In an ongoing discussion of The WTC 7 collapse on 9/11. Commenter Sigivald brought up the fact that other high rise fires have caused buildings to collapse. He did not leave any links. So I went looking and found this Truther site: 9-11 Research which has the results of quite a few high rise fires. They say:
Excepting the three 9-11 collapses, no fire, however severe, has ever caused a steel-framed high-rise building to collapse. Following are examples of high-rise fires that were far more severe than those in WTC 1 and 2, and Building 7. In these precedents, the fires consumed multiple floors, produced extensive window breakage, exhibited large areas of emergent flames, and went on for several hours. The fires in the WTC towers did none of these things.
This fire particularly struck me:
The Beijing Mandarin Oriental Hotel Fire
The most recent example of a spectacular skyscraper fire was the burning of the Hotel Mandarin Oriental starting on February 9, 2009. The nearly completed 520-foot-tall skyscraper in Beijing caught fire around 8:00 pm, was engulfed within 20 minutes, and burned for at least 3 hours until midnight. Despite the fact that the fire extended across all of the floors for a period of time and burned out of control for hours, no large portion of the structure collapsed.
It is tempting to draw parallels between this spectacle and the destruction of WTC 1, 2, and 7 because of the stark opposites: on 9/11/01, three skyscrapers were transformed into piles of rubble primarily as a consequence, supposedly, of fires — fires spanning small fractions of each building; and on 2/09/09, a skyscraper remained intact after burning like a torch for hours. However such parallels may be limited by major structural differences between the buildings in the two cases — one being that the Hotel Mandarin Oriental, designed by the famous Dutch architect Rem Koolhaas, had a full-height interior atrium, and thus had the hollowness that the 9-11 Commission deceptively attempted to attribute to the Twin Towers. 10
There are others at the site. If anyone has a link to a high rise fire that caused a building collapse (other than on 911) leave it/them in the comments and I will add it to this post.
Update:
I found this how it was done post of interest. It is called: Attack Scenario 404. 404 in internet lingo is “page not found”. Amusing. The opening scene of “404” is reminiscent of the 20 July Plot Against Hitler where the defenses of Germany were put in the hands of the conspirators ostensibly for another purpose. That was called Operation Valkyrie. So the general ideas are not new.
Me? Well it is interesting. What is also interesting in light of the 404 theory is that D. Rumsfeld, Sec. of Defense, was outside the Pentagon helping the wounded instead of at his post (or an alternate one) directing America’s air defenses as the hijacking protocol called for. A lapse under stress? Could be.
Update: 5 February 2014 0151z
A firefighter talks about the evidence and destruction of evidence.
A much longer video (almost 2 hours) can be found here.
Comments
42 responses to “Building Fires”
Some time ago I calculated the total energy of a 747 hitting a building. There’s two parts to that; the impact from the mass of a large airplane hitting a target; 1/2 MV^2 and the combustion of thousands of gallons of fuel. IIRC it came out to between 1.5 and 3 kilotons depending on the exact assumptions of speed and fuel load. Also consider that so much jet fuel impacting at upwards of 400 MPH yields a fuel-air explosion as it instantly vaporizes. Not to mention other combustibles such as internal structure and the body fat from several hundred passengers.
Lets try to generate a null hypothesis:
Choice a) A massive government conspiracy places thousands of explosive charges in several enormous buildings, fakes 19 islamic wackos hijacking commercial airliners which they then cause to crash into said buildings and coordinates the crash with the the explosions to cause said buildings to collapse spectacularly.
Choice b) 19 islamic wackos hijack commercial airliners and crash them into some enormous buildings causing massive damage leading to the spectacular collapse of said buildings.
Lets look at some known cover up / conspiracies.
Waco.
TWA 800. Over 100 people say they saw a missile.
Moscow building explosions that led to the second war in Chechnya. People saw KGB agents placing the explosives.
