The Progressive Collapse Challenge

Originally posted by bsbray11
Soot is indicative of a poor burn; specifically, it means the fire is not making efficient use of its fuel sources. Darker smoke also carries away more heat than lighter smoke. Light smoke to dark smoke = higher efficiency to lower efficiency = cooler temperatures.

The color of the smoke is not definitive evidence of cooler temperatures. While it may have been burning with lower efficiency that does not mean it was going out. The materials burned also affect the color of the smoke.

If black smoke automatically means dying fires, then how do you explain this?



That is from the Branch Davidians compound in Waco. Those fires, while producing black smoke, are just getting started in the above pic. The entire building burned to the ground.


So while black smoke can mean a fire is dying, it is not definitive proof.

Originally posted by LeftBehind
The color of the smoke is not definitive evidence of cooler temperatures. While it may have been burning with lower efficiency that does not mean it was going out. The materials burned also affect the color of the smoke.

If black smoke automatically means dying fires, then how do you explain this?

Oh my god, dude. You are seriously slow.

Originally posted by bsbray11
Soot is indicative of a poor burn; specifically, it means the fire is not making efficient use of its fuel sources.

Now look.

There is more than one way for a fire to not be making efficient use of its fuel sources.

Soot in smoke is uncombusted hydrocarbons.

That means the following:

The fire is doing a poor job making use of its fuel, for one reason or another.

Or, in other words:

The fire isn't combusting all of the hydrocarbons at its disposal.

Does it make sense yet? Has it clicked yet? I hope so or you won't be able to understand this next part.

The reason the fires in your pic are producing black smoke is because of uncombusted hydrocarbons, of course but IT'S BECAUSE THERE'S EXCESSIVE FUEL AND THE FUEL ISN'T BEING COMPLETELY BURNED BY THE FIRE AND IS BEING PICKED UP IN THE SMOKE.

Does THAT make sense yet?

If so then I hope you'll realize the complete stupidity in comparing those fires to the WTC fires.

In the WTC fires, most of the fuel was burned up in the first 15 minutes of the fires, and even then the smoke was not black. It was light. There was a healthier burn (more efficient, less uncombusted hydrocarbons!). Now for the smoke to have turned black, AGAIN, means UNCOMBUSTED HYDROCARBONS. Now you tell me whether you think that that means (a) there was suddenly too much fuel, or (b) the fires were DYING and could not properly burn what little was left!

I'll give you a BIG hint!:

No more planes crashed into either buildings after the first two, and I don't think there was anyone running around pouring more plane tanks of gas onto them!

I hope to god that you finally realize what I'm saying.

Black smoke means uncombusted hydrocarbons. Ok, your posts would be made a lot better without the condesencion.


Why are you assuming the jet fuel was the only source for the fire. All the material in the offices on multiple floors was also burning, so to make an assumption just based off the black smoke is disingenous.

What I have been saying is that this black smoke does not mean it was a dying fire. Just as the Waco fire was still burning strong after sending out black smoke. The office material provided plenty of fuel.


I am only making one point with this:

Black smoke does not automatically mean a dying fire.

[edit on 15-1-2006 by LeftBehind]

Originally posted by LeftBehind
Black smoke means uncombusted hydrocarbons. Ok, your posts would be made a lot better without the condesencion.

Sorry about that, man. It'd been a while since the grind, you know? I'd been taking it easy, and you know how this stuff can get to the nerves. It's probably the most prominent thing you and I have in common, buddy.

Why are you assuming the jet fuel was the only source for the fire. All the material in the offices on multiple floors was also burning, so to make an assumption just based off the black smoke is disingenous.

I'm not, but there was absolutely nothing added to the fires the whole time they were burning. There was the initial jet fuel, the initial plastics, etc., and those were there the entire time (excepting when they were burned away), and nothing more was added.

I am only making one point with this:

Black smoke does not automatically mean a dying fire.

Well, alright. But then let me make this point:

No additional fuel was added to the fires, so the most plausible conclusion is that a dying fire was making less efficient use of the same fuel sources.

Jet fuel is made of hydrocarbons and contains aromatic hydrocarbons. Aromatic hydrocarbons always produce sooty smoke. Plastics such as those found in a typical office environment also produce sooty smoke.
That doesn't affect the amount of heat released by the combustion of the fuel. That is fixed by hard and fast scientific laws.

