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NIST Releases Report On WTC 7 Collapse
photonic writes "After three years of study, the National Institute of Standards and Technology (NIST) finally released its report on the collapse of World Trade Center building 7. The main conclusion is that the building came down due to fire, not due to debris damage or some conspiracy demolition team. The fire started pretty small after the collapse of WTC 1, but was left to burn several floors out completely. The important finding is that the collapse was triggered by thermal expansion of beams, which could detach asymmetrically loaded girders from the main columns. Some limited pancaking of floors then caused a lack of lateral support and buckling of a single column. This triggered the failure of the entire core of the building, which finally fell down as a single piece. Crackpot theories can be discussed elsewhere; please limit the discussion to the science here. All documents can be found at NIST's WTC page, which read like a porn magazine for finite element junkies. Simulation movies are also available. And yes, they used Beowulf clusters to do the simulations, some of which lasted for several months."
Not long after this shit, there was a building in Europe, where the fire was so intense, it burned everything off. The steel structure was still standing [...]
I'm pretty sure you're talking about the Windsor building in Madrid.
I've got news for you, buddy: It actually works against you.
First, the Windsor building had a concrete core and two concrete technical floors. A very different design from that of the Twin Towers.
Second, the steel portions of the building exposed to the fire did in fact get all melty and collapsey. The only reason the building is still standing is because of the features I mentioned above.
http://www.911myths.com/html/madrid_windsor_tower.html
http://www.debunking911.com/madrid.htm
People will pass up steak once a week, for crap every day.
About 23,000 gal. of diesel fuel was stored in the bldg, mainly on the bottom floors but some as high as the 7th. "Several months after the WTC 7 collapse, a contractor recovered" the fuel from the tanks and, "unaccounted fuel totaled... somewhere between 0 and 2,000 gallons..." And "The worst-case scenarios associated with fires being fed by ruptured fuel lines-or from fuel stored in day tanks on the lower floors-could not have been sustained long enough, could not have generated sufficient heat to weaken critical interior columns, and/or would have produced large amounts of visible smoke from the lower floors, which were not observed."
http://www.nist.gov/public_affairs/factsheet/wtc_qa_082108.html
Anyway, steel bends in fires, that's why it has to be insulated and why steel bldg's must have sprinkler systems. I doubt the fire dept. was able to respond effectively in time.
This is pretty simple math; the weight increases with the cube of the scaling factor as you scale up a model, yet the strength of the materials used only increases with the square of the scaling factor since it depends on the area of the cross section of the member.
I saw the video link, it might be helpful to you to be accurate and precise with what the owner said when you report. The owner said the firefighters had come to him and said they couldn't sustain the effort needed to control the fire and that they should pull "it". The "it" referred to the effort to control the fire, not pull the building down. The firefighters were admitting what they were doing was ineffective and they couldn't sustain the effort. They concluded there was nothing they could do so they told the owner they'd pull out the effort spent on the building.
The abutment of that clip with the building collapsing is misleading as is the whole clip. It is just someone's effort for 15 minutes of fame and nimrods like you help him...pathetic...
Gerry
Um, fires can pretty much bring down every building without some sort of suppression.
The sole exception is concrete, which can leave a hollow shell. Of course, no one on earth can build a 47 story concrete building.
Any building with steel as part of the support, on fire long enough, is eventually going to see that steel buckle, which will bring down the building. You can't just let tall buildings burn and then walk in the next day with new paint and furniture.
When they build steel buildings, they spray insulation on the steel to keep it intact during fires. For the WTC7, that was something called 'Monokote', which is rated for three hours for steel columns. (There is an entirely different 'Monokote' which is just a kind of plastic shrink wrap. Don't get confused.)
This would have been more than enough if the fire-suppression systems had been working, but they were not. It is also why the firefighters pulled out when they did...enough of the steel had started to buckle that the building was listing to the side.
If corporations are people, aren't stockholders guilty of slavery?
