Melting point of Steel? Temperature of burning Jet Fuel?

Question

http://www.opednews.com/maxwrite/page.php?a=32710

Seems a fair enough question.
Does anyone know?

Wow, Dave. Are you always this hostile? Why are you so agitated about this? Do you get this worked up over everything? What about Bigfoot, UFOs, and the Loch Ness Monster? I'll bet you could work up a mild stroke over all of those, couldn't you?

You know what I think, Dave? I think Elvis Presley is still alive. How about you?

Relax, Dave. Even if he is still alive, how does it afffect you?

Breathe. Just breathe.

Answer 1

As is typical of folks who do not have a scientific background, the question is purely one of temperatures. But anyone with any knowledge of the science of combustion and melting knows that it is much more complicated than that.

If it were purely a matter of temperature, then as soon as the fire reached its maximum temperature, the steel would have melted, and the buildings would have collapsed -- all in a matter of seconds.

But it didn't take seconds, did it? It took nearly an hour before the first building fell. Why is that?

Because the problem isn't one of pure temperature, it is one of HEAT CAPACITY and THERMAL CONDUCTIVITY.

"Heat capacity (usually denoted by a capital C, often with subscripts) is a measurable physical quantity that characterizes the ability of a body to store heat as it changes in temperature. It is defined as the rate of change of temperature as heat is added to a body at the given conditions and state of the body (foremost its temperature). In the International System of Units, heat capacity is expressed in units of joules per kelvin. It is termed an "extensive quantity" because it is sensitive to the size of the object (for example, a bathtub of water has a greater heat capacity than a cup of water). Dividing heat capacity by the body's mass yields a specific heat capacity (also called more properly "mass-specific heat capacity" or more loosely "specific heat"), which is an "intensive quantity," meaning it is no longer dependent on amount of material, and is now more dependent on the type of material, as well as the physical conditions of heating." http://en.wikipedia.org/wiki/Heat_capacity

"In physics, thermal conductivity, k, is the intensive property of a material that indicates its ability to conduct heat.

It is defined as the quantity of heat, Q, transmitted in time t through a thickness L, in a direction normal to a surface of area A, due to a temperature difference ΔT, under steady state conditions and when the heat transfer is dependent only on the temperature gradient.

Thermal conductivity = heat flow rate × distance / (area × temperature difference) "
http://en.wikipedia.org/wiki/Thermal_conductivity

So, the poroblem here is not strictly one of temperature, but how much heat was being pumped into the steel, versus how quickly it could conduct that heat to other areas to cool itself down. If the steel conducts heat away from the fire faster than it is being pumped into the steel, the steel remains rigid. If heat is pumped into the steel faster than it can be conducted away, the temperature of the steel RISES ABOVE THE TEMPERATURE OF THE FIRE, eventually reaching the plastic deformation (softening) temperature. At that point, the steel girders deform, and the rest is purely momemtum (mass times velocity).

So, get off the bulls**t of the temperatures of the system, and look into the physics. The supporting girders did not need to melt (liquify) to cause the buildings to collapse, they just needed to soften enough to deform and start the collapse.

No explosives are required, no CIA or FBI involvement, no mysterious conspiracies from the Federal government, nothing.

Build a freakin' bridge and get over it, losers. The freakin' al-Qaeda terrorists knew their engineering far better than any of you idiots out there, and used that knowledge to bring down the towers. They have admitted it. So cut the cr*p and get on with life!

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Hostile? You haven't even begun to see me when I'm hostile.

I'm just REALLY freakin' tired of this same old BS question being pandered on this site. I have responded to this garbage hundreds of times, and still the stupidity persists. And it particularly pisses me off to hear you young pukes spout this drivel -- I was THERE, okay?! I watched it happen. I helped with the response. Where the bleep were you?

Answer 2

Dave,

Why the hostile response. Further, are you a Registered Professional Engineer., a Structural Engineer or even an AIA? The explanation provided by you seems personal, as well as being inaccurate. The only explanation for the free fall collapse, the melting steel shown in the videos, and steel members being thrown seventy feet laterally is the use of thermite or other agents of demolition.

