Learn to use Google.
Its pretty simple, the towers were actually designed to withstand a commercial airliner strike, which they did perfectly well, however the subsequent fire caused severe structural damage which resulted in a collapse.
The reason for that is because during the towers construction the American environmental agency banned the use of asbestos in construction, as a result only the lower halves of the towers got asbestos spray coating on their steelwork, the construction couldn't wait around for an acceptable replacement for asbestos so the rest of the buildings were completed without fire protection on the steelwork (building would never have gone ahead if the was no protection in the original plans).
Had the towers steelwork been properly protected against fire then it would have given the occupants more than enough time for a full evacuation and its believed it would also given the fire suppression system and the fire crews enough time to save the towers.
NB: it would actually have been perfectly safe to continue the spray coating on the rest of the building as the workers used filtered masks which would have protected them sufficiently form breathing in any asbestos dust which would have been difficult anyway as the spray was wet, but a blanket ban was in place.
how the hell could they test or even calculate that a building could withstand such an attack by such a plane at such a speed and at such an altitude?
Oh god you've been on conspiracy sites.
how the hell could they test or even calculate that a building could withstand such an attack by such a plane at such a speed and at such an altitude?
No way could they do that.
the steelwork WAS sprayed with the asbestos replacement as far as i'm aware. it's just that almost nothing on earth is as good as asbestos for insulating things and retarding fire.
That's not a conspiracy theory, just facts about the buildings construction, in fact it actually de-bunks a few conspiracy theories (like why a tower designed to survive a commercial airliner hit was toppled by a commercial airliner hit).
Except that they did a fire test on an abandoned hotel in the UK that used the same steel construction as the towers
And they discovered that in their tests the towers should not have fallen even without fireproofing on the steel work.
The WTC as such were never designed or built with this in mind. You need to check your facts, as they are plain lies and you won't find any evidence to back up your claims.
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 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."
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."
FFS show some respect, almost three thousand people lost their lives in the event![]()
You mean plane-proof???![]()
9th of November, I might have been thinking about my birthday on the 28th not sure.