Ugh, ok, I'm tired of this, so let me explain to you exactly how the building collapsed from my perspective, watching it across the Hudson a few miles away, and then seeing it up close on the news:
Pancaking, a term which you completely misunderstand, is the event which occurs when you cause the upper floors of a building to collapse suddenly. You question how the fire in the upper floors weakened the lower floors. The answer is that it didn't have to. When the upper floors gave way, they impacted the floors directly beneath them. The kinetic energy that is gained by those floors basically free falling 1 story down is immense, and this cause the floor beneath, also weakened by the fire, to collapse, and so on this process went until it reached low enough that the floor beneath the collapsing floors was undamaged by the impact or fire.
The problem though is two-fold: first of all, those collapsing upper floors sent a huge shockwave of compressing air down the elevator shafts and stairwells, blowing out the windows on the floors below and causing some very minor structural damage. No big deal, but it's what makes people think the lower floors were "blown out". The big thing is that by this point, the upper floors have gained such an incredible amount of momentum from their falling, which is only increasing with their mass, that the lower floors have no hope of "catching" them. I say "catching" because they're not supporting them, they have to stop them from a freefall, and stopping an object in motion, especially an object composed of tons of concrete and steel falling directly downward, requires more structural integrity than any skyscraper has.
This is why the Windsor building is a poor example. This event did not occur. It was the WTC's own height working against it, giving the collapsing segments more and more mass until it was enough energy to break through the structurally sound floors.
People who claim there should have been a core, or or more left of it are people who try to compare this to other events, and often lack an understanding of physics and engineering. ALL of the steel in the WTC towers did not have to melt or be weakened. Only a small portion, in a small area, had to be structurally weakened enough to give way. The rest is simply F=ma
Presuming, of course, that such efforts existed.
"Uncontrolled" collapses of very large buildings are exceedingly rare events, so nobody would really know a priori how the WTC collapses "ought" to have looked. After the fact, the way the floors pancaked doesn't seem at all improbable. As the force of the collapse propagates downward, it meets elements designed to spread a fraction of a single floor's weight onto vertical supports. Since the force of the collapse would be orders of magnitude greater than what these elements were designed to support, it seems probable that they would impede the progress of the collapse to about the same degree that a cloud of smoke would impede a lazily swung sledgehammer.
Of course, this is just after the fact rationalization, but the engineering analysis confirms it the intuition that no special measures would need to be taken in order for the collapse to proceed in a way that superficially resembles a controlled implosion.
This conspiracy theory has the usual problems of conspiracy theories, such as providing what mystery writers call "motive, means and opportunity". Motive is a particularly vexing issue, given that seven buildings were destroyed past recovery and numerous other ones damaged, it's hard to connect the end result to the purported motive. Another commonsense question would be whether a government that could not keep Abu Ghraib, Guantanamo, Echelon, or warrantless surveillance under wraps could have engaged in what must have been a substantial engineering effort on three busy Manhattan buildings without anybody noticing.
The real appeal of any conspiracy theory is this:it provides an illusion of control. Limited control, that is certain, but the seat of the pants risk evaluation is actually quite astute: if it were some cabal of government officials, you'd actually be less exposed than if twenty men, each armed with a tool costing $1, could kill nearly three thousand people and bring the country to a virtual standstill for weeks.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
God I get sick of this. Same arguments again and again, 7 years now, 7 years and we are still faced with the same psuedo-scientific babble.
I'm afraid I'm going to have to summarise here. Steel does not need to be 'melted' to be weakened well beyond safety margins, and beyond its required design strength. At moderately high temperatures it is weakened significantly. Go look up a materials handbook or two. The buildings collapsed in an entirely ordinary and predictable manner, they did not 'free fall'. Structures such as that are designed to collapse pancake style, like a concertina, they do not ever topple over. Can you imagine the extreme dangers that a toppling building of say 110 stories would pose to say, half of the surrounding CBD? The bomber in the 40s was not a jumbo jet, not even remotely close, there weren't even planes that big built back then. Neither did the planes that existed in those days have the same high strength materials embedded in them as in this case. I believe the NIST report suggests that elements such as the titanium axles used in the engines caused significant structural damage to the building core in certain places.
You *are* peddling a conspiracy theory. Multiple investigations and simulations have drawn the conclusion that the buildings fell down as a result of the observed evidence: Two fucking giant jumbo jets flew into them. Occams razor my friend. And you are here jabbering on repeating the same debunked theories of a small group of complete crackpots in the face of it.