Explosions underneath the WTC Towers b4 they collapsed

Here, just go to the site and read the report

members.fortunecity.com...



POPUP WARNING


[Edited on 26-5-2004 by HowardRoark]

Originally posted by Satyr
Being how there had NEVER EVER been a single instance of any steel framed building collapsing due to fire, I'd say that's a pretty far fetched theory. I've also read that that particular building was made with more steel than almost any other building. There's no way it should've came down, even if it was 100% gutted by fire.

Wow, I never saw into that. I will have to do some research. Digging up 9/11 stories, most fake, what a nightmare!

Keep in mind, however that there had also NEVER EVER been a steel framd building that was allowed to burn unchecked for seven hours either.

Are you sure about that? I'm almost positive there has. The point is, if you research this, even a jet fuel fire wouldn't burn hot enough to melt steel. It's a physical impossibility. I can see how it may have weakened the towers, but not WTC7. There's just no way. That building was about as stout as they get.

Ahh excellent resolution for a city seismic monitoring station. I now believe the explosion they thought they were seeing from an explosion under the building was the actual impact event from the plane propagating through the steel frame of the building and into the substructure like a tuning fork. I see ABSOLUTELY nothing that looks like a detonation. Explosive sources, ie. bomb, dynamite, etc. are very wide frequency ranging, propagating, disturbances that create a sinusoidal wave that decreases in amplitude with time. That is why dynomite is a good source for seismic surveying, because it disperses with a wide range of frequeny and amplitude variation so that different lithologies reflect different characteristics of the wave front. That is not what I see in those siesmographs, I see a single pulses which increases, peaks, and decreases. Consistant with an impact event, like hitting a nail with the head of a hammer.

End Introduction to Geophysics--

Actually, Ive seen a program on Discovery that talked about what you are saying. The central spine of WTC was composed of interlocking steel beams wrapped in rebar (sp?) and concrete. Each floor was suspended from the central spine by more rebar and concrete. The floors had almost no load bearing walls in themselves. Think of it like an artificial christmas tree. Youve got the stalk and all the branches attach only to the stalk. What happened at WTC is that the floor/floors of the tower that recieved the intial plane impact were ignited by jet fuel which in turn splilled down the building facade and onto the surrounding building. The jet fuel burned everything in this floor essentially gutting it and creating a void suspended only by the spine. The fire superheated the concrete which superheat the spine of the building. See it like a blacksmith sticking a piece of metal in the fire and then hammering it. The impact microfractured the steel. The jet fuel superheated it, so heated metal expands correct? The expanding beams began to warp under the weight of the floors above and the shear stress cause the linkage rivets to pop. All of this has been observed in the junk yard where they carted the debris to. With weakened supports and less a couple thousand rivets the building failed and pancaked on its way down, each floor breaking the struts off the spine of the floor below. WTC 7 was in the way and it got hosed, much smaller building, lots of debris, ...

WTC 7: Sigh, Do I have to go over this again?

OK

1) It really doesn�t matter what the fuel was. Look around on google. There are studies that measure the temperature over burning bunkbeds, office cubicles, etc. can quickly exceed 1000 degrees and higher.

2) It is not necessary to melt the steel. Steel looses strength rapidly at fire temperatures. That is why they spray fireproofing on steel columns. The fireproofing is not there to prevent the steel from burning, that would be silly, no, the fireproofing is there to insulate the steel from the heat of the fire. Fireproofing is only rated as effective for four hours at the most.

There are also some reports on metallurgical tests that were done on wtc 7 steel. These tests indicate that prolonged exposure to high temperature combustion byproducts high in sulfur may have resulted in localized �erosion� of the steel, thus contributing to the loss of structural integrity.


[Edited on 26-5-2004 by HowardRoark]

Zsandman, Close, but not quite. The core of the towers was steel columns like the exterior. In fact the towers were inovative in that there was no structural masonry used in the core area at all. The core area firewalls consisted of double layers of 1� drywall. This would have been good enough in a typical office fire, but could not have withstood the impact from the planes.

