The Madrid fire, WTC7, and a conversation with my wife this morning.

[robertpaulsen]

For those unfamiliar with the Madrid office building fire:

Madrid's Biggest Fire Destroys Skyscraper

MADRID (Reuters) - A fire described as the worst in Madrid's history ravaged a 32-story skyscraper in the Spanish capital's financial district on Sunday, causing no injuries, but the tower stayed upright despite fears of collapse.

http://story.news.yahoo.com/news?tmpl=story&cid=564&ncid=564&e=13&u=/nm/20050213/ts_nm/spain_fire_dc


Seeing the destruction that this fire inflicted on this skyscraper, I couldn't help thinking of the collapse of the 47 story WTC building 7 on September 11, just eight hours after planes crashed into the north and south towers. No plane crashed into WTC7 along with the accompanying tank of jumbo jet fuel that melted the steel support structure of the north and south towers. (I believe that's the official story anyway.) Yet from the fires created by debris crashing into WTC7, we are supposed to believe the fire was so intense that it caused WTC7 to collapse in its own footprint eight hours later. Comparing the destruction of WTC7 with the destruction of the Madrid building, that just doesn't seem plausible.

http://911research.wtc7.net/wtc/analysis/compare/fires.html
http://news.globalfreepress.com/movs/wtc-7_collapse.mpg

So this was the subject during breakfast this morning with my wife. I'm thoroughly convinced that our unelected government either actively participated in or allowed the attacks on September 11 to happen on purpose. My wife, while despising the misadministration with all her heart, is not so convinced. However, both of us believe there was a cover-up by the US regarding the full truth of 9/11. (I don't see how anyone could not. 28 censored pages in the congressional report on 9/11 is proof of a cover-up. The only question is what are they hiding and who does it implicate?) http://www.cbsnews.com/stories/2003/07/30/world/main565782.shtml

So the point I tried to make with my wife in comparing the destruction of these two skyscrapers was that WTC7 had to have been brought down by explosives, which proves conspiracy. My wife approached it from another angle that I had not thought of. Perhaps, in the aftermath of the 1993 WTC bombing, a decision was made to wire the WTC buildings with explosives so that, in the event of a fire or another terror attack, the building could be detonated so that it would not crash into other unaffected buildings. I hypothesized further that perhaps this is what WTC leaseholder Larry Silverstein is referring to when he says the decision was made to "pull" WTC7. http://www.whatreallyhappened.com/wtc7.html
Perhaps the twin towers were also wired with explosives and the fires from the planes triggered the bombs, causing them to fall in their footprints. Perhaps the government is only covering up their incompetence and prior secrecy.

Far-fetched? Perhaps, but no more so than some other theories I won't mention to avoid unnecessary flames. I don't believe it myself, the current misadministration wouldn't pass up the chance to expose Clinton-era secrecy, and I don't see the reasons for keeping such a security measure a secret in the first place. But I don't think any theory should be blithely dismissed regarding the reason for the collapse of WTC7. The "independent" 9/11 Commission never mentioned WTC7 once in their report of their investigation, so I believe the truth behind the collapse of WTC7 on 9/11 is still wide open for discussion.

[SheilaT]

1. When buildings are wired with explosives

it takes weeks, sometimes months (depending on the size of the building) to do the job. And that's working 8 hours per day on the wiring. With no need to cover the evidence that the building is being wired.

How long do you suppose it would take to fully wire the Twin Towers with such explosives. How difficult would it be to do this in secrecy, so that not a single person who worked there would have any idea that such a thing was being done. What would be the logistics of getting crews in, doing the wiring, and then covering up all the evidence at the end of the night (since presumably this would be done at night, when most regular employees have gone home) so that not a singe worker would ever suspect something strange was happening overnight.

Also, in my limited understanding of explosives, they are not terribly stable, and to suppose that a building could be wired, and the explosives simply left in place for an indeterminate number of years, and not have to worry about them going off, or become unusable, seems counter to the real shelf-life of explosives.

The fact that the building in Madrid did not collapse says little or nothing about how and why the twin towers and WTC 7 collapsed. Jet fuel burns at a very high temperature, despite claims to the contrary.

Anyway, please think through some of the implications of the notion that the buildings in NYC were wired, and perhaps you'll decide that particular scenario is quite unlikely.

[robertpaulsen]

5. About those jet fuel burns...

What does that have to do with WTC7? Take into account the fact that no plane along with the obligatory tank of jet fuel crashed into WTC7 and I think you'll have to agree the question of how WTC7 collapsed in its own footprint is very much open for discussion. And the non-collapse of the Madrid building illustrates that point. I'm not saying I have the definitive answers. I am saying that NOBODY in authority has definitively answered the questions.

Have you read or listened to what Larry Silverstein has to say on the subject? What's your interpretation of that?

[SheilaT]

6. I happen to think

that coming up with the theory that the WTC buildings were all wired with explosives simply isn't one that holds together. Buildings that burn have been known to collapse. They usually collapse straight down, rather like the TTs did. The Twin Towers were EXTREMELY tall buildings, and so as they collapsed they build up and incredible amount of momentum. I believe that each collapse was the equivalent of a small, localized earthquake.

I don't claim to be an expert. But I've read plenty, and I like to think I recognize sloppy thinking when I see it.

[robertpaulsen]

12. "Buildings that burn have been known to collapse."

Could you provide an example of a skyscraper besides the WTC buildings that collapsed "straight down"? Please read the links I provided in my OP, I know of no other skyscraper in history that has done so without being wired.

I don't claim to be an expert either. So the more evidence that can be provided, regardless of your theory, the better.

Oh, about each collapse being the equivalent of a small, localized earthquake? You're right. That's exactly what happened on 9/11. Columbia University recorded a 2.1 shock when the south tower collapsed and a 2.3 shock when the north tower collapsed. Funny thing, though. The strongest spike occurred at the beginning of each tower's collapse.

http://www.reopen911.org/Tarpley_ch_6.pdf

[SheilaT]

21. So sorry that I can't provide a link

but I've seen news footage in the past of multi-story buildings collapsing pretty much straight down, although not with the total destruction of the twin towers. Again, keep in mind, that these were huge buildings, much, much larger than pretty much any other building out there.

[robertpaulsen]

24. That's OK. But remember, the focus of my OP is WTC7, not the twin towers.

I'd like to direct you to post 13 by Minstrel Boy, for an even more appropriate comparison for what an absurd idea it is that WTC7 fell in its own footprint after only burning for 8 hours without having a plane crash into it. And here's a link for the story Minstrel Boy is referring to:

http://www.cbsnews.com/stories/2004/10/18/world/main649824.shtml

Do you see now my incredulity?

[Bolo Boffin]

27. WTC 7

Larry Silverstein's "pull it" is not invoking the demolition meaning of that phrase. He was talking to a firefighter. The term "pull" for firefighters means to abandon a dangerous building to the uncontrollable fire engulfing it. It's a throwback to days before radio communication, when such an abandonment was signaled to the firefighters on the front line by pulling on the fire hose.

Silverstein makes that clear by repeating the word "pull" in his next statement: "so they pulled". They, being the firefighters.

WTC 7 didn't have a plane crash into it. It did have one of the Twin Towers fall into it, ripping out a pedestrian walkway connecting it with that very tower. Eyewitnesses have reported extensive damage to the side facing the towers after the collapse of the last tower. As much as 25% of some floors were gouged out by the falling debris.

There is no scientific evidence to believe that WTC 7 was anything more than a classic progressive collapse.

[Blackthorn]

31. .....

"WTC 7 didn't have a plane crash into it. It did have one of the Twin Towers fall into it, ripping out a pedestrian walkway connecting it with that very tower. Eyewitnesses have reported extensive damage to the side facing the towers after the collapse of the last tower. As much as 25% of some floors were gouged out by the falling debris.

There is no scientific evidence to believe that WTC 7 was anything more than a classic progressive collapse."

If as much as 25% of some floors were gouged out, presumably from the side, not the middle, then why did the building collapse in its footprint, rather than collapsing over the side of the building that was damaged? The video of WTC7 collapsing is consistent with controlled demolitons.

I also suspect the TT were controlled demolitions as well.

[Dancing_Dave]

60. WTC 7 was NOT right across the street from EITHER of the towers

Really, Boloboffin, you ought to at least look at a map before you make this official B.S. up!

[Bolo Boffin]

132. Did that feel good, D_D?

Catching me in an obvious mistake?

Yep, WTC 7 was not right across the street from the towers. There was a building between the towers and WTC 7. I was wrong.

