The idea of me taking the time to provide the images was precisely so that you would not have to go trawling through NIST’s papers. The figure references they are taken from are as follows: -

NCSTAR 1-3 Figure 5-4. page 34
NCSTAR 1-5 Figure 6-5. page 116

Call me cynical, but I suspect this is just a delaying tactic on your part as you are struggling to fabricate a reasonable answer.

That is blatant lie Aroces. When are you going to stop lying?

The other day I busted you lying trying to say that the US didn't sell Saddam bio and chem weapons.

I am starting to think that someone should report you to the mods for lying.

==========

And as you are fully aware, 911 widows were some of the first ones to question the official story and get the ball rolling on the truth movement.

Refer to the film 911 press for truth.

Remember, Anne Coulter was calling them names.

================

But I will say this: Either you have no idea what is going on, or you are just lying and trying to spread falsehoods.

I am sick of it.

I mean you don't even try to correct yourself after you are proven wrong.

You just keep pumping out the same lie.

Perhaps you could find a truly objective person to ask, to me it still looks like you just make up any technology that your theory needs.

More unfalsifiable theories. Perhaps you might consider how much material is in that cascade and then tell me how big a charge you think caused it.

You don't understand the difference between heat and temperature, do you?
The earth is heated by the sun, which has a surface temperature of some 6000 deg. On your argument we should all be fried.

You do have difficulty understanding structural matters, don't you? If column to column impacts cannot stop the fall, then nothing else can. If the columns move past each other, their cross-beams will impact each other with the results I mentioned above, because it is geometrically impossible for them to miss. The top of the building would have to move sideways by the total width of the core structure before you get the columns hitting the floors alone, and this is clearly not happening.

I find this whole argument a quibble - do you keep playing it because you can't come up with a proper argument against the fact that eyewitnesses said the building was unsafe?

Perhaps you could get an understanding of the burden of proof thing? If you think NIST is tampering with the photos it is up to you to prove it.

Those aspects may look like CD to you, but they don't to me. The only aspect that looks like a CD in any of the collapses is the final fall of WTC7, and that resemblance is contradicted by the previous several hours of fire and the previous several seconds of the penthouse collapse.

On the contrary, I just didn't see why I should dowload the best part of 100 Meg of documents to find your pictures.

From the table accompanying the picture I identified the three panels on the east side of WTC1 as the ones listed by NIST as K-2, N-12 and S-10. I'm not sure which of the three was the one nearest the corner. Only the lower half of S-10 was recovered, so the bit at the 94th floor is missing. These samples are mentioned elsewhere in the reports (1-3C, p224 onwards) as having much more fire exposure than most of the recovered samples, and K-2 in particular is one of your three "high-temperature" recovered sections. The NIST report mentions several factors which may have shielded the samples from the worst of the fires, including the possibility of intact fire-proofing, which I believe you have been arguing for, and the fact that windows breaking could have let in cold air to reduce the temperatures at the walls.

I don't think you have proved your case.

I consider that the transit measurements made of WTC7 being out of line before its collapse to be hard evidence in support of my position.

Is it possible for transit measurements to be out of line for a building that didn't collapse?

Ummm. Bob, you're replying to a post from Aroces back in June. Six months or so ago.

I think it's safe to say that it might be a while before Aroces notices your reply. If ever.

I was objective (with a sceptical slant even) when I first looked into the theories. Therefore I can say without doubt that a truly objective person can indeed see the possibilities.



The above is all irrelevant. I have said each to his own regarding the most plausible cause of the high debris pile temperatures. Again, an objective person finds thermite plausible but office fires and an accidental smelting process beneath the rubble not, in creating the “foundry” and “lava” effects described.



Regarding your first sentence, once again you have difficulty understanding that stopping the already falling material does not equate to stopping the collapse. Of course once the block begins moving it will not stop dead, though that does not mean it will symmetrically ‘crush’ all of the lower intact area.

1. Are the columns, cross-bracing or floor trusses the most important element in holding the building up? The columns are most important – I believe at any given floor the secondary structure could be fully removed, leaving the Towers standing, but fully removing the columns would cause a collapse.
   
   
2. In reality, did all of the impact energy channel into the column cross-sections? No – the energy was split between the columns, its secondary elements and also all the space between.

Therefore, just answering the above two questions shows that the B&Z paper has assumed the most important elements, the most structurally vital in keeping the Towers standing, were struck with more energy than ever possible.

