NIST says the fires mostly lasted only 10 to 20 minutes in any one place, moving along as they consumed fuel. It is not credible that such a fire could have produced the temperatures they claim. Also if you look at their own photos you will see the fire on floor 12, which would be heating floor 13, was dying out, and it was floor 13 where they say it started.

However, let’s say it is true about the temperature. NIST says that the long floor beams running from the east wall to the girder at column 79 expanded due to heat about 4.5 inches. I have searched the report to see if I can find any reference to the outer ends of the floor beams. There is no calculation to show how much resistance the outer columns could have provided to restrain the beams. Clearly the columns would have bowed out if pushed, but how far? 4.5 inches? If the whole tower was heated the whole thing would expand and there would be no pressure generated whatsoever. The truth must be somewhere in between, as temperature would not have been uniform. Once again NIST asks us to accept their findings without evidence of anything, only a computer simulation, and that does not include a critical factor, the force provided by the outer columns.

You asked: “Why were “they” exploding charges hours before the building was to collapse?”

I said >> “It is perfectly clear that in controlled demolitions they do not do the whole job at once. It is normal to work for weeks, weakening the building using oxy torches and the like."

You said: “No way.…”

Well you are wrong. They do work on the buildings for weeks, weakening them. They weaken them substantially but they are experts, they know how to calculate how much weakening is safe. In the same way it would logically be possible to set off some preliminary explosives without endangering the building. And if you can do it, and it would help to obscure what you were really doing, why wouldn’t you

Amoeba,

You say >> “Funny isn’t it. We were right all the time and NIST was wrong.”

Frankly, the truth movement have made so many erroneous claims that it was about time they got one right. Even a broken clock is right twice a day.

What time does Chandler measure the collapse to the 17th floor? It’s about 5 seconds isn’t it? Certainly is a lot closer to 5.4 seconds than it is to 3.9.

You say >> “Sunder was challenged at the presentation he gave about NIST’s new theory of thermal expansion, regarding the evidence for free fall, and he tried to wave it away. Some unknown figure poked his head into the video and said they would fix it in the final version.”

Well that’s not what I saw in the video, I saw them reacting to Jones question about freefall, and saying they would clarify it in the final report. But given the fact that the material was highly edited by Chandler to enhance his position, its hard to tell what exactly that exchange was about.

You say >> “and I suppose you will agree with NIST now when they say the fall was partly at free fall rate”

I’d had already agreed that the collapse was at close to freefall. NISTS model also reflects the largely unopposed fall for 8 stories.

You say >> NIST says the fires mostly lasted only 10 to 20 minutes in any one place… Also if you look at their own photos you will see the fire on floor 12, which would be heating floor 13, was dying out, and it was floor 13 where they say it started”

That’s not right at all. If you look at page 13 of the final report, Draft for Public Comment ( I can’t find the new one), you’ll see the fires on floor 12 over a 4 hour period, with temperatures in the 900-1000 degrees C range. They are concentrated in the area around column 79.
http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

TBC,

cont,

You say >> “Well you are wrong. They do work on the buildings for weeks, weakening them”

I never suggested that demolition workers didn’t do that. What I was suggesting is that doing this in a building you are trying to make look like a progressive failure due to fire, is ridiculous.

You say >> “In the same way it would logically be possible to set off some preliminary explosives without endangering the building.”

The idea that they set off charges which trapped Jennings defies belief. Why would they provide evidence like this, when all they had to do was collapse it all at once? All it would take is one person who witnessed an explosion to bring the whole thing down. NO WAY did they explode charges before the final collapse.

How is it that this massive explosion, which wiped out floors, wasn't seen on the outside of the building? The building did take a massive hit by the North Tower however.

you said >> "Here is what you said in the past: “The NIST analysis shows that the building took 5.3 seconds to fall 18 stories. At freefall speeds this would have only taken 3.9seconds.”

I haven’t yet seen this proved incorrect. All Chandler has shown is that during the 5.3 second period, 2.25 seconds were at freefall.“

Here’s what you said earlier >> “No upward force implies that all support columns were simultaneously severed.”

