Negligence is not on the level of premeditated murder.



No, you can provide excuses so as the areas do not directly contradict each other but still they in no way support one another. For instance, through metallurgical testing of steel recovered from the WTC debris pile, NIST found no evidence of consistent or extreme temperatures and stated: -

“From the limited number of recovered structural steel elements, no conclusive evidence was found to indicate that pre-collapse fires were severe enough to have a significant effect on the microstructure that would have resulted in weakening of the steel structure.”

The above clearly does not support the fire induced collapse scenario given in the structural response area.



Are you seriously trying to say that NIST considered an alternative to the damage and fire scenario?



I’m not ‘trying’ to say the severe case simulation damage predictions were on the high side; it’s just a plain fact made apparent in the NIST report, and yes this does mean the input figures were overstated. Apart from that I quite agree with what you say and it is a situation that leaves us without a conclusive answer.



As an example, the very first article on the AE911T technical page is by engineer Rodger Herbst and another would be the presentation by architect Richard Gage, neither of whom are involved with J911S.



The most obvious reason for a new investigation is that NIST wholly failed to prove the impacts and fires were the cause of collapse. Evidence not even considered is all that supportive of controlled demolition, most of which occurred after the collapse initiation, ie virtually symmetrical, near freefall, complete collapses with visible squibs and molten steel in the debris pile, along of course with the high temperature steel corrosion sample, thermite signature in the dust and low level explosions.



You severely misinterpret what Urich is stating in many areas and how it matches up to what I am saying. My um.. ‘mantra’.. is not in dispute - the features were witnessed in the WTC collapses and are shared by controlled demolitions.



There is no possible way you could know the results of a mid-case without NIST running the simulation so despite what you say, beyond your predetermined conclusion, you have no reason to believe anything.

No, any result greater than the design safety factor means collapse. The figure from the equation is the ratio of the dynamic load to the static load. The structure will be designed to carry a load greater than the static load for safety. This is normally a factor of at least 1.6, but I have seen 2.5 quoted for the towers, I forget where.

Since the static load is also proportional to the mass, I would think that a "common sense" guess would be for a constant factor. The approximately square-root dependance comes from the non-linear relationship between the energy absorbed and the distance the column compresses. A greater mass will compress the column more, but this absorbs more energy proportionately than the extra potential energy of the greater mass, so the dynamic load increases less with mass than the static load does.

I've tried to explain to you ad nauseam why the NIST explanation makes engineering sense to me.

Even if the NIST explanation is unsatisfactory, that does not mean that controlled demolition is proven by default. If a new investigation concluded that NIST was wrong, it could still come up with an alternative collapse mechanism that did not involve CD. Quintiere, for example, is questioning NIST's work on the insulation. If he is right, the fire affected the steel because the insulation was inadequate from the start rather than because the impact damaged it. However, this would not affect the rest of the collapse process.

So actually your 418 are no support for your controlled demolition theory at all?

That's rich coming from someone who doesn't know the first thing about engineering.

I'm not handwaving, I'm pointing out that in both the 911 case and a controlled demolition, gravity does a very large proportion of the work. A proportion so large that "ample" is fully justified. How much slower that free-fall is a normal CD collapse?

And of course, the worse the crime, the less likely someone is to report it? The goalposts are shifting again. This started with incriminating or damaging the paymaster, I've shown that this is possible, now it has to be accusations of murder.

The evidence for the temperatures of the fires comes from the simulations, the simulations are validated against the lab tests. The recovered steel samples, though not from the hottest parts of the fire, are consistent with the simulation results for their positions. You are trying to make these inconsistent when they are not.

I am saying that if there had been a shred of evidence for controlled demolition, they would have followed it up. As even a conspiracist like Urich admits, there wasn't any evidence, so they didn't have anything to investigate.

It's an answer that I understand and a collapse mechanism that I am happy with.

Unless I've missed something in Herbst's long paper, it's just a repeat of the usual claims with no new technical analysis. The claims that Urich disputes.
We've already established that even you don't believe all Gage's points.

Oh dear, the mantra again. As Urich shows, the features in your mantra are either incorrect or not the evidence of CD that you claim them to be. If you think that Urich is wrong, let's have your point by point rebuttal.

I can see how things are changing from case to case, I can see what a middle case would be, I can see how such a result would be similar in outcome to the severe case.