Originally posted by zsandmann
WTC 7 was in the way and it got hosed, much smaller building, lots of debris, ...

You need to look at the video again, and do some research. WTC7 was not in the way. It didn't even get hit by anything. Furthermore, most of the debris was either, melted, burried or sold and shipped before anyone was allowed to investigate.

www.wtc7.net...
www.wtc7.net...

Oh yeah...here's your building fire examples. There have been many...

Recent examples of highrise fires include the 1991 One Meridian Plaza fire in Philadelphia, which raged for 18 hours and gutted 8 floors of the 38 floor building; 1 and the 1988 First Interstate Bank Building fire in Los Angeles, which burned out of control for 3 1/2 hours and gutted 4 floors of the 64 floor tower. Both of these fires were far more severe than any fires seen in Building 7, but those buildings did not collapse. The Los Angeles fire was described as producing "no damage to the main structural members".

www.wtc7.net...

Furthermore...

In the mid-1990s British Steel and the Building Research Establishment performed a series of six experiments at Cardington to investigate the behavior of steel frame buildings. These experiments were conducted in a simulated, eight-story building. Secondary steel beams were not protected. Despite the temperature of the steel beams reaching 800-900 C (1,500-1,700 F) in three of the tests (well above the traditionally assumed critical temperature of 600 C (1,100 F), no collapse was observed in any of the six experiments).

[Edited on 5-26-2004 by Satyr]

Originally posted by zsandmann
Ahh excellent resolution for a city seismic monitoring station. I now believe the explosion they thought they were seeing from an explosion under the building was the actual impact event from the plane propagating through the steel frame of the building and into the substructure like a tuning fork. I see ABSOLUTELY nothing that looks like a detonation. Explosive sources, ie. bomb, dynamite, etc. are very wide frequency ranging, propagating, disturbances that create a sinusoidal wave that decreases in amplitude with time. That is why dynomite is a good source for seismic surveying, because it disperses with a wide range of frequeny and amplitude variation so that different lithologies reflect different characteristics of the wave front. That is not what I see in those siesmographs, I see a single pulses which increases, peaks, and decreases. Consistant with an impact event, like hitting a nail with the head of a hammer.

End Introduction to Geophysics--

Well done zsandmann, this dead horse has been beaten so many times already that I don't even know why people keep coming up with these wild theories. Some people seem to want to keep swimming in their own ignorance for some reason....

Below is one link to one of the many discussions we had about this already..
www.abovetopsecret.com...

Originally posted by HowardRoark

Originally posted by Phoenix
There may be a plausible explanation on why a 2.0 tremor was recorded even though the main debris had not hit yet.

Phoenix, look at the seismograph posted above. Please point out to me where you see evidence of a 2.0 tremor before the impact of the main debris.

HR I was at work and was answering DR post, had to walk away before you posted your graph, when I returned I finished answer for the post DR was claiming the 2.0 seismic event ahead of the main event.

Wow by the time zsandmann posted his first post in this thread and i found the link i posted above a lot of people responded.

BTW satyr, the excerpt you posted on the 6 experiments... they are not taking in consideration that the propagation in fires are always different and not always uniform, much less in skyscrapers, and when there is a difference of 150 C from one location to another it produces yield level residual stress which will explain the buckling effect.

Satyr
The First Interstate Building fire only burned for 3.5 hours before it was brought under control through the combined efforts of over 300 LA firefighters.

WTC burned for over seven hours and had no firefighters.


One Meridian Plaza fire

�The 12-alarms brought 51 engine companies, 15 ladder companies, 11 specialized units, and over 300 firefighters to the scene.�

It should be noted that this building came dangerously close to total collapse.

