WTC Collapses

[Tony Szamboti]

You don't have to raise the temperature of a ton of steel, all you need to do is raise the Temperature of a section of of that steel to 1130 F and you compromise the structural strength of that beam.

The other thing is that many of the support beams were of thin steel bent bar truss construction instead of solid steel beams.

Here is a good read on the construction techniques of the WTC in comparison to the Empire State Building.

Concrete removal

I have previously read Vincent Dunn's opinion on why the towers collapsed, and I read it again here.

I fully understand the floor trusses were not heavy thick columns or beams, but we have no physical evidence of them experiencing extremely high temperatures either. In order to get a collapse initiation on their computer model NIST had to cause the floor trusses to sag by over 40 inches. However, in the actual testing they did, at Underwriter's Laboratoiries per ASTM E119, the trusses only sagged by 3 inches, with full heat and physical loads.

Many try to say the testing was done on 35 foot trusses and the trusses that failed would have been the 60 footers. That is true, but 3 inches on 35 footers doesn't scale up to 40 plus inches on 60 footers.

There have been huge fires in buildings constructed in the manner the twin towers were, including the North Tower in 1975, and there was not even a hint of a possible collapse. Why weren't the floor trusses affected then? The SFRM being knocked off by the aircraft is not very plausible as the collapses initiated above where the major impacts occurred.

Additionally, the perimeter columns were so strong that just nine columns on each corner of each side, or 72 perimeter columns, could support the entire weight of the building above them, core included. So if a perimeter column buckled due to a floor truss pulling on it through catenary action, why would the nearby columns buckle? They had a huge amount of redundancy. This is proven by the aircraft impact holes. The still intact perimeter columns on that face did not all of a sudden wilt due to those nearby being cut. It is highly unlikely that the rapid collapse initiations occurred due to a few sagging floor trusses and a couple of buckled perimeter columns. On top of that the floor trusses would not have been able to drag down core columns as the core beam connections were stronger than the floor truss connections.

A much more plausible explanation is that the outer core columns were cut and the perimeter columns were bowed inwardly and buckled through their connection to the core columns via the floor trusses.

I am extremely suspicious that NONE of the steel from WTC 7 was saved for NIST to analyze and less than 0.5% of that from the towers. Real investigations are not done this way. If NIST had that steel there would be no question as to why the towers and WTC 7 collapsed.

Please forgive my removal of the URL you posted, as the forum won't allow any URLs, even in quotes of posts being replied to, until the poster has 20 posts. This is only my 7th post here.

 

[cryogene]

Hi all, I'm new here.
This is a large thread so I have not gone through all the posts, so maybe what I'm about to ask has been covered. If so please forgive me.

How was it that a bbc newsreporter reported the collapse of WTC7 twenty-five or so minutes before it actually collapsed?
Could it have been known prior to the event?

 

[Buffalo Roam]

Hi all, I'm new here.
This is a large thread so I have not gone through all the posts, so maybe what I'm about to ask has been covered. If so please forgive me.

How was it that a bbc newsreporter reported the collapse of WTC7 twenty-five or so minutes before it actually collapsed?
Could it have been known prior to the event?

(http://www.archive.org/details/abc200109111323-1404)

ABC News covered the events from a news helicopter, capturing footage of 7 World Trade Center and damage it sustained before it collapsed. This footage has been subject of much commentary and discussion. Few photos and video clips exist that show the damage sustained to south face of 7 World Trade Center on 9/11, and no free images. What few images are available, along with firefighter testimony, have been used by NIST for investigation of the collapse.

The building collapsed completely at 5:20 p.m., when a critical column on the 13th floor buckled and triggered structural failure throughout:

Let hear from the BBC:

http://www.bbc.co.uk/blogs/theeditors/2007/02/part_of_the_conspiracy.html

Part of the conspiracy?Richard Porter 27 Feb 07, 05:12 PM

The 9/11 conspiracy theories are pretty well known by now. The BBC addressed them earlier this month with a documentary, The Conspiracy Files, shown within the UK.

Until now, I don't think we've been accused of being part of the conspiracy. But now some websites are using news footage from BBC World on September 11th 2001 to suggest we were actively participating in some sort of attempt to manipulate the audience. As a result, we're now getting lots of emails asking us to clarify our position. So here goes:

1. We're not part of a conspiracy. Nobody told us what to say or do on September 11th. We didn't get told in advance that buildings were going to fall down. We didn't receive press releases or scripts in advance of events happening.