Kansas city. Hundreds of people say they heard two distinct explosions. BATF agents based in that building took the day off. BATF manager shows up afterward and tells story about having to kick open the door of an elevator. (huh?; sliding door)Fuel/fertilizer is a very low yield explosive. (5’/second. Black powder is 10’/second, TNT is 5000’/second. How does a delivery truck on the street full of fertilizer cause so much damage?
And nobody involved in this conspiracy ever leaked. The only evidence is that some engineers and architects think the the WTC buildings collapsed other than how they expected.
Also, E Howard Hunt disguised himself as a wino and shot JFK from the grassy knoll. Mae Brussels said so.
Aliens built the pyramids.
George W. Bush is a reptiloid.
Or a man/ape hybrid (Behold the Protong)
Area 51!!!!!!!
How many of those fires involved large amounts of burning jet fuel in buildings first weakened by impact? None.
http://www.debunking911.com/firsttime.htm
If you scroll down, you will see that the proponents of this particular theory are ignoring this aspect, as well as the fact that this was not the first steel frame building to collapse from a fire.
They are engaged in sophistry, and remind me of the birth certificate truthers.
http://classicalvalues.com/2014/02/building-fires/#comment-102079
Well ok the impact and Jet fuel is worth 4 Kilotons of explosive power. Over a period of about an hour. Letting a LOT of that 4 Kilotons dissipate.
In addition the buildings were DESIGNED to absorb that level of shock and fire. With safety factors of around 2X or more.
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Eric. You are correct – about jet fuel. That is special. Compared to local scaffolding. With the same energy value.
And you are correct about intact.
What would I expect? From such a weakened condition? A local failure. Not a progressive collapse.
I have actually studied building and truss design and concrete. I have run the numbers.
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I know I will not convince anyone. But all I will say is that from what I know of building design the official theory is not credible. The explosives theory? Well that may not be credible either. But the sceptics did pick up on one point that I have already asked questions about:
http://911research.wtc7.net/essays/nist/index.html
The ASCE’s Disclosures of Steel Sulfidation
One of the more interesting parts of FEMA’s report is Appendix C: Limited Metallurgical Examination in which the investigators revealed that examination of the macro- and micro-structure of specimens of the steel show that it was rapidly corroded by sulfidation. Appendix C concludes with:
The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified. … A detailed study into the mechanisms of this phenomenon is needed to determine what risk, if any, is presented to existing steel structures exposed to severe and long-burning fires.
The authors don’t speculate on whether the findings are evidence of explosives, but the New York Times called them “perhaps the deepest mystery uncovered in the investigation.”
Despite the ASCE’s call for further investigation, NIST’s Report ignores the findings. Its five pages in Section 6.4 Learning from the Recovered Steel (p 86/136) includes a subsection on damage analysis with considerable detail, including some “observations of the microstructure of the steel.” It fails to mention the sulfidation discovered by ASCE volunteers.
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And no tests were ever performed to prove that wall board was the source of the sulfur. That wouldn’t be too difficult. Or too costly.
You properly explain the source of the sulfur and the whole explosives theory dissolves. Along with the wall board dissolving the steel.
http://www.gypsum.org/wp/wp-content/uploads/2011/11/GA-610-13.pdf
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Now about the fire loading used in the NIST simulations:
From NIST:
Observations of paint cracking due to thermal expansion. Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250 ºC: east face, floor 98, inner web; east face, floor 92, inner web; and north face, floor 98, floor truss connector. 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. (p 90/140)
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And the critics say:
The highest temperatures estimated for the samples was 250 ºC (482 ºF). That’s consistent with the results of fire tests in uninsulated steel-framed parking garages, which showed maximum steel temperatures of 360 ºC (680 ºF). How interesting then, that NIST’s sagging truss model has the truss heated to 700 ºC (1292 ºF).
http://911research.wtc7.net/essays/nist/index.html
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They do a detailed take down of the NIST simulation. It was referred to in one of the videos as NIST doubling the temperatures. Which is what it looks like.
