Offer to the Truth Movement: Let's Settle It

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Dictator Cheney said:
how can you conclude that it was not strange?
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Because:

Steel framed structures are vulnerable to fire.

The building was reached by the debris of the towers collapse

The building was on fire and had been for a period far in excess of any normal fireproofing system

The building had a cantilevered construction over a pre-existing structure and cantilevers are very highly stressed elements of a structure

There is no believable motive for wtc7 to have been deliberately destroyed

There is no believable method which could have been employed on the day to deliberately destroy the building.

What little visual record there is available shows the building collapsing due to structural failure, the logical reason for that structural failure was the debris impact damage and the unfought fires.

The insurers are happy.

No one died.
 
R.Mackey said:
As Dr. Bazant, Dr. Greening, Dr. Seffen, and Gregory Urich have all shown independently, the collapse mechanics are driven primarily by momentum. The lower floors simply do not have enough strength to counteract all of this momentum before they fail.
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Well I am not talking about floors, I am talking about levels and including all of the steel and concrete in the core and perimeter columns. Oh but we don't have a table giving us that information in a readable manner and can be trusted.

I mentioned Doctor Greening back on page 8 and he responded with post #312 and I responded with #314 and we have not heard from him since.

Now he admits that Urich's data is the best but I have found what may be an anomaly in that.

http://www.internationalskeptics.com/forums/showpost.php?p=3687362&postcount=7

Now how is it that the NIST can't tell us the number of each type of only 12 different kinds of perimeter wall panels on world famous buildings designed before the moon landing? And why do so many EXPERTS make these pronouncements without reliable data?

psik
 
It really is tremendously simple mate. It's the same reason they can't tell you how the deck chairs were arranged on the Titanic.

If you think any of this is truly relevant then forget about it! Immediately! Seriously - it's a side show. What's vastly more significant is that every single engineering or academic institution, government or intelligence agency, across the ENTIRE planet has utterly failed to notice, despite many of them having an ideological predisposition towards poking holes in anything the US government does.

Until you can explain that, I'd stop worrying about a couple of collapsed buildings.
 
REPLY TO R.MACKEY
http://www.internationalskeptics.com/forums/showthread.php?postid=3685247#post3685247

Scheuerman is or knows a good writer, and has a book to sell.

NIST knows how to write politically 'safe teflon' reports.

My biggest problem with all 3 of those building fires, was that regardless of the observed precursors, the collapses were so "sudden."

I don't expect my incredulity to carry any weight with you, but on the other hand, you admittedly are making a presentation based on "some assumptions" about the "initiating failure event" and "the condition of the structure", and you further qualify your remarks "to be somewhat speculative."

We know to produce the type of collapse observed with WTC 7, it's necessary to create structural damage which acts in the same manner, close your eyes, as a controlled demolition.

We know there must have been a lower core failure.

We know that controlled demolition is capable of generating such an instant core failure, and that depending on how it was orchestrated, could have produced the observed collapse results, including the pre-collapse of the east penthouse.

Unlike your hypothesis, the 'ability of a controlled demolition' to produced the observed collapse results, requires no assumptions or speculations.

We also have testimony from an acknowledged expert in controlled demolitions who unhesitatingly states his conviction that the observed collapse was a result of a controlled demolition and not the consequence of debris and fire damage.
http://s1.zetaboards.com/LooseChangeForums/topic/52021/3/#new

We have testimony from an NYPD police officer and a radio report, that there were explosions occurring just prior to the observed collapse of WTC 7.
http://www.internationalskeptics.com/forums/showthread.php?postid=3685514#post3685514

Regardless, you prefer to support the NIST and Arthur Scheuerman hypothesis which eliminates any notion that unknown others, besides the 19 Al Qaeda terrorists were involved in the destruction at WTC Ground Zero.

That hypothesis centers around the premise that a single core column failure lead to the global collapse of WTC 7.