2. In the chaos and confusion of the day, I'm quite sure we said things which turned out to be untrue or inaccurate - but at the time were based on the best information we had. We did what we always did - sourced our reports, used qualifying words like "apparently" or "it's reported" or "we're hearing" and constantly tried to check and double check the information we were receiving.

3. Our reporter Jane Standley was in New York on the day of the attacks, and like everyone who was there, has the events seared on her mind. I've spoken to her today and unsurprisingly, she doesn't remember minute-by-minute what she said or did - like everybody else that day she was trying to make sense of what she was seeing; what she was being told; and what was being told to her by colleagues in London who were monitoring feeds and wires services.

4. We no longer have the original tapes of our 9/11 coverage (for reasons of cock-up, not conspiracy). So if someone has got a recording of our output, I'd love to get hold of it. We do have the tapes for our sister channel News 24, but they don't help clear up the issue one way or another.

5. If we reported the building had collapsed before it had done so, it would have been an error - no more than that. As one of the comments on You Tube says today "so the guy in the studio didn't quite know what was going on? Woah, that totally proves conspiracy... "

 

[John99]

Steel just starts to lose strength at 350 degrees C (662 degrees F) and loses half of it at 600 degrees C (1112 degrees F). After considering the aircraft impact damage, the factor of safety in the tower columns shows all the undamaged columns would have to get to 650 degrees C (1202 degrees F) before any collapse would even be possible.

Do you believe all of the steel could have reached 1200 degrees Fahrenheit?

If you do a little analysis and see how much energy it takes to raise just a ton of steel 1130 degrees F you might start to see the point.

There was no physical evidence, for these extremely high steel temperatures, found in the testing done by the NIST on tower steel they got for analysis. Doesn't that give you any reason to wonder?

Air temperatures are not steel temperatures.

You are making an unsupported statement that I am wrong. Please be specific.

I dont know what to tell you. I already stated the i believe you are wrong and gave my reasons why. I dont know you from a hole in the ground and if i saw you are wrong then i say you are wrong. For all i know you work at a dairy queen or maybe you are an engineer at a farm equipment factory.

I am not being facetious but telling you like it is.

Yours is only an opinion. You say potatoe i say potato.

 

[John99]

Hi all, I'm new here.
This is a large thread so I have not gone through all the posts, so maybe what I'm about to ask has been covered. If so please forgive me.

How was it that a bbc newsreporter reported the collapse of WTC7 twenty-five or so minutes before it actually collapsed?
Could it have been known prior to the event?

Why dont you ask them? Seems a little stupid to ask us here though. Twenty five minutes is a long time and a conspirator would probably be smarter than that.

Maybe you are trying to bring my IQ down.

 

[KennyJC]

I fully understand the floor trusses were not heavy thick columns or beams, but we have no physical evidence of them experiencing extremely high temperatures either. In order to get a collapse initiation on their computer model NIST had to cause the floor trusses to sag by over 40 inches. However, in the actual testing they did, at Underwriter's Laboratoiries per ASTM E119, the trusses only sagged by 3 inches, with full heat and physical loads.

If I am to trust you that they trusses that sagged by 3 inches were full heat and physical loads (identical to that of the WTC), then have you thought of any other reasons why there is such a differential in the sagging?

I'm not familiar with these tests, so I can't comment on this, but with my experience of truther behavior it is probably misleading information.

There have been huge fires in buildings constructed in the manner the twin towers were, including the North Tower in 1975, and there was not even a hint of a possible collapse. Why weren't the floor trusses affected then? The SFRM being knocked off by the aircraft is not very plausible as the collapses initiated above where the major impacts occurred.

Huge fires in buildings constructed like the WTC? This is surprising since civil engineers often comment on the uniqueness of the WTC's structure.

As for the fire in 1975... This is exactly what I mean about truthers giving misleading information. That was a SMALL fire by comparison. No structural damage was done by a 200 ton bullet, and firefighters were able to fight the fire and contain it.

Additionally, the perimeter columns were so strong that just nine columns on each corner of each side, or 72 perimeter columns, could support the entire weight of the building above them, core included. So if a perimeter column buckled due to a floor truss pulling on it through catenary action, why would the nearby columns buckle? They had a huge amount of redundancy. This is proven by the aircraft impact holes. The still intact perimeter columns on that face did not all of a sudden wilt due to those nearby being cut. It is highly unlikely that the rapid collapse initiations occurred due to a few sagging floor trusses and a couple of buckled perimeter columns. On top of that the floor trusses would not have been able to drag down core columns as the core beam connections were stronger than the floor truss connections.