This whole point is a quibble as every time I see the immense, strong Tower cores…



… I realise how ridiculous it is to think that the core could crush itself at near freefall due to heating.



I keep on this argument as it appears to be a prime example of NIST forcing the evidence toward a preconceived conclusion. I just want to know why anyone would find it acceptable for NIST to show an extreme maximum amount of damage but not the possible minimum.



No, it is up to the official story to prove their theories of bowing, that is not clearly evident in images of the Towers, to be viable. Also if there was any minor bowing of the walls there is no evidence this was increasing from the time of the impacts to the moment of the collapses, or that this was caused by heating rather than the explosives and thermite placed in the buildings.

From left to right we have K-2, then S-10, followed by N-12 closest to the corner.



This is not important as even looking at the fire model for the 93rd floor, the 1,000^oC temperatures are still there.



Throughout the thread you have been claiming that the fire models are validated by the physical evidence: -


Here, I have shown that not only does the physical evidence not validate the fire models – it contradicts it. Please note that while I have only given examples of a few analysed areas that do not match the fire models, there are plenty of others. It is therefore safe to say that the fire models are in fact not based on any physical analysis or evidence. Or, in your own words above, the fire models are not based on the “good evidence” you assumed.



I have absolutely proven the case that the NIST fire models were not based on physical analysis, visual evidence or eyewitness testimony. The only question left is what were they based on other than the parameters input and tweaked by NIST?

Yes, but it is an indication of major structural damage, which is all I'm claiming.

To me, "objective" implies an attitude where you actually investigate claims, work out the calculations of anything quantative. I have seen nothing of this in your posts.

What is relevant here is your complete failure to back up a quantative claim.

You seem to have great difficulty in understanding some very basic points about structures, here.
All the beams and secondary elements evetually feed their loads into the columns. Whether the impact loads the columns directly or indirectly, the result will be the same. If the beams break before they load the columns, then the columns are no longer stabilised and will collapse anyway. If the beams do not break, the calculation with all the load going into the columns applies.
The "immense, strong cores" are designed to take the loads of the building above them, plus a safety factor. The dynamic loads in the collapse are much higher, hence the columns were overloaded. However impressive a structure looks, there is always a load it will not support.
Try this to help visualise what happens if the cores do not impact directly:
Picture four columns (NSEW) linked by cross members to form a tubular truss of square section. Drop a similar truss on to it. For the columns to miss each other, say the top is offset slightly to the E. The W column of the top part will therefore fall into the gap between the four columns of the lower part. The NW and SW cross members of the top part will impact the NE and SE cross-members of the lower part. This is what I mean by it being geometrically impossible for the cross-members to miss each other. For an array of columns rather than a simple square, all the cross-members will meet except the ones on two sides of the outside of the array. The only way for this not to happen is for the top to be moved sideways by more than the width of the core structure, and if you compare your picture of the core with the videos of the collapse, it is obvious that this did not happen.

This only applies if the NIST analysis depends on the exact size of the damaged area.

There are very clear pictures of bowing in NCSTAR 1-3, page 61 onwards. I linked you to some and your only reaction was to claim that NIST was tampering with photos - with no evidence, yet another unfalsifiable get-out. Bowing fits in very well with NIST's proposed failure mechanism. Could you explain how it fits any plausible CD scenario?

Good, the two highest temperatures match.

And the high-temperature exposure of S-10 is noted in the reference I gave.

For a start, I have also been arguing that the steel evidence is only one source of validation for the fire model. If you check the actual comparison of model with evidence (NCSTAR 1-5, page 106 on), you will see that it is mostly concerned with how the fire developed and spread, as seen in the video evidence.

Has it occured to you that maybe NIST had trouble getting the temperatures in their model low enough to match the physical evidence - that all their runs predicted high temperatures - after all such temperatures are not unexpected in office fires? If this was the case they then had to look for reasons why the measurements of the steel were lower. What is implausible about their reasons for the discrepancy, which include something which you yourself have been suggesting?

Another point worth noting is the position of the measured steel shown in the picture you posted from NCSTAR 1-3. You keep saying how few of the panels showed high temperatures, but note that a lot of the panels came from nowhere near the fires, so you can remove them from your total. The reason is that the panels were collected for more than just the fire aspect of the analysis.