Nevertheless, a pedestrian walkway was torn out of WTC 7 when the towers collapsed, and severe damage to the tower-facing side of WTC 7 was observed, as noted in the PM article. Include that raging, abandoned fire, an unusual design in the building's structure, and an emergency fuel tank or two into the mix, and you have more than enough ingredients for a "classic progressive collapse".

About that, I'm still right, and no amount of "doesn't it look like a controlled demolition" will prove that theory wrong.

[robertpaulsen]

62. Interesting interpretation.

I'm curious, is that Larry Silverstein's clarification on his prior statement? I can certainly see the possibility that he was NOT referring to detonating the building, because there was no way the building could have been wired for detonation after the attack. It would have to have occurred before 9/11, which would make it a conspiracy. I find it highly unlikely that Larry Silverstein, the leaseholder, would be high enough up the neo-con food chain to be privy to such a plot. So I concur with you, boloboffin, Silverstein may not be referring to demolition. But do you know whether he ever did clarify that?

Regarding that pedestrian walkway, I'm not sure whether that would be sufficient to imply the foundation was compromised. I know you didn't say that specifically, but many other DU posters have said that, but I have yet to see a link that proves this. Do you have a link to that statement that 25% of some floors were gouged out? It would be very interesting to know which floors those were and where the damage occurred. Obviously, since FEMA hasn't yet determined what exactly brought WTC7 down, as paulthompson showed in his post, any information regarding this is of great importance.

[TankLV]

16. You are closer to the truth. And I AM an expert on this subject.

Anyone who claims such a thing as explosives, etc. doesn't have a CLUE as to what they are talking about.

It hurts the larger search for truth.

[ashmanonar]

20. the only thing that hurts the larger search for truth

is someone claiming that they have the only answer. someone giving into authority blindly without considering the validity of other explanations, or their evidence. someone bashing every other explanation, with or without cause or evidence. were you in the buildings for months ahead of time, watching to see that explosives weren't put up? did you tour them constantly, looking into all the hidden crevices that could hide such explosives?

no?

then do you really know?

[punpirate]

8. Except for one thing....

WTC7 did not suffer nearly enough damage to collapse on its own, and the owner has said that it was "pulled" down. That describes intent, not accident.

As for explosives, yes, dynamite is fairly unstable, but new plastic-based explosives are not. They remain stable for quite some time. As for installation, I suspect that such could go on unnoticed, disguising it as ordinary electrical work. In fact, it could be done using the building's own electrical system. Yes, it would take weeks to do, but in such buildings, maintenance is ongoing and could have been hidden by, say, upgrading network wiring, or some such.

There's a curious little article in a building maintenance trade magazine from a couple of years ago in which one of the maintenance supervisors of the towers was interviewed, and in which he described significant damage in the sub-basements of the building occurring shortly after the plane hit, despite the fact that he only felt a thump when the plane hit the building. Since he was on duty when the 1993 bombing took place, his first reaction was "they've done it again," meaning bombs in the basement of the building.

He also described what seemed to be a large press brake (with a weight of likely ten to fifteen tons) in one sub-basement room going through a reinforced floor into the room below, an exceedingly unlikely event to happen in the basement of a building designed to take the shock of an airplane striking it. He went on to describe other damage in the sub-basements consistent with an explosion, rather than from the shock of an aircraft striking the building eighty stories up.

I'm keeping an open mind about all this, but, with regard to WTC7, specifically, it was intentionally taken down, and that meant the work to do it had been done before the attack.

Cheers.

[WoodrowFan]

23. as has been explained numerous times

as has been explained numerous times the "pull" command was to pull out the firemen and let the building burn. sheesh.

[Garbo 2004]

28. Actually Silverstein didn't specifically say that the building was

pulled down or intentionally demolished. That interpretation still requires some extrapolation if you read/hear the text. One can also extrapolate it referred to pulling any efforts to fight the fire/save the building, and/or "pull it," as in write it off, declare it lost.

I have a video recording made by a free lance photographer/former NYC EMT on the scene after the towers collapsed. No real production values or commentary. Just a guy in different areas of the scene, filming.

But it was interesting to note WTC 7 was indeed burning and smoke was coming out along one side of the building from bottom to top. I'm figuring it's the Vesey Street side (looking at a pic on the net), across from WTC 6. (There was also some fire on what I think must be the Washington Street side, but it was still adjacent to the Vesey side.) This was not what I recall seeing in other depictions of the building where from front or back or on the other side it looked ok and intact. There appeared to be damage not just at the top (which appeared minor) but also more substantial damage toward the bottom on that same side (Vesey and Washington Street) from what I could see. From that view the building sure was not in as pristine condition as it would have appeared from other perspectives.

Since the video has mainly just ambient sound, one can hear radio calls and occasional talking around or apparently with the guy filming. Unfortunately the video isn't time stamped. Regarding WTC 7 there's various comments over time. One guy said "There's no water on that." (There's talk about having no water.) Much later someone says "It's hot enough to...(garbled with background noise)...that's why he's pulled everybody out of there." Another voice says, "That building's 50 stories, it could definitely reach you over here." The "here" was well more than a large NY block away from WTC 7. Sounded as if there was concern it would topple over on its own rather than there was going to be a controlled demolition. Later the camera's back on WTC 7 and a voice says: "Look at the hole in that building...(garbled, too much other noise)..it looks like it's going to come down." Another voice: "Let's get everyone out of here." It was evident to me anyway that the concern was about WTC 7 collapsing as a fire truck and equipment were pulled back from what I guess was WTC 6.

Unfortunately the tape doesn't include the building going down.

I just don't see if it was intentionally demolished, why do so that day and why the alleged secrecy. Now the FDNY isn't into demolishing buildings as far as I know. That takes specialists. And if the FDNY knew that it was going to be demolished that day since Silverstein had talked to them, the guys on the job sure didn't seem to know about it. Why supposedly secretly demolish a building that looked like it was pretty well trashed on its own (at least potentially structually suspect to me)? Other buildings were demolished since the damage they sustained made them structurally unsound. Those weren't secret. And how convenient that, given the big secret of the alleged demolition, Silverstein would supposedly "slip up" and reveal the secret in a pretaped interview for a TV show? Silverstein was going to get insurance money one way or the other out of that and the other buildings. I just don't get what the alleged motivation would be for this sort of alleged action/coverup. What would be the point?

Also what about the structural design since it was built apparently on/around a Con Ed substation? I saw something about the reconstruction and they were remarking how they were building it stronger, that the original design around the substation was weaker and may have contributed to the collapse. Whatever.

Anyway, the video I saw suggests a greater amount of visible structural damage to the building than I previously saw from other videos and photos and that firefighters were concerned about the building collapsing based on what they were seeing. (No doubt especially after having two other buildings falling on them they weren't going to take another chance.)

[Colorado Blue]

32. There is a phenomenon known as "punch-shear" - hope...

I'm spelling it correctly.

Stress occurs where the force of the pillars, the internal pillars that support the building, meet the slab floor.

Big buildings are engineered in such a way that the rebar - the reinforcing steel bars that help harden the concrete slabs - and the strength of the concrete itself - carry and distribute the thrust force of the columns.

Occasionally, due to improper type or positioning of rebar, poor concrete, or other factors such as sudden stress, the balance of the floor gets out of whack. In cases like this the punch-shear phenomenon occurs. Instead of the force being distributed evenly across the floors cracks appear. They can appear slowly over time or all at once. But at a certain point, the integrity of the floor slab is compromised and it shatters, falling straight down.

Buildings have collapsed EXACTLY like WTC7 and for far less obvious reasons. There was an unfinished 5 story building in Florida that pancaked and a huge department store in Seoul, Korea, that pancaked and killed hundreds of people. These cases were detailed on the History Channel series about engineering disasters. You can probably get tapes.

Both occurred due to punch-shear but for different reasons. The Florida building had rebar inserted into the slab on one floor in steel "chairs" - support for the rebar - that were the wrong height. In the Seoul disaster additional floors were added to the building against the advice of the original engineers. This caused the building to collapse and the owners went to jail.

My point: WTC7 looked just like the films of those two buildings. IMO it fell due to the stress incurred during the attacks.

This is a known engineering phenomenon. Skyscrapers are, for all their strength, delicately woven structures in which all the forces must be carefully balanced. Similarly, in Towers 1 and 2, horrendous stresses due to fire and structural damage - unforeseen stresses - occurred.

I do not see any reason to suspect internal explosives. I'm NOT an engineer by the way but I love skyscrapers and have studied how they are put together and used to manage one. There are excellent documentaries on the subject; try the History Channel.