That hypothesis requires fires of extremely high temperature that were supposedly capable of forcing a major core support column to buckle and snap.

NIST in it's public memorandum explaining the further delay in it's final draft WTC 7 Collapse Report, indicated that they were no longer considering diesel fuel as a factor in the fuel that supplied the known fires.

This leaves us with office contents as fuel, and if you allow me to extrapolate from NIST's WTC Collapse Report, NIST found that individual fires had a life expectancy of approximately 20 minutes before peaking and moving on. In WTC 7 we aren't dealing with the reasonable assumption of some initial core damage (as would have occurred with aircraft impacts) and we don't have the NIST argument of bowing trusses.

You say the whole building was sagging. Why? What does that really mean? Why would a mammoth building like WTC 7 sag and create a 3 story "bulge" based on the limited structural damage it sustained?

Much like the Official Story's view of the Twin Towers collapses, I see this as another hypothesis that is reverse engineered based on a pre-conceived modus operandi.

It starts with the premise that fire caused the core failure and proceeds to create a very elaborate working hypothesis that confines itself to supporting that highly questionable assumption.

It's very easy to make argument supporting assumptions once you commit yourself to a "why" conclusion.

My impression is that all these assumptions are being too casually embraced because to do otherwise leads in a direction that you and those who follow your beliefs, absolutely do not want to go.

MM
 
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R.Mackey said:
Again, I'm forced to speculate, and anything I come up with may be replaced by a far superior explanation in the future. However, based on the phenomenology as well as the long delay between the impacts and the collapse, I'm inclined to think the failure was caused almost exclusively by heat.

While the debris impacts were severe, perhaps weakening the structure's stability, nevertheless the failure mode was relatively global, and that suggests there was global connectivity in the structure to the very last.

Additionally, the fires burned for over seven hours. The fireproofing was set to withstand at most two or three in any given location, i.e. steel would have been heated to a "critical temperature" where it would buckle under normal loads in two or three hours. Yet it did not, but took longer. This can be explained in one of three ways:

  • Fireproofing greatly exceeded its specification -- I see no evidence of this
  • Fires in most locations burned out and cooled before the steel reached its critical temperature, leaving the structure to fail later, after a new area with especially poor fireproofing or a high fuel load ignited
  • Fires over a series of floors did not locally defeat the fireproofing completely, but inflicted a small amount of deformation; after spreading over several floors, these locally minor problems contributed to a global catastrophe
Either of the latter two explanations seems reasonable given the vulnerabilities of the design. If impact damage was a significant structural contributor, it would bias us towards the second case over the third. However, I suspect the failure, being low in the structure, was on a floor that was burning pretty much the entire time, and that leads me towards the third explanation. The third case is also bolstered by the relatively early appearance of visible deformations, as reported by the FDNY, several hours before the collapse actually occurred. In this case, the effect of significant impact damage would be to reduce the effective "critical temperature," but had that been so, I would have expected collapse much sooner.

The impacts, of course, were still no doubt significant in terms of starting the fires in the first place, opening ventilation paths in the exterior, and possibly knocking down interior partitions that could have acted as firebreaks. But it's my guess that the structural damage caused by the impacts had little contribution to the failure mode we saw in the collapse.



I've enjoyed it myself, and it's exceeded my expectations.
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So we're back to a fire theory for 7. Now an office bldg fire in a diffused flame environment has to get hot enough to compromise the key column which would cause global collapse.

As I said before I think NIST is going to agree with you, but perhaps this long delay is due to the fact that this is now a very untenable position for NIST to be in when they don't have the suspect column to test, nor do they have evidence of a fire intense enough to do this.
 
Miragememories said:
REPLY TO R.MACKEY
http://www.internationalskeptics.com/forums/showthread.php?postid=3685247#post3685247


Much like the Official Story's view of the Twin Towers collapses, I see this as another hypothesis that is reverse engineered based on a pre-conceived modus operandi.