I investigated every aspect and claim of 9/11 that I could for 6 months solid and even then I found it difficult to accept an inside job – no hiding from the truth though is there. Here is a calculation for you…



… yes… … no… … at near freefall?



Safety factor of 2.25 for the core columns I believe – the building could support well over double the load intended at any given point. The dynamic loads predicted by B&Z are B&S I am afraid as there is no explanation for how every column at a level simultaneously gave way allowing an instant freefall drop or why all the energy should channel into the column cross-sections.



I already know exactly what you mean and have said I believe at any given level the secondary structure could be fully removed, leaving the Towers standing. If the cross bracing comes together this does not imply an immediate collapse of the core columns, thus downward momentum is not built so fast… then the floors are going to impact the ones below, slowing the collapse… all the time the upper block is breaking up, dispersing the impact forces… eventually the initial block which ‘hammered’ the intact structure will be destroyed and its debris embedded in with the lower section of the structure. I see no reason for the Towers to completely collapse and certainly never at near freefall.



Of course the size of the damaged area is important. In any case the question was – why did NIST show the extreme maximum but not the possible minimum damage to WTC7? Why can you not answer that directly?



Explosives in the buildings and thermite charges initiating the collapses would cause any bowing present.

Which two highest temperatures match what exactly?



‘High-temperature’ exposure? Only 3 of 170 samples showed any temperature perhaps above 250^oC!



If the models were mostly concerned with how the fire spread, why do NIST feel the need to embellish their figures with unrealistic 1,000^oC temperatures? Barring the steel analysis which does not validate them at all, what are the other sources of support for the temperatures in the fire models?



For sure, it occurred to me that NIST have a great deal of trouble with many things. As above – ‘their runs’ based on what? What leads you to believe 1,000^oC temperatures should be widespread and long lasting? This was an office fire, not a chemical or fireworks factory. Do you have any suggestions what was burning? If you say tables, chairs, carpets, paperwork, jet fuel, etc, sustained 1,000^oC temperatures then I am just going to laugh.



Now you are talking – NIST had to look for reasons (excuses) as to why their fire models contradicted the physical evidence. So NIST are saying a large amount of the fireproofing was knocked off but where it suits them the fireproofing was intact. These guys are really just making it up as they go along in an attempt to promote non-existent events fitting their pre-conceived conclusion.



It does not matter as there is no physical evidence for temperatures higher than 250^oC anywhere.

I have an interesting point of note as well regarding the fireproofing/temperatures. NIST are saying the fireproofing was knocked off, thus a large part of the reason the Towers collapsed. They also, where it suits, say areas of the fireproofing were intact as an excuse for the fire models not matching with the analysed areas. Whilst utterly unsupported, this idea may appear passable until it runs into trouble with the recovered and analysed core column 603 from WTC1.

You see, this column 603 from floors 92-93 showed a peak temperature exposure of approximately 100^oC (NIST PowerPoint presentation Project #3: Analysis of Structural Steel Update). At the same time NIST’s fire models show approximately 500^oC temperatures alongside this column. So, to make things sit nicely, NIST had to say in the presentation this was due to the column fireproofing being intact.

But looking at the location of core column 603 (arrowed) and its said intact fire-proofing in relation to the impact/damage zone…



… we see it is in the area of the airliner impact, adjacent to two supposed severed columns and surrounded by others with heavy to moderate damage! If the fireproofing of this column survived, how can NIST assume that any other, apart from where directly struck by the airliner, was removed?

In the end, by attempting to make excuses for their fire models, NIST have inadvertently contradicted their ‘fireproofing was knocked off’ theory. When you are telling lies you cannot win – the truth will always come out in the end.

Very convincing, your mathematical skills are unbelievable.

You have of course the calculations to show what you think the dynamic loads were instead of B&Z's values? Thought not.

Well, I explained it as well as I could and you still don't get it. You don't believe me and you dare not ask an expert, so you are left with your opinion. But then you have no engineering skills whatever, so what is your opinion worth? Overloaded structures break, and they can break very fast. You have only to see the way the aircraft penetrated the buildings for a demonstration of that fact.

The size of the damaged area is not that important because of the other evidence that the damage was sufficient to make the building unsafe. Given that, I have no problem with the way that NIST have treated the eyewitness evidence. For all either of us know, they may have also used other evidence. Your inference that they have a theory of the collapse that depends on the size of the hole is pure speculation on your part. Until they publish the WTC7 report this discussion is utterly pointless.

I asked you to explain how, not just repeat the allegation.