[vincent_vega_lives]

38. Detonators

are NOT stable. Vibration, static electricity, can set them off.

"As for explosives, yes, dynamite is fairly unstable, but new plastic-based explosives are not. "

No but they burn very nicely.



"They remain stable for quite some time. As for installation, I suspect that such could go on unnoticed, disguising it as ordinary electrical work. In fact, it could be done using the building's own electrical system. Yes, it would take weeks to do, but in such buildings, maintenance is ongoing and could have been hidden by, say, upgrading network wiring, or some such."

Very risky to say the least. It only takes one person with knowlege of electrical wiring or explosives to blow the whole thing. How many people worked in the WTC? 50,000?

[Sterling]

15. Is it true Neil Bush is part of the security company for the WTC?

If that were the case that might offer an explanation?

[DrWeird]

2. It was chupacabras.

that were flying UFOs.

[Skink]

3. Building 7 holds the Key

[DrWeird]

4. The Key to Atlantis?

agreed.

[Middle Finger Bush]

10. WTC7 was control demolished

The evidence is right in plane sight...

How/Why?

[Sterling]

17. Check this out...

http://shadowgov.info/video_wtc7.html

[disillusioned1]

7. The Madrid building is still standing

after burning for 2 days. The structure's frame is concrete, which is less fire-resistant than steel, per my Fireman brother in law.

Can anyone else substantiate his claim about concrete? I've been looking all day.

[LARED]

11. Concrete is more fire resistant than steel

They are two different animals in terms of how they behave in a fire. To grossly simplify it, steel will loose much of its strength at temperatures well within a normal office fire, concrete does not.

As an example an oil refinery, where fires are always a concern, the main supports of the large steel structures are covered with a thick concrete layer to protect the steel from high temperatures.

[TankLV]

18. Actually, concret is quite an effective fireproofing.

Concrete columns and structure don't require additional "fireproofing" because of the nature of the sheilding of the concrete.

They are the best fireproofing-wise.

Concret is the most fire-resistant structural material you can have.

Your fireman brother should stick to what he does best and that is fighting fires, not assuming knowledge of structural issues, of which he has proven he know absolutely NOTHING.

[never cry wolf]

25. Agreed

I am an architect and concrete is about the best way to fireproof a builging. While steel doesn't burn, it does lose it's strength properties. It also has a much, much higher coeficient of thermal expansion and thermal transmission than does concrete.

There would certainly be steel embedded within the concrete, as concrete works great under compression, but sucks in tension, so steel (rebars or embedded structural steel shapes) are added into this combined system to take the tensile loads and the concrete very effectively insulates it.

Also, the buildings did NOT fall in their footprint, debris was scattered for blocks but due to the scale of the buildings, and their height, it appeared they fell into their footprints. If you jumped from the top (as many unfortunatley did) and tried to leap as far away from the building as possible, your arc would be a parabola that soon would be indisyinguishable from a straight vertical drop. Gravity sucks, it pulls things as straight as possible towards the center of the earth at an acceleration of 32 ft. per sec. squared. Do these people expect that it would fall like a tree being logged? Buildings collapse and fall down, they don't fall over.

Don't get me wrong, I am heavy LIHOP bordering on MIHOP, but the way the buildings fell are not evidence of that in any way. Of course the only building you've seen collapse seemingly straight down were by controlled demolition. How many other types of collapses have you ever seen? That is the way buildings fall, in general.

[Dancing_Dave]

108. A whole lot of the Twin Towers scattered far and wide.

They were blown to smithereens, as this aerial picture of the North Tower shows:



The physics analysis of this requires energy inputs (such as explosions) far larger than the fires and gravitational "collapse" can account for:

http://911research.wtc7.net/papers/dustvolume/volumev3.html

[AZCat]

113. Response to energy imbalance

I looked at the web page you link in your post. I haven't gone through all of Hoffman's calculations yet because I wanted to address something else first using his results. I was curious how much explosive material would be necessary to restore balance to Hoffman's calculations. I have had difficulty figuring out how to calculate the energy released with RDX/HMX composites so I will be using the numbers for TNT.

Missing Energy from Hoffman's Model

At the bottom of the page Hoffman lists his energy analysis conclusions. Summing the most conservative of his estimates (using the second set of heat sink #s) gives a net energy deficiency of 2,706,000 KWH (9,741,600 MJ).

TNT Energy Calculations

TNT has a specific combustion energy of 4.6 MJ/kg, so it would take about 2.1 million kg (2300 english tons) of TNT to contribute the "missing" energy in Hoffman's model. Since pure TNT has a density of 1.654 g/cm^3, this is the equivalent of 1.28x10^9 cm^3, or 1,280 m^3. This is a cube with about 10.8 meters (35.6 feet) per side. Obviously this wouldn't have to all be lumped together (someone might spot a block of TNT that size).

Comparisons With Other Exposives

As I said above, my attempts to calculate the specific combustion energy of plastic explosives were for naught. I can, however, give some idea of how they compare to TNT.

RDX dates back to WW2 and is a component in many compound explosives including C-4 and Semtex. You may recognize the name from the Al Qaqaa stories last fall. It has a density of 1.82 g/cm^3 (slightly more dense than TNT) and from what I read is between 140% and 180% more powerful than TNT. Using the lower and upper bounds of this, I can estimate how much RDX would be used. The lower estimate (140% power of TNT) requires about 1.51 million kg of RDX (1,667 english tons) or a cube measuring 9.4 meters (30.8 feet) per side. The upper estimate (180% power of TNT) requires about 1.18 million kg of RDX (1,297 english tons) or a cube measuring 8.6 meters (28.4 feet) per side.

Aluminum Nitrate / Fuel Oil (ANFO) is a well-known explosive (aka the fertilizer bomb) that, when purchased commercially, has a density of 0.88 g/cm^3. It is slightly less powerful than TNT, with a specific combustion energy of 3.88 MJ/kg. Our energy requirements would take 2.51 million kg of ANFO (2,768 english tons), or a cube with sides measuring 14.2 meters (46.5 feet).

Comparisons to Other Bombs

The Oklahoma City bombing of April 19, 1995, used 2,300 kg (2.5 english tons) of ANFO explosive. This is approximately 0.09% the size of the WTC energy deficiency.

The World Trade Center bombing of February 26, 1993, used 600 kg (0.66 english tons) of a mixture of substances: urea pellets, nitroglycerin, sulphuric acid, aluminum azide, magnesium azide, and bottled hydrogen. As I cannot calculate the explosive power of this mixture I cannot compare the size of the explosions, only the size of the bombs.




I hope you find this interesting. If you find a mistake or have something to add, please post a reply.

[LARED]

116. I think you will need A LOT more TNT

This comment is based on Mr. Hoffman's analysis only and in no way indicates it is valid method.

Mr. Hoffman calculation for the energy to grind and heat the concrete assumes concrete was the only solid material that was heated to 1400 deg F. :crazy:

He forgot about the thousands of tons of wallboards, vermiculite, glass, insulation, papers, etc. By only calculating the mass of the concrete he has missed an enormous requirement for energy.

[AZCat]

117. I know, but it is a starting point

I also had difficulty downloading and reading the pdf for the FEMA studies - if anyone knows how to actually get these opened I would appreciate it - so I couldn't check some of the stuff in Hoffman's analysis.

I just wanted to get an idea of how much TNT we were talking about in general. I admit that I expected several orders of magnitude more, but there is a definite possibility I made a mistake somewhere and I hoped some kind person would check my work. It's still a much larger amount of explosives than used in the '93 bombing, for example. I'm going to look for info on amounts of explosives used in actual building demolition work so I can compare that also.

My theory was that if we could determine that the amount of explosives was too large to be possible then we could rule out "controlled demolition" once and for all.

[LARED]

121. It's a good theory

but I wonder what volume the explosives would need to be in order to get the true believer to acknowledge controlled demolition is not required to bring down the towers?

Also even using Mr. Hoffman's method to disprove his own theory is giving it far too much legitimacy.

[AZCat]

123. Even if it were proven physically impossible...

I doubt it would achieve much "penetration" into the CT community. Some of this stuff is done for my own benefit, as I find certain problems "interesting" and like to discuss them.

When the NIST report comes out (hopefully this summer) maybe I'll update my results using their numbers.

[demodewd]

118. and your point is?

And your point is? It would take even more energy to pulverize the composite of materials leaving less to create such a high temperature of escaping flow?

[LARED]

122. My point is quite simple

His "analysis" is nonsense for a host of reason.

