WTC Visual Explosives ('Squibs')

Originally posted by HowardRoark
at some point as the liguid dispersed, the right vapor air mixture is reached. . . Kabloom!

This is a huge stretch of the imagination.

I'd like to see anyone dump jet fuel down anything and try to get a fuel-air explosion simply by lighting it as it falls.

I'd venture to say it's a hell of a lot more exact of a science than that.

my apologies if some of this has been addressed before : i have three kids and two jobs and get onto ATS ...erm not very often...

1. Burning Aviation fuel creates intense heat and pressure. One 45 gallon drum is enough to generate heathly respect in the open let alone inside a building. It is also able to spall concrete and degrade it, exposing sections and exploiting gaps.

2. A combustible area such as an office does not have to be directly connected to another area for that area to ignite. The fire gases can contain enough heat to induce pyrolisis in another place.

3. Water expands into steam by a ratio of 3400:1 therefore a 5 litre water cooler makes ...erm...17000 litres of steam plus each floor had a fire suppressant sprinkler system both ( as i understand it ) dry riser and gravity fed. Therefore it is reasonably safe to assume that there was a lot of water and steam pressure in and between floors.

4. However this pressure from steam and fire does not HAVE to be sufficient to blow out windows. If the oxygen levels in the fire areas below the main impact are low enough then the fire will die back but will not be extinguished. As the main building began to collapse, oxygen was entrained and the flammable mixture exited by the weakest routes ie improperly manufactured or fitted windows, ducts, stairwells and exposed joints in the steelwork and concrete.

like i said... its taken me over an hour to type this cos jr keeps waking up...

There were expulsions from over 50 stories below the fires. Hot air rises, not descends. Neither were the buildings airtight anyway (to build immense pressure in the first place -- not that the windows could have taken immense pressure in the first place, without giving out way ahead of time).


But if jet fuel produces such healthy fires (and I don't doubt that they do), why so long after the jet fuel had burned away, the smoke turned sooty, and visible flames died back, before the collapses initiated? Was the steel suddenly pushed over the threshold by less efficient fire, producing less heat?

[edit on 29-6-2006 by bsbray11]

Originally posted by bsbray11

Originally posted by DoomX
Is there a certain amount of time needed to be called a "withstand" ?

Yeah. If they didn't fall immediately after the impacts then they withstood them. In fact, look up the word "impact". Notice that nothing inherent about the word itself involves fire of any sort.

Here's an interesting point on the fires, though: they apparently didn't heat the steel to some critical temperature until after the jet fuel had already burned away much earlier and they'd gone from fuel-efficient (lighter smoke) to more inefficient (darker smoke outputs). Considering less inefficient means less combusted hydrocarbons and less heat, that's a kind of puzzler.

Dark smoke doesn't necessarily mean low temps. The color of the smoke depends on what material is in combustion.

Originally posted by mark ten
my apologies if some of this has been addressed before : i have three kids and two jobs and get onto ATS ...erm not very often...

1. Burning Aviation fuel creates intense heat and pressure. One 45 gallon drum is enough to generate heathly respect in the open let alone inside a building. It is also able to spall concrete and degrade it, exposing sections and exploiting gaps.

2. A combustible area such as an office does not have to be directly connected to another area for that area to ignite. The fire gases can contain enough heat to induce pyrolisis in another place.

3. Water expands into steam by a ratio of 3400:1 therefore a 5 litre water cooler makes ...erm...17000 litres of steam plus each floor had a fire suppressant sprinkler system both ( as i understand it ) dry riser and gravity fed. Therefore it is reasonably safe to assume that there was a lot of water and steam pressure in and between floors.

4. However this pressure from steam and fire does not HAVE to be sufficient to blow out windows. If the oxygen levels in the fire areas below the main impact are low enough then the fire will die back but will not be extinguished. As the main building began to collapse, oxygen was entrained and the flammable mixture exited by the weakest routes ie improperly manufactured or fitted windows, ducts, stairwells and exposed joints in the steelwork and concrete.

like i said... its taken me over an hour to type this cos jr keeps waking up...

The fuel was not in the offices where the jetting debris blows out autonoumously and containment of the fuel vapor was not sufifcient to create pressues that would blow concrete out windows 60 feet.

The black smoke coming from the towers shows that little oxygen was available. Temperatures were low.

The near free fall rates of the towers descent must be explained, pulverization of the buildings contents must be explained. Collapse does not explain these things, demolition does. Not just any demolition tho, the fine breakage of concrete debis expanding at rates consistent with high explosive that are well contained show that the placement and distribution were too optimum for ordinary controlled demolition. The explosive material had to be built in to the concrete walls to get that effect.