It was already said of the designers that the building would withstand an aircraft impact, and that's what happened on 9/11. Yet, it was the fire that did it. Steel heats up very quickly in the midst of 1800 degree temperatures. This is why we see sagging steel in ANY steel structure subjected to high temperatures. We see sagging in the WTC were such temperatures existed, case closed.

And the floor trusses by and large did not bring down the core columns. A lot of the core columns were still standing after the floors around them collapsed.

A much more plausible explanation is that the outer core columns were cut and the perimeter columns were bowed inwardly and buckled through their connection to the core columns via the floor trusses.

I have to laugh... I really do. The collapse in both towers was initiated in exactly the same place were the bulk of the plane damage and fire damage occurred.

So if your made-up story of core columns being cut is more "plausible", how did the explosives (or whatever) not detonate the moment the plane impacted and fires raged?

I am extremely suspicious that NONE of the steel from WTC 7 was saved for NIST to analyze and less than 0.5% of that from the towers. Real investigations are not done this way. If NIST had that steel there would be no question as to why the towers and WTC 7 collapsed.

Every peice of debris was removed/overseen by people who have experience in clearing up demolished buildings. They state on camera that if the building was demolished, they would have known. Should we just add these people to your convenient list of liars?

You fail to demonstrate the mechanics of the demolition (silent explosions etc), and you fail to provide a logical motive. You just fail period.

A building that is already damaged, on fire all day long uncontested, fire fighters saying it will collapse, and we are supposed to believe there is something suspicious behind it? Give your childish imagination a rest and grow up.

 

[Tony Szamboti]

I dont know what to tell you. I already stated the i believe you are wrong and gave my reasons why. I dont know you from a hole in the ground and if i saw you are wrong then i say you are wrong. For all i know you work at a dairy queen or maybe you are an engineer at a farm equipment factory.

I am not being facetious but telling you like it is.

Yours is only an opinion. You say potatoe i say potato.

It is a shame you couldn't offer more of a basis to back up your beliefs. It isn't an opinion that there is no physical evidence for the extremely high steel temperatures which would be needed to cause a collapse. It seems you didn't want to go there and are only sticking to strong opinions. I have to call them the way I see them too.

 

[KennyJC]

Steel just starts to lose strength at 350 degrees C (662 degrees F) and loses half of it at 600 degrees C (1112 degrees F). After considering the aircraft impact damage, the factor of safety in the tower columns shows all the undamaged columns would have to get to 650 degrees C (1202 degrees F) before any collapse would even be possible.

Do you believe all of the steel could have reached 1200 degrees Fahrenheit?

If you do a little analysis and see how much energy it takes to raise just a ton of steel 1130 degrees F you might start to see the point.

There was no physical evidence, for these extremely high steel temperatures, found in the testing done by the NIST on tower steel they got for analysis. Doesn't that give you any reason to wonder?

Air temperatures are not steel temperatures.

You are making an unsupported statement that I am wrong. Please be specific.

I have shown in this thread already (or another thread), independent tests done on steel fire damage in a regular office building.

The tests show that steel can reach 1000 Celcius in just 40 minutes. The temperature lags slightly behind the temperature of a fire, then exceeds the temperature of the fire as the fire dies down.

So with this in mind, no... It does not surprise me in the slightest that the steel in the WTC was heated to breaking point.

If you really want me to, I can go find the link to this data. It already shut the mouths of other truthers in this thread, I would be happy to shut you up too.

 

[John99]

I already did back it up with actual\practical experience. Not good enough for you?

I have to call them the way I see them too.

Good for you.

 

[Tony Szamboti]

I have shown in this thread already (or another thread), independent tests done on steel fire damage in a regular office building.

The tests show that steel can reach 1000 Celcius in just 40 minutes. The temperature lags slightly behind the temperature of a fire, then exceeds the temperature of the fire as the fire dies down.

So with this in mind, no... It does not surprise me in the slightest that the steel in the WTC was heated to breaking point.

If you really want me to, I can go find the link to this data. It already shut the mouths of other truthers in this thread, I would be happy to shut you up too.

I would be willing to bet you are discussing the Cardington tests. However, there was no collapse there and they were able to discern why it didn't collapse as they saved the steel.

