Behavior of steel framed structures under fire conditions.

All jet engines require high temperature gas for good effiniency, typically achieved by combusting hydrocarbon or hydrogen fuels. Combustion temps can be as high as 5000 degrees F, above the melting point of most materials

.
www.solarnavigator.net/aviation_and_space_travel/jetengine.htm
That if from just one web sight that I have found. the temps quoted there are even higher than my original source. Also I think you may misunderstand me. I never said that the steel was melted...I just think that it got hot enough to significantly weaken the steel to the point that even the built in safety factor could not prevent the collapse. Every fire training book that I have looked at states that steel will weaken above 1000 degrees.. I just have a hard time beliving that this was just made up.

Another source I found was a test that they conducted in Prague for hydrocarbon fires in tunnels...They achieved temps of 2480 degrees F just from 396 gal. of gasoline. This was a independent test not even connected to 9/11. Jet fuel burns hotter than gas. ..
www.ita-aites.org/cms/fileadmin/filemounts/ovion/doc/safety/prague/HI&AL.pdf

In the controlled demo thread you have some excellent pics of a beam that was sulfidated..Hats off by the way...In that thread you stated that for this to have happened the temp would have to be above 1832 degrees F (1000 degrees C ). And this was up and down the entire beam, which indicates that the beam was at some point totally emersed in fire. Could not the temps from everything burning ie. paper, carpet, plastic, foam, the fire load if you will.... get hot enough to weaken steel, enough of the steel to override to built in safety factor?

In our training burn building...we have gotten temps as high as 2000 degrees at the ceiling.....off of ordinary combustibles ie wood pallets.

Also fires that are hot enough and big enough, with enough fuel to burn, will "create" their own weather. For example..the wildfires that are presently going on will "feed" themselves..create their own wind...pulling back in the hot air and products of combustion. I have seen this..to a much smaller scale.. in large aparment fires. Do you think that it is possible that there may have been enough structure left to create the insulating effect that you mentioned?

The part about paper, well...I looked at serveral of my books...and googled it....451 degrees F was the given figure from numerous sources


bsbray11,
Jet fuel ( JP4 is what I looked up ) can burn up to temps of 2700 degrees F (1422 Degrees C ). Paper burns at 451 degrees F (232.7 degrees C )

Where'd you get this? Because even Popular Mechanics disagrees with you:

Jet fuel burns at 800° to 1500°F, not hot enough to melt steel (2750°F).

www.popularmechanics.com...

I could find you other sources if you also believe that PM is a bad source, because there are also plenty of legit ones.

In an open atmosphere environment, jet fuel is not going to burn at 1422 C. Not even close. Hydrocarbon fires all max out around ~820 C. That's in ideal conditions. If you have not-so-good conditions, like not enough oxygen, then you get sooty smoke, and that's uncombusted particles and it serves as a heat sink and etc. Those are what the WTC fires looked like, and those are more around 700 C. But around 820 C is about the absolute max in an open environment, where air is flowing and smoke is pouring out and etc. To get any hotter, you're pumping hot air into it and insulating it or something.









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[

[edit on 21-8-2007 by six]

Some how the above post was not how it was supposed to look..... It is backwards...I appologize

Originally posted by Valhall
Well, I guess my point, six, is that don't we have to operate within the confines of the data in the NIST report in order to address whether the NIST conclusions were correct or not?

I'm not trying to be pissy - I'm trying to make a point. This is my contention with the NIST report. It presents data and science - and then draws conclusions that violate it's own data. Kind of makes the whole endeavour a big waste of time on what was supposed to be one of the most important investigations in U.S. history. [/quote



I know your not being pissy... Your are just trying to defend your point on your beliefs.... absolutly nothing wrong with that. That is what this site is here for...informed discussion. But I am also trying to make a point. I also have a problem with the report....I am just having a hard time with the controlled demo theory.

[edit on 21-8-2007 by six]

Originally posted by six
In our training burn building...we have gotten temps as high as 2000 degrees at the ceiling.....off of ordinary combustibles ie wood pallets.

Does your burn building collapse at freefall with no resistance left? Or collapse at all for that matter?


[edit on 8/21/2007 by Griff]

Originally posted by Griff

Originally posted by six
In our training burn building...we have gotten temps as high as 2000 degrees at the ceiling.....off of ordinary combustibles ie wood pallets.

Does your burn building collapse at freefall with no resistance left? Or collapse at all for that matter?

Nope. Specifically designed for the purpose of burning in.....Tiles similar to the space shuttles. The fires that are set are not uncontrolled. Limited fuel. Do not burn for more than 15 to 20 min at a time. Temp sensors at various levels in the building.

[edit on 8/21/2007 by Griff]

reply to post by six



You say you get high temps at the ceilings. Do they have heat sensors there to measure the heat of the members also. That would be interesting to see the difference. Even if they are tile with an R factor of 1 billion. We could still relate it to steel's R value.

reply to post by Griff


To honest, I dont think that steel was used in the construction of the building, but cant say with 100% certainty. The outside is block. Floors and ceiling are concrete as well as the supports for the floors and ceilings. I dont know if those are concrete over steel. The walls and ceiling are lined with a special tile. Temp sensors are at the floor and ceiling for safety purposes with a continuously running printer that is similar to a seismograph that constantly measures temps before , during , and after the exercise.

www.firetrain.com/gettingthefacts

Look under system 203..that is what is used..it gives the specs ..Must protect from up to 2000 F while not allow temperature exceeding 300-350 F to be transmitted to the structure. Does not give a R value. But with what is given..I am sure that could be figured out.