One being if the missing energy requires a massive amount of explosive materials to explain the destruction it needs to be located inside the building at critical locations like columns and beams. If the amount becomes so large it is ridiculous to imagine it would be unnoticed in an occupied building the controlled demo theory falls by the wayside.

[demodewd]

124. collapse characteristics

The characteristics of the collapse point to planted explosives for a number of reasons.
1. The rate of collapse,near free fall.
2. The speed of the pyroclastic flow.
3. The lack of a "hammer" as exhibited especially with Tower 2.

I could go on..

I would like to ask you this... How do you explain the tilting of the top section of the South Tower. I interpret as the top section being completely severed from the lower section because the core was blown out and the floor by floor explosives started at the crash point.If the east wall were to give out,wouldn't the top section begin tilting in that dirction? Instead it tilts to the west.

I believe the core was blown out...I don't know about each floor. How difficult would it be to plant plastic explosives that were triggered by radio transmission?

[AZCat]

125. It's not a pyroclastic flow

Pyroclastic flows are from volcanos. Unless I have missed a new theory, volcanic flows have nothing to do with the events of September 11th.

Hoffman states that the "dust clouds behaved like pyroclastic flows", not that they are pyroclastic flows. While I may not agree with him (I haven't decided) there is a distinct difference between his claim and yours.

[demodewd]

126. OK

OK Stand corrected. The dust clouds behaved like pyroclastic flows.
That doesn't refute any of my claims.
You tell me why the South Tower tilted away from east wall?

[AZCat]

127. Thanks

I know my literalist rants can be irritating, but thanks for correcting the statement. I appreciate it.

Regarding your south tower theory, why do you think it was necessary for explosives to be placed both at the core and on each floor, or are you guessing because of the collapse sequence that the floors were demolished individually?

Regarding a lack of hammer/pancake in the south tower: there are generally multiple failure paths for complex systems such as buildings, and I think it is incorrect to claim that both towers should have collapsed in the same way absent any extra influences (i.e. controlled demolition).

One of the theories I have heard about the south tower "split" is that the single-bolt connection between the floors and the external columns played a significant role in the collapse, and that double-bolt connections should have been used. When these bolts sheared the building began to collapse. I don't know why it tilted the way it did, I am interested to see what the final NIST report has to say.

[demodewd]

128. quandry

NIST is a government subsidized agency ...so they obviously aren't going to contend with exposives ideas.

I observe the top section exploding from the bottom up in similar fashion as the bottom section exploding from the top down.Lared is convinced that the top section was "disintegrating". By exploding in a similar fashion as to the base? That's "disintegrating"?Boy...that's awfulfast for a block of a building to disintegrate in such rapidly violent fashion.

I contend that if the top section were falling down immediately on the base you would have seen an intermingling of smoke filled dust from the top and the greyish white dust from the bottom. Instead there is a sharp delineation of the dust colorations of the two sections.

To me the bottom section of the top is detonated and that creates a second or two where that part is actually suspended in air by the detonation's violent momentum. Of course the rest of top section continues to fall in the meantime. But it is this initial second or two where the top secion is not immediately falling on the base that puts me into quandry. What force is causing the top of the base to instantly begin to pulverize if the top section is not immediatly falling down onto it?

[AZCat]

129. I don't know of a good way to answer your questions

I think you're stuck in an unfortunate position - the agencies with the resources available to study your questions are not going to address those questions.

Regarding the speed of "disintegration": Once a structural member fails, the load borne by that particular member must be transferred to other structural members. If they are then loaded beyond their capacity, then they also will fail. This can happen very rapidly. The impulse (the transient load) isn't quite as problematic. I saw an interesting study done on the pressure vessels used to contain nuclear core detonations during testing. The length of the impulse in that case was very short (on the order of milliseconds IIRC) but if it could be dampened before a certain amount of deformation occurred in the containment vessel then the vessel could survive, even though the load spike of the impulse was very high (several times the yield strength of the materials).

An interesting comparison is with the Hyatt Regency Walkway collapse in Kansas City in the early eighties. Design flaws caused the supporting members to be much weaker than they should have been. When one was overloaded during an opening celebration, the rest just popped and the walkway rapidly collapsed, killing around 100 people IIRC.

I have not done much investigation into the dust issue discussed here. I have noticed that it pops up occasionally and I think I will look into it, but I can't really offer an informed opinion right now.

[LARED]

130. Q & A

1. The rate of collapse,near free fall.

This is another internet myth. The collapse of the towers took around 12 to 15 seconds. It is very difficult to determine the end point of collapse. What is observable is that at the free fall time of just under 10 seconds, the tower were still collapsing.

Why do you continue to repeat this myth when you know it is false?

2. The speed of the pyroclastic flow.

The speed of the dust cloud is related to explosives in what way?

3. The lack of a "hammer" as exhibited especially with Tower 2.

What is a 'hammer' and why do you think it existed?

[peacetalksforall]

9. That morning my gut told me that there were explosives. Can't

substantiate it with logic.

[ashmanonar]

26. i can.

linky

to shorten it: the dust clouds of the towers grew at a faster rate and to a greater volume than can be accounted for considering all the energy sources and potential energy of hte towers. thus, something was adding heat energy to the fall (explosives?)

also on that site is further explanation of explosives being on-site.

[vincent_vega_lives]

43. That is NOT how controlled demolitions work.

You don't "add energy". You simply kick the legs out and let gravity and let all that potential energy you mentioned do the work. WTC 1 & 2 was like no "controlled demolition" ever engineered.

[ashmanonar]

54. maybe that's the point.

and that's why none of this makes sense.

everyone who saw the collapses (who had training) said it: the buiildings seemed to EXPLODE; not IMPLODE like a conventional demolition. they burst out with all this debris, when a conventional demolition looks more like the wtc 7 fall- straight down with debris coming up at the end.

[vincent_vega_lives]

59. Correct it did not IMPLODE

conventional demolition works from the bottom up. The WTC 1&2 worked from the point where the aircraft hit.

Think about it, the floors of the WTC were 4" thick concrete the size of half a city block, aprox 10' apart verticaly, the mass of 20 of them collapsed all at once on one, initiating the sequential pancaking. Each floor DID literally explode, along wihth all the drywall, office stuff, everything, forced out by the volume of air suddenly going from several thousand cubic feet to zero in a fraction of a second.

[ashmanonar]

65. :/

something doesn't seem right about the sequence tho. it seemed to expand out of the windows BEFORE the top had really caused the air to compress. (as in each layer of windows exploded outward all around before the top had reached it). i agree that a falling building will have air compression. but the series of compressions just seemed mis-timed. and there's still the question of the dust cloud expansion: its volume was several (nearly 10x) the volume of the tower, and the potential energy of the tower: why was the dust cloud so large, and so dense? from reports and from the videos, it seemed more like pyroclastic ash behavior than dust behavior. why would the concrete powder itself on the way down, and leave a pile something like 2 stories tall?

something just doesn't seem right about the whole sequence.

[LARED]

66. Let me take a stab at this

There were X (5 to 10 as an estimate) number of floors pancaked inside the towers before the exterior walls gave way. This is why the venting takes place below the line of collapse.

The dust cloud becomes a lot less mysterious when you remember that the WTC was filled with wall board and ceiling tiles. Hundreds of offices on each floor. Also the stairways and elevators each (something like 40 or 50 of them) had 2.5" in wallboard as fireproofing on each side. Also each exterior column was filled with vermiculite between the steel and the aluminum facade. If memory serves me correctly there was 8 million pounds of it in each tower. All of those materials are very friable.

[ashmanonar]

67. i'm not the one who came up with this.

911 Research

look at it, and think with an open mind. on that site the math is all done.

i'm not saying either you or the owner of the site is right or wrong. just think about it, and try to not be biased to either pole of the theory.

[LARED]

71. What math?

If you want to believe that pile of nonsense, have fun. Did you notice almost none of it has a name attached to it. Wonder why? I don't. The only name I saw was Jim Hoffman. Zero credibility.

Nearly all of it was debunked over two years ago.

[demodewd]

72. the debunker

Nearly all of it was debunked over two years ago.

Debunked by you no doubt.

[ashmanonar]

74. don't ya love the unsupported statements?

cuz yea, i'm enjoying it. :D

[LARED]

75. Unsupported statements?

Are you referring to mine or the hundreds on the web page you linked?

Again I'll ask where is the math?

I read stuff like this and snicker.

The towers' tops mushroomed into thick dust clouds much larger than the original volumes of the buildings. Without the addition of large sources of pressure beyond the collapse itself, the falling building and its debris should have occupied about the same volume as the intact building.

