Fire Fire Everywhere, but wait it didn't collapse...

[libertypirate]

Three buildings collapse all officially been deemed fire as the reason. Wait a minute this building burned and gutted in an all night fire; so why didn't it collapse. Still only three steel structured buildings in history to collapse via reason of fire. Magically all of them on the same day and within spitting distance to each other. What a coincidence...



02-2005

[hack89]

1. Be honest and compare apples to apples...

Show me building that suffered severe structural damage before it caught on fire.

The WTC fell because of combination of three factors:

- loss of structural integrity due to the impact of a 767.
- weakening of the steel structure due to fires, and
- the massive weight of the towers above the impact zone.

It is a simple concept: The impact of the aircraft damages the steel structure of the building, redistributing the stress of the weight they are supporting (same weight fewer supports). The fires weaken some of the steel supports until they reach their load carrying limit and give way. The weight is transferred to the remaining supports (remember- same weight fewer supports) and they are progressively overloaded and collapse.

It was a combination of things - if the fire was weaker or the plane had hit higher (thereby lessening the weight) the towers might have survived.

Now - show me an honest example to compare the WTC to instead of parroting the "no steel structured building ever collapsed" talking point.

[Kevin Fenton]

12. Explosives

You describe how the WTC might have collapsed, but, unfortunately, the evidence contradicts this scenario.
The north tower was hit on the north side in the middle and half the columns on this side were destroyed. However, it was not the north side that collapsed first but the core, which must have suffered much less impact damage. You can clearly see this on the video - the mast on top of the north tower (directly above the core) starts to descend before any other symptoms of the collapse are visible.

"The fires weaken some of the steel supports until they reach their load carrying limit and give way."
This would mean the steel supporting columns would have to be very hot, around 1200 degrees, and would have been glowing red. There are several videos which show they had not changed colour at all.

"The weight is transferred to the remaining supports (remember- same weight fewer supports) and they are progressively overloaded and collapse."
In the case of the south tower, the video clearly shows that there is no such progressive collapse. The whole east wall of one of the floors where the impact was (78, I think) goes at the same time. In addition, the steel supports are visibly turned to dust, no snapping is visible. If they snapped, where did the dust come from?

The kind of progressive collapse you are suggesting may be possible in theory in some buildings, but it would have to be clearly visible. "Invisible progressive collapse" is not a good theory.

I doubt the government did it just to invade Afghanistan and Iraq, but it's hard to see how the WTC could have fallen as it did without explosives.

[hack89]

14. "Explosives" Not

The north tower was hit on the north side in the middle and half the columns on this side were destroyed. However, it was not the north side that collapsed first but the core, which must have suffered much less impact damage. You can clearly see this on the video - the mast on top of the north tower (directly above the core) starts to descend before any other symptoms of the collapse are visible.

Well, since the north side supports were destroyed - wouldn't it make sense that the core would absorb some of the load that those missing supports were carrying? Wouldn't it then make sense that as the columns in the core weakened and overloaded, they would collapse - hence the core collapsing first?

"The fires weaken some of the steel supports until they reach their load carrying limit and give way."
This would mean the steel supporting columns would have to be very hot, around 1200 degrees, and would have been glowing red. There are several videos which show they had not changed color at all.

Show me the video of the internal columns - you know, the ones inside the building that can't be seen.

Read this excellent report by the Canadian research council on the role of fire resistance in the WTC http://irc.nrc-cnrc.gc.ca/fulltext/nrcc42466/nrcc42466 ....

According to this web site for forensic fire investigators http://www.tcforensic.com.au/docs/article10.html#1.3

steel loses 50% of its structural strength and sags at 550°C (1022°F) while smoldering combustion in a regular house/office fire can reach 600°C (1112°F)

"The weight is transferred to the remaining supports (remember- same weight fewer supports) and they are progressively overloaded and collapse."
In the case of the south tower, the video clearly shows that there is no such progressive collapse. The whole east wall of one of the floors where the impact was (78, I think) goes at the same time. In addition, the steel supports are visibly turned to dust, no snapping is visible. If they snapped, where did the dust come from?

