Molten Steel in the Debris Pile, Cool Down Time?

[Fromage]

Yes, he's not a steel foundry worker or a materials scientist. And this is getting off topic.

FYI: As far as I am aware, the only photos that relate to Loizeaux's claims are the famous red-hot chunks of broken steel beams being pulled out by excavators/demolition claws. Molten metal doesn't look like chunks of broken steel beams, red-hot or otherwise. Obviously. You can't pick up melted steel with a claw. You need a ladle. You wouldn't even try to pick up melted steel with an excavator, because the risk of severe damage to the excavator. There is a long-standing confusion between "red-hot" and "melted", and the the truthers encourage this confusion elsewhere.

I think the cool down time of molten steel to non-flowable is a bit of a red-herring here, because much of the steel ended up in smoldering piles that, IIRC, were measured at up to about 1000F more than a month after the event.

But anyway:

My father-in-law died about a year ago, after retiring from shift-supervisor on a major steel company (rolling mill, not structural channel/other). He'd know melt-to-solidify times. My wife had to copy his "little black book" for heating times to bring ingots (of sizes up to 20 tons, and of various types of steel) up from room temperature to rolling temperature - with coke-gas furnaces, it'd take 18-24 hours to bring them up to rolling heat.

Her best guess (should be a pretty good one because she worked there as a student), of molten to solid/de-moldable is about a day. In 20 ton ingots. But remember, this is second hand from 30 years ago. Also remember that they would be trying to speed this process up to keep the amount of super-hot inventory/molds necessary on hand to a reasonable minimum.

I did see the unit in operation - at the time the most advanced hot roll mill in the world.

Oh heck, I'll just ask the company and see what they say.

 

[Nada Truther]

I asked myself that question a few months ago, and my research seemed to indicate that "channel rail" was a relatively light U-channel member used to hold vertical panels in place. Often used in construction where the building "skin" is prefabricated panels - but not prefab structural steel panels in the case of WTC1/2. Or sometimes with glass panels (which generally means they're not very big)

I would think that any sort of channel that is in the shape of a long trough might constitute a "channel rail". So, it really could have been anything. As long as they are saying that it is molten, then it must have been made of a material that could withstand the heat of the molten metal. The focus would be on how much it was and was it already flowing. As was eluded to earlier.... could it have been pooled up and then just released when they saw it. The "truthers" would have you believe that there is a river of molten metal running under the pile like the river of slime from Ghostbusters 2. It really only had to be a running stream to fit what I understood that the firefighters saw. It could have been more, but if I saw a stream of metal, no matter the volume, it could be classifieds as "running down" the rails. These guys didn't say anything about it being suspicious or like something that was done under deliberate circumstances, so maybe it seemed like it made sense to them. I trust the guys that see fires all the time when they say something. if they said that it seemed like it couldn't be normal, then I would be concerned. But they didn't. They were just in awe by the massive power and scale of what they were involved in.

 

[Fromage]

I would think that any sort of channel that is in the shape of a long trough might constitute a "channel rail".

"Channel rail" is a pretty specific "term of art" in the steel industry, as is "car rail". Well trained fire fighters with lots of tall steel buildings in their turf are likely to be fairly familiar with the terms so that instructions and reports referring to structural members are clearly understood.

Car rail is also a "U channel". Wider than high. I believe named that because it was used as skin stiffening in railway and subway cars.

But I guess that's a bit speculative.

 

[JohnJones]

Attached to this post is an Excel spreadsheet implementing an explicit finite-difference model of the cooling of a spherical ball of hot iron surrounded by cooler debris. It should be straightforward to change material properties and boundary conditions and see what happens. Everything is in SI units.

Starting with 10 tons of molten iron at thermite combustion temperature, I have varied the initial temperature of the debris pile to see how this affects cool-down times, with the following results:

T(debris) 100 C: iron solidifies after 36 hours
T(debris) 500 C: iron solidifies after 49 hours
T(debris) 1000 C: iron solidifies after 86 hours

If the debris pile were at 1,000 C, it would all be glowing red, which you'd think someone would have noticed.

 

[Tomi]

Attached to this post is an Excel spreadsheet implementing an explicit finite-difference model of the cooling of a spherical ball of hot iron surrounded by cooler debris. It should be straightforward to change material properties and boundary conditions and see what happens. Everything is in SI units.

Starting with 10 tons of molten iron at thermite combustion temperature, I have varied the initial temperature of the debris pile to see how this affects cool-down times, with the following results:

T(debris) 100 C: iron solidifies after 36 hours
T(debris) 500 C: iron solidifies after 49 hours
T(debris) 1000 C: iron solidifies after 86 hours

If the debris pile were at 1,000 C, it would all be glowing red, which you'd think someone would have noticed.