You can be silly if you want, but we both know we changed our positions on this as the discussion matured.

You say >> “If the whole tower was heated the whole thing would expand and there would be no pressure generated whatsoever”

Really? You don’t want to rethink that? You know of fires which heat everything in a 47 story building equally? You know of 47 story buildings in which all columns and girders are made of the same material, with the same fire resistance and with the same options for deformation?

Paul,

I don’t want to continue debating the fall behaviour of WTC 7 with you because I believe we will never agree. To finish off, I will simply list the things NIST asks us to take on trust with no evidence, and leave it at that.

1. The floor in the NE corner of floor 13 was very hot, near column 79.

In June of 2004, when they did not realize they needed this floor to be very hot, NIST honestly said that the fire on floor 12, which was heating floor 13, had died out. If you look at the photos in NIST you will see that this is correct. http://wtc.nist.gov/progress_report_june04/appendixl.pdf

2. The NIST simulation of collapse is satisfactory.

If you look at their simulation you will see it is nothing like what really happened. For free fall to be possible according to the NIST scheme there must be a section of the building, at least 8 storeys high, totally disintegrating, low down, out of sight of the video. This must happen to allow the top to drop as the videos show. However the simulation shows a huge amount of destruction and distortion has occurred at the top before the top starts to move down. Clearly the simulation is grossly incorrect and cannot be relied upon.

3. It is reasonable to believe that a vertical collapse could occur without explosives.

Many columns might collapse before general failure occurs, with load being taken up by the remaining columns. For this to lead to a vertical collapse all remaining columns must simultaneously disintegrate at the moment of collapse. NIST has not addressed this question and provides no explanation of how all the exterior columns still holding up the building could let go at the same moment. If they don’t let go together the building must lean. Videos show that it did not – it came down with almost perfect verticality

It's hard to know what the purpose of Paul's last two posts was, unless it was to lay a smokescreen behind which to retreat.

He made several attempts to imply that David Chandler was dishonest and, at least once, referred to him as a moron, only to end up essentially agreeing with him, but not before making another totally unfounded accusation that he may have edited the footage of his latest video in order to mislead (as if David Chandler would not have been very quickly shown up if he had).

---

Paul wrote "Frankly, the truth movement have made so many erroneous claims that it was about time they got one right."

If Paul is agreeing that the truth movement has got this right, then he must surely agree that a new investigation, in which all the evidence which stands in contradiction with NIST's current findings is properly considered, should be held.

Again I reject Paul's implication contained in the above statement and in many other places that he has refuted my arguments.

He has been shown to be wrong in his assertion that the only firefighter who testified that explosions occurred at the World Trade Center before and during the collapses was John Schroeder, he has been shown to be wrong in his assertion that rivers of molten steel were not found underneath the ruins of the three towers and he can be shown to have been wrong in just about every other assertion he has made during the course of this discussion, if he has not already.

4. It is reasonable to believe that a collapse which initiates by buckling of columns could pass suddenly into free fall without explosives.

It is true that once a buckle is well established a column can provide little support, however in the early stages of a buckle there will be considerable support. If this buckling is happening over a span of about 8 storeys, there will be a substantial drop of the roof before something close to free fall is established. This is not what was observed – there was brief lurch followed immediately by full free fall acceleration. The graph of velocity took up a straight line suddenly.

5. NIST states that thermal expansion of 4.5 inches of a section of floor pushed a girder off its support, triggering the collapse.

It is true that expanding metal can generate a very powerful force. For this force to be applied to something however, the other end of the expanding metal must be restrained. The other end of the floor section is against the outer wall. It is certain that the outer wall would bend outward under pressure and reduce the available movement and hence reduce the force. It is also certain that other floors in the area would have been somewhat heated, so that they would all push outward on the wall and further reduce the force. NIST does not address this issue so we are left to accept that there was in fact enough movement to break the fastenings and push the girder off, without evidence.

The probability of each of these things is extremely small. The probability that the NIST explanation is correct is the probability of all these things multiplied together – a really small number. Most rational, humane people agree, after they have considered the evidence, and discovered the glaring improbability of the NIST explanation, that a new investigation is warranted.