The two out of the three samples that show high temperatures are the two that are near the high-temp part of the fire simulation.

The NIST report says that only 3 panel samples (of 13 in the fire zone, so your persistent mention of 160 samples is misleading) show paint cracking patterns indicating high temp, but for a further seven samples, including S-10, the temperature could not be determined because the paint was no longer there due to causes such as damage, corrosion or fire.

Laugh as much as you like, but that is what happens. Here is a link that gives some data:
http://www.interactfire.co.uk/legislation.asp
"Recent live testing of a typical furnished office has shown that the temperature curve was similar to the hydrocarbon curve at the outset, reaching temperatures of 1,300°C before dropping down to follow more closely the cellulosic curve."

No, the physics is built into the simulation. If the simulation says that a fire in that space with that amount of combustibles will reach that temperature, you cannot say that they are contradicting the physics.

Not even your cascade? That looks pretty hot to me. Which reminds me, you never answered my question about how big a thermite charge you think caused it. There is an awful lot of material and it lasts an appreciable time.

So the fireproofing is intact where you want it to be but not where NIST wants it to be? No-one is claiming that all the fireproofing was damaged, but you were claiming that not much of it was.

I checked the location of the recovered piece of column 603 (NCSTAR 1-3C, p10). It's from the lower edge of the impact zone, 93rd floor, and appears to have been damaged in the collapse, not the impact (p 200). The fire temperatures on that floor vary a lot around the location of the column and while there are peaks of around 500 near the column, the temperature at column 603 stays around 100 (NCSTAR 1-5, p 114-5). Presumably the high spacial temperature gradients indicate the position of partitions.

Calculations are not needed to know that all impact energy did not immediately freefall through the height of a floor or to know that all the impact forces did not channel into the cross-sections of the columns. B&Z’s calculations may be accurate, but founded on ridiculous assumptions not based in reality they are worthless.



I get you flyingswan, I just don’t agree with you. Your reference to how the aircraft punctured the buildings is out of place as, unless I missed something, the upper blocks of the Towers did not descend at 500mph. Actually, if you want to use that as an argument… I could ask – how come the whole of the aircraft did not fly right through the Towers and out the other side? I think it is to do with something called “resistance”. The same resistance that stopped the bulk of the airliners, slowing them from 500mph to 0mph in a second, should also have slowed/stopped the Tower collapses.

What is wrong with the picture I laid out: -

If the cross bracing comes together this does not imply an immediate collapse of the core columns, thus downward momentum is not built so fast… then the floors are going to impact the ones below, slowing the collapse… all the time the upper block is breaking up, dispersing the impact forces… eventually the initial block which ‘hammered’ the intact structure will be destroyed and its debris embedded in with the lower section of the structure.

Put another way, should the upper block of the Towers break up at approximately the same rate as the lower intact portion? I would say yes. If you agree, then how can the upper block, now broken up, continue to crush the much larger lower region all the way to ground level?



I am not asking if you find the damage estimate acceptable or even if it is important to the collapse (though I do find the idea of the damage to WTC7 not being important to be absurd). I am asking why did NIST choose to show the extreme maximum damage but not the possible minimum? Or have you just fallen back on the idea that NIST have some secret evidence they do not wish to share? Remember, the NIST report itself states they are working on eyewitness estimates of a quarter to one third. You said yourself one quarter could possibly cover only 3 external columns.



I would have thought it obvious how explosives and thermite active within the buildings could weaken the structure causing a bowing to overloaded columns.

Firstly, you missed out the question - what are the other sources of support for the temperatures in NIST’s fire models? We have got far enough to know that the steel analysis does not validate them at all, though you said there were other sources of validation.



So in other words there is absolutely no physical evidence of the 1,000^oC temperatures NIST are showing. In fact, there is no physical evidence at all of temperatures above 250^oC.



Those interactive fire people were really going for worst case scenario weren’t they!? This article The 9/11 WTC Fires: Where's the Inferno? covers fires in the Towers including eyewitnesses and visual evidence. As an example, this is the best photo showing inside WTC1…



… where is the 1,000^oC inferno? There is no inferno; it does not exist.



I did not say the physics were contradicted. I said NIST are covering up the possible contradiction posed by physical evidence in claiming the fire proofing was/wasn’t intact as they feel free.