In a 2004 presentation NIST gave the overall factor of safety for the Tower cores as 2.25 and for the perimeter as 5. Unfortunately I cannot now find the presentation, only Figure 8-9 in NCSTAR 1-6 which shows individual core columns with a factor of safety ranging from approximately 1.6 to 2.7, though a no-show of the external columns. As the cores carried 60% of the structure’s load and the perimeter 40%, using NIST’s figures that would, very roughly obviously, give an overall factor of safety of 3.35 for each Tower.

Anyhow, thank you for assisting in my understanding of Bazant’s equation. I have now been able to adjust the figures and found it practically impossible to provide any result that does not cause collapse. For instance, if we input only a 50cm freefall drop initiating from the 109th floor, collapse still progresses – clearly an unrealistic result. Sure, Bazant admits to and covers part of this anomaly in his notes but what this shows is that the equation does not work for all situations; specifically and worryingly that is, situations that would validly result in the collapse being arrested.

To make clear, it seems Bazant provided an equation that was set for only one answer no matter the reality of the situation on 9/11. This brings me to realise Bazant started with a preconceived conclusion every bit as much as NIST, without ever considering that the collapses were in fact not natural.



You think it reasonable that a reduced mass of the upper block causes greater overload and vice versa? In that case, Urich’s reworking of the Tower’s mass would mean a greater chance of collapse progression. This is wrong and apparently not what you thought the case would be as shown in your post #78 – “What does it matter if the loads were 30 times what the structure was designed for or only 15 times?”



I understand you think the NIST explanation makes sense though the reason for that is the lack of comprehensive conclusion which allows you leeway to believe whatever you want.



Agreed, that is why I said controlled demolition will be proven by default once it is shown the collapses could not occur naturally. If the damage and fire theory on its own cannot be conclusively proven then sure other areas such as building inadequacies should be studied and if that fails, an investigation into alternatives must be carried out. This is why a new investigation is necessary – to take these steps that NIST failed to.



The members of Architects & Engineers for 9/11 Truth are not content with the official collapse theory and many of them state the WTC buildings exhibited the characteristics of controlled demolition. You only show your lack of logic if you want to claim this shows ‘no support at all’ for the controlled demolition.



I know enough and will add in this case that all the engineering knowledge in the world is no use without the critical thinking skills to apply it usefully.



Are you trying to equate the gravity driven collapse of a controlled demolition with the way the upper mass of the Towers supposedly ‘crushed’ the much larger intact structure below? Because once again, that would not make any sense. Still, looking at conventional controlled demolitions the fall time seems to be slightly slower than freefall, much the same rate as the WTC collapses.

To the question: It could be the case that the crime is too terrible to contemplate, particularly in cases where an easy get-out is available. What this started with is that political issues can drive investigations leading them to supply the ‘acceptable’ answer rather than give the correct answer. Although you have not been in this situation yourself you accept that such a case could exist and that’s the end of it for me.



Once again, I am not saying the areas are necessarily inconsistent or contradictory, I am just stating that they do not support one another – the quote I gave from NIST could not demonstrate the point anymore clearly. The only two areas that do support one another are the fire model and structural response simulation (figures human input into a computer and tweaked by NIST), neither of which are backed-up by the real world areas of physical evidence or lab-tests.



Can you just get it straight in your head whether Urich is a ‘conspiracist’ or not because you seem to keep changing his position to suit your argument. Anyway, despite the great deal of evidence supportive of a controlled demolition, how did NIST expect to find anything else without looking for it? The clearest example of this is obviously the high temperature steel corrosion described by FEMA as “very unusual” and for which they said a “detailed study” was required… a recommendation NIST completely ignored.



I don’t have time at the moment so I will just pick one point as an example. In my ‘mantra’ I say that the collapses were virtually symmetrical. You attempt to counter this by quoting Urich – “This is simply incorrect. Neither collapse was symmetrical. In WTC2, most debris falling outside the footprint went east and south. In WTC1, most debris falling outside the footprint went north and west.” The only reason debris fell in the areas stated is that this was the direction from which the airliners impacted and damaged the structures, allowing debris in the initial collapse movement to move more freely that way. After the initial movement and tilt had passed, the collapses did progress virtually symmetrically. It’s in the interpretation you see and as video evidence shows neither a great degree of tilting or that one side of the collapse progressed greatly faster than the other, we can say “virtually symmetrical”. Even conventional controlled demolitions are not perfectly symmetrical.



