A 9-11 Conspiracy

Originally Posted by Phil

So, these buildings mark the first total collapses due to steel encountering fires. The first problem with this is that there have been hundreds of fires before that have lasted for many hours and never resulted in anything even remotely close to the behavior seen in buildings 1, 2 and 7.

http://www.whatreallyhappened.com/IM...sor.fire.1.wmv
Now that’s a raging inferno, and shows what steel looks like when it finally weakens enough to collapse.

The argument of lacking fireproofing material or that jet fuels fires are much hotter are laughable. Steel has a melting point of 2750F. Jet Fuel fires at absolute maximum could not peak past 1800F. Not only that, but those extremely hot fires last no more then 10 minutes. Regular office fires run anywhere between 400-1200F depending on concentration and what is being ignited. Important to note is the mass amount of black smoke coming from WTC2 before it’s collapse. That is a clear sign of oxygen-deprived fires that are having a hard time surviving.

I'm actually curious, what does the melting point of steel have to do with mechanical faliure?

How ya doing, buddy?

See, the thing is, you don't need a metal to melt in order for mechanical failure. Once you hit halfway to the melting point you have to start to worry about increased fatigue and at 70% you're going to get creep and lots of slip going on.

Of course, there's also the phase transformation from ferrite to austenite at 1330°F which makes the steel go from a BCC crystal structure with a lattice constant of around 0.2866nm to austinic FCC with a lattice constant of 0.3605nm or so. That's around a 20% mismatch. Add on to that austenite's higher ductility over ferrite and you get a good reason why a building could collapse well below steel's melting point.

One of the main reasons cited as to why it's not seen in other large buildings during fires is that in this fire, the heat resistant coating around the columns had been blown off during impact. So without both the structural support of the concrete around the steel and its insulating properties, the steel was just sitting there failing.

Also, I believe the explanation for the building collapsing before the stuff on top of it is because of a pressure wave travelling down inside of the building. Much like how when you drop a book there's a high pressure zone underneath the book and a low pressure area above it, air would be forced down infront of the collapsing structure causing those exposions seen in the lobby (air getting pushed down an elevator only has so many places to try and escape).

There's nowhere I can't reach.

God damnit, accidentally his back and lost the whole post I had written. It's going to be a bit more concise this time, I guess.

I was curious about this article the professor you seem to have copy and pasted most of your arguments from. After a bit of googling (his in-text citations weren't exactly the best) I was able to find the article he refers to. http://wtc.nist.gov/pubs/NISTNCSTAR1Draft.pdf

His use of elipses and boldface font really do help his argument out.

Let's take a look one of those lines I saw particularly interesting when viewed with the rest of NIST's response.

Quote:

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; emphasis added.)

So there's what he cited. But, perhaps conveniently, he left out the last part of that bullet.

Quote:

NIST did not generalize these results, since the examined columns represented only 3 percent of the perimeter columns and 1 percent of the core columns from the fire floors.

I'd also like to note that his page citation is incorrect, the previous paragraph actually occurrs at the bottom of page 88 of the report and nowhere else. Most certainly not page 176/177, though they do have some stuff I'll hit later

And, let's look at the paragraph following that one.

Quote:

These results were for a very small fraction of the steel in the impact and fire zones. Nonetheless, these analyses indicated some zones within WTC 1 where the computer simulations should not, and did not, predict highly elevated steel temperatures.

(emphasis mine, obviously)

Oh my, what's this? Finding that those beams weren't really hot actually reinforces their predictions. Guess leaving parts of paragraphs out is a really good tactic.

Quote:

Further, FEMA states jet fuel fires are not enough to make a building collapse but the overall normal office fire is.

Well, let's see why they say about that (pardon any typos, the FEMA document doesn't allow copy+pasting).

Quote:

However, as the burning jet fuel spread across several floors of the buildings, it ignited much of the buildings' contents, causing simultaneous fires across several floors of both buildings. The heat output from these fires is estimated to have been comparable to the power produced by a large commercial power generating station. Over a period of many minutes, this heat induced additional stresses into the damaged structural frames while simultaneously softening and weakending these frames. This additional loading and the resulting damage were sufficient to induce the collapse of both structures.

http://www.fema.gov/pdf/library/fema403_ch2.pdf

As any person worth their salt that deals with materials knows, pure temperature alone isn't enough, time is crucial as well.

Oh, and as for your MIT professor, might want to read what he had to say in context as well.

Quote:

Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.

The additional problem was distortion of the steel in the fire. The temperature of the fire was not uniform everywhere, and the temperature on the outside of the box columns was clearly lower than on the side facing the fire. The temperature along the 18 m long joists was certainly not uniform. Given the thermal expansion of steel, a 150°C temperature difference from one location to another will produce yield-level residual stresses. This produced distortions in the slender structural steel, which resulted in buckling failures. Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire.


http://www.tms.org/pubs/journals/JOM...agar-0112.html

He also decides to comment on the 'implosion issue' you're talking about.

Quote:

It has been suggested that it was fortunate that the WTC did not tip over onto other buildings surrounding the area. There are several points that should be made. First, the building is not solid; it is 95 percent air and, hence, can implode onto itself. Second, there is no lateral load, even the impact of a speeding aircraft, which is sufficient to move the center of gravity one hundred feet to the side such that it is not within the base footprint of the structure. Third, given the near free-fall collapse, there was insufficient time for portions to attain significant lateral velocity. To summarize all of these points, a 500,000 t structure has too much inertia to fall in any direction other than nearly straight down.

So, yeah, please check your facts next time.

Also, lollin' at how the guy you're copying the original argument from doesn't even have support from anyone in the civil/structural at his own university.

Edit: Screw you guys for ruining the thread even more and making styphon close it. >=(

This thing is sticky, and I don't like it. I don't appreciate it.