I have explained before that the thermite charges would be localised and focussed on particular columns and not be widespread throughout the Towers – therefore it would not be expected to recover and identify these specific samples. Fires though were supposedly raging at 1,000^oC in large areas at many points across the impact levels so I find it unacceptable that not one of these areas could be found.

I do not see the relevance of the size of thermite charge used but if it is so simple to quantify and you really feel the need to know, you work it out and let me know.



In my opinion the sprayed on fireproofing could not be ‘shaken off’ and would only be removed where the airliners directly impacted. Column 603 with its intact fireproofing despite being surrounded by severed and damaged columns proves this.

Now if NIST are saying from hands on physical evidence this core column showed a peak temperature exposure of approximately 100^oC, why should it be assumed that other core columns reached anything higher?

You have still failed to provide any explanation of what you think was happening. Either the loads went into the columns, overloading them and causing them to fail, or there were no loads at all and nothing to stop the collapse. You think B&Z are making ridiculous assumptions? Then find an engineer to publish this fact in a peer-reviewed journal.

Apart from the fact that aircraft debris comes out the other side of the building in the videos? I am not talking here about how fast the aircraft was going, I'm talking about how fast both aircraft and building components were damaged at the impact. You seem to think a grossly overloaded structure should still provide some resistance, but this resistance is used up in getting to the ultimate load.

If the columns are not taking the load, the downward momentum builds faster because breaking the cross-beams provides less resistance. Whatever bits are hitting each other, the loads have to go into the columns eventually, and the later that happens, the higher the dynamic loads on the columns.

The difference between the two blocks is that the bottom of the lower one is fixed to the ground, the top of the upper one is free.

"A quarter" is consistent with three or four damaged columns, depending on exactly where the limits of the damage are with respect to the columns. The NIST drawing is thus consistent with the evidence. They could equally well have included a sixth column at the upper limit, but they didn't do that either. Your quibbling like mad on this point suggests to me that you can't find a real argument.

That's the third time you've said that without explaining how. Are you working on the Bellman principle - "What I tell you three times is true" - because reality doesn't work like that?

The physics is built into the equations used in the simulation. The simulation methods are validated by lab experiments and previous use, the actual comparison with the WTC fires is mainly with location and spread.

So the videos showing the presence of fires are not evidence?

Worst case indeed, but 1300 deg C is a lot higher than the NIST simulation actually shows. You were claiming that no office fire could even reach 1000 deg, how about an admission that you were wrong?

OK, I'll bite, when was that photo taken, what does the simulation say was happening then?

If the steel shows lower temperatures that the simulation, why isn't intact fireproofing a plausible physical explanation? How are they covering something up when it is in their report?

Your claim, you should do the maths. However, I can't see it being less that several hundred kgs of material.

The column wasn't in the direct impact zone, but below it, and we've already established what your opinions are worth.

Because other columns were in the impact and fire zone, and column 603 was below the impact zone and shielded from the fire by a partition.

What I actually think happened is that pre-planted explosives were detonated in the building allowing the upper floors to drop at freefall encountering no or very limited resistance; a top-down, unconventional controlled demolition.

Where the loads may pass around the columns such as through lift shafts, stairwells, broken sections of cross bracing or floor trusses you keep assuming there is then “nothing to stop the collapse”. What it really means is that there is nothing to stop the currently falling mass. By my reckoning, in attempting to give what you describe as a conservative estimate, trying to stop dead the collapse by impacting and destroying the core columns with more force than they could take, this is only ensuring the collapse continues. If the most important part of the Towers, the core columns, only take a fraction of the full force, I agree it will not stop the currently falling mass but it will give the Towers more chance of slowing that current fall to an eventual stop as with some of the core columns intact there must be more resistance.

Why would I want to go to the lengths of finding an engineer? I am not that bothered. Do you think an article stating an alternative energy source brought the Towers down would pass peer-review in any case? I do not think so – best for structural engineers to play it safe with the ‘accepted’ version.



Apart from the fact I said “whole of the aircraft”. But yes, you see how part of the aircraft passed through the structures – that is what I am talking about above, not all impact forces go into the columns, some passes through open areas or weaker structure.

Talking about how fast the structure breaks – I think there is a difference between the massive and sudden energy transfer of an aircraft moving at 500mph and the slow weakening of columns due to heating. Fire can never at a point immediately remove the entire strength of a column as a sudden sharp impact may. Even a column weakened is going to continue giving a level of resistance. Unless you believe the Tower core columns were progressively failing as you do WTC7? Though there is no evidence of a chain or progression of collapses in the Towers.