[edit on 29-6-2006 by Christophera]

Originally posted by Masisoar
Still looking for a reasonable answer for the squibs or jets of air being pushed out the sides of the building as it was collapsing.

Whats unreasonable about airspace being compressed?

Originally posted by Vushta
Dark smoke doesn't necessarily mean low temps. The color of the smoke depends on what material is in combustion.

I didn't imply "low" temperature, but lower. As in lower than when the fires produced lighter smoke.

Jet fuel was dumped on impact. The fires produced lighter smoke at that time.

About 15 minutes pass, and at this time even NIST admits most of the jet fuel had burned away. Suddenly the smoke turns darker.

I ask a question with a very obvious answer: why did the smoke turn darker when the jet fuel finished burning away? Some kind of correlation there, maybe, or just another *coincidence*?

When the jet fuel burned away, was the fire suddenly fuel-rich, or lower on fuel, or was it just as well-fueled as when the planes first impacted?

Again, the answer is obvious. It's sad that I have to break down such an obvious logical problem, too, or even tell you that it's obvious. People don't like being wrong, I guess.

And yes, more inefficient fires do produce less heat. Less hydrocarbons are combusted (uncombusted hydrocarbons are actually what makes the smoke darker and filthier). Therefore less energy output.

The fuel was not in the offices where the jetting debris blows out autonoumously and containment of the fuel vapor was not sufifcient to create pressues that would blow concrete out windows 60 feet.

i didn't say there was any Aviation fuel in these offices. Presumably they had desks, carpets, pictures, copius quantities of paper, plastics etc etc... If there was any transfer of the IMMENSE heat produced by the burning aviation fuel it is not unreasonable to expect that pyrolysis would occur.

The black smoke coming from the towers shows that little oxygen was available. Temperatures were low.

erm... black smoke does not mean temperatures were low (and what exactly do you mean by 'low') Avaition fuel burns with an acrid, black smoke. Fires in a backdraft situation will also burn with a black smoke. It means that there is insufficient oxygen to support combustion NOT that temperatures are low.

"pulverization of the buildings contents must be explained. Collapse does not explain these things, demolition does."

do you mean that to "pulverize" all the stories of the building there must have been charges laid on all floors? Someone has already posted that when a building is CD they leave the debris as rubble because it is easier to clear away... So Demoltion = rubble ...what = pulverization?

The black smoke coming from the towers shows that little oxygen was available. Temperatures were low.

Is there any other reason for black smoke other than representing lower temps?

Why don't you do research and find out, Vushta.

We've already had a huge discussion on this before, use the search button and look around bud, enlighten yourself.

Originally posted by ChristopheraThe fuel was not in the offices where the jetting debris blows out autonoumously and containment of the fuel vapor was not sufifcient to create pressues that would blow concrete out windows 60 feet.

Originally posted by mark teni didn't say there was any Aviation fuel in these offices. Presumably they had desks, carpets, pictures, copius quantities of paper, plastics etc etc... If there was any transfer of the IMMENSE heat produced by the burning aviation fuel it is not unreasonable to expect that pyrolysis would occur.

Yes that could be expected above the fire directly to a large degree and off to the sides for a smaller effect.

Originally posted by ChristopheraThe black smoke coming from the towers shows that little oxygen was available. Temperatures were low.

Originally posted by mark tenerm... black smoke does not mean temperatures were low (and what exactly do you mean by 'low') Avaition fuel burns with an acrid, black smoke. Fires in a backdraft situation will also burn with a black smoke. It means that there is insufficient oxygen to support combustion NOT that temperatures are low.

Higher temps have the black smoke further from the center of the fire. Flames are seen. Cold fires have less or no flame and more smoke closer to the exhaust of the building.

Originally posted by Christophera"pulverization of the buildings contents must be explained. Collapse does not explain these things, demolition does."

Originally posted by mark tendo you mean that to "pulverize" all the stories of the building there must have been charges laid on all floors? Someone has already posted that when a building is CD they leave the debris as rubble because it is easier to clear away... So Demoltion = rubble ...what = pulverization?

I've been involved in blasting projects. If possible everything is turned to sand and gravel so dozers and loaders can move it, the job is much easier. Chunks small enough to load are preferable and left at a standard demo if possible. The WTC had no chunks of concrete from the towers steel reinforced concrete core, and it was massive. It is usually impossible to do a demolition where maximum breakage is possible because the debris is thrown so far there is liability.

Black smoke is not an indication of low temps.
Sorry it just isn't.

Jet fuel was dumped on impact. The fires produced lighter smoke at that time.

About 15 minutes pass, and at this time even NIST admits most of the jet fuel had burned away. Suddenly the smoke turns darker.