Yes. I know. If any of this has any veracity it is much worse than we thought. And that even with the Drug War thrown in.
I’m willing to entertain that possibility. But I have an engineering mind. I have no preconceived notions. I just look at the evidence. I know. It is a failing.
A detailed study into the mechanisms of this phenomenon is needed to determine what risk, if any, is presented to existing steel structures exposed to severe and long-burning fires.
The building industry should be all over this. Doing tests themselves. For insurance purposes if nothing else.
And yet……
Curious.
To make any sense of this you need structural engineering experience (or at least education) and a feel for the forces involved. Knowledge of structural failures. And too much time on your hands or an obsession.
How many people meet that criteria? Probably not enough to matter.
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One thing to keep in mind. Structural failure is designed to redistribute the loads so that failures if any are local. That is the beauty of geodesic structures. Any deformation distributes the load over the whole structure instead of maximizing it locally (other than at the point of contact). I have STUDIED this. Intensively for two or three years.
Show me another building that has been pulverized from a fire. Fire and collapse don’t do that – except for the WTC structures.
From an engineering stand point there are too many holes in the official story.
MMM,
Choice a) A massive government conspiracy places thousands of explosive charges in several enormous buildings, fakes 19 islamic wackos hijacking commercial airliners which they then cause to crash into said buildings and coordinates the crash with the the explosions to cause said buildings to collapse spectacularly.
Scenario 404 explains how it could be done with 12 people. You don’t need 19.
But OK. 19. Explain why no one has squealed on the logistics required to put the 19 in place? And why did the flyers who obviously had superior intel behind them train with a drug smuggling operation?
And explain to me how the piloting skills required to put the plane into the Pentagon match the purported flyer?
Yeah. I know. What I am contemplating is just too monstrous for any one but a Hitler, A Stalin, A Mao, A Pol Pot, etc. to contemplate. How many such people do you find in history? Enough.
Add in Rommel. Except he failed.
The right to lifers block a constitutional amendment to put a right to privacy very specific that will punish those who violate are privacy go and spam anti abortionists!
I put above in wrong place it goes with- I have had it! As for this everyone should know 9-11 was a business deal between bush family and bin ladin family to take heat off young shrub for republicans on supreme court stealing 2000 election. Look up progress for new american century and their need for a “second pearl harbor” 1998 so the neo-con artists could attack iraq.
Eric:
From your link. I note a building toppled. Not one pulverized. I would expect intact sections from the WTC even if some floors pancaked.
And this:
3) And is a “Tube in a tube” design
True – it was new with the WTC. It has been widely used since.
And this:
5) Which was struck by another building or airliner and had structural damage as a result.
WTC was designed to absorb a large airplane strike. And have only local damage.
7) And had trusses that were bolted on with two 5/8″ bolts.
What was the rating of the bolts?
http://www.engineeringtoolbox.com/steel-bolts-sae-grades-d_1426.html
Let us go with top rated bolts. Proofed at 120K psi. Minimum.
5/8″ = 0.6135 sq in (roughly). That is 73,500 lbf rating. Two of them get you to 147,000 lbf. not too shabby for local loads. But I’d have to see the blueprints to see if that is adequate.
You can find the blueprints here:
http://www.ae911truth.org/en/news-section/41-articles/611-wtc-7-blueprints-exposed-via-foia-request.html
Funny question though. Why would they need an FOIA to get the prints? Are they like the Climate guys who fear independent replication?
I’m going to see if I can find out what SAE grade is called for.
A point made in the sidebar of the last link:
WTC7 exhibited none of the characteristics of destruction by fire:
1. Slow onset with large visible deformations
2. Asymmetrical collapse which follows the path of least resistance (laws of conservation of momentum would cause a falling, to the side most damaged by the fires)
3. Evidence of fire temperatures capable of softening steel
4. High-rise buildings with much larger, hotter, and longer lasting fires have never collapsed
Even if you discount 2 thru 4 – #1 is very telling. When fire turns the frame to rubber you would expect the frame to act like rubber. At least for a while.