No momentum is built by breaking the less resistant structure as with the cores lasting longer the momentum of the main mass supposedly crushing the building cannot gather. The longer the cores survive, the less mass continues to build up in the fall, the less momentum and energy to continue the collapses. I do not agree the loads all have to go into the columns eventually. Due to the pieces in the upper block breaking up, the debris can more readily pass through open areas. Due to pieces in the lower structure breaking up, connections into the columns will be broken.



I am not sure how that answers the questions – “should the upper block of the Towers break up at approximately the same rate as the lower intact portion? I would say yes. If you agree, then how can the upper block, now broken up, continue to crush the much larger lower region all the way to ground level?”

For all of the above so far, you seem to be treating the upper block as some sort of hammer and the floor as an anvil all the way through the collapses, whereas I am accepting the blocks were twisted, broken and pulverised into many pieces during the collapses. Perhaps that is where we are differing.



NIST did include a sixth column at the upper limit - that is one thing I am not happy with! They took the maximum then stretched it to more whilst not showing the possible minimum damage. I cannot fathom how you think the damage estimate to WTC7 is somehow not important.



I do not know what you are looking for me to explain. Explosives below the impact zones damaged the core columns, weakening the above structure and overloading the adjacent columns possibly causing any bowing of the perimeter. Sorry if you find that repetitive but I cannot explain it anymore clearly.

I am not questioning the physics of the models once the parameter values have been input. I am also concerned with and have been addressing validation of the temperatures rather than the location or spread. There does not appear to be any validation of the fire temperatures - certainly not in the physically analysed evidence. I think it difficult to validate fire temperatures from video, especially as most of the fire was not visible; supposedly inside the structures.



Shall we get my claim right first? Of course patches of fire in areas may for a short period of time reach 1,000^oC. What I actually said was that these temperatures would not be “widespread and long lasting” or “sustained”. Whilst briefly achievable in areas, I would not go so far as to say that 1,000^oC fires are to be expected. Engineering professor Thomas Eagar (who incidentally argues the official line) says: -

“Thus, for virtually any hydrocarbons, the maximum flame temperature, starting at ambient temperature and using pure oxygen, is approximately 3,000°C.

This maximum flame temperature is reduced by two-thirds if air is used rather than pure oxygen. The reason is that every molecule of oxygen releases the heat of formation of a molecule of carbon monoxide and a molecule of water. If pure oxygen is used, this heat only needs to heat two molecules (carbon monoxide and water), while with air, these two molecules must be heated plus four molecules of nitrogen. Thus, burning hydrocarbons in air produces only one-third the temperature increase as burning in pure oxygen because three times as many molecules must be heated when air is used. The maximum flame temperature increase for burning hydrocarbons (jet fuel) in air is, thus, about 1,000°C—hardly sufficient to melt steel at 1,500°C.

But it is very difficult to reach this maximum temperature with a diffuse flame. There is nothing to ensure that the fuel and air in a diffuse flame are mixed in the best ratio. Typically, diffuse flames are fuel rich, meaning that the excess fuel molecules, which are unburned, must also be heated. It is known that most diffuse fires are fuel rich because blowing on a campfire or using a blacksmith’s bellows increases the rate of combustion by adding more oxygen. This fuel-rich diffuse flame can drop the temperature by up to a factor of two again. This is why the temperatures in a residential fire are usually in the 500°C to 650°C range.”
Link

Then we have NIST’s own Simulation of the Fires in WTC 1, 2 and 7 where peak temperatures of approximately 1,000^oC were sustained for less than 5 minutes. All well and good until we look again at the fire models where 1,000^oC temperatures are consistently depicted in regions for 30 minutes plus. Not exactly tallying up is it?



I cannot find the time of the photo, so agreed it only shows that at some point the fires at the impact zone and as far as we can see into the building were not severe. If the photo was taken in the 15 minutes prior to collapse we may finally have found something the fire models match with!



I do not find it great confirmation as, in one breath NIST use the lack of fireproofing to account for the weakening of steel, then in the next NIST use the present fireproofing to excuse their fire models from the physical analysis. Whilst the state of the fireproofing is not in reality accurately known, NIST are having their cake and eating it.