It starts with the premise that fire caused the core failure and proceeds to create a very elaborate working hypothesis that confines itself to supporting that highly questionable assumption.


MM
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Well said.
 
I'm sorry, but who said that WTC7 came down only due to fire? What happened to the damage from the larger collapsing buildings?

ETA: I see R.Mackay refers to impacts, but Red I. has evidently decided the theory is merely fire.

Oh, Red I., why oh why must you do that?
 
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SDC said:
I'm sorry, but who said that WTC7 came down only due to fire? What happened to the damage from the larger collapsing buildings?

ETA: I see R.Mackay refers to impacts, but Red I. has evidently decided the theory is merely fire.

Oh, Red I., why oh why must you do that?
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Yes, he refers to impacts but he says this, "However, based on the phenomenology as well as the long delay between the impacts and the collapse, I'm inclined to think the failure was caused almost exclusively by heat."

With his usual intellectual integrity Mackey admits that this is speculation, which actually makes his response more presuasive, as opposed to the feigned omniscience that is often thrown about around here.

If you disagree with Mackey, why don't you question him? Just because you might be on the same side of the larger debate in question, there should be nothing stopping you from disagreeing about specific points.
 
Miragememories said:
Scheuerman is or knows a good writer, and has a book to sell.
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Mr. Scheuerman wrote up his comments, provided them to NIST, and has made them available for free on the 'net. You don't have to buy his book.

I remind you, as I remind everyone periodically, to keep this thread respectful.

Miragememories said:
My biggest problem with all 3 of those building fires, was that regardless of the observed precursors, the collapses were so "sudden."

[...]

We know that controlled demolition is capable of generating such an instant core failure, and that depending on how it was orchestrated, could have produced the observed collapse results, including the pre-collapse of the east penthouse.

Unlike your hypothesis, the 'ability of a controlled demolition' to produced the observed collapse results, requires no assumptions or speculations.
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There is a fundamental confusion that you have, and that is that a fire-induced collapse would be gradual. This simply is not expected under almost any conditions.

With only the rarest of exceptions, buildings are not designed to move. Their strength is calculated to support their static load, with a generous reserve, but that is all. Once a structure begins to move, however, if the remaining structure is to survive, it must not only continue to provide the static strength, but must also provide enough additional force to overcome the inertia of the descending pieces. This force requirement can easily be ten or even a hundred times the static strength in an ordinary collapse. Needless to say, few structures indeed have this kind of reserve.

If you want a slow and gradual collapse, you need one of two things -- either a case where the structure has multiple independent cells, or you need a collapse near the very top.

There are cases of structures, typically concrete structures in earthquakes, where, say, one half of the building collapses while leaving the other half standing, at least for a little while. This is because concrete is very strong in compression but fails quickly in tension, and some of these structures (i.e. old ones with weak or corroded rebar) will have one section completely break off rather than pull the other section along with it. This is a bug, not a feature, because this shearing behavior precludes using the rest of the structure as an alternate load path. The structure that doesn't break apart, leaving pieces standing, might have not experienced any collapse at all. Ronan Point is one example of this situation.

The other case, more familiar to us because it is much more common, involves lightweight structures including barns, warehouses, and the like. Here you do see a gradual collapse in most fires, and this is typically because of the structure's design, uneven heating, and the plastic behavior of steel. Once steel exceeds its maximum strength, it can still stretch, and its strength doesn't go to zero immediately. Before it snaps, it still retains perhaps 80% of its pre-damage strength, and can deflect another few percent as it does so. This slows down the collapse. However, this is not a buckling failure. This is a more ordinary overload, typically of long roof beams, with very little weight above it.