And when did you first learn of these psychic abilities that you posses Mr. flyingswan?

So Bazant's equation is wrong because it doesn't give the answer you want? Why couldn't a 50 cm drop overload a structure? In fact, the equation just shows what I've been claiming all along - in general dynamic forces are much greater than static forces, and because they are so much greater, engineers don't find the collapses surprising.

Yes, I've just explained that, what don't you understand?

I've already said that no thought at all went into "15 or 30".

It makes sense to me because I can see the way the severity of the impact affects the outcome in the different cases.

The situation at present is that the impact and fire theory satisfies most engineers, and that there is no evidence whatever for a controlled demolition theory. If a few engineers think a new investigation is necessary, it is up to them to convince the rest of us. So far, they are not doing too well.

You keep mentioning them as support for your position. If only some of them agree with your controlled demolition theory, it is dishonest of you to keep claiming that you have all 418 as supporters.

You know much less than you think you do. The difficulty you had just putting a few numbers into an equation showed that. Perhaps you should look into the rather deep gulf between critical thinking and confirmation bias before you pursue this line of argument.

Yes. The gravitational energy available is more than sufficient to destroy both upper and lower parts.

Does that last sentence of yours mean that "near free-fall" is no longer part of your mantra?

I said that engineers can find themselves in that position, but I did not accept that they would react in the way that you need them to for your theory to work.

You are claiming contradictions where none exist. The fire models and the lab tests (NCSTAR 1-5E) look in reasonable agreement to me.

Urich appears to be a conspiracist, but one who finds the existing conspiracy claims to be unconvincing.

Since you last brought up this argument, I've seen the WTC7 documentary with the confirmation that the investigators did look for evidence of explosives.

FEMA had already raised the need to look at high-temperature sulphut corrosion, why should NIST have to raise it again?

The question is not how unsymmetrical the collapses were, it is whether this is evidence for a controlled demolition or not.

It doesn't require psychic ability to use my knowledge of engineering.

Not wrong per se, the equation is just too inflexible to cover scenarios that would arrest the collapse – even Bazant admits to this in his notes. Please note in my example I stated a 50cm drop initiating from the 109th floor. If you can really imagine the upper 2 floors crushing the entire lower 108 floors when dropped from around the height of your knee there is something seriously wrong with your perception of how physical objects in the real world react with each other. Of course dynamic forces are greater than static forces but that level of hand waving is not convincing.



It just seems odd to me that if the upper block had been constructed from a denser material, let’s say iridium instead of concrete, the lower structure would have had a better chance of arresting collapse, more so than say polystyrene which would apparently have caused certain overload of the lower structure. For instance, according to the equation, if the mass is input as 1kg then the overload ratio goes through the roof, yet if the upper block is input as around 12 million tons the collapse is arrested. What this shows is that it is not nearly as straightforward as simply “putting his [Urich’s] figures into the equations” to “see if the results are any different” as you first suggested I do.



Was that before or after I pointed out to you exactly which case NIST were using? Anyhow, you can see how the impact severity affects the outcome in the base and severe cases NIST simulated, as I or anyone else can, though anything further than that is guesswork.



Every one of them is demanding a new independent investigation that would comprehensively address all issues of a natural collapse and controlled demolition. I think I just might keep using them in support of my argument.



Perhaps you could explain what relevance 71 GN/m has to critical thinking?



My last sentence – “Still, looking at conventional controlled demolitions the fall time seems to be slightly slower than freefall, much the same rate as the WTC collapses” – highlights a feature that controlled demolition and the WTC structures shared.

I am not saying the areas are necessarily contradictory, I am saying they are unsupported by one another. I have inserted links to definitions of the words to prevent you misunderstanding me again.



Yes and as he also finds the NIST investigation to be unconvincing this leaves an engineer with a lot of outstanding questions regarding 9/11.



No they didn’t. Please direct me to the explosives study or stop being utterly ridiculous.



Because as FEMA stated, “It is also possible that the phenomenon started prior to collapse and accelerated the weakening of the steel structure.” That is an event present in the building completely aside from the impacts or fires that may have contributed to the collapse. How can a study team responsible for determining the cause of collapse completely ignore an event that may have been a part of the cause of collapse?!?!