This is true only in someones fantasy land. If you genuinely are interesting in the facts, spend some time getting an understanding of the relationship between particulate matter and opacity. The anonymous person that wrote that is either willfully ignorant or a shyster.

I have no intention of taking each section of the "research" and explaining why the anonymous person that wrote it is full of crap. If you want to believe it, suit yourself. Life is full of choices.

[ashmanonar]

78. there is math on that site examining the discrepancies of the thermal

dynamics. i just can't remember precisely which page on the site.

since you didn't provide a link or evidence to the claims of "that site was debunked 2 years ago", then yes, i'm calling them unsupported statements.

when you do provide evidence, i will look over it and decide for myself.

i'll let you know this much: you and vincent vega lives have shaken my reasoning in this more than anybody ever. for that i salute you.

[LARED]

80. Ok

I stated;

The dust cloud becomes a lot less mysterious when you remember that the WTC was filled with wall board and ceiling tiles. Hundreds of offices on each floor. Also the stairways and elevators each (something like 40 or 50 of them) had 2.5" of wallboard as fireproofing on each side. Also each exterior column was filled with vermiculite between the steel and the aluminum facade. If memory serves me correctly there was 8 million pounds of it in each tower. All of those materials are very friable.

Apparently you do not believe this or discount it as a reasonable explanation for the large amount of dust. If true, what part of what is said is problematic?

[ashmanonar]

84. i missed that, apparently.

i'm not an engineer, or an architect. but the "dust" cloud, which behaviorally was more like a pyroclastic flow than a dust cloud (in terms of speed of advance, density, etc.), expanded at a far greater rate than what would seem to be logical. (i wish i had the math of it figured out, or the time and patience to figure it all out.)

i'll admit, this explanation isn't perfect, but it's a start.

besides, there's another factor which seems to get left behind every time someone starts arguing this topic: the fall speed of the towers. both of them fell at nearly free-fall speed. (14.9 seconds?) 9.8 m/s2 is the rate of fall in a vacuum. i did the math (using the number 14.9 seconds as S and the figure 351m as distance of fall (i looked up the height of the tower 1, which was 417: the floors were an average height of 3.9m, so 90 floors up was 351 m.
now: 9.8 divided by 222 (14.9 squared) (9.8/222) multiplied by 351 equals 15.9. (check my math if you don't trust it, it's been a long time since i've done any: i know the time isn't EXACT but like i said, i haven't done math in 4 years.) thus: the towers fell at free-fall speeds.

if the pancake theory was remotely true, the fall would have taken longer. the middle was pulled out from under the tower, and it fell at free-fall speeds.

feel free to check it yourself and tell me what you get. i'd be interested to know.

[LARED]

87. Free Fall and energy conversion

http://www.democraticunderground.com/cgi-bin/duforum/duboard.cgi?az=show_thread&om=4840&forum=DCForumID43&archive=yes#2


Just before going to bed I realized I made a fundamental error in the energy balance in how I handled the mass. So here is the corrected version.

PE = KE of the towers moving down + W of the towers breaking up.

If 1/3 of the PE energy is converted to work the equation now looks like this;

1/3 PE = W

Substituting;

PE = KE (falling) + 1/3 PE( breaking up)

So ;

PE = 3/2 KE

Doing the math again

mgh = 3/2 * 1/2 m v^2

solving for v

V = (4/3 gh)^0.5

V= 73.2 m/sec

Solving for t

t = 2 * H / v (for free fall)

This part is added in this post for clarification; 30 percent of the potential energy going into breaking up the building at 11.2 seconds. Free fall is something just under 10 seconds. Also free fall starts from the top of the building not floor 90, as the whole building fell not just the first 90 floors.)

t = 11.2 sec

So if 1/3 of the potential energy went into destroyng the building the building falls in 11 + sec's, still well within the observed fall time.

[ashmanonar]

90. no, free fall is 9.8 meters acceleration.

free fall isn't saying that any object will fall to earth from any height in 9.8 seconds: it's the acceleration of the mass. an object will gain velocity at 9.8 meters a second for every second.

i'm not so sure about my math right now, something seemed off...but i'll take your word at the kinetic energy/potential energy calculations. something still bothers me about the speed with which the building fell, bc 15 seconds seems far too short a time for a pancake theory fall; if each floor is getting crushed, the rate of fall will be slower bc of the slight hesitation of each crushed floor. the center dropped slightly before the fall really began too, which makes core failure due to some excess force possible...

center dropped

changing stories?

[gbwarming]

91. x= 1/2 at^2 or rearrange to find t = sqrt(2x/a)

I think you left out a factor of 2 in your previous calculation. Happens to me all the time.

t = sqrt(2 * 417m / 9.8m/s^2) = 9.2s
(or 8.5 seconds for 351m)

[ashmanonar]

93. i think you're right that i messed up the math.

like i said, i haven't actually done it in too long.

[LARED]

98. I was not saying free fall meant

anything fell to earth in 9.8 sec. I covered Newton's laws in high school nearly 30 years ago

I was saying if you calculate the free fall time of the WTC at its full height it is just under 10 sec.

My little inexact calculation was designed to see what free fall time would be if 30% of the available potential energy was transfered into work that broke the tower into pieces.

The conclusion is that if ones assumes that 30 percent of the available potential energy went into work energy and 70 percent went into kinetic energy the fall time is 11.2 sec. As pointed out by you and others the fall time was somewhere over 11 or 12 seconds so it is reasonable to conclude that a significant portion of the potential energy was converted to work energy.

It also shows that a 15 second fall time is well within reason for the pancake theory.

[ashmanonar]

94. i had a thought regarding this

while i was snowshoeing just now.

how accurate, really, can any of our equations be? we don't know what was really in those towers, how many desks, how much office supplies, etc...and not to be gruesome, but people add to the potential energy.

i don't think your equations are entirely accurate, but neither are mine. agree to disagree?

[LARED]

100. Mass always adds to potential energy

But mass does not change the free fall time.

BTW, not to sound unpleasant, but my equations are accurate. Issac Newton developed them, and I just rearranged them to compare conservation of energy. So agree to disagree with him.

[ashmanonar]

104. i'm not trying to say you're wrong.

i'm trying to say that we're plugging in variables, wherein the outcome could be vastly different given two different sets of variables. (should the estimates be conservative or radical, etc.) btw, i didn't say anything about changed freefall time. if you will refer to another post i made, i admitted that my math was off...(a little rusty i'm afraid)...

i'm gonna quit arguing about this bc i'm not gonna let it monopolize my time. suffice it to say that i still think there was massive foul play. draw your own conclusions, figure out your own answers.

[AZCat]

106. You are suggesting that it is nonlinear as opposed to linear

A small change in the values of the variables of a nonlinear system can cause radically different results, while the same small change for a linear system will cause very little change in the results.

It certainly is possible that the "system" we are discussing behaved nonlinearly during the period of time we are examining. I am waiting for the NIST report to see how they addressed it - there are numerical methods available for approximating such systems and it will be interesting to see what they used.

[ashmanonar]

110. well, i'm not so much thinking non-linear and linear...

although you're right, i hadn't really thought about that. i'm just thinking in terms that the low estimate could be greatly different than the high estimate, it's just how optimistic or pessimistic you are in the variables.

[LARED]

109. I think you missed the point

This is not about variables. This is about looking at the conversation of energy and asking does what was observed make sense if it is compared against simple but foundation laws of physics.

My little derivation was not designed to provide any definitive answers. It simply looked at the how work (ie. work as in breaking stuff) slows down the collapse and its effect on fall times.

If you go back and plug in different percentages of work into the math you will see there there is plenty of room in the conservation of energy to provide the energy needed to destroy the building in the observed time.

It was meant to be a gut check calculation. It's done all the time in all engineering fields. It tells you if the assumptions are close.

[ashmanonar]

111. apparently you didn't notice that i'm not arguing anymore.

and apparently you want to keep arguing. you go ahead and do that, but don't be surprised when i'm not responding in a timely fashion. i have a life to live and homework to do. good day, sir.

[ashmanonar]

73. show me where it says it was debunked.

i want to see. i want to see exactly what evidence you have. otherwise, i'm gonna quit arguing this with you.

[LARED]

76. DU has archives,

Use them.

If you are interested in a specific claim made on the link you provided, I'll be happy to respond to the best of my ability.