BTW you call the A&E911 people sophists. I call them engineers. There is a difference. They conform to what I would expect from engineers doing failure analysis.
WTC7 wasn’t hit by a jet.
Eric – from your link:
2) The fires were on the upper floors. The fire affected steel did not have anywhere near the same weight on them as the WTC7.
Funny. Taller building use mre steel to absorb the extra loads i.e. the taller building will be stronger to compensate for the extra height. This is one of the things that limits the height of a building.
The site you link to is for fooling people who do not know structural engineering.
Captain – I have no idea who made the deal. Your theory is pure speculation.
All I know is that it likely wasn’t fire that brought down WTC7.
If the building pancaked as you think here is what it would look like.
Floors pancaked together falling. Meet resistance of next lower floor – decelerate converting motion into elastic deformation of next lower floor. Floor breaks free. Motion of the pancake further slowed accelerating lowest floor to speed of the mass. All the while gravity is now adding to the acceleration of the new larger pancake.
The energy lost breaking the lowest floor free does not get converted back into velocity. It is effectively turned into heat.
If the pancake theory is correct the collapse will not happen at anywhere near the speed of an explosively demolished building where all the supports are removed quickly almost all at once in a precisely controlled manner. And yet WTC7 appears to do exactly that.
Here is a paper which treats that with more rigor than the above explanation:
http://www.benthamscience.com/open/tociej/articles/V005/25TOCIEJ.pdf
When the r/l (diameter to length) of a column is greater than .15 the column crushes and does not bend (think crushing a pop can vs bending it vs crushing one of the old thicker beer cans.). Crushing absorbs more energy. So the tubes derided in your link actually make the free fall scenario less likely. Now you can also get into a mixed mode at r/l between .15 and .03. The mixed mode takes more energy than pure bending but less than pure crushing. It is also less deterministic. Now all this also depends in part on the thickness of the material the tube is made of. Up to a point.
Some good books on the subject:
Structural Design in Architecture
Structure in Architecture: The Building of Buildings
Yawn. The point of proving WTC was bombed is what, that our government is engaged in manipulating the populace in order to achieve complete and total control? We already know that. Snowden confirmed it.
These links might be helpful.
http://www.debunking911.com/moltensteel.htm
http://www.skeptic.com/eskeptic/11-09-07/
http://www.scientificamerican.com/article/fahrenheit-2777/
The 9/11 Truthers remind me of the debate over evolution. There are many gaps and holes in the fossil record and many unaccounted for anomalies. I don’t consider it worth my time to worry about them, because to me, evolution comes down to common sense. So does my rejection of the controlled demolition conspiracy theory. It is simply too outlandish, and requires too much nit-picking, too much hypothesizing, and too much time. (The latter is in short supply right now.)
Rummy does not actively direct air defense. His Commanders in the field do. That’s why they wear stars and eagles on their shoulders. It is what they get paid for. Otherwise it is rote micromanagmeent.
Shortly after 9-11 they did a test with a surplus F-4 on a rocket sled impacting a concrete block at over 500 knots / hour. The test was intended to find out if an aircraft impact would be able to breach containment on a reactor. The F-4 shredded like tissue paper. Aircraft are strong. But they are also very light and not nearly as strong as the ground. Video of the test follows. Cheers –
http://www.youtube.com/watch?v=RZjhxuhTmGk
Simon,
There is testimony from first responders who observed WTC7 bulging and deforming on the lower floors earlier in the day. That’s why all fire and rescue teams were pulled out of the area.
I think that’s also adequate explanation for the mistaken media reports that the building had collapsed. They misunderstood a report that the building was in danger of collapsing.