1. Progressive does not mean slow - with the massive weights involved it was nearly instantaneous.

2. How the hell does steel get turned into dust? Link please. Did you ever consider that millions of square feet of particle board as well as the cement floors as a possible source of the dust?

[Kevin Fenton]

20. 'Fraid So

"Well, since the north side supports were destroyed - wouldn't it make sense that the core would absorb some of the load that those missing supports were carrying? Wouldn't it then make sense that as the columns in the core weakened and overloaded, they would collapse - hence the core collapsing first?"

I'm glad you agree that it was the core of the north tower that went first. The core would obviously absorb some of the load. I agree that the columns in the core must have been weakened (to some degree) and overloaded, although there is no actual video evidence of this. However, it is highly unlikely that the core would be weakened and overloaded to a greater extent than the north side. The north side, which suffered tremendous impact damage, held, whereas the core, which suffered less impact damage, did not. This is unusual, don't you think?

"Show me the video of the internal columns - you know, the ones inside the building that can't be seen."
I was refering to the east wall of the south tower, which was the first part to collapse. You can find various videos of it here: http://www.911research.wtc7.net/wtc/evidence/videos/index.html.

"Read this excellent report by the Canadian research council on the role of fire resistance in the WTC http://irc.nrc-cnrc.gc.ca/fulltext/nrcc42466/nrcc42466 ...."
This link appears to be broken.

"steel loses 50% of its structural strength and sags at 550°C (1022°F) while smoldering combustion in a regular house/office fire can reach 600°C (1112°F)"
The steel in the WTC was designed to hold five times the load it actually carried. The steel supports would therefore have to have been heated up to a point (around 1,200 to 1,300 degrees) where they lost 80% of their strength, not just 50%. I'm glad you made the point about sagging, which, again, should be visible in the east wall of the south tower, but is not.

[LARED]

2. I had no idea the investigation was over

Three buildings collapse all officially been deemed fire as the reason.

When did that happen?

It is also probably worth noting that there are significant differences between the construction of the WTC buildings and Madrid's Windsor skyscraper.



Madrid fire services have just announced that the 99 percent of the fire which has gutted one of Spanish capital's tallest buildings has been put out. Firemen have been working all day to try and control Madrid's biggest ever fire. The Windsor building is in the heart of Madrid's commercial and banking center, and it has been destroyed by the fire. Emergency services are now concerned about the burned building collapsing to the ground.

What not stated in this article is that there was a partial collapse.

http://www.euroresidentes.com/Blogs/2005/02/madrids-windsor-skyscraper-99-fire.htm


Lets play who can spot the difference

Let me start. There is no impact zone from a large commercial jet.

[philb]

3. Want to explain why that makes a difference??

what difference did the jet impact have on the buildings?
I haven't seen any indication that it would have had a significant effect regarding whether the buildings would collapse.
Not much structural effects and fires not hot enough to melt steel or weaken the WTC beams enough to have major effect.

do you know of any cases of a major building that virtually all of the solid materials in the building were pulverized into small powder by a building falling down?

[LARED]

4. Could you be more specific?

I'm not a mind reader.

[LARED]

5. Please tell me your kidding

what difference did the jet impact have on the buildings?

Your kidding right???? Right???????? I need to explain how a jet hitting a building at 500 mph makes a difference??????

I haven't seen any indication that it would have had a significant effect regarding whether the buildings would collapse.

I would suggest you look over some of the NIST investigation. They did a pretty nice job of explaining your concern.

Not much structural effects and fires not hot enough to melt steel or weaken the WTC beams enough to have major effect.

An ordinary office fire is hot enough to weaken steel. That's why steel is fireproofed in buildings. It ain't complicated.

do you know of any cases of a major building that virtually all of the solid materials in the building were pulverized into small powder by a building falling down?