[ashmanonar]

77. i would like a specific link, if you don't mind.

bc i'm sure i could go around du and find ANYTHING. to me clear evidence means more than rhetoric and anecdotes.

i'll admit, i take anything on the web with a grain of salt: bc it is just that, the internet; you don't really know who you're talking to or what they really believe. i treat du the same way.

[LARED]

79. DU archives 9/11

http://www.democraticunderground.com/cgi-bin/duforum/duboard.cgi?az=list&forum=DCForumID43&mm=0&archive=yes

Have a look;

As I said if you have a specific issue raised on the 9/11 'research' site I will be more than willing to provide my position on it.

[demodewd]

97. shit

You expect him to spend hours tracking down YOUR arguments? You are arrogant. He is a nice fellow going out of his way for you and you treat him like shit.

[LARED]

99. What he does with his time is up to him

I just supplied the link. I'm not going to spend a lot to time defending the obvious, that has already been rehashed about twenty times.

[demodewd]

102. re: rehash

If you don't want to rehash why do you still hang around?

[ashmanonar]

105. don't worry about it dewd, i'm not gonna fight this fight anymore.

thanks for the support, but i'm just gonna let him think what he will. live and let live.

[demodewd]

69. re: volume

It's not just volume,it's the speed.

[vincent_vega_lives]

39. People's gut also told them

The earth was flat and the center of the universe.

[ashmanonar]

57. no, that was reasoned "scientific" thought at the time.

the greeks actually acknowledged that the earth was spherical some few hundred years before the middle ages. (i wish i could remember what book i read that in)

people also reasoned that there were 4 elements: water, earth, fire, and air...that there were 4 humors that controlled human health...that demons were the cause of psychological problems in humans...that witches could fly on brooms and had "familiars"...

(interestingly enough, it was religio-political pressure that maintained that the earth was flat (and the center of the universe; silly geocentrists): (the bible says nothing about the shape of the earth.) the church (and thereby the spanish monarchy) had a vested interest in maintaining that it was right, and it was wrong about the earth's shape. it put galileo to the inquisition, along with most every other major scientist of the time: rebellion against the church was heresy.)

[Minstrel Boy]

13. Remember the high-rise fire in Caracas a few months ago?

The 56-storey steel-framed East Tower of the Parque Central block burned out of control for days, and still didn't fall into its footprint.



Go figure.



Tenants of Building 7 included the CIA, which had a clandestine bunker on the 23rd floor; the Department of Defense; the US Secret Service; New York City's Office of Emergency Management (immediately replaced by the bigger, better FEMA camp established in lower Manhattan for the coincidentally scheduled "TRIPOD 2" biowar drill); a number of banks implicated in wire transactions to the 9/11 hijackers; and the Securities and Exchange Commission, which lost many irreplaceable filings in the collapse, including those pertaining to Enron.

Add it up, and see what ya got.

[robertpaulsen]

22. I sure do remember, though many cry, "Nothing to see here. Move along!"

I remember almost every coincidence theory response to this was something along the lines of, "You can't compare the two! The Caracas building never had a plane crash into it!" Conveniently forgetting, of course, that WTC7 never had a plane crash into it, never had a tank of jetfuel melting its steel frame, yet collapsed after 8 hours of being hit by burning debris!

Anyone who posts here without addressing WTC7 deserves to be ignored. I believe the links I provided in my OP, as well as the information in this post explains my position clearly. Thanks Minstrel Boy.

[vincent_vega_lives]

42. WTC 7 discussion is not new

It's been adressed here over and over and over. Simple ignorance of the details continue to keep it alive. And in disaster science the details are everything.

[robertpaulsen]

63. I didn't mean to imply WTC7 discussion WAS new.

Sorry if I left that impression with you. The point I was trying to make is that the truth about the collapse of WTC7 has not been proven. Blithe dismissal of conspiracy theory with a Gerald Posner "Case Closed" attitude, and there has been plenty of that on this forum, is just as much a denial of the truth as any tinfoiler insisting that their theory is the only correct theory. My point in my OP that this subject is still open for discussion still stands. Yes, there have been a lot of details. But no conclusive proof.

[ashmanonar]

68. indeeed

"My point in my OP that this subject is still open for discussion still stands. Yes, there have been a lot of details. But no conclusive proof."


THANK YOU! :toast:

[vincent_vega_lives]

70. Hardly is the burden of proof ever applied to disaster science

No one has "proven" what caused the sinking of the Titanic, the collapse of the Tacoma Narrows Bridge, or the cause of the TWA Flight 800 crash. In fact, very few engineering disasters have had their causes "proven" without a doubt.

There is plenty of educated analysis that results in the most likely causes however.

http://www.civil.columbia.edu/ce4210/FEMA_403CD/html/pdfs/403_ch5.pdf

[robertpaulsen]

103. Thanks for the link. I'll try to read it.

I say "try" because the printed text is extremely small, even when enlarged. I may need a magnifying glass. :) But it certainly looks like a very informative study. Lots of great pictures, including some I have never seen before.

I agree, disaster science does not guarantee conclusive proof. That's why I think this study may only be part of the puzzle. What happened on 9/11 was not only a disaster, it was also a crime. I'm not sure if FEMA considered the possibility of direct detonation of WTC7 as a possibility for the collapse, as their scope of the criminal aspects may have been limited to the effects of planes crashing into the north and south towers. Of course, I'll find that out when I actually read it, so give me time.

Just one question: is this the same FEMA study that paulthompson is referring to in post 44 on this thread?

[AZCat]

107. FEMA is not doing the final study on WTC 1, 2, and 7

The NIST is running the investigation that should be the most conclusive. From the NIST study home page:

In response to the WTC tragedy, the National Institute of Standards and Technology is conducting a three-part plan: a 24-month building and fire safety investigation to study the factors contributing to the probable cause (or causes) of post-impact collapse of the WTC Towers (WTC 1 and 2) and WTC 7; a research and development program to provide the technical basis for improved building and fire codes, standards, and practices; and a dissemination and technical assistance program to engage leaders of the construction and building community in implementing proposed changes to practices, standards and codes. Also it will provide practical guidance and tools to better prepare facility owners, contractors, architects, engineers, emergency responders, and regulatory authorities to respond to future disasters.
</quote>

They are not (as far as I can tell) considering controlled detonation as a possibility in any of the collapses.

[vincent_vega_lives]

115. The fact that there is no mention of "controlled demolition"

Is that there is no evidence of it. It would leave a signature.

[robertpaulsen]

133. My reaction to the FEMA report.

Well, I finally finished reading the FEMA report and I have to say I'm extremely disappointed. It seems like they spent most of their time apologizing for the fact that they didn't have enough information to make their analysis thorough and that further study needed to be conducted. This is the vague and superficial report Paul Thompson was talking about which says the cause of the collapse could not be determined.

Since you brought up TWA Flight 800 as an example of disaster science pinpointing the most likely cause, compare this rushed report to the NTSB report on TWA Flight 800:

http://www.ntsb.gov/Publictn/2000/AAR0003.pdf

Here every possible hypothesis is examined, from lightning to meteorites to, believe it or not, a missile strike. The appearance this report leaves is that no stone is left unturned in the search for truth. The FEMA report leaves the opposite appearance. I'm not sure how you can assume that if there had been a detonation they would have found it in the evidence. I see nothing in the report that the signature of detonation was ever a consideration that they were looking for. It was a consideration the NTSB looked into for TWA Flight 800, but since FEMA didn't even mention it, I assume they did not.

I'm sure they had their reasons, like time and budget considerations. But take into account the Congressional and Kean Commission's omission of WTC7, along with NIST's future study which, if AZCat is correct, will not consider the possibility of detonation, then perhaps you can understand why I have such little faith in our government's search for the truth on this matter, whether you agree with me or not.

[vincent_vega_lives]

134. explosive signature

not sure how you can assume that if there had been a detonation they would have found it in the evidence. I see nothing in the report that the signature of detonation was ever a consideration that they were looking for.

unless all the FEMA engineers are completely incompetent, they don't need to consider the use of explosives in order to find them. They leave pretty significant trace. Steel girders that are cut, blast residue.

[vincent_vega_lives]

40. Same construction involved?

over an electrical substation?

Same firefighting efforts?

Same structural damage?

Same emergency management generators w/fuel in the building?

[TankLV]

14. Wrong conclusion. The buildings couldn't be more different structurally.

The WTC was a "tube" building - consisting a core (walls of elevators) & the STRUCTURAL exterior skin - with NO intermediate supporting columns.

The Madrid building is a traditional structure - a regular "grid" of columns within the interior and near the exterior with the "skin" just a cosmetic and weatherproof enlcosure with not structural components.