In a well-designed and large steel building, the root failure is quite different -- it's a buckling failure. Unlike the shed example above, when a steel column begins to buckle, its strength goes to zero very quickly. This is because the mechanics of buckling are different. Instead of bowing a long beam in the middle, i.e. transverse stress which is rather "springy," the column is loaded along its axis. This is not so "springy," and the load compared to the amount of steel in use is typically much higher. Columns can buckle before getting anywhere near their plastic limit, so called elastic buckling, depending on the load and their dimensions. So the creeping and necking behavior of steel makes no difference here. Once those columns buckle, the load above is almost completely unsupported.

When only a single column buckles, the amount of displacement in the structure -- again, in a well-designed building -- is minimal. The load formerly borne by that column is distributed to other, nearby columns. So the building's appearance only changes slightly. At least, it does until it has no more load-sharing to give. At that point, the next buckling failure will immediately cause motion, and unless the horizontal connections all break before the remaining columns (which are already loaded to the brink) fail, the whole thing will come down. This is exactly what we expect in a steel-framed structure. Under no circumstances do we expect a partial or a gradual collapse.

This is also why every post-9/11 skyscraper I know of has been built with a concrete core. Concrete has different fire resistance, different creeping behavior, and if built into a monolithic core is virtually immune to buckling failure. You may see steel components break off of the concrete sections, as we saw in the Windsor Madrid, but it is unlikely for both to fail. On the other hand, the concrete core is so massive that if it was to be fractured low in the structure, there's no way to keep it from tumbling. New skyscrapers are thus much more collapse-proof with respect to fires, but require other countermeasures against earthquakes. And large bombs.

Miragememories said:
Regardless, you prefer to support the NIST and Arthur Scheuerman hypothesis which eliminates any notion that unknown others, besides the 19 Al Qaeda terrorists were involved in the destruction at WTC Ground Zero.

That hypothesis centers around the premise that a single core column failure lead to the global collapse of WTC 7.

That hypothesis requires fires of extremely high temperature that were supposedly capable of forcing a major core support column to buckle and snap.

NIST in it's public memorandum explaining the further delay in it's final draft WTC 7 Collapse Report, indicated that they were no longer considering diesel fuel as a factor in the fuel that supplied the known fires.
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The single-column failure hypothesis I described previously is based on an observation of the collapse dynamics, and nothing else. It was not specifically chosen to repudiate any set of actors. Had WTC 7 collapsed in this manner without fires, I would still have proposed a single-column failure low in the structure, but instead suggested that an explosion, accident, or structural flaw had been at the initiating location.

The specific design of WTC 7 does not require "extremely high temperatures" to collapse. Ordinary temperatures at a long duration or over many different areas is sufficient. As we saw in the WTC Towers, designs incorporating many long-span floor elements are especially susceptible to fire. The "critical temperature" that the steel columns require to buckle is not determined solely by the properties of steel. Instead, it is closely coupled to design. Because of the long-span trusses and the potential for eccentric loading and loss of horizontal stability, the "critical temperature" in WTC 7 could have been very low, perhaps 500oC or even less. This is a difficult question to answer without sophisticated modeling, so again I remind you that I am speculating, and waiting for the NIST Report.

Miragememories said:
This leaves us with office contents as fuel, and if you allow me to extrapolate from NIST's WTC Collapse Report, NIST found that individual fires had a life expectancy of approximately 20 minutes before peaking and moving on. In WTC 7 we aren't dealing with the reasonable assumption of some initial core damage (as would have occurred with aircraft impacts) and we don't have the NIST argument of bowing trusses.
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Yes, NIST found in NCSTAR1-5B that individual workstations in WTC 1 would burn for perhaps 20 or 30 minutes before entering a longer smouldering period. However, we know for a fact that several floors low in WTC 7 were burning continuously for several hours. Some of this is going to be due to slow spread of fires. Some will be due to the more oxygen-starved nature of WTC 7. There also could have been a much higher fuel load in WTC 7. Nonetheless, direct visual evidence confirms that some areas of WTC 7 were exposed to heat for much, much longer periods than 20 minutes. In my mind, there is little doubt that it was one of these regions where the initial failure occurred.

