdy
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I was referring to the interior, Herb. It strikes me that the claimed temperatures didn’t cause fire on lower floors causing broken windows and such that would be visible. The fuel would find any opening between floors other than those impacted.
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Herb Rose
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Hi Howdy,
The floors were poured concrete and I would presume that they were designed to prevent a water leaks/sprinkler activation on one floor from damaging all the lower floors.
The heat of the fire was going up causing air to be sucked up from below. The high temperature was on the steel beams holding the floor above.
Herb
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Howdy
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Still need cable and service runs through floors, Herb. There’s nothing to say that a sudden influx of fluid under a volume not accounted for wouldn’t overwhelm the expected seals around those services. Were those seals to be displaced…
Indeed, I expect the sprinkler would be catered for by a purpose built drain system of it’s own, rather than chance standing water collection due to no escape route. Still wouldn’t be enough capacity to handle aircraft tank volumes.
Richard
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Office fires can reach 1500 degrees –
“All of our work is guided by a specialist knowledge of how steel is affected by fire damage. Depending on the severity of conditions, a structural fire can exceed temperatures of 800°C or higher. Temperatures of around 550°C will cause a decline in the load-bearing properties of structural steel. Unprotected steel frames can resist fire for approximately 15 minutes. Our team of installers offer a range of solutions to increase minimum periods of resistance, in line with industry fireproofing requirements for structural steel”
The steel in the twin towers were not protected all the way to the top .
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Richard
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“During a fire event, a steel structure will suffer from material property changes, such as thermal elongation, strength reduction and a reduction in stiffness. The steel would lose the strength of its yield and buckle, causing it to bend, twist and eventually collapse”
https://fire-proof.co.uk/resources/impact-of-fire-on-structural-steel#:~:text=During%20a%20fire%20event%2C%20a,bend%2C%20twist%20and%20eventually%20collapse.
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Richard
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The time the towers collapsed after being hit – 1hr 30 mins and 55 mins – would indicate a buckle
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VOWG
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I do not believe in the BS of the government taking down the buildings. Anyone who watched this knows what brought the buildings down and killed about 3000 people. Idiots need to wake the hell up and stop with their stupidity. Yes, jet fuel can melt steel. Those who think otherwise need to be reeducated.
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denis dombas
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Not concrete encased steel WOWG, so learn something before you call people idiots, shame on you!
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VOWG
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They were not all encased in concrete and have you ever seen melted bricks from a natural gas fire. The structures were not as you think they were.
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Size
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Nothing mentioned here… fuel ‘trickling down’, jet fuel ‘melting steel’, steel ‘losing strength and eventually buckling’, a ‘decline in the load-bearing properties of steel’, the ‘outline of thevwings as they penetrated the facade of the towers’ (?), etc, etc, accounts for the free-fall velocity of these buildings, not to mention the and farcical Building 7 demolition. Hello?
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Joseph Olson
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“Unequivocal 9/11 Nukes” > “Breathtaking: Solving Nuclear 9/11” >
“Exposing NIST Jenga Game” > VeteransToday.com
https://bitchute.com/video/qsSdSIWX9Jxl/
Thousands of hours research by a structural engineer
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Mario M
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Actually NO PLANES FLEW.
It is impossible to pilot such a machine with only few lessons on small aircraft, and there are plenty of other reasons that exclude any aircraft.
Miles Mathis has investigated on the identity of several supposed passengers and discovered they were faked.
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Joe
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Three months before the Towers cane down the contact to service the elevators was changed from Otis Elevator, who installed the elevators, to Ace Elevator . So, for three months, 87 people had access to all the shafts of the buildings….and nobody batted an eye!
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T. C. Clark
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Concrete does not like heat any more than steel likes it, no? I believe a duplicate of the Twin Towers could be collapsed by over weight alone….just load lead bricks on to an upper story until it collapses on to the floor beneath which would also fail and the cascade has begun to collapse the whole building….I doubt that any doubters would agree to stand on the roof while this little experiment was conducted….maybe contact the Crop Circle people…..I bet they know what happened (snicker).
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Herb Rose
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An overpass on I=95 has just collapsed due to a fire from a tank truck accident. The overpass has prestressed steel reinforced beams a yard thick supporting the roadway made from steel reinforced poured concrete over a yard thick. Even though the underpass was well vented the fire caused one section to buckle and so weakened the other lanes that they also will have to be demolished and rebuilt. For those who don’t believe a fuel fire (less fuel than in the airplanes) could cause a collapse due to heat come to Philadelphia and take a drive on I-95.
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