Fact is that the physically analysed core column evidence we have shows the steel, directly one floor below the impact zone and in a fire region, to have its fireproofing intact and having been exposed to a peak temperature of approximately only 100^oC. The only other recovered core column, from one floor above the impact zone, shows again fireproofing intact and peak temperature less than 200^oC. For the purpose of showing the NIST report to be based on a preconceived conclusion rather than evidence, this proves the point once again.

One more thing I found for you to chew on – it seems I have fairly strong support for all of the above I am stating - James Quintiere with 35 years of fire research experience, 19 years in the NIST fire program, founding member and past-Chair of the International Association for Fire Safety Science—the principal world forum for fire research. Here are some excerpts from his recommendations to NIST (bolding mine): -

“In my opinion, the WTC investigation by NIST falls short of expectations by not definitively finding cause, by not sufficiently linking recommendations of specificity to cause, by not fully invoking all of their authority to seek facts in the investigation, and by the guidance of government lawyers to deter rather than develop fact finding.”

“Why were not alternative collapse hypotheses investigated and discussed as NIST had stated repeatedly that they would do? Their current explanation for the collapse of the towers is critically based on an assumption that the insulation was removed from the steel in the path of the aircraft, particularly the core columns. NIST does not show calculations or experiments to satisfactorily confirm that the insulation was removed in the core. As some large aircraft components went directly through the buildings, and NIST indicates the others were splintered on impact, can they explain why these small splinters could still denude the steel?”

“Spoliation of a fire scene is a basis for destroying a legal case in an investigation. Most of the steel was discarded, although the key elements of the core steel were demographically labeled. A careful reading of the NIST report shows that they have no evidence that the temperatures they predict as necessary for failure are corroborated by findings of the little steel debris they have. Why hasn't NIST declared that this spoliation of the steel was a gross error?”

“NIST used computer models that they said have never been used in such an application before and are the state of the art. For this they should be commended for their skill. But the validation of these modeling results is in question. Others have computed aspects with different conclusions on the cause mechanism of the collapse. Moreover, it is common in fire investigation to compute a time-line and compare it to known events. NIST has not done that.”

That seems case closed on NIST. But flyingswan, you must understand I am not trashing the whole NIST study here - just showing that whilst following a preconceived conclusion, it is at best severely lacking in the most important areas.

Either the columns take the impact directly or they take it indirectly through the cross-beams. There is no way the cross-beams can miss each other. As the cross-beams break they will also place dynamic loads on the columns, and even if they didn't, the columns need the cross beams to stabilise them - they won't stand without them. The later the load goes into the columns, the faster the top is falling and the higher the loads produced. There is no way to wriggle around this, which is no doubt why you won't risk asking a structural engineer.

If you think structural engineers are untrustworthy, does that mean that you never enter a building or cross a bridge? Do you realise how many people you have just added to the conspiracy?

Either way, most of the impact momentum of the aircraft went into making the building bend. Whatever building component eventually stopped a given piece of the aircraft, the load would feed back into the primary structure of the building. Maybe a wider building would have caught all the debris and bent a little more, but in any case no-one has suggested that there is any mis-match between the cause and effect. Similarly, whatever part of the top of the building hit the bottom of the building, the load goes eventually into the structure.

Eh? I was comparing the impact of the top and the bottom parts to the aircraft impact - you were arguing (on the basis of no evidence) that structures must fail slowly.

I've already pointed out the evidence for a slower onset of the collapse - the pictures of bowing - to which your only response was to suggest that they had been faked. Anyhow, even if the onset is slow, once the point is reached at which the load on a component exceeds the ultimate strength, the component can provide no further resistance.

The smaller the resisting forces, the faster the top falls, the greater its momentum, the greater the loads on the columns when they eventually take the load.

I am pointing out that the situation is not symmetrical - the attachment of the lower block to the ground means the loads on it are higher. There is also another assymmetry - components that break away fall on the lower block, but do no further damage to the upper block.

Hammer and workpiece is a better comparison, with the ground taking the role of the anvil.

Look at the diagram again - the sixth column only comes inside the "roof damage" contour, not the main damage upper limit one. This evidence is not important because of all the other evidence that the building was unsafe.

I am looking for a mechanism for a thermal charge to pull the outer wall columns inwards, long before the top of the building starts to move.

It seems to me that you are questioning the model. If you think that some tweaking of the input data will provide significantly lower mean temperatures, rather than merely a different rate of spread or pattern of high and low temperature areas, you are indeed questioning physics. Getting back to my earlier discussion with Coughymachine, those details are specifics, but the fact that a fire in a given space with a given amount of combustibles will reach a certain temperature is a general.