As with the near freefall speed, virtually symmetrical collapses are a feature that controlled demolition and the WTC structures shared.



So how exactly does your “knowledge of engineering” allow you to “see what a middle case would be”? As I said in my previous post, you are using nothing more than guesswork. You can say what a mid-case “could” perhaps be, so can I, but you cannot say for sure what it “would” be.

Bazant says that the problem for such a short block of floors is that the safety factor is effectively much higher, so the overload may still be large, but will be met by a similarly large safety factor. Even in your house, note how the walls don't taper down at the top, so the top parts are much stronger than they need to be just to support the static load. Similarly, the columns in a steel frame are not tapered down over the top few floors.
This is irrelevant to the situation lower down.

You don't get this at all, do you? The equation gives the ratio of dynamic to static load. Static load is assumed proportional to the mass of the building that is supported. Dynamic load is approximately proportional to the square root of that mass. If the upper structure had been constructed from iridium, then its mass would be bigger, but the lower part would have been stronger to support than mass. The dynamic load would also have been greater, but by a smaller ratio of the static load than for the actual steel.
If the upper floors only had a mass of 1 kg, then the safety factor would have been enormous too, see above.

It's hardly guesswork to compare the two cases and work out where an intermediate case would be.

Only if the whole of your argument is that the NIST investigation wasn't adequate. If your argument is also that there was a controlled demolition, then counting people who don't support that theory is dishonest.

It was a clear example of your ignorance of technical matters, and should have been a warning to you that you are completely out of your depth.

It highlights a feature of your theory that you claim requires a special explanation, but which occurs in other circumstances without needing such an explanation.
It is nothing to do with the initiation of the collapse, whether impact/fire or CD, it is to do with how the collapse subsequently progresses. In a controlled demolition, gravitational collapse does most of the work, and it does it at near free-fall speed. You are claiming that the near free-fall WTC collapses require all sorts of extra explosive charges because the resistance of the building would otherwise halt the collapse, and that your "squibs" are these charges going off. If gravity does the work in a CD, why can't gravity do the work on the towers?

So if they are consistent rather than contradictory, what is the problem?

Likewise a conspiracist. There is a vast difference between thinking that an investigation is inadequate and thinking that it should have come to a completely different conclusion, for which no-one can provide any evidence. For an investigation to have any chance of coming up with "It was CD", you will have to start with a better list of "evidence" than Gage's, which even a supporter like Urich can rubbish.

I didn't take notes during the WTC7 TV programme, but I do remember one of the on-site investigators interviewed saying they looked for evidence of explosives and found none.
Edit to add: I've checked the BBC website and this appears to be the bit I remembered:
Dr Gene Corley, the lead investigator for the first inquiry by the Federal Emergency Management Agency (Fema) told the BBC: "We looked at everything.

"Controlled demolition was ruled out because there was no evidence of controlled demolition ... we looked for it, yes, and we found no evidence of controlled demolition."

A number of people from the Fema investigation helped out immediately after the attacks, and shortly afterwards other team members began arriving to begin their investigation.

Every inch of the site was picked over by hundreds of people. No one reported any signs of explosives.
http://news.bbc.co.uk/1/hi/programmes/cons...les/7434230.stm

I expect that was just FEMA covering their backs. I am happy with the debris-pile fire explanation, and I expect most other engineers would be too.

...and also features shared with other building collapses from other causes, eg the San Marco Campanile. They are not features that only occur in a CD.

Do I really have to explain this yet again? See the earlier thread.

It’s not entirely irrelevant to the situation because it shows that had the safety factors been built in it would have made the equation more flexible in providing comparable answers for different scenarios.



Which goes to show what I said in my last post and above is correct: it is not as straightforward as only altering the mass figure; other figures, particularly the factor of safety, must also be considered to give a comparable answer.



All members apparently find enough evidence of controlled demolition present to make an independent investigation worthwhile.



That has no bearing on what I asked you to explain – a clear example of your ignorance of plain English. I will though add that I do not dispute the pure technical details put forward by professionals, only the biased estimates or false assumptions they are based upon. For instance, I would not say that Bazant’s equation is wrong, only that it is aimed at demonstrating a preconceived conclusion, eg anyone with technical knowledge or not can understand that the 3.7m freefall is incorrect. The same for NIST’s work, I do not dispute the computer models themselves, only the human inputs they are based upon.



