How hot were the fires in the World Trade Center?

First, jet fuel burns at 980 degrees Celsious well below the melting temperature for steel which can range from 1400 to 1600 degrees Celsious. One important thing to remember is that steel does not need to melt in order to fail it only needs to be weakend. As you can see in the phase diagram below once plain carbon steel (similar to that in highrise construction with less than 2.03% C) is heated above 723 degrees Celsious it becomes austenite and shifts from body centered cubic to face centered cubic. This transition and the fact that it is about 3/4 of its melting temperature would make the building to weak to support the 30 or floors that were above where the plane crashed. This also explains how the building collapsed. The top floors all fell together do to the support failure and then peeled the rest of the building down.

I claim no knowledge of "the temperature of combustion" of Jet fuel, but as a child I spent many hours watching a blacksmith soften steel plowshares etc. with nothing more than charcoal and a lot of air. I also have done glassblowing where simply blowing through a small hole using lung air (which has already been partially depleted of oxygen) increases the flame temperature sufficiently to melt a local area of glass. In those towers the fires would induce their own winds, which surely would have caused increased local heating in some areas. With that much weight above, a single beam being weakened could easily initiate collapse.

There are some facts that should be understood. The Towers had no heavy steel beams or columns. The supporting structure was the outer walls, which formed a rigid box. The walls were held in a vertical tube shape by floor trusses, which were made of thinner rods in a truss construction.

As I understand it, the collapse happened thusly:

1 The blast removed the asbestos fireproofing

2 The jet fuel ignited massive fires of all combustible materials in the building

3 The heat made the now exposed floor trusses soften and sag

4 The sagging trusses broke the connecting bolts to the outer walls

5. Once the outer walls were not held in a vertical box shape, they bulged and were too weak to hold up the upper portions of the walls.

6. Once the upper walls and floors started to accordian, the weight and momentum continued the vertical collapse.

I believe another consideration is that the asbestos did not go all the way up. It was during construction of the towers that asbestos was being considered a safety hazard and it's use became restricted. Alternative "fire-proofing" materials were used at the top of the towers but they were not as effective as asbestos. What irony that we try to save ourselves from cancer and end up thus!

First, I believe those are ignition temp.s.
They bear little relation to the heat produced by combustion.

Second, as pointed out elsewhere, the strength of steel is reduced as
temperature rises. The melting point need not be closely approached
to cause structural failure of stressed steel. Thats why building steel
is insulated, and why there was so much asbestos in the buildings.

(IIRC the stuff was banned during the construction and there was
quite a scramble to find a substitute material as effective.)

Unfortunately the internet allows anyone to produce a nice glossy statement
of half truths or outright nonsense, and our ingrained respect for the printed
word renders us vulnerable this behavior.

I suggest you post a debunk of this where-ever you saw it.

They do seem to be in the range of ingition temperatures! That is probably what they are - rather than an actual flame temperature.

Getting that Wiki article on jet fuel made clearer would be the first step.

Got any good sources to refer to?

Sorry, I was so annoyed at the article cited, I forgot to address
your origional question.

The simplest and most undeniable 'debunker` available is simply
to refer to the orange-yellow color of the flames observed both
at the WTC incident and wherever hydrocarbons are burning in general.

That color is carbon radiating a color temp. well above 2000 Deg. F.

If you keep it that simple then even the idiots will understand.

Here's some reading for you. Your "debunker" just got debunked!

http://en.wikipedia.org/wiki/Flamed

http://www.ae911truth.org/news/41-articles/351-advanced-pyrotechnic-or-explosive-material-discovered-in-wtc-dust.html

http://www.doctorfire.com/flametmp.html

http://www.ae911truth.org/