The WTC had planes smash into 2 corners thru the opposite side of the 1/2 of the only structure of the building, damaging the lace-like lattice work of trusses that composed the floor beams.

Nothing sinister or complicated about the collapse.

I imagine with a fire like the Madrid building had still had some bad tempering and structural impact of the building's steel, but the fireproofing didn't "flake off" because of impact as it did in the WTC, ant the beams supporting the floors were standard large W sections, not the lattice-like lightweight trusses of the WTC.

[ashmanonar]

19. you still haven't explained wtc 7.

did it just magically catch fire and fall into it's own footprint, in much the same manner as the two buildings that WERE hit with airplanes?

it sounds like you don't really want us to investigate, or think about it, or come up with hypotheses that might explain a bunch of buildings coming down (and the subsequent rise to virtual dictatorship of bush). considering there was no independent investigation of the 911 "attacks", and there was very little "official" investigation (before it was hauled off to the scrap heap), can you even say that the official story is anything more than a hypothesis or a guess?

do you really know?

(oh, interesting question...one airplane hit the tower (south tower, i believe?) on an angle, missing most of the internal stuff...how do you explain the collapse after it didn't do much damage to the core support and caused a huge fireball of jet fuel (which probably burned most of it away)?)

[Sweet Pea]

34. One needs to be careful.....

championing the logic of an analysis that includes the word "probably". As in:

(which probably burned most of it away)?

It implies they really don't know one way or the other about a particular event.

Not trying to be persnickity.....just looking for a small bit of analytical verbiage and thought.

[ashmanonar]

37. yea, i know.

i just don't know exact figures...considering we don't really know. but that was an awful damn big fireball on the south tower...so was the north, for that matter...O.o

points of contention on the size of fireball: how much fuel was actually in the jets? how much vaporized and detonated at a greater volume? how much stayed in the building, and didn't burn?

so many questions, and no way to answer them.

i just try to tell it like i see it.

but considering i still didn't get an answer from the other poster, i'm assuming he/she didn't want to answer. if they can come up with exact figures, exact information, i'd be glad to hear it. prove me wrong! show me evidence.


oh, wait...they got rid of it all, didn't they?

[spooked911]

29. The outer columns weren't holding up the WTC.

There was an incredibly strong inner core of steel columns. It wasn't a hollow tube at all.

[gbwarming]

33. Of course they were, and so was the core.

I don't think Tank was implying that the core was not structural, but rather that the outer skin was in fact also a major structural element which is not the case in the Madrid building. The floors trusses were supported by the inner core and the outer skin - the trusses themselves were not connected in a way, nor were they most likely strong enough to be cantlivered from either support alone.

It may be true that either the core or outer wall could have taken a static compressive load equivalent to all the floors, but this doesn't mean the building could stand if any of these elements was removed. I suspect the outer skin needed the floor diaphrams to maintain it's cross section to avoid buckling, and the inner core may have been too slender to stand on it's own under wind loads.

The WTC was a "tube" building - consisting a core (walls of elevators) & the STRUCTURAL exterior skin - with NO intermediate supporting columns.

The Madrid building is a traditional structure - a regular "grid" of columns within the interior and near the exterior with the "skin" just a cosmetic and weatherproof enlcosure with not structural components.

[spooked911]

35. I understand most of what you wrote but could you please explain this?

"the trusses themselves were not connected in a way, nor were they most likely strong enough to be cantlivered from either support alone."

Thanks.

[gbwarming]

36. Ok

A cantilevered beam sticks out from it's support with no support on the other end. I'm saying that the WTC (1&2) trusses were not attached in a way that would have held them up if one end wasn't supported. Look at the image below - detail A shows the outer connection which is attached at the top with 2 5/8 diameter bolts and a welded gusset. The bottom of the truss is connected to a damper so it can move. This connection is like a hinge. Imagine trying to hold a long object, like a 2x4 stud, straight out with only one hand - it tries to rotate downward because your wrist can't resist the torque. The inner end of the trusses has a similar, bolted connection. This is why I am certain the trusses could not have stood without both supports.

Beam (or truss) supports like this would be called pinned-pinned in engineering courses signifying that the connection can't transmit moments (torques). For the same beam, with the same uniform load on it the maximum stress will be four times higher if it is cantilevered from one end than if it's supported at both.

[vincent_vega_lives]

41. Define "incredibly strong".

Is that an engineering term?

The outer columns WERE taking a portion of the load. THAT is what allowed for the the wide open floor spaces.

Think about it. NO WAY those floors were strong enough to support themselves on the outer perimeter of the building. Take away the the outer colums and the floors collapse, the momentum of the floors collapsing would be too much even for the "incredibly strong" core.

[spooked911]

30. WTC7 was an unusual design. Several floors above the first two entry

floors contained a huge diesel-driven power generator.

One thing that may have caused the collpase of WTC7 was the weakening of the overall structure by the diesel fuel-generated fire, followed by this huge generator crashing down, and then weakening the overall structure.

I'm not saying there was no controlled demolition, just that the building did have an unusual feature-- a large generator on floors 3-7.


Good overall page on WTC7 here:
http://thewebfairy.com/killtown/wtc7.html

[rman]

131. you're telling only part of the story

another aspect of the unusual design of WTC7 is that it was build extra strong to cope with the load of those fuel tanks.

Also FEMA isn't so sure the diesel fire could have brought down the building:

FEMA
World Trade Center Building Performance Study
http://www.fema.gov/library/wtcstudy.shtm (pdfs)
Chapter 5
5.7 Observations and Findings

"It also stored a significant amount of diesel oil and had a structural system with numerous horizontal transfers for gravity and lateral loads."

..."Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence. Further research, investigation, and analyses are needed to resolve this issue."

[paulthompson]

44. FEMA?

I generally avoid these types of issues, because my engineering knowledge is quite low. However, I find it interesting that in 2002, the government agency FEMA did a study on WTC 7's collapse and basically couldn't figure out why it collapsed the way it did:

“The specifics of the fires in WTC 7 and how they caused the building to collapse remain unknown at this time. Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence.”

Does anybody know if that's still so, or if further studies have come to other conclusions?

[AZCat]

45. The NIST WTC 7 study has been decoupled from the main report

Because of an overlap of personnel, the NIST decoupled the WTC 7 study from the main report. It should be released within a couple of months of the final version of the main report, which is due this summer.

[ashmanonar]

46. what? study a mysterious collapse?

why would anyone do that? nothing to see here, move along folks. :eyes:

[LARED]

47. Actually the WTC 7 collapse is of great interest to civil engineers

and architects. They do want to find the failure modes. The WTC 7 collapse possibly points to some fundamental flaws in its design. They very much do not want to make similar errors in the future.

[ashmanonar]

52. i'm sure it is.

but is there any evidence left? it all got put on a boat to china. sold to Controlled Demolition...whose ceo is the only person who thought immediately..."those buildings are coming down." strange, huh? everyone else thought "we can save those buildings". but mr. "i'll make a big profit off of it" ceo said "those are coming down."

makes you wonder what those civil engineers could find out.

[AZCat]

48. I know - funny, isn't it?

You get a bunch of engineers together and they actually start to look at what happened to a structure. Sooner or later they produce a report that talks about their observations, and states some conclusions.

Then they get all excited about changes to codes and verification of models and stuff, and some graduate student(s) somewhere gets a nice dissertation topic.

Pretty cool.

[ashmanonar]

51. amazing, isn't it?

that studying the collapse of a building could actually help the science of engineering.

:D

[AZCat]

55. It is pretty cool.

There's this entire chapter of engineering where everyone was puzzled by iron bridge collapses. They were actually failing about as fast as they could be built. This was the nineteenth century and the problem was that the engineers didn't really understand what was going on with the metal as it "aged" under fluctuating stresses and temperature changes. Nobody knows how many bridges failed before they figured it out but it is thought to be in the hundreds. But in the end, all those collapses taught the engineers something that they might not necessarily have investigated if nothing had gone wrong. Perhaps the building failures of 9/11 will be the same way - that there will be some sort of silver lining to that dark cloud.

