Posted by JohnMV. on September 24, 2001 at 01:01:46:In Reply to: Re: WTC Collapse posted by John A. Giambalvo on September 23, 2001 at 11:32:40:
Are you really an engineer? The design of the WTC Preformed beyond what was expected or needed. The building, designed in the 60's was able to take the impact of a 767. I will tell you, because you clearly don't know, a 767 has a wingspan of 181 feet, it is 203 feet long and, full of fuel is over 600,000 lbs. It can travel over 500 mph and carries over 45,000 gal.. of jet fuel. An engineer can calculate the force of impact and the amazing stress on a building of that height (hit high) The fact that it did not fall over, but took the hit is amazing, the fact the many of the egress stairs were not penetrated is also a sign ow what a good design it had. The "tube" frame was able to take most of the energy of the impact, and while it proved to be fatal, the steel had the ability, as a result of the "tube design" to allow the core to -work- as it was designed to, and evac everyone who reacted quickly to the emergency. I know, my father was on the 91st floor of WTC2 and he was able to get out, and get to 14th street before it fell. He was sure that 3 of the 4 main stair towers were lit, and without smoke, even after the 2nd jet hit. As for fire sprinklers; jet fuel has an octane of 103 to 109, that is a fuel that is super efficient in it's use of oxygen and it needs very little to burn. Water will do nothing! in fact, at that temp (over 2200F) water will evaporate about 3 feet from the sprinkler head, and NEVER hit the steel. Halon, what the WTC used for fire suppression in emergency was not triggered. This is why, Halon is a chemical that eats oxygen, and starves a fire. In the case of a fire that risks structural failure, the halon is used, it will kill everyone on the floor, no oxygen, but the building will stand. Now they could have shot off the halon, and killed 1000's of people that were on there way out, but that would have done NOTHING for the fire, you see, the huge HOLE in the side of the building would supply all the oxygen the fire needs no matter how much halon you pump in. The halon would have clearly killed 10's of 1000's more. It was right to not use it. -back to the building; now with over 40,000 gal of fuel, sprayed evenly all over the surfaces both in and out, I am amazed that the building did not fall sooner! Jet fuel burns VERY HOT, and temps of over 10,000 F were easily reached. With a 2" cover of fire proofing (that was soaked with jet fuel), the steel lasted almost an hour. This is not luck, or voodoo, it is a result of good design, a design that allowed the tube-steel frame of the exterior to translate the load to the center core and use the slabs as transfer beams. This dynamic allowed for a temporary "truss" to be formed with slabs and core moving the load from the perimeter frame, where damaged to the center, than back out to the tube frame. If the jets were not going to California and did not have full tanks, or if parts of the jets missed the building and did not all enter the structure, the towers may have had a chance, but given the volume and octane, they had no chance, and despite that, more people got out than I think anyone expected. The WTC preformed, yes it did, it Preformed amazingly well.
I am a PE and RA, in NY,NJ,CA,AZ and VA
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