It is an incorrect statement to say that the WTC fires were oxygen poor. With the holes in the windows from the impact and the people smashing out the windows, the fire was well ventilated. It you absolutely must make a judgment based on the color of the smoke, then say that the fire was fuel rich, not oxygen poor. In that case, as the superheated combustion gases such as carbon monoxide (which will burn) made their way up the building and encountered open floors with broken windows, the gases can and will ignite releasing more heat.

The key issue here is not how much of the smoke was escaping out the side of the building, but that the fire was spreading up the building through the core. The stack affect of natural air movement up the core shafts would have fed the fire all the oxygen it would have needed. That is why you see smoke coming out on the top mechanical areas of the building. Anyone who has ever felt the stack effect in a high rise building will know instantly what I am talking about.





Thus it is a myth that the fire was somehow cooler because of the smoke. The amount of heat released by the combustion is fixed. The combustion products would have still consist of high temperature gases in the upper parts of the floors and traveling up the core shafts.

Originally posted by HowardRoark

Jet fuel is made of hydrocarbons and contains aromatic hydrocarbons. Aromatic hydrocarbons always produce sooty smoke.

And yet apparently there are not enough of such hydrocarbons, as the fire was initially much lighter, and I think you'll agree that the initial fuel source was primarily jet fuel.

Plastics such as those found in a typical office environment also produce sooty smoke.
That doesn't affect the amount of heat released by the combustion of the fuel. That is fixed by hard and fast scientific laws.

The change in color is not ultimately the point. The point is that there were no additions to the fuel sources, and yet the smoke still turned black, which is STILL an indication of inefficient use of fuel.

Black smoke also serves to carry heat away from a fire in ways that lighter smoke does not.

It is an incorrect statement to say that the WTC fires were oxygen poor. With the holes in the windows from the impact and the people smashing out the windows, the fire was well ventilated. It you absolutely must make a judgment based on the color of the smoke, then say that the fire was fuel rich, not oxygen poor. In that case, as the superheated combustion gases such as carbon monoxide (which will burn) made their way up the building and encountered open floors with broken windows, the gases can and will ignite releasing more heat.

I have not made the argument that the fires were oxygen poor, now have I? I've not assumed any particular causes of the inefficiency, but any fire around the core structure would not be as well ventilated (you focused only on the perimeter columns). Also note that the fact that the perimeter columns were so exposed to open air would inhibit their heating. Also, I'm not aware of anything being "superheated," so if you could provide any evidence of what you suggest there (not just information on the idea - but EVIDENCE, as you seem to get the two confused) then that'd be great.

But I can tell you that the discoloration was not from being fuel-rich. If that were the case, the fires would INITIALLY be black. But instead, they started with lighter smoke and then went black. Make sense? Because it doesn't make sense when you suggest all of this fuel only became available so far into the fires. That defies the logic of the fact that the fuel was deposited with the impacts, and nothing more was ever added to the offices.

The key issue here is not how much of the smoke was escaping out the side of the building, but that the fire was spreading up the building through the core.

Evidence?

The stack affect of natural air movement up the core shafts would have fed the fire all the oxygen it would have needed. That is why you see smoke coming out on the top mechanical areas of the building. Anyone who has ever felt the stack effect in a high rise building will know instantly what I am talking about.

Smoke was being carried through the building, I'll give you that, but to say that there was sufficient internal ventilation for the fires (which in themselves we know little about around the core) is conjecture.

Thus it is a myth that the fire was somehow cooler because of the smoke. The amount of heat released by the combustion is fixed.

What was fixed was the amount of fuel in the system. Again, with the same body of fuel, the smoke goes from indicating a combustion-efficient fire, to a combustion-inefficient fire. An inefficient fire will not produce the same energy, and thus HEAT, that an efficient fire will.

Basic chemistry, Howard. Less hydrocarbon combustion = less energy output in the system.

And basic physics, Howard. Less energy output = less heat (in this case) in the system.

And I'll emphasize one more time, for good measure, that there were no additions to the fuel in the system. In other words, the fires were NOT fuel-rich, or else the fires would have STARTED black. Once again, it would not make sense for the fires to suddenly be fuel-rich after much of the fixed amount of fuel is already gone.

The combustion products would have still consist of high temperature gases in the upper parts of the floors and traveling up the core shafts.

And this just sounds like you're just trying to throw jargon around, because this makes 0 sense.

The combustion products consisted of gases in the upper parts of the floors? I honestly don't even know what you originally meant with this, whether you meant the materials being combusted or what, but saying that the products were "in the upper parts of the floors" makes absolutely no sense unless the fires were already there, or unless you are assuming time does not exist or something funky like that.