I think it is naive to assume the whole pile was at the same temperature. Since we know that there were large variations in temperatures and that the locations of hot spots and cooler spots moved around

 

[Fromage]

If the debris pile were at 1,000 C, it would all be glowing red, which you'd think someone would have noticed.

I think it is naive to assume the whole pile was at the same temperature. Since we know that there were large variations in temperatures and that the locations of hot spots and cooler spots moved around

I think it pretty obvious from photographs that there were hot spots, eg: numerous chunks of glowing hot steel being pulled from the pile, IIRC, a month or two after the collapses (google for images). Also, IIRC, something like 3 million gallons of water being poured on the piles over several months. So we're looking at a lot of hot and cold spots.

Someone ran some calculations (in a place where I'm not going to be able to find now) that seemed to indicate that the collapse energy _alone_ could have been responsible for the majority of the heat energy from the piles. But I have my doubts, and my physics was too rusty to verify the calculations. Can't help but think he left out quite a number of factors.

 

[Jeffrey Orling]

There certainly was a lot of energy from friction which we know generates heat. But this was over many acres of land and the debris pile was many stories deep and quite the heat sink.

 

[Oystein]

There certainly was a lot of energy from friction which we know generates heat. But this was over many acres of land and the debris pile was many stories deep and quite the heat sink.

Totally irrelevant.

"Energy from friction" is only the smaller part of Potential Energy, which in turn totally pales in comparison with the heat from burning office material. It has been said that the PE of each tower was equivalent to something like 125 tons of TNT. That's 30 tons of paper. That's 5 pounds of paper per workstation, roughly. I'd guess less than half of that is turned into temperature increase, more into material deformation. Let's say 2 lbs of paper equivalent turned to "heat". How much combustibles are there per workstation? 200 pounds? So you are talking 1% of the heat from smouldering office contents fires.

Even the 1,000 incinerated dead bodies per tower (75 tons, twice the energy density of TNT) provided more heat than friction.

 

[deirdre]

Someone ran some calculations (in a place where I'm not going to be able to find now) that seemed to indicate that the collapse energy _alone_ could have been responsible for the majority of the heat energy from the piles. But I have my doubts, and my physics was too rusty to verify the calculations. Can't help but think he left out quite a number of factors.

Moderator Note - deirdre

this line of commentary is off topic. Please everyone stay on topic. There are other threads that discuss such things as this comment.

 

[JohnJones]

I think it is naive to assume the whole pile was at the same temperature. Since we know that there were large variations in temperatures and that the locations of hot spots and cooler spots moved around

Yes, it is naive to suppose that the whole pile was at uniform temperature. But it will take longer for molten iron to solidify in a pile at a uniform 1000 C than in a pile in which some parts are cooler than this. So the cool down time we calculate for a uniformly-hot pile will be longer than the cool down time in a pile of mixed or changing temperatures, and the result of our calculation will be an upper bound on possible cool down times.

Similarly, it is naive to suppose that the molten iron from multiple putative thermite charges all flowed into a single spherical blob. But the cool down time for the spherical blob will be longer than the cool down time for any other geometric configuration of the iron, and so the time we calculate will be a robust upper bound on possible cool down times.

Since on the basis of these naive but conservative assumptions, we calculate an upper bound on cool down times of a few days, we can conclude with confidence that, if molten metal were found in the debris a few weeks after 9-11, its presence cannot be explained as the lingering heat from charges of thermite that burned on 9-11. To keep iron molten that long, we would have to postulate intense fires in the debris pile.

So the dilemma facing anyone who wants to make the argument "Molten iron found weeks after 9-11, therefore thermite" is that they have to postulate intense fires in the debris reaching over 1,000 C (to keep the iron molten), but never reaching 1,500 C (which would melt iron without needing any thermite).

 

[Jeffrey Orling]

Molten metal under/ inside the pile presumably... if we are to accept the truth guys contention that the molten metal was part of a CD which we assume was placed at columns? or would that be beams in the core? or where?

Wouldn't a CD attack melting steel show some sort of organized or uniform pattern?... likely related to the column grid? And wouldn't this be more or less the same under both towers? The claim is they fell into their own footprints...

The of course we like to see evidence of significant number of steel columns and beams where the "organized CD" was showing missing bits from being melted away.... ?

Their case is incoherent and illogical... no?

 

[Fromage]

Oh heck, I'll just ask the company and see what they say.

They came through:

"Sorry for the late reply. I've inquired with our steelmakers and while we no longer use ingots (we stopped using them in 1991) the general rule was that from the time the ingot was poured to the time it was stripped was 2-3 hours. Hopefully this helps!" Amy (Public Affairs, ArcorMittal Dofasco).

This is for 20 ton ingots.