In a conventional controlled demolition the work is done largely by gravity where low level charges cause the structure to fall. In the Tower collapses the upper block would be required to crush the much larger, stronger and intact lower structure. Obviously, crushing a structure rather than it simply falling requires considerably greater energy and must slow/stop the collapse… that is, unless the lower structure is already weakened.

The problem is that the physical evidence and lab tests do not support NIST’s conclusion. As the computer modelling is the only area that, given a slanted view, could be seen as supporting NIST’s theory, they may as well have not bothered with the physical analysis at all for what it was worth to their conclusion. If the official story that the impacts and fires caused collapse was correct, it should not have been too much for NIST to produce evidence of consistent extreme temperatures in the steel.



There is a great deal of evidence for controlled demolition. Even if there wasn’t this evidence, your double standards are amusing because we know for sure there is no real evidence, as I describe above, supportive of the official story.



So if Gene Corley wants to give the easy answer to avoid anymore questions on the subject, we should take his word for it? What does he even mean by “we looked for it”? Is he on the same page as Mark Loizeaux who said something like, “well umm… durr… dere wuz no detcord or blasting caps found… so I fink it weren’t a controlled demolition… huh huh ha ha”?

If they looked for explosives there must have been a document setting out the aims and strategy for this search with a paper describing the methods of testing and details of the results – where is it?



Exactly, you are happy with your pre-conceived conclusion, supporting a theory without an investigation rather than entertain any other possibility that may get in the way of it.



A 16th century bell tower is not comparable in any way to modern day skyscrapers.



You explained only your theory of where an intermediate damage case “could” possibly fall, not how you know this “would” lead to collapse.

Bazant wrote his paper for an audience of engineers who appreciate the points that I've had to spell out for you over several posts. The bottom line is that apart from the extreme top parts of the buildings, the safety factors are much smaller than the dynamic overload from Bazant's equation, and that is why the buildings collapse.

Only around half of them mention controlled demolition, so you are putting words into the mouths of the rest to bolster your position. That's dishonest.

Anyone with technical knowledge understands how steel columns fail: they buckle. In that, a column rapidly loses strength as the buckling starts so all the resistance is in the first small movement, after which there is very little further resistance so the drop of 3.7 m is a reasonable approximation. I might also point out that the result is the same with a much smaller drop.
However, Bazant's equation is actually an energy one. The energy input from the drop is potential energy, mgh, it's available whether it's a free-fall drop or a slower one. You are just putting up objections that arise from your lack of understanding of structures.

The top parts of the towers can be considered high-rise buildings in their own right. If they had fallen on to the ground rather than the bottom parts, you would see exactly the same type of gravity-driven collapse damage as in a CD. Now consider that the bottom parts had the same strength as the top parts at the level of the collapse initiation, so you should see no problem in the bottom part also being destroyed. It requires about twice the energy to destroy part of the bottom with the same height as the top, and by the time that has happened, not only has the top part fallen a greater distance, providing that extra energy, but the destroyed part of the bottom has also fallen, providing yet more energy to continue the collapse. Even if the energy from the top part falling was only just sufficient to destroy the top part, instead of being much greater, there is no problem with the collapse continuing.

The computer models were verified against the lab fire tests, and their results do not show temperatures that are unrealistic compared with other office fires. The steel samples are consistent with the predicted fire temperatures. What is the problem?

If a conspiracist like Urich can see the absence of evidence for CD, how are you going to convince anyone else? The fact that you don't understand the evidence for impact and fires is immaterial, you don't understand engineering full stop.

Why? If you are writing up a report, you describe what you find. If you start describing everything you don't find, the report becomes infinitely long. There were plenty of engineers with experience of explosive damage on the site, Corley himself had been an army engineer in his younger days and had also investigated the Oklahoma bomb, so if the evidence you claim was there, they would have found it. The only alternative you have is to claim that all the investigators were part of the conspiracy.

I see a simple explanation that seems highly probable, with a very small chance that that it might be something else. That something else is already the subject of study, going back long before 911.

So explain again exactly the difference that allows one but not the other to collapse symmetrically.

The observed way in which the collapses began is consistent with the NIST Case B model, but inconsistent with CD. I've explained this in much greater detail several times already in the other threads.