I ask a question with a very obvious answer: why did the smoke turn darker when the jet fuel finished burning away? Some kind of correlation there, maybe, or just another *coincidence*?

That sounds about right--15 mins. to get the interior combustibules to begin burning their own fuel sources. The smoke turned darker because the fuel was different.

When the jet fuel burned away, was the fire suddenly fuel-rich, or lower on fuel, or was it just as well-fueled as when the planes first impacted?

No one will ever know, but the question really is not was there more or less fuel but how much of the damage was already done.

People don't like being wrong, I guess.

I guess.

Originally posted by Masisoar
Why don't you do research and find out, Vushta.

We've already had a huge discussion on this before, use the search button and look around bud, enlighten yourself.

I know the answer.
I was interested in what the poster of that information thought. He may be able to learn something from some research though.

About 15 minutes pass, and at this time even NIST admits most of the jet fuel had burned away. Suddenly the smoke turns darker.

I ask a question with a very obvious answer: why did the smoke turn darker when the jet fuel finished burning away? Some kind of correlation there, maybe, or just another *coincidence*?

When the jet fuel burned away, was the fire suddenly fuel-rich, or lower on fuel, or was it just as well-fueled as when the planes first impacted?

there are a number of points here.

1. some of the aviation fuel will have been burned off on impact
2. aviation fuel is easily hot enough to ignite the airframe which will continue to burn after the aviation fuel has burnt off
3. whilst the process of combustion is occurring other materials are becoming involved in the fire including furnishings, plastics, dust, etc these cause the smoke to tak the pallour that it does
4. indeed in some areas of the building the fire will become "fuel rich" others will be "lower on fuel" having burned all available material
5.

Hot air rises, not descends

absolutely, if you're in a balloon. but not always in a fire. overpressure can cause hot fire gases to eject from surpising places and while they tend to want to rise up they may be forced in other directions

its far too late for me bsbray!

Vushta, you keep using "I guess we will never know", that's why we're speculating with some ideas, but not all.

Every situation in a fire is unique.

The WTC had the jet fuel combust ..

Hold on: By the way, the jet fuel travelling down the "elevator shafts" and igniting.

Quick few things about that:

- Kerosene (Jet Fuel) takes longer to ignite, which is why they use it, so only god can explain how it caught fire spilling down the elevator.
- Only 1 Elevator comes down to the lobby, the mechanic express elevator.

Like I said, refer to Valhall's statements in the Pyroclastic cloud thread: Need a link?

-------------------------------

The WTC had jet fuel combust as the aircraft hit the building, you then had materials setting ablaze while the remaining jet fuel was being used up, it wasn't solely the jet fuel burning. So you have a very good efficient flame, for the most part, for open atmosphere flames, burning.

You see the black smoke because the fire no longer has an efficient fuel source, so thus, because of lack of efficieny, it was cooling down from its original state.

That's what BSB was getting at.

Vushta, you keep using "I guess we will never know", that's why we're speculating with some ideas, but not all.

Thats true. But some things ARE known and some of those things rule out a lot of whats being speculated.

- Kerosene (Jet Fuel) takes longer to ignite, which is why they use it, so only god can explain how it caught fire spilling down the elevator.

Well I'm not god, but why is it difficult to understand that it may have?

Like I said, refer to Valhall's statements in the Pyroclastic cloud thread: Need a link?

That would help. I think I missed that whole thread. Thanks.

You see the black smoke because the fire no longer has an efficient fuel source, so thus, because of lack of efficieny, it was cooling down from its original state.

Lack of efficiency is not the same thing as lower temps. And I think that the basic assumption is wrong. I've seen different materials from plastics to old rigid board insulation to furniture etc. burn in completely open air environments producing nothing but pitch black smoke while burning EXTREMELY hot and rapidly.

The cooling down process can actually produce more damage to connecting joints the the heating does.
The heating can cause expansion and sagging,distorting and weaking of the steel.
When it cools, it begins to contract but its no longer in its original shape and can create great shearing forces because in a sense it shrinks to a "shorter" length than its original form so the real damage beginning after the fires begin to cool is not unusual

I'll post the link but first look at this Vushta.

When the jet fuel ignited, it was a catalyst in assistance with office/building materials nearby, of a fuel efficient fire, so it burned hotter. When the jet fuel went out, the smoke turned black because it was cooling. Cooling because the fire wasn't efficient.

You can throw gasoline on a fire, and what? BOOM. You have a fire that's very hot and burning more richly, when it's exhausted, it turns more sooty and less efficient and cools down.