�Firefighting Operations Suspended
All interior firefighting efforts were halted after almost 11 hours of uninterrupted fire in the building. Consultation with a structural engineer and structural damage observed by units operating in the building led to the belief that there was a possibility of a pancake structural collapse of the fire damaged floors. Bearing this risk in mind along with the loss of three personnel and the lack of progress against the fire despite having secured adequate water pressure and flow for interior fire streams, an order was given to evacuate the building at 0700 on February 24. At the time of the evacuation, the fire appeared to be under control on the 22nd though 24th floors. It continued to bum on floors 25 and 26 and was spreading upward. There was a heavy smoke condition throughout most of the upper floors. The evacuation was completed by 0730.�

Finally, it should be noted that each building is unique and it is rather pointless to compare the behavior of one structure in a fire to another. Check out some of the pictures from the Cardington tests. Even though the failure point was never actually reached, the pictures show that sever structural damage was just starting to occur. It doesn�t take much imagination to see that in a real world situation, a total collapse would not be very far off.

Yep. I've seen those tests, and those beams are nothing compared to WTC7. I don't have time to find them now, but go hunting for some pics. You'll be surprised at the sheer thickness of the beams. They dwarf those used in most buildings.

Found a good site that explains this.

"The additional problem was distortion of the steel in the fire. The temperature of the fire was not uniform everywhere, and the temperature on the outside of the box columns was clearly lower than on the side facing the fire. The temperature along the 18 m long joists was certainly not uniform. Given the thermal expansion of steel, a 150�C temperature difference from one location to another will produce yield-level residual stresses. This produced distortions in the slender structural steel, which resulted in buckling failures. Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire."

Excerpt taken from.
www.tms.org...

Originally posted by Satyr
Yep. I've seen those tests, and those beams are nothing compared to WTC7. I don't have time to find them now, but go hunting for some pics. You'll be surprised at the sheer thickness of the beams. They dwarf those used in most buildings.

Satr as a former constuction worker and now an operating engineer it was common to see 2"-4" cross sections on vertical steel "I" columns in 20 - 40 story buildings. Taken by themselves they are impressive to look at. When loaded with several million pounds of weight and then subjected to heat, they are not as monolithically strong as they appear. I'm skeptical that any simulation can provide the proper loading for a fair analysis, especially when load tranfer from other damaged sections are considered.

The fires in Building were not severe:

limited to isolated regions of 2 floors
no broken glass on north side
puny compared to other building fires

911research.wtc7.net...

I'm not buying it.

This is a really good view of how perfect it went down. It's just as if it were demolished with too perfect of precision. It all fell in a neat pile, within it's own footprint.

911research.wtc7.net...

Here...I found the picture with the comparison of the WTC7 I-beam and a standard I-beam. That building had massive beams.



[Edited on 5-26-2004 by Satyr]

Puny compared to other building fires?

Those were fully fueled jets. You could only make a worse fire by setting fire to a refinery.

I'm talking about building 7. It hardly even had a fire, compared to some other buildings that didn't collapse. If you look at the video and pics, practically all the windows were still in it when it went down. We all know fire doesn't burn too hot without plenty of oxygen. It also went down completely level....as I said, too perfectly. I've watched enough demolition documentaries to know that it's not easy to get a building to fall like that. In demolition, they put a charge on every main beam, and blow them all at once to get that type of effect. Anyone who knows anything about physics should know that there's no way in hell that fire is going to achieve that same precise action.

I'll tell you what. You find a piece of steel as thick as the beam in that pic, and I'll challenge you to even soften it with any heat source you can find. Go ahead, get some jet fuel. I'll watch and laugh as you learn something about steel and fire. Good luck!

[Edited on 5-27-2004 by Satyr]

Originally posted by Satyr
I'll tell you what. You find a piece of steel as thick as the beam in that pic, and I'll challenge you to even soften it with any heat source you can find. Go ahead, get some jet fuel. I'll watch and laugh as you learn something about steel and fire. Good luck!

[Edited on 5-27-2004 by Satyr]

Did you happen to forget that the jet fuel was not the only source for the fire? How about all the wooden desks, papers, plasitcs, paint, etc that were in the building? Coupled together and over time they generated enough heat to deform the metal. Once the metal was deformed it lost most of its strength and that is why the buildings collapsed.