Maybe you just had a brain fart on that one, or didn't word it quite right, but it's totally irrelevant to the smoke discoloration anyway, and I seriously doubt the existence of any corroborating evidence for what you *meant* to say (whatever that may have been), because you know just as well as I that no one was walking around the cores making scientific observations that day. Otherwise we would know exactly how many core columns were knocked out.



[edit on 17-1-2006 by bsbray11]

Is it not possible that fuel could have pooled in some areas and not have started burning until later on?

Not to mention that the plastics and other things wouldn't have all started burning at the same time. Some things would have ignited right away, and others later on. As the jet fuel burned off and the office materials started burning, the fuel source changed, and you got a darker color smoke.

[edit on 1/18/2006 by Zaphod58]

Did they still have those nasty polystyrene ceiling tiles then, or did they get rid of them? They are pretty nasty when they burn.. Very smoky..

Originally posted by AgentSmith
Is it not possible that fuel could have pooled in some areas and not have started burning until later on?

For this to have been the reason the smoke darkened, much more would necessarily have had to have "pooled" in areas without burning than actually caught fire, so that with the sudden ignition, I assume you're saying there would be caused a fuel-rich hydrocarbon burn, producing darker smoke.

Aside from the assumption that a good majority of the fuel laid around without catching fire for a good 15 minutes (which is completely unsupported by anything to begin with), and the general implausity of certain assumptions this idea makes, you should also find early, lighter smoke coming from the same areas from which darker smoke would later arise. Those theoretical pools would've had to have been lying around awfully damned close without catching fire, not to mention laying around all across the floor.

Originally posted by Zaphod58
Not to mention that the plastics and other things wouldn't have all started burning at the same time. Some things would have ignited right away, and others later on. As the jet fuel burned off and the office materials started burning, the fuel source changed, and you got a darker color smoke.

The official explanation of the discoloration has been the change from fire predominantly fueled by jet fuel to fire predominantly fueled by other hydrocarbons (plastics, etc.) available throughout the offices.

The logical problem with this explanation is the timing of the alleged outburst of office fires, which coincides perfectly with the time frame generally accepted as the period in which the jet fuel was exhausted. During the first whole ~15 minutes of fire, only when the fires by jet fuel started to die (which in itself would have produced darker smoke) are we told that the plastics in the offices caught fire.

In reality, the plastics would have caught fire as soon as they were heated by nearby jet-fuel fire to autoignition temperatures.

Logically, these temperatures would be hit before the jet fuel fires began to die, but, rather, between the time of their ignitions and hitting around their max temperatures/heat outputs/etc., which would've been sustained until the fuel began running out.

For hydrocarbon fires, this temperature is usually no more than 600ºC unless special advantageous conditions - not present at the WTC that morning - are present. This would've achieved fairly rapidly within the WTC given the circumstances of the fuel being immediately available in its largest amounts, etc. In other words, these fires did not have to build up gradually, as other fires might. As soon as the local air, etc., was heated, these things would be exerting full force (heat) on nearby objects, with all of the available jet fuel already there for them. This way, more heat would have been produced that would have been transferred to other objects, etc. more quickly. Such objects would of course include plastics.

Thus, the plastics would have already been ignited and burning much before the jet fuel was fully exhausted, if the said plastics could be expected to autoignite at all. It would obviously not have taken the jet fuel fires 15 minutes to reach their max (sustained) temps, and in reality, around 15 minutes or so, the jet fuel was already mostly depleted, as even government reports have attested given the circumstantial evidence of the very smoke output. The jet fuel was constantly decreasing in quantity, and while the temperatures of the fires would have remained constant, the overall heat output would have declined from the jet fuel fires as the jet fuel itself depleted and those fires became smaller.

So, assuming the plastics did not ignite until after the jet fuel fires were nearly dead is illogical. They had virtually all of the first 15 minutes of fire to ignite considering constant initial temperatures provided by the jet fuel fires.

Originally posted by AgenthSmith
Did they still have those nasty polystyrene ceiling tiles then, or did they get rid of them? They are pretty nasty when they burn.. Very smoky..

"Very [smokey]" is not so much the issue, though the volume of smoke didn't exactly increase as time went on. The color, again, is indicative of dying fires (less efficient use of the available fuel) considering the set amount of fuel (which was all there the entire time), and the tiles, I'm sure, were similarly available the whole time, unless workers were still trying to run them in and put them up while the fires were still present.