Posted on 08/21/2008 3:19:07 PM PDT by yankeedame
Bookmarking. Thanks!!
The troofers know the troof...
The truthers forget that Popular Mechanics is a very highly respected magazine.
FIST BUMP
Your cutting torch is a controlled burn, and it burns at 5800 to 6300 degrees. An open air fire, which is what any office building fire is, burns at between 1200 to 1500 degrees.
The temperature of an open air fire, like what happened at the WTC, is between 1200 and 1500 degrees. At a steel plant, a controlled burn occurs in a closed furnace in order to melt the steel. Much higher temperatures occur in a furnace.
NIST my a$$! Who are these guys at NIST? What qualifications do they have to make this sort of judgment? Have they ever been a nationally syndicated talk show host? Have they?
I rest my case! </Rosie>
Steel melted, trust me. Rosie O’donut is an idiot. What happened was the pins holding the structure together softened and that caused the buildings to fall. Don’t tell me you actually think Bush and the boys brought the trade center down and the planes were just for show?
My point was that her claim that flame had never before melted steel is false. I do realize that the flame is hotter in the torch, but it is a flame.
I will say that it is not necessary for a fire to actually melt the steel for the building to collapse. All that is necessary is for the steel to be weakened enough by the heat so that it cannot support the weight it holds up. This happens all the time during fires in structures with steel beams and columns. It is nothing new.
Underwriter's Laboratories (UL) tested the steel beams from the WTC buildings. They heated it to 2000 degrees for two solid hours, and "it did beautifully". Keep in mind the temp of an open air fire is between 1200 and 1500 degrees. That's the temperature of the FIRE, not the steel itself. The fire in WTC 7 was billowing black smoke, indicating that it was oxygen starved, so it wasn't even 1200 degrees in there. NIST's report on this just leaves more questions.
Oh, I know steel melted. FEMA's report said, "Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure. A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel… The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified." I don't know if Bush was involved or not, but I do know fire alone didn't bring that building down at a free fall speed all at once. If you believe pins failing made building 7 fall at free fall speed, that sounds like more of a conspiracy theory to me.
I have no problem believing a fire, even a black smoking fire as you say was the case at WTC7, caused the collapse.
I am a licensed Mechanical Engineer, was a firefighter for 5 years earlier in my life, and worked at a coal burning power plant where we dealt with fire and flame damage in boilers.
Beams and columns loaded with weight carry stress. Add the stress of restrained thermal expansion and the weakening of the steel with temperature, and you have a perfect recipe for sudden building element failure that will then overload the next element, and the domino effect happens. I have seen single story steel buildings collapse and crumble during a fire due to these effects.
What did the NIST mean by "it did beautifully"? Material tests under lab conditions may not have simulated the actual conditions of the first building element to fail in the field that day.
The bottom line is, I do not see anything but a building failing due to a fire and damage from what went on in adjacent buildings that day. Any other conclusion is bordering on paranoia.
I wouldn't have much of a problem with it either, if it hadn't fallen the way it did, and as fast as it did. I wouldn't have expected such a straight down descent like we see in all the videos. I have no doubt that a domino effect can happen, but each floor would meet resistance when it hit the next floor and that would prolong the collapse. You are right the lab conditions did not accurately simulate the conditions on 9/11. The fire they applied was not oxygen starved and burned hotter. I don't think questioning the official story is paranoia. I think too many questions have not been answered.
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