Electron microscope analysis of steel spheres from WTC site

[kerowo]

Something must be wrong with them because your conclusion is wrong. Unless your conclusion is "I'm a kook."

[Phil153]

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is nothing wrong with the above 5 statements?

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No, people are just tired of wankers and have better things to spend their time on. The people who believe in the conspiracy are never going to have any impact on the world anyway (since they're mostly morons), so it's not worth anyone's time.

But I'll humor you this time...

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the temperature of burning jet fuel (kerosene) is about a thousand degrees below the melting point of steel.

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What does that have to do with anything? The melting point of steel is irrelevant, it's the weakening point which matters. If you want to see how heat weakens steel, try this:

Get a piece of wire, grab both ends, and vigorously bend it back and forth. The bend point will heat up to a couple of hundred of degrees C, and the wire will snap easily after a minute of so. Now try the same thing with the bend point immersed in water. You'll never snap the wire. Even low temperature weakens steel immensely.

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the fires were producing rich black smoke, indicative of fuel-rich, oxygen starved, cool burning flames.

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Cool burning? I invite all conspiracy believers to jump into a "cool burning" fuel rich fire. The fires were many hundreds of degrees, and most importantly high heat (which is not the same as temperature). As for the black smoke, that can be caused by burning around the edges, by office furniture, and so on. Black smoke proves nothing.

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the fires burned for only 56 min, and 1:23 minutes in WTC2 and WTC1 respectively, while the steel was certified to withstand 2000 degree fires for 6 hours.

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Link to evidence please. I would like to see how steel can withstand 2000 degree temperatures for 6 hours. As evidence of fire weakening steel, have a look at this story about a bridge collapsing after a tanker fire weakened the steel:
http://www.cbsnews.com/stories/2007/...n2739222.shtml

This is a low temperature, low heat (do you know what the difference is?), open air fire, and it collapsed a steel bridge designed to take hundreds of tons.

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in the history of high-rise buildings, number that have went down due to fire aside from 9/11: 0

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In the history of high rise buildings, number that remained standing after a 767 hit them at 500mph: 0

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both WTC building were designed to withstand a jumbo jet crashing into it - yet they went down at freefall speeds.

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1. They DID withstand it, dummy, as evidenced by the fact that they remained standing for an hour after impact.
2. They did not fall at freefall speeds.


You're welcome.

[Bill Haywood]

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the temperature of burning jet fuel (kerosene) is about a thousand degrees below the melting point of steel.

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You have not heard the response to this? It burns plenty hot to soften and expand the steel, which is all it took. There was something about floor supports sagging and coming out of their fixtures.

[bunny]

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Cool burning? I invite all conspiracy believers to jump into a "cool burning" fuel rich fire.

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[img]/images/graemlins/grin.gif[/img]

[Kaj]

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the temperature of burning jet fuel (kerosene) is about a thousand degrees below the melting point of steel.

...

*please point out if any of these above are wrong

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I'll easily refute this one (although Bill already did). Any documentary of 9/11 that is promoting this ridiculous argument is either produced by morons or those advancing an agenda by appealing to morons.

A 2 second Google on high-temperature material behavior reveals something like this for engineering metals:



Notice the massive drop in strength starting at 1200 degrees? Well guess what -- the melting point of this alloy is 2300-2450 degrees. This is typical behavior. Do you really think steel is as "strong as steel" right up until its a melted pool of sludge? Knowledge of high-temp loss of strength of metals should be elementary to even an undergraduate in mechanical engineering. And yet I've heard it from 9/11 conspiracy theorists at least a half dozen times.

[jono]

According to Engineering and Technical Handbook by McNeese and Hoag, Prentice Hall, 3rd printing, September 1959: page 47 (Table) Safety Factors of Various Materials, the mandatory safety factor for structural steel is 600%.

The Corus page on fire vs. steel supports (http://www.corusconstruction.com/fire/fr006.htm) shows that the steel would have to be heated to about 720 degrees C (1320 F) to weaken the steel to 20% of its cool strength.

-this would still enable the towers to handle the load
-the fires did not reach these temperatures anyway
-Phil, your example is comparing apples and oranges. Find me an example with a skyscraper

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Intense fires lasted only minutes

The NIST report states that: “The initial jet fuel fires themselves lasted at most a few minutes and office material fires would burn out within about 20 minutes in a given location." (NIST, 2005; p. 179.)

This is further corroborated by the fact that intense dark choking smoke was being emitted from the towers before they collapsed indicating the fires were oxygen starved and burning at low temperatures.

In addition NIST stated that of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250ºC… Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250 ºC. … Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600 ºC. (NIST, 2005, pp. 176-177)

At any given location, the duration of [air, not steel] temperatures near 1,000 C was about 15 min to 20 min. The rest of the time, the calculated temperatures were near 500 C or below.” (NIST, 2005, p. 127, emphasis added.)

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http://wtc.nist.gov/solicitations/wtc_awardQ0281.htm

What about all the other inferiorly built skyscrapers that burnt for much longer with hotter fires but did not fall?



20+ hours burning at 800 C and did not fall

http://www.whatreallyhappened.com/spain_fire_2005.html (one of MANY examples)

[oe39]

are you trying to conclude that these buildings are still standing?

THAT would be a cover-up

[jono]

Your use of sarcasm to try to divert attention away from my post only strengthens my position. I am providing data and research, not weak humor.

[kerowo]

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I am providing data and research, not weak humor.

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No, it's pretty funny how you think there was some conspiracy involved in this. Not always Ha Ha funny, but still funny.

Makes me feel better about myself that there are maroons like you out there.

[Kaj]

Jet fuel burns at 800° to 1500°F, not hot enough to melt steel (2750°F). However, experts agree that for the towers to collapse, their steel frames didn't need to melt, they just had to lose some of their structural strength--and that required exposure to much less heat. "I have never seen melted steel in a building fire," says retired New York deputy fire chief Vincent Dunn, author of The Collapse Of Burning Buildings: A Guide To Fireground Safety. "But I've seen a lot of twisted, warped, bent and sagging steel. What happens is that the steel tries to expand at both ends, but when it can no longer expand, it sags and the surrounding concrete cracks."

"Steel loses about 50 percent of its strength at 1100°F," notes senior engineer Farid Alfawak-hiri of the American Institute of Steel Construction. "And at 1800° it is probably at less than 10 percent." NIST also believes that a great deal of the spray-on fireproofing insulation was likely knocked off the steel beams that were in the path of the crashing jets, leaving the metal more vulnerable to the heat.

But jet fuel wasn't the only thing burning, notes Forman Williams, a professor of engineering at the University of California, San Diego, and one of seven structural engineers and fire experts that PM consulted. He says that while the jet fuel was the catalyst for the WTC fires, the resulting inferno was intensified by the combustible material inside the buildings, including rugs, curtains, furniture and paper. NIST reports that pockets of fire hit 1832°F.

"The jet fuel was the ignition source," Williams tells PM. "It burned for maybe 10 minutes, and [the towers] were still standing in 10 minutes. It was the rest of the stuff burning afterward that was responsible for the heat transfer that eventually brought them down."

http://www.popularmechanics.com/tech...42.html?page=4