The amount of steel and its ability to transfer heat along with the energy of the fire, and composite floor systems, all have something to do with it. Additionally, office fires are known to burn out in specific areas within 20 minutes.

However, this is all really moot and the following questions need to be answered before anyone gets shut up. Why wasn't the steel from the towers and WTC 7 saved? Where is the evidence for these high steel temperatures people like you and John99 believe occured in the towers?

You do know that NIST won't even say the WTC 7 steel got very hot don't you?

 

[John99]

What stupid questions you ask.

Read this:

http://news.bbc.co.uk/2/hi/americas/1540044.stm

 

[KennyJC]

I would be willing to bet you are discussing the Cardington tests. However, there was no collapse there and they were able to discern why it didn't collapse as they saved the steel.

I don't believe the fact of whether it collapsed or not is important, because they are two entirely different structures even if we ignore the fact that one of them was hit by a fully layden 767 at 550mph and the other wasn't. The important point here is that office fires can heat steel to very high temperatures in quick time.

This is verified by pictures of warped steel before and after collapse. There was a link in this nutty forum a while back about a steel inspector inspecting the steel AFTER the clean up operation and the damage was consistent with very high temperatures and he had pictures to show for it.

If you think I'm going looking for the link again, you can go do it yourself.

Why wasn't the steel from the towers and WTC 7 saved?

It was removed over a period of months/years and kept in a scrapyard where I already told of a steel inspector having access to it. And I am sure I saw a link of a hanger where much of the WTC is being stored. There was even a 360 degree photograph of this steel.

Where is the evidence for these high steel temperatures people like you and John99 believe occured in the towers?

Well the link I spoke of above would be a good place to start. Since you already knew of the fire tests I spoke of, you will know about the steel inspection of the WTC, saves me having to go find links.

You do know that NIST won't even say the WTC 7 steel got very hot don't you?

Even if they didn't, it would not prompt me to believe that it was a controlled demolition. It takes a special kind of crazy to jump to that.

 

[shaman_]

What stupid questions you ask.

Read this:

http://news.bbc.co.uk/2/hi/americas/1540044.stm

Read it but ignore the picture with the columns covered in concrete. That is wrong.

 

[psikeyhackr]

You don't have to raise the temperature of a ton of steel, all you need to do is raise the Temperature of a section of of that steel to 1130 F and you compromise the structural strength of that beam.

ROFL

Like that is possible the way steel conducts heat. A normal fire would take a LONG TIME to heat enough steel. But that is a major part of the problem with WTC 1 & 2. Any explanation of what happened has to do it in less than 1 hour for tower 2 and 2 hours for tower 1. I think that is part of why some people don't want to talk about how much steel there was in the impact area.

Heating steel fast enough to weaken in a localized area requires a LOT OF HEAT which means HIGH TEMPERATURES. Acetylene can do it.

Acetylene when combined with oxygen burns at a temperature of 3200 °C to 3500 °C (5800 °F to 6300 °F), highest among commonly used gaseous fuels.

http://en.wikipedia.org/wiki/Oxy-fuel_welding_and_cutting

Of course, so can thermite.

psik

 

[shaman_]

I would be willing to bet you are discussing the Cardington tests. However, there was no collapse there

The cardington tests were controlled fire tests performed in different areas on different floors of a building. The columns were shielded from the fires and recorded relatively low temperatures but the beams were not. The beams buckled. In one of the tests, part of a column was not shielded and it started buckling, so they made sure the columns were shielded completely in the remaining tests. The point of these tests was not to see if a building would collapse in a fire.

and they were able to discern why it didn't collapse as they saved the steel.

The amount of steel and its ability to transfer heat along with the energy of the fire,

In the Cardington tests, steel pieces transferred heat poorly. The differences in temperature between two connected pieces were significant.

and composite floor systems, all have something to do with it. Additionally, office fires are known to burn out in specific areas within 20 minutes.

You are right that the peak temperature of the fires lasts about twenty minutes in specific areas. However with peak temperatures at or above 1000C, even after the peak the temperature is still in a range high enough to sufficiently weaken the unprotected steel. The temperature doesn't drop quickly.

Why wasn't the steel from the towers and WTC 7 saved?

Don’t know. A lot is made of the lack of investigation of WTC7. You have to remember that WTC7 was not a target and no one died. To the firefighters at the scene it was no mystery that it collapsed as they pulled out for fear that it would.