No I don't, and neither do you. That did not happen to any of the WTC collapses.

[demodewd]

8. it's over folks

well,that solves everything

[spooked911]

6. There WAS a partial collapse here. Why only partial?

Why wasn't there a cascading rapid collapse of the whole building? Why didn't the floors that collapsed start a chain reaction leading to total collapse? How did the floor right below the collapsed section that DIDN'T collapse manage to support the weight of the eight or so upper floors that did collapse down?

[hack89]

9. Perhaps..

1. Because the structure was intact when the fire started.

2. Because there was less weight above the fire zone.

3. Because it is a completely different design.

You are allowed to apply logic and try to answer your own questions.

[spooked911]

10. Oh Thanks.

But those are all "perhaps", right?

Perhaps the complete systematic collapse of the WTC was facilitated by explosives.

[hack89]

11. Hold on a second..

We were talking about the Madrid fire - you asked why it didn't completely collapse and I gave you some possible reasons. As to the WTC - feel free to explain why my points in my post above (1) don't apply and then we can talk.

Classic CT moment on your part - take one word out of context, stretch it's meaning beyond recognition and then use it as a foundation for a CT house of cards.

[spooked911]

13. Response

Classic CT moment on your part - take one word out of context, stretch it's meaning beyond recognition and then use it as a foundation for a CT house of cards.

You are exaggerating quite a bit. I did not take "perhaps" out of context, I hardly stretched its meaning, and all I said was maybe there were addtional explosives-- hardly a "house of cards".


1. Because the structure was intact when the fire started.
Once the collapse started, it doesn't much matter how intact the structure was before collapse, does it? The collapse will wreck the structure anyway. Unless you are saying that the initial collapse didn't involve parts of the building that were damaged by the plane.

2. Because there was less weight above the fire zone.
In the North tower collapse, the collapse started right at the top or very near the top. Moreover, the fire in that Madrid fire was very extensive--basically it took over the whole building. One can hardly say there wasn't a lot of weight above the fire zone.

3. Because it is a completely different design.
Do we know that for sure?

[hack89]

16. Response to response.

1. If the structure is intact then it won't collapse because the supports can still hold the weight. The impact destroyed many of those support, therefore overloading the remaining supports before the fire starts.

2. Are you saying they brought down the WTC by putting explosives at the top of the building? Above where the plane hit? That seems to defy the logic behind controlled demolition - you know, let gravity do the work. Shouldn't the collapse have started at the bottom of the tower?

3. Yamasaki and engineers John Skilling and Les Robertson worked closely, and the relationship between the towers’ design and structure is clear. Faced with the difficulties of building to unprecedented heights, the engineers employed an innovative structural model: a rigid "hollow tube" of closely spaced steel columns with floor trusses extending across to a central core. The columns, finished with a silver-colored aluminum alloy, were 18 3/4" wide and set only 22" apart, making the towers appear from afar to have no windows at all.

Also unique to the engineering design were its core and elevator system. The twin towers were the first supertall buildings designed

[demodewd]

17. Answer to #2

Answer to 2 >> They had to start the demolitions on the floors where the planes had crashed to simulate the most logical explanation that would be posited by those advocating the Government's version of events.

[hack89]

18. But the planes didn't hit near the top...

why didn't the collapse start where the planes hit?

[demodewd]

19. they....

they did

[demodewd]

7. is it really?

Is that the WTC7?

[highlonesome]

15. Temperature

The major factor in the structural collapse of the WTC towers wasn't simply the fire, but also the temperature of the fire.

The burning jet fuel created temperatures sufficient to soften the steel and structurally undermine it. The other buildings didn't collapse because the heat generated by the burning of the building materials wasn't sufficient to soften the steel.

Unfortunately in designing the Twin Towers, engineers didn't take into account that someone would fly a fuel laden jet into them.