You seem to think that all this somehow supports your argument?
With your usual misleading habit, you stop Eager's quote just before he gives reasons why the temperatures were indeed higher that the figure you stopped at. He then goes on to develop a mechanism for collapse initiation that only involves the temperatures he thinks likely.
The NIST lab tests in that reference show good agreement between measurement and simulation, so why are you questioning the building simulation?

They suggest damaged firepoofing in the impact zone and undamaged fireproofing outside, how is that unreasonable?

No, it just shows the difficulty of identifying components from the impact zone.

No-one is claiming that the NIST study is perfect, but equally, Quintiere is not showing any doubt that the collapses were the result of the impacts and fires. The "alternative collapse hypotheses" he mentions are not CD, but other "natural" mechanisms like those proposed by Eager in your other link. Engineers may continue to argue specifics of the exact sequence of events, but they agree on the general point that the collapses were not unexpected in the circumstances.

There is a world of difference between calculating factors for a safe bridge and putting everything on the line by publishing figures showing government/intelligence involvement in the most important event in recent history.



So your argument is that given enough impact energy, structures can fail rapidly – well ‘doh’, state the obvious. What I wrote - “there is a difference between the massive and sudden energy transfer of an aircraft moving at 500mph and the slow weakening of columns due to heating. Fire can never at a point immediately remove the entire strength of a column as a sudden sharp impact may. Even a column weakened is going to continue giving a level of resistance.” – questions how the dynamic loads, such as those given by B&Z, were achieved when the stationery upper block was supported on columns that were giving resistance.



This is the second post in a row where you have grossly misrepresented what I said. I have not claimed any photos possibly showing external walls bowing were faked, only that I do not entirely trust NIST’s calculations or that the best picture was used. Any bowing can be accounted for by the alternative theory, so I am not fussed.

I need to clear something up about your belief of what happens when a column is overloaded. If we theoretically had a single column, loaded it up to its maximum bearing and then very gradually continued loading it some more… what happens to the column? Does it bend, twist and buckle and at what speed? Or does it snap like a toothpick?



And another one – the impact forces on the lower section are channelled throughout a larger area than the smaller upper block. But still, should the upper and lower sections coming together break up at approximately the same rate?



Yes, where I described the floor as the anvil I meant ground. So in the official version, throughout the complete collapses, we have the upper falling mass (hammer), intact lower structure (workpiece) and ground (anvil). That is bizarre when you consider that the workpiece is made from a larger and stronger amount of the same material as the hammer and we have only one strike. Actually it is just a really useless analogy – yet virtually how the official fairytale is describing events.



The widest area of damage in the estimate encompasses 6 external columns: -



The fact WTC7 was reported as unsafe is secondary to the question of how it became unsafe. As the official version suggests fire and damage compromised the integrity of the structure, the damage estimate is of great importance in supporting the theory. Equally, the alternative version suggests explosives and/or thermite caused the reported weakening of the structure. On its own, that WTC7 at some point became unsafe does not support either theory.



As said, I cannot explain anymore clearly than I have done. If you believe fire can cause bowing of the columns I am sure you can understand how explosives could have at least as great an effect.

As our points are practically the same in areas, I will quote Professor James Quintiere in response – I am sure you can respect he is, after all, far more qualified than you…


“But the validation of these modeling results is in question.”



“A careful reading of the NIST report shows that they have no evidence that the temperatures they predict as necessary for failure are corroborated by findings of the little steel debris they have.



May I interrupt, James? As I said, NIST’s experiment showed 1,000^oC temperatures to peak and fall within an approximately 5 minute window. The fire models on the other hand show 1,000^oC temperatures in single locations for 30 minutes plus. This is not an agreement between physical reality and the computer simulations. Carry on James…



“NIST does not show calculations or experiments to satisfactorily confirm that the insulation was removed in the core. As some large aircraft components went directly through the buildings, and NIST indicates the others were splintered on impact, can they explain why these small splinters could still denude the steel?”



“Why hasn't NIST declared that this spoliation of the steel was a gross error?


So do you agree with Quintiere or not, flyingswan, that the NIST report is lacking? You are always keen to reference professionals who support the official line, so let’s see how you fall in line when an expert questions NIST's study. A clear yes or no, agree or disagree, to the question please if you can.