Crazy stuff... :)

[vincent_vega_lives]

61. Take a look

http://wtc.nist.gov/

Status of World Trade Center Investigation and Discussion
Project 2 – Baseline Structural Performance and Aircraft Impact Damage Analysis
Project 5 - Simulation of the Fires in WTC 1 and 2
Project 5 - Simulating the Coupled Fire, Thermal, Structural Response of World Trade Center Towers
Project 5 – Reconstruction of Fires in WTC 1 and WTC 2

http://wtc.nist.gov/media/gallery2.htm
Project 6 – Standard Fire Tests of WTC Tower Typical Floor Construction
Project 6 - Strength and Impact Response of SFRM
Project 6 – Structural Fire Response and Collapse Analysis
Project 8 – Fire Service Technologies and Guidelines
Project 7 – Occupant Behavior, Egress, and Emergency Communications
Project 4 – Investigation of Active Fire Protection Systems
Project 3 – Mechanical and Metallurgical Analysis of Structural Steel

http://wtc.nist.gov/media/gallery.htm#recover
The Station Nightclub Investigation
Latest Findings from NIST World Trade Center Investigation Released; Leading Collapse Sequence for Each WTC Tower Defined (New)
NCST Advisory Committee to Meet on October 19 and 20 World Trade Center, Rhode Island Nightclub Fire Investigations to be Discussed (New)
Presentation by Shyam Sunder to the Chicago Committee on High-Rise Buildings, Sept. 9, 2004 (.pdf)
Fact Sheet - "NIST Tests Provide Fire Resistance Data on World Trade Center Floor Systems" (Updated 9/9/04)
Fire Resistance Testing of WTC Floor System, Aug. 25, 2004, Presentation by S. Shyam Sunder
Fire Resistance Testing of WTC Floor System, Aug. 25, 2004, Presentation by John Gross
Federal Investigators Classify WTC Victims’ Locations Within Collapsed Buildings
News Release - "Interim Findings from NIST World Trade Center Building and Fire Safety Investigation Identify Issues with Current Standards, Codes and Practices"
Fact Sheet - "Key Findings of NIST’s June 2004 Progress Report on the Federal Building and Fire Safety Investigation of the World Trade Center Disaster"
Minutes from the National Construction Safety Team Advisory Committee June 22-23, 2004 Meeting
Agenda and Presentations for National Construction Safety Team Advisory Committee Meeting June 22-23, 2004
World Trade Center Investigation Status Presentation (6-18-04) by S. Shyam Sunder (.pdf)
June 2004 Progress Report on the Federal Building and Fire Safety Investigation of the World Trade Center

[demodewd]

49. I wonder

I wonder how much Bush is budgeting for NIST in fiscal 2005?

[AZCat]

50. I don't know.

Why do you ask?

[ashmanonar]

53. i think dewd is implying that the nist will be way underfunded from now on

bc they dared to try to investigate, and create reports on the collapses. or were they taken out in the giant cut bush is trying to get pushed through?

[AZCat]

56. I think the giant cuts are for 2006

Hasn't the 2005 money been allocated already? I should probably know this stuff...

I would be pissed if the NIST funding was cut - they do important work and I would see it as part of Bush's fear of "science".

[ashmanonar]

58. i'd be pissed too.

but it wouldn't surprise me a BIT.

[OmmmSweetOmmm]

81. How come everyone is ignoring Silverstein's own words that he wanted

the building "pulled"?
http://www.prisonplanet.com/011904wtc7.html
Scroll down for video of this

In a September 2002 PBS documentary called 'America Rebuilds,' Silverstein states, in reference to World Trade Center Building 7, "I remember getting a call from the, er, fire department commander, telling me that they were not sure they were gonna be able to contain the fire, and I said, "We've had such terrible loss of life, maybe the smartest thing to do is pull it. And they made that decision to pull and we watched the building collapse."

[LARED]

82. No one is ignoring his words

I all depends on how you interpret 'pull it.'

In the context of his entire statment it is clear to me he means pull out the firemen.

[OmmmSweetOmmm]

83. It must be all in the listening. I hear quite the contrary. Pulling IT,

not Them. "It" is an inanimate object. Pulling is a term used in demolition.

I think this is very clear cut.

Edited to include this as an example

http://www.southcoasttoday.com/daily/10-04/10-17-04/a04lo075.htm

Demolition of Keystone Building begins
By JOHN DOHERTY, Standard-Times staff writer


JACK IDDON/The Standard-Times
Demolition of the Keystone Building on Union Street in New Bedford started yesterday.
NEW BEDFORD -- Demolition crews began pulling down the remnants of the Keystone Building yesterday, a good portion of which crashed into the street two weeks ago.

[vincent_vega_lives]

86. It refers to the hose.

Before radio you would "pull it" to get the firefighters out of the building. It

"Because of the amount of fire, we decided to pull folks out and go on the defensive, and concentrate on protecting the dwellings next door," Louisville Fire Department Lt. Col. Tom Carroll said. "There was very little space between the dwellings."

http://www.thelouisvillechannel.com/news/3685975/detail.html

[OmmmSweetOmmm]

88. And how would Silverstein know the term about pulling a hose? He's

in Real Estate......

[vincent_vega_lives]

89. Do I have to spell it out for you?

The Fire chief consulted with Silverstein before he ordered the firefighting operation pulled. He obviously just repeated the term to the media.

[OmmmSweetOmmm]

92. I know what I heard, and I know that pulling a building is a term when

it comes to demolition, and yes it looked liked a planned demolition not too much long later. Anyone can listen to Silverstein themselves, and come to their own conclusion.

Here is the link to my original post about it, and there is a link to listen to Silverstein.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=33663&mesg_id=33952&page=

[vincent_vega_lives]

95. "I know that pulling a building is a term whenit comes to demolition"

And just how do you know that might I ask? :eyes:

What exactly do you "pull" when you initiate the demolition of a building?

[carlvs]

112. Then I guess this building was imploded too...

"... Once the building became unsafe to operate in the commissioner felt that he would not risk the firefighters. At about eleven o'clock that evening three firefighters got lost above the fire, were overcome by carbon monoxide and died. An engineer told the commissioner that this building was structurally unsafe to operate in, that the potential existed for it to collapse, so his decision was to pull (my emphasis) everybody out. They knew that there was a sprinkler system on the thirtieth floor and, the hope was that it would contain the fire, which it did. At least that was ultimately successful."

Fire battalion chief George Yaeger (of the Philadelphia Fire Brigade) commenting on the deadly One Meridian Plaza fire in February of 1991 - from page 62 of Blaze: The Forensics of Fire by Nicholas Faith; St. Martin's Press, Copyright 1999

(NOTE: The building's upper stories were so severely damaged by the fire that the entire structure had to be abandoned. It was eventually dismantled in 1999.)

[Sweet Pea]

119. Yer barkin' up a dead tree.....

...so his decision was to pull (my emphasis) everybody out.

You'll never convince the hard core here that "pull" is standard firefighting terminology for getting the boys the heck out of Dodge.

I'm glad nobody used the term "execute" to commence an operation. They'd claim it was a call to shoot.

[demodewd]

120. surprise surprise

Perhaps the decision to "pull" was done to stop the fire fighting because they had full intention of bringing the building down.

I get the impression that Silverstein is attempting to convince the public that the fire fighters were pulled because so many had already perished that day and there was need in upping the total.

So the firefighters were pulled not because they thought the building was going to collapse but it did anyway. Surprise Surprise.

[OmmmSweetOmmm]

96. And since when in NYC do firefighters leave a building burning? n/t

[LARED]

101. When it is too dangerous to fight the fire,

When there are other pressing needs like hundreds of fellow firefighters buried in the rubble of WTC 1 & 2.

Fire fighters routinely let buildings burn.

[vincent_vega_lives]

114. When it's in danger of collapsing.

"Training the imager on the ceiling, firefighters saw that the entire ceiling showed as gleaming white on the screen, indicating that it contained heavy concealed fire. Fire officials sensed an imminent structural collapse, and both crews were pulled out of the building. Minutes later, the ceiling collapsed."

http://wildfiremag.com/ar/firefighting_constructive_command/

[vincent_vega_lives]

85. Nobody has ignored it

It has been discussed over and over and over.

"Pull-it" is a firefighter's term for pulling the firefighters out of a building. It was done by literally pulling on the hose.

[robertpaulsen]

64. Thanks paulthompson!

I think your inquiry definitely helps give focus to an important question: why did WTC7 collapse the way it did? I wish we had conclusive proof. But it's certainly an important question to research. I definitely appreciate all the research you have done on this subject, I always refer people to your timeline when they have questions about 9/11. I believe I used part of it to write American Judas, which I have linked to my signature line. I'm pretty sure it's the part about Mahmood Ahmed wiring $100,000 to Mohammed Atta.

Sorry I haven't bought your book yet, but it is on my list of books to buy this year! Again, thanks for posting here.

[Lithos]

135. Locking

Whatreallyhappened.com is not an acceptable source for citation on DU.