You can also look at a Bunsen Burner. You have the source of fuel, the gas in combination with the air, to cause the light blue flame that burns hottest, the less enriched the flame is, the more yellow and sooty it is. Thus not burning as hot. There are lots of classic examples that black smoke equals a oxygen starved fire.

Now by oxygen starved, what do we mean? We mean the fuel/air ratio is poor, so everything's not combusting efficiently.

That's what the point is that we are in fact getting at.

The fires were cooling because they weren't efficient enough anymore. The hottest the flames could of reached were that within the 15 minutes of the jet fuel burning, from then on it was a cooling fire, maybe not necessarily a dying fire but cooling none the less due to lack of efficiency in its burn.

So any weakening has to of mainly happened during that time. And don't forget what the NIST said:

"Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250ºC… Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250 ºC. ... Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600" ºC. (NIST, 2005, pp. 176-177)"

Which points to, from the samples they've collected, there was no evidence of the fires of reaching over 600 degree Celsius. This is an interesting point to look at however which way because then that shows that the jet fuel never really did get as hot as some may claim.

So how much damage did the jet fuel fires have on the steel? Within the 15 minutes anyways.

-----------------------------

Thread with Valhall's points:

www.abovetopsecret.com...

----------------------------

Getting back to the point of the thread...

Originally posted by Masisoar
I'll post the link but first look at this Vushta.

When the jet fuel ignited, it was a catalyst in assistance with office/building materials nearby, of a fuel efficient fire, so it burned hotter. When the jet fuel went out, the smoke turned black because it was cooling. Cooling because the fire wasn't efficient.

You can throw gasoline on a fire, and what? BOOM. You have a fire that's very hot and burning more richly, when it's exhausted, it turns more sooty and less efficient and cools down.

You can also look at a Bunsen Burner. You have the source of fuel, the gas in combination with the air, to cause the light blue flame that burns hottest, the less enriched the flame is, the more yellow and sooty it is. Thus not burning as hot. There are lots of classic examples that black smoke equals a oxygen starved fire.

Now by oxygen starved, what do we mean? We mean the fuel/air ratio is poor, so everything's not combusting efficiently.

That's what the point is that we are in fact getting at.

The fires were cooling because they weren't efficient enough anymore. The hottest the flames could of reached were that within the 15 minutes of the jet fuel burning, from then on it was a cooling fire, maybe not necessarily a dying fire but cooling none the less due to lack of efficiency in its burn.

So any weakening has to of mainly happened during that time. And don't forget what the NIST said:

"Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250ºC… Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250 ºC. ... Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600" ºC. (NIST, 2005, pp. 176-177)"

Which points to, from the samples they've collected, there was no evidence of the fires of reaching over 600 degree Celsius. This is an interesting point to look at however which way because then that shows that the jet fuel never really did get as hot as some may claim.

So how much damage did the jet fuel fires have on the steel? Within the 15 minutes anyways.

-----------------------------

Thread with Valhall's points:

www.abovetopsecret.com...

----------------------------

Getting back to the point of the thread...

Thats a whole lot of assumptions. I'll have to comment tomorrow. I'm wrapping it up for tonite.

The nist blip you posted was in regards to the perimeter columns? I would think that the fires in the areas of deeper penetration where the planes ended up might be a bit warmer.
Enough for now---me so sleepy. 'nite all.

VUSHTA




The exterior panels represented the 250 degrees Celsius measurements, the rest of the samples didn't show evidence of fires over 600 degrees Celsius, am I wrong.

Further more, what are you going to argue again?

Different fuels make black smoke.

In the WTC case, I think you are really full of it. And are so full of it, I'm seriously not even going to consider your point valid anymore, I take Howard for more credit than you.

Back to the different fuels.

The fuels never changed, they stayed the same. And anyways, with the pictures posted earlier..Black smoke = bad air/fuel ratio.. maybe it's just.. there wasn't enough air to burn efficiently.

Hey, what do you know now? OXYGEN STARVED.

How far are you going to ignorantly argue this..

Originally posted by Vushta

Originally posted by Masisoar
So any weakening has to of mainly happened during that time. And don't forget what the NIST said:

"Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250ºC… Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250 ºC. ... Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600" ºC. (NIST, 2005, pp. 176-177)"

Thats a whole lot of assumptions. I'll have to comment tomorrow. I'm wrapping it up for tonite.

The nist blip you posted was in regards to the perimeter columns? I would think that the fires in the areas of deeper penetration where the planes ended up might be a bit warmer.
Enough for now---me so sleepy. 'nite all.

Wow, you found some good information at NIST. I guess it all can't be bad can it now? Certainly there was more fuel next to the damaged core, even in it, but because the core was concrete.



The fire could only heat the massive interior interior box columns outside of it. and they were very thick, and of course there is little oxygen back there so the fire will be cooler.