I suspect there’s plenty of poorly-understood structural dynamics here, but lack of deformation isn’t part of it.
Neil,
You still have the problem of the unexplained sulfur (NIST agrees that is a problem) and molten iron in the debris. You can’t melt iron with ordinary fires. They don’t get hot enough.
There is also a LOT of testimony from first responders about explosions.
I look at the AE911 people as providing an engineering report and critique of government reports. All I can say is that a few days ago I was ridiculing 911 Truthers. I still ridicule most of them. But an engineering report? By sceptical engineers? I attach some credence to that.
And if our government was in on it? So what? They have been in on the Drug War for the longest time. This would just be another.
Not to mention the Global Warming scam.
I must say I’m impressed by the artistry of it. A made for TV movie made in real time. With none of the participants aware that they are on a movie set. The bodies are real.
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Buildings don’t collapse straight down in a nice neat pile. They bend. Sections fail. You don’t get all the supports failing at once (NIST agrees that happened – they provide no explanation). The NIST report says support 79 failed. They do not then explain how all the other supports failed simultaneously or nearly so.
May I suggest a thorough study of the structural design books mentioned in this comment:
http://classicalvalues.com/2014/02/building-fires/#comment-102101
Structural Design in Architecture
Structure in Architecture: The Building of Buildings
It is how I learned structural design. They get very good ratings at Amazon. The comments by the rating people are good too. They go into quite a bit of detail on how buildings fail. What happened on 911 is not what you would expect from the usual types of failure.
In one of the videos one of the AE911 folks said the buildings were 100 times stronger than necessary for the imposed loading which is just what I would expect based on stiffness criteria. The Truther said gravity is hardly a factor in the design. And that is what I would expect based on first principles.
Seeing a building is not the same as understanding building engineering.
Eric,
Your first link says it has to be thermite or explosions. Why not both?
Thermite to weaken the steel explosions to blow it out.
And they assume the thermite has to be applied at floor level. Why? Aren’t the false ceilings in the building good enough cover?
Any way – I like this link for a possible how it was done:
http://911research.wtc7.net/sept11/analysis/scenario404.html
Molten metal was aluminum alloys from the aircraft? I could buy that. Except for this infrared photo of the area some 5 days after 911.
http://www.ae911truth.org/news/41-articles/347-high-temperatures-persistent-heat-a-molten-steel-at-wtc-site-challenge-official-story.html
And how do you explain the melted steel noted by a structural engineer in the debris? (see above ae911 link). Steel will deform from ordinary fires if it is hot enough. It will not melt.
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In many ways this is like getting to the bottom of the Global Warming scam. If you are unfamiliar with the details. Not an engineer. Not conversant with mechanics. Only familiar with materials in everyday circumstances you are reduced to taking people’s word for it. Under those circumstances who would I trust? Certainly not Truthers.
I might change the mind of an engineer or two. Most especially structural engineers, mechanical engineers, or architects. But regular people? Not a chance.
I’m staying out of this one, except to say that I take choice (b) from MMM’s second post. Occam’s razor and all that.
BTW The airliner aluminum is thermite if powdered finely enough and supplied with a source of oxygen. In thermite the oxygen is supplied with iron oxide in direct contact with the aluminum powder. If aluminum powder and air was sufficient for the desired effect you can be sure the iron oxide would be dispensed with.
So burning aluminum? Yes. Hot enough to melt steel and sufficient amounts of it in direct contact with the steel columns to at least weaken if not melt them?
On at least 10 floors if not more? Given the strength of the building compared to gravity loads. Even accelerated by gravity loads? Gremlins hard at work.
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All this would be much easier to sort out if the debris hadn’t been carted away and melted down in such haste.
That was in fact objected to by those who wanted to forensically investigate at the time. I remember that controversy quite clearly.
OK. Enough for link one. Now two.