[edit on 21-8-2007 by six]

[edit on 21-8-2007 by six]

[edit on 21-8-2007 by six]

Originally posted by six

All jet engines require high temperature gas for good effiniency, typically achieved by combusting hydrocarbon or hydrogen fuels. Combustion temps can be as high as 5000 degrees F, above the melting point of most materials

.
www.solarnavigator.net/aviation_and_space_travel/jetengine.htm
That if from just one web sight that I have found.

Yeah, this is in the engine.

I'm talking about open-atmosphere combustion. This is also what Popular Mechanics is talking about when they themselves say that jet fuel fires don't burn hot enough to melt OR significantly soften steel. Not even close. Only thermal expansion, IF the steel was heated to ~2/3 the temperatures of the flames themselves, which takes a LOT of time given the amount of steel vs. the amount of fire.

[edit on 21-8-2007 by bsbray11]

Originally posted by six

I know your not being pissy... Your are just trying to defend your point on your beliefs.... absolutly nothing wrong with that. That is what this site is here for...informed discussion. But I am also trying to make a point. I also have a problem with the report....I am just having a hard time with the controlled demo theory.

[edit on 21-8-2007 by six]

Well, I'm actually not defending any "beliefs". I'm trying to stay with the facts we have - not go into speculation. And I have a hard time wit the controlled demo theory as well. In fact, I have a very hard time with it...kind of around the order of I have to reject it at this time due to lack of evidence. But that doesn't mean something more than planes weren't involved.

reply to post by Valhall



So you would be in the D crowd instead of the CD crowd? That's where I am at this point. Still on the fence though as to a true CD.

I am curious on what you 2 think what happened...

I haven't really known what you 2 think... is there somewhere you can point me to... or something like that..

Cause I am not familiar with your idea on what happened that day...

reply to post by ThichHeaded


I have no set in stone theory actually. I know the core had to be taken out in some way for the towers to collapse. The evidence points to explosives on floors and all but I can't get past the idea of the amount of noise for conventional CD explosives. Now, in 50 years when they come out with muffled explosives, I'll be more inclined to agree with them. That's why I'm on the fence and haven't made up my mind.

Don't get me wrong. I still believe there is far more to 9/11 than what we are being told.

Originally posted by ThichHeaded
I am curious on what you 2 think what happened...

I haven't really known what you 2 think... is there somewhere you can point me to... or something like that..

Cause I am not familiar with your idea on what happened that day...

I thought I had already stated that in this very thread. I tend toward thinking that there was more preparation and planning in the 9/11 attacks than just hijacking planes and flying into buildings. I suspect they got into the WTC prior to the attacks and planted "brute force" explosives in the lower levels at the central core area, and I speculate there was probably operatives located in the area who remote detonated those explosives.

That's what I lean toward.

I didn't read the whole thread.. I just pop in and out and make stupid comments here and there..

Ok.. I guess its time for me to be official story person..

Ok.. someone put explosives in the building.. How would that of happened if they had bomb sniffing dogs.. or the all so popular one.. you know how long that would take?

On a side note.. what is brute force explosives?? aren't they they same as CD ones?

[edit on 8/21/2007 by ThichHeaded]

The bomb sniffing dogs weren't used in the week to 2 weeks prior to the attack. And there were mid-eastern men who were in at least WTC 1 in the week prior to the attack who claimed to have been there "working on the sprinkler system" through a contractor. But the PA say they don't use contractors for maintenance on their sprinkler system they do the maintenance themselves. And the contracting company couldn't be located.

A CD explosive is not a brute force explosive device.

[edit on 8-21-2007 by Valhall]

Originally posted by Griff

six full-scale fire tests on a real composite frame structure at Cardington showed that despite large deflections of structural members affected by fire, runaway type failures did not occur in real frame structures when subjected to realistic fires in a variety of compartments.

First paragraph.

Of the identified phenomena, the dominant effect is that of restrained thermal expansion in the main structural elements. In the early stages of the fire, lateral restraint to translation (causing compression), coupled with rotational restraint to thermal bowing (causing hogging moments), leads to local buckling in the steel beams which limits the forces applied to the rest of the structure and to increasing deflections in a post-buckled state.

Part of the conclusion.


[edit on 8/15/2007 by Griff]

[edit on 8/15/2007 by Griff]

Were the models hit by airliners doing 500+ mph?

Anyway, what about the overpass that collapsed in San Fran this summer. Steel and concrete contruction, collapsed from fire with 87 octane car gas, not high octane jet fuel.

Originally posted by PriapismJoe
Were the models hit by airliners doing 500+ mph?

Now there is something to wonder about...

Altho stated a zillion times already the planes were not a factor in collapse..

Research is KEY.

Originally posted by PriapismJoe
Anyway, what about the overpass that collapsed in San Fran this summer. Steel and concrete contruction, collapsed from fire with 87 octane car gas, not high octane jet fuel.

Apples and oranges.

It didn't not melt the steel from what I am told.. The steel actually is being reused to rebuilt that highway.

Originally posted by PriapismJoe


Anyway, what about the overpass that collapsed in San Fran this summer. Steel and concrete contruction, collapsed from fire with 87 octane car gas, not high octane jet fuel.

It really is an apple and oranges comparison.

But with that argument aside, I'd like to ask you something that I can't seem to find the answer to myself - relative to the initial impact of the tanker against the support columns of the overpass, how much time passed before the first section of the overpass collapsed?

Originally posted by Valhall
relative to the initial impact of the tanker against the support columns of the overpass, how much time passed before the first section of the overpass collapsed?

I believe it was about 20-30 minutes. Could be wrong. The underpass is an excellent example to use in this thread actually. I have been saying from the first day that I saw a picture of that collapse that it was due to the expansion of the steel and not it melting. Seems I was right. Or they wouldn't be reusing it.

Actually, Griff, if you don't mind, I'd like to see the source you pull that time from. There is very good reason for me insisting on where that number comes from.

And thanks in advance!