Where is the evidence for these high steel temperatures people like you and John99 believe occured in the towers?

I don’t know if it was mentioned in the NIST report but there were news reports showing softened and twisted steel caused by high temperatures. Do a youtube search for Dr. Abolhassan Astaneh-Asl discussing the steel he is examining. Tests such as the Cardington ones and NISTs own office fire tests reached temperatures around 1000C. The floors near the impact area were seen bowing minutes before the collapse. While computer simulations were done, no one seems to put much faith in them. Considering the number of times fire has caused steel to weaken it really isn’t that surprising though.

 

[psikeyhackr]

the fact that one of them was hit by a fully layden 767 at 550mph

I love these words that try to encourage people to believe this was possible.

What does "fully layden" mean? There were 10,000 gallons of fuel at impact. That is not a full fuel load. A full load is 24,000 gallons so it wasn't even half full.

psik

 

[Buffalo Roam]

I love these words that try to encourage people to believe this was possible.

What does "fully layden" mean? There were 10,000 gallons of fuel at impact. That is not a full fuel load. A full load is 24,000 gallons so it wasn't even half full.

psik

Even if it wasn't a full fuel load do you realise how much 10,000 gallons of Jet A is?

Now how about the 412,000 pounds, 206 tons of aircraft at 550 mph, slaming into the WTC, just how much kenetic energy was released in the target by that?

You dismiss very lightly all of those facts, and the ammount of damage that is inflicted by the impact alone let alone, let alone the fire from 10,000+ gallons of Jet A.

 

[Headspin]

does anyone know how big the plane was that didn't hit wtc 7. I've heard it might have been much bigger than a 747.

 

[scott3x]

Scott, the paper was originally published in May 2007 and updated in February 2008, to use the actual core column data which was released by NIST in the summer of 2007, and a refined tower weight which was available due to Gregory Urich's Tower Mass Analysis being available in Dec. 2007. Prior to that I had to estimate column sizes based on photos from the Engineering News Record, the anecdotal tower weight of 500,000 tons, and minimum factor of safety requirements. The tower columns exceeded the minimum factors of safety by a significant margin.

Even if they are updated papers are usually kept in the monthly volume they were originally published in.

Ah, ok, thanks for explaining that.

I joined the conversation here after seeing that Psikeyhacker was still wondering why we don't have all of the information about the amount of steel and concrete in the towers on each floor. With the release of the core column data we essentially do have that information now. The actual sizes of the core columns was difficult to estimate as there was a significant amount of variance on each floor depending on where in the core the columns were located. There is no question on them now. The only thing we are still estimating is the perimeter column wall thickness and they are much easier to estimate since their external configuration is constant and known, the density of steel is constant, the strength was published for given areas by the Engineering News Record in the 1960's, and we have contract data giving total weight of the perimeter steel. Both collapse areas of the towers had perimeter column steel yield strengths of 65,000 psi. NIST does make the comment in its tower report that the wall thickness of the perimeter columns never went below .250 inches. Using the known external configuration and the interpolated weight of those columns for the 98th floor I found a wall thickness of .289 inches. Additionally, when calculating the wall thickness of the perimeter columns for other floors, with a known mass above them, the factor of safety stays relatively constant at between 5.00 and 6.00 to 1. These multiple correlations provide a reasonable level of confidence in the estimate.

Cool. I'm thinking I may perhaps take a break. Sometimes official story supporters come up with some interesting twists but the language they use is a definite turn off for me. In my mind, it's obvious that the WTC buildings couldn't have been brought down by the jets/fires/debris. Perhaps in the ending, what they most want to do is, as Kenny put it, shut us up, not actually listen to what we have to say.

Anyway, if you get turned off by the tone of some of the official story supporters here and decide to take a break (temporary or otherwise), I hope you'll still check your PMs in case there's a certain technical issue regarding the WTC collapses that I'm having trouble with.

 

[Buffalo Roam]

does anyone know how big the plane was that didn't hit wtc 7. I've heard it might have been much bigger than a 747.

WTC 7 wasn't hit by a airplane, only WTC 1, and WTC 2 were struck by aircraft.


One was a Boeing 767 the other was a Boeing 757, both aircraft are aproxamatly 1/3 and 1/2 the Size of a Boeing 747.

Boeing 757, weighs in at 123,500 lb.

Boeing 767, weighs in at 229.000 lb.

Boeing 747, weighs in at 410,000 lb.