EXPLOSIVE DEVICES WERE CAREFULLY AND SECRETLY PLANTED IN THE WTC BUILDINGS. You cannot secretly prepare a controlled demolition of the two World Trade Center buildings containing 50,000 workers, plus extensive security systems and guards, working round the clock, without anyone noticing anything unusual.
HVAC “contractors” would be quite sufficient. After hours. So minimal contact with the 50,000 workers. It wouldn’t take an army. Just enough workers over enough time. A building retrofit would do it.
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Point two:
This is what Delft University looked like after the fire:
http://www.archdaily.com/19431/tu-delft-competition-all-entries-exhibition/
Not exactly as described. And what I would expect. Partial collapse of some sections.
So the guy is flat out lying. I’m not going to waste any more time with him.
Randy,
I would be inclined to b) myself and was for the longest time. Until I read the ae911 engineering reports.
Now to the Scientific American link. I will not deal with the politics. I have no idea about the who. Just about the how.
SA says jet fuel did it. Burning jet fuel under optimum conditions You get 1,517 degrees F. Excellent. And further. “steel loses 50 percent of its strength at 1,200 degrees F” very good.
But based on stiffness criteria the building was 100 times as strong as necessary for the mechanical loads. Whoops.
On top of that the jet fuel burns out in 20 or 30 minutes as do the building furnishings. In fact the design criteria without safety factors assumes furnishings alone will burn out in 20 minutes. The safety factor is 3X – one hour before there is a 350C temperature at the structure.
Now after the 30 minutes the structure is cooling. Getting stronger. Whoops. The first building didn’t go down until almost an hour after the hit. Whoops. Whoops. Whoops.
As I said. Unless you know about structure. Building design. Mechanics. Chemistry. Combustion. Physics. All the explanations seem reasonable. I bought them myself until a few days ago. And then I started thinking like an engineer. I have to stop doing that. It gets me in trouble. But on some days it earns me a living.
agimarc,
It is true Rummy does not direct air defense. But in the case of hijackings on that day he was required to give approval.
What was he doing away from his post? Why was he doing a “heroic” rescue mission on the lawn instead of at a “secret location” directing operations?
A lapse of judgment? Could be.
According to Erik Lawyer, founder of Firefighters for 9/11 Truth, officials in charge of the scene admitted that “the majority of the evidence was destroyed.” Building fire expert and editor-in-chief of Fire Engineering Magazine Bill Manning wrote, “Such destruction of evidence shows the astounding ignorance of government officials to the value of a thorough, scientific investigation…I have combed through our national standard for fire investigation, NFPA 921, but nowhere in it does one find an exemption allowing the destruction of evidence. To treat the September 11 incident any differently would be the height of stupidity and ignorance… The destruction and removal of evidence must stop immediately.”
http://www.ae911truth.org/en/news-section/41-articles/350-evidence-destroyed-is-justice-denied.html
Good video on evidence destruction:
http://www.youtube.com/watch?v=TULmLtqRXZ4
In the longer Erik Lawyer video (link in the update to this post) he states that for a very long time he was a non-truther. That pretty much describes my position. Until a few days ago.
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Was the molten metal iron?
In 2005, the United States Geological Survey (USGS) published a report entitled “Particle Atlas of World Trade Center Dust,” which was intended to aid the “identification of WTC dust components.” Among the components, it reported, were “metal or metal oxides” (which could not be distinguished by the USGS’s methods). “The primary metal and metal-oxide phases in WTC dust,” the report said, “are Fe-rich [iron-rich] and Zn-rich [zinc-rich] particles.”[26] The report included a micrograph of an “iron-rich sphere.”[27]
These iron-rich spherical particles – or “spherules,” as they are sometimes called – could only come about if iron is melted and then “sprayed into the air so that surface tension draws the molten droplets into near-spherical shapes.”[28]
Accordingly, the USGS report mentioned (without explaining) the existence of particles in the dust that should not have been there, according to the NIST explanation of the collapses.
http://www.consensus911.org/point-tt-6/
That does not prove the molten metal was iron. Only that a lot of molten iron got aerosolized. Fitting in with my above speculation. About thermite followed by a detonation.