Here are the points you neglected to mention, there was a great heat conductive capacity present in the building itself, the entire steel superstructure is a heat sink, and gravity acts vertically not laterally. Molten liquid does not result, then run as seen on the video as a result of jet fuel. Only thermite or another agent can precipitate that. Perhaps you need to finish school, or specialize in the subject.

In my experience, angry defensive reports and emotional outbursts in technical memoranda only occur when someone is trying to: hide a lack of knowledge, hide a paid mendacious motivation or other inducements.

Perhaps the following report from Professional Engineers and Architects, including a 30 year veteran with the Army Corps of Engineers would help people understand. Please watch it.

https://www.youtube.com/watch?v=IYUYya6bPGw

Answer 3

I think you also have to consider, jet fuel max temp is in the range of Iron Oxide aka rust melts and will retain that heat for longer to allow a fire to fuel that temp higher to the actual softening point of steel to then collapse a structure. Look at how Thermite is made people... People say Thermite in conspiracies, what was the building and plane made out of ? If you don't know I'm not saying it, but if you know, then you should know its not a conspiracy, but just plain science. How many Tons of concrete do you think feel onto the lower buildings gaining speed as it feel? Believe what you want, but I don't agree even with my wife on this subject and were still married. HA.

Answer 4

Melting Point Of Steel

Answer 5

I note that Dave didn't answer the question. The best answer I've gotten so far is that the open air burning temp of av gas, depending on it's quality and additives, is from 500 degrees F to 599 degrees F. Steel, depending on the alloy, gets soft around 1000 degrees, and melts around 2500-2750 degrees. I'm sure Dave's physics are better than mine, but I don't see a mass's temp rising above the temp of the heat source. Certainly not with a material as conductive of heat as is steel. Even if his thesis is correct, it doesn't explain the collapse of the floors beneath the fire, which weren't exposed to the heat., or the collapse of Building 7, which wasn't exposed to burning av gas, at all. The real question, in my mind, however, is, where did the gigantic puddle of molten steel that filled the basement come from. I remember that efforts to clear the rubble was delayed for a month while it cooled. I remember that the search for survivors/remains was hampered by that.

Answer 6

The simple facts of temperatures:

1535ºC (2795ºF) - melting point of iron
~1510ºC (2750ºF) - melting point of typical structural steel
~825ºC (1517ºF) - maximum temperature of hydrocarbon fires burning in the atmosphere without pressurization or pre-heating (premixed fuel and air - blue flame)

Diffuse flames burn far cooler.
Oxygen-starved diffuse flames are cooler yet.

The fires in the towers were diffuse -- well below 800ºC.
Their dark smoke showed they were oxygen-starved -- particularly in the South Tower.

Larry Silverstein the owner of the towers admitted to detonating building 7. Not a stretch he murdered the people in the twin towers.Mayor Guilani was warned the towers were going to colapse after the planes hit them.

Larry and his two kids were no where near the towers that day. A statistical impossibility unless they all knew what was going to happen.

Answer 7

what was seen at the base of the buildings and coming out of multiple windows of the towers ,, as a welder i believe it was Thurmite plasma. please forgive my spelling, but thurmite is used in building demo because it gets so hot if it is strapped to a steel reinforced concrete structure it will cut/burn though the concrete and steel to garentee that the structure's strength is overwhelmingly compromise. I wish people would stop thinking that this was the first time a political figure tore some stuff up himself and then blamed it on his political add-vis-sary. ya ya im a bad speller which must mean i dont know anything about anything. Hitler burned down german congress and blamed it on the jews. Im sure when he told his people it was the jews most of them believed it "The great masses of the people will more easily be convinced by a big lie than a small one" so I ask you all , who's quote is that ?

Answer 8

1

Answer 9

ya dave...nice lesson...you really took us back to the class room with that...except for the fact that your lesson has nothing to do with what happened..if you do your research you will find that there were tons of molten steel at the site...literally tons..im not saying that Al-Qaeda didnt help. i am saying that at the least of u.s involvement it was another pearl harbor..which is general info now..we knew it was going to happen, but what better than an attack on our soil to get the ppls hearts into the war.sound familiar? my brother spent 5 years as a marine 3rd recon sniper and he even believes there were shenanigans involved

Answer 10

What was burning in world trade center 7!? Before it collapsed!?

Answer 11

Must have been all that jet fuel in building 7 that caused it to collapse....