Two questions though. Shouldn’t we see aluminum or aluminum oxide in the dust? Which is part of the thermite reaction.
And where did the Zn (zinc) come from? This report poses as many questions as it answers.
http://www.consensus911.org/point-tt-6/
Jones and his colleagues performed tests using their own samples of WTC dust, which had been collected shortly after the destruction of the WTC – either very shortly afterwards or from the inside of nearby buildings (which means that the dust could not have been contaminated by clean-up operations at Ground Zero). They reported finding “an abundance of tiny solidified droplets roughly spherical in shape (spherules),” which were primarily “iron-rich . . . and silicates.” The iron-rich spherules would have required a temperature of 1,538°C (2,800°F). The silicates often contained aluminum, and aluminosilicate spherules, which were found in abundance in the dust, would have required a temperature of 1,450°C (2,652°F).[29]
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OK. That accounts for the aluminum. Now about the silicates? Glass? That is possible. Where are the aluminum oxides?
Well this is interesting a paper on the points of agreement between government investigators and Truthers.
I will only take up point 3 here.
http://www.benthamscience.com/open/tociej/articles/V002/35TOCIEJ.pdf
3. Pancake Theory Not Supported NIST: “NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers… Thus, the floors did not fail progressively to cause a pancaking phenomenon” [3].
Agreed: the “pancake theory of collapse” is incorrect and should be rejected. This theory of collapse was proposed by the earlier FEMA report and promoted in the documentary “Why the Towers Fell” produced by NOVA [7]. The “pancake theory of collapse” is strongly promoted in a Popular Mechanics article along with a number of other discredited ideas [8, 9]. We, on the other hand, agree with NIST that the “pancake theory” is not scientifically tenable and ought to be set aside in serious discussions regarding the destruction of the WTC Towers and WTC 7.
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I never much liked the pancake theory either. I mentioned it around here I think. Or at least in e-mails discussing the subject. At the very minimum the pancake theory does not account for the rate of fall.
Point 7 of the “Agreement” paper.
7. Fires of Short Duration
NIST: “The initial jet fuel fires themselves lasted at most a few minutes” [4]. “At any given location, the duration of [air, not steel] temperatures near 1,000 °C was about 15 min to 20 min. The rest of the time, the calculated temperatures were near 500 °C or below” [4].
We agree. But then, given that the fires were brief and patchy, how did both towers experience sudden-onset failure of structural steel over a broad area in each tower and how could the collapses of all three WTC high-rises have been so symmetrical and complete? [13, 14, 17] We seek discussion on these points.
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Just for comparison wit the SA article
1,000 C = 1832F
500 C = 932F
That is air temperature.
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And just for the sake of accuracy and because I WAY overestimated. The core was designed to carry double the load it was carrying and the outer walls were carrying only 1/5th their rated load. Plenty of reserve margin. But not near as much as I postulated (100X).
Simon-
It’s not hard to find zinc in an office building. Lots of little parts cast from pot metal. Galvanized fasteners and frames. Things like that. Zinc has a boiling point less than 1000F, so it could have even been raining zinc inside prior to the collapse.
Now about the liquid metal seen in one of Eric’s links and explained as aluminum. Which has a low melting point. Which is actually irrelevant. The color tells the temperature and the metal does not much matter. Wein’s Law. The so called debunking site is supposed to have people knowledgeable in physics. You would think they had heard of Wein’s Law. I have. Maybe it was inconvenient to mention.
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10. Unusual Bright Flame and Glowing Liquid (WTC 2)
NIST: “An unusual flame is visible within this fire. In the upper photograph {Fig 9-44} a very bright flame, as opposed to the typical yellow or orange surrounding flames, which is generating a plume of white smoke, stands out” [4].
“NIST reported (NCSTAR 1-5A) that just before 9:52 a.m., a bright spot appeared at the top of a window on the 80th floor of WTC 2, four windows removed from the east edge on the north face, followed by the flow of a glowing liquid. This flow lasted approximately four seconds before subsiding. Many such liquid flows were observed from near this location in the seven minutes leading up to the collapse of this tower” [3].
We agree and congratulate NIST for including these observations of an “unusual flame… which is generating a plume of white smoke” [4] “followed by the flow of a glowing liquid” having “an orange glow” [3].
With regard to the “very bright flame… which is generating a plume of white smoke”, NIST effectively rules out burning aluminum, because “Aluminum is not expected to ignite at normal fire temperatures…” [3].
Again, we agree. The origins of this very bright flame and of the associ- ated flow of an orange-glowing liquid remain open questions in the NIST report. NIST opened a very appropriate line of investigation by publishing these significant clues from the data, [3,4] providing an important starting point for further discussion which we seek.
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http://www.banksengineering.com/Refrac_Temp_vs_Color_Chart.jpg
An orange temperature would be about 1650F if the color rendering is correct. That is about 900C. So what ever the liquid is – it is not molten iron. Assuming the color rendering is roughly correct.
Neil,
Thanks for the pot metal!
So, here’s a question: What if the curtain walls came down first? There was tremendous damage happening at the top floors–my understanding is that not many of the staff of Windows on the World survived. What if the curtain walls let go at the top, the floors started buckling one by one, and dragged the core supports down after them?
If that is possible, it might explain a lot of this. The sparks and flame as the floor supports let go. The falling curtain walls on the opposite side from the crash zone could have straightened the fall out. The spurts of smoke and debris, as well as explosive noises, as the supports snap.
Then the question is whether converting all that potential energy into heat could have left molten pools of iron in the rubble for the next few days.
Neil,
The NIST doesn’t like the pancake theory.
In addition the curtain walls are very over rated – 5X their actual load. i.e. they were loaded 20% of their rated load. Failure in some sections? Sure. Total failure? Not likely.
BTW better gradations for Wein’s Law (text) page 8 here:
http://www.journalof911studies.com/volume/200609/Why_Indeed_Did_the_WTC_Buildings_Completely_Collapse_Jones_Thermite_World_Trade_Center.pdf
Why the metal coming out of WTC 2 was likely molten iron/steel. (Same link as above)
Was it Molten Aluminum or Iron with Experiments.
Simon –
I think you are misinterpreting the safety factor and stiffness criteria.
In most construction, safety factor is 1.5. This means that the structure needs to be able to handle 1.5 times the design load without complete failure.
Stiffness does not deal with all loads on the structure, only those involved in flexing or torsion, which are normally wind or earthquake induced. Most of the load on the structure is keeping the bloody thing upright, erect, and in one piece.
OTOH, you can build 100% over the design loads without being overly massive. I think the AE911 guy misspoke.
Aerospace structures used to be built at 1.25 the design loads. Don’t know what they are done to today.
Last on Rummy – the air defense order was already given. The plan was being executed by the uniformed military including delegation of shoot-down authority. He had done his job pulling the trigger. Cheers –
Aircraft have a 10% safety factor. They are designed to carry 1.1X the rated load. They make up for the low design margins with frequent inspections.
It has been 1.1 for as long as I can remember.
Thanks on the Rummy info. I believe you are correct. Or it doesn’t matter because subordinates had already made the decision.
I don’t know what skyscraper design safety factors are. Building construction is normally 2X because of the low quality and poor ethics of the construction industry. Cheating on cement quality is notorious.
And you may have missed my
“And just for the sake of accuracy and because I WAY overestimated. The core was designed to carry double the load it was carrying and the outer walls were carrying only 1/5th their rated load. Plenty of reserve margin. But not near as much as I postulated (100X).”
from up thread.