Miragememories said:
You say the whole building was sagging. Why? What does that really mean? Why would a mammoth building like WTC 7 sag and create a 3 story "bulge" based on the limited structural damage it sustained?
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The sagging, like the collapse, is in my opinion due to heat, not the impacts. But this is absolutely proof positive that the fires not only could cause structural damage, but did.

The bulge can only mean that the structure was deforming, and therefore some parts of the structure were no longer able to carry their load. There is no other explanation possible. That this occured about five hours before the eventual collapse should give you some pause. What probably happened, again, to create the bulge is the following:

  • Fires on several floors weaken the long spans between perimeter and core
  • Long spans lose compressive strength and sag
  • Weakening floors remove horizontal support for core and perimeter columns and introduce eccentric loads on both
  • The upper structure tilts slightly (~ 1 degree or less)
  • Some loads are redistributed, and the upper structure halts at a new, temporary equilibrium
  • Tilt in the structure compresses the perimeter along one side, creating a visible bulge in the exterior
I further speculate that it is this mechanism that led to the initial failure. The floors may not have needed to sag very much in order to contribute to a loss of stability, provided that several floors did -- and the duration and numerous floors of the fire suggest this indeed happened. The more floors sag, even if only a slight amount, the longer the effective column length becomes in the core, and the less resistance it has to buckling. Even if the core column itself isn't weakened by fire, which it certainly was.

There is also contraction after cooling to take into account. I don't know when burnout occurred on any floor, so I cannot evaluate this, but combined with sagging on floors still burning, there are many contributory mechanisms to core failure, even at moderate temperatures. Again, the "bulge" proves this was taking place.

Miragememories said:
Much like the Official Story's view of the Twin Towers collapses, I see this as another hypothesis that is reverse engineered based on a pre-conceived modus operandi.

It starts with the premise that fire caused the core failure and proceeds to create a very elaborate working hypothesis that confines itself to supporting that highly questionable assumption.

It's very easy to make argument supporting assumptions once you commit yourself to a "why" conclusion.
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There are several ways to attack this concern. One of them, the one that I've followed here, is simply to explain that the collapse phenomenology is completely consistent with a plausible fire-induced failure mechanism. At that point, you have to accept that both fire-induced and explosive-induced hypotheses are valid, and compare them directly. I have not yet answered this new question.

If you'd like to take a swing at this new question yourself, you should start with the following: How does the "bulge" fit in with the explosives-induced hypothesis? If it doesn't, then you've already determined which of the two phenomena is the better theory. And there are numerous other tests as well.
 
RedIbis said:
So we're back to a fire theory for 7. Now an office bldg fire in a diffused flame environment has to get hot enough to compromise the key column which would cause global collapse.
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Yes, that is my speculative opinion. Except I should point out that there is no "one key column." The design of WTC 7 is susceptible to this type of failure, and it could well be that any of the core columns, on any of a number of floors, could be the "one key column." This is not like the Death Star in Star Wars where there's only one lucky point of vulnerability. This is a design with a vulnerable mode, and that mode can be induced at any of a number of places in the structure.

One of the remaining questions I have about WTC 7 is why certain floors burned for so long. The length of time fire was seen on the lower floors (5 through 11, I believe) was extraordinary. This fire was not as oxygen-rich as either WTC Tower case, so that would slow it down considerably, but nonetheless the lower floors burned longer than any comparable system I know of. This is one of the things I expect to find in the NIST Report. It's also important because, given the duration, the temperature need not have been all that high. Particularly combined with the special vulnerabilities of the structure.

RedIbis said:
As I said before I think NIST is going to agree with you, but perhaps this long delay is due to the fact that this is now a very untenable position for NIST to be in when they don't have the suspect column to test, nor do they have evidence of a fire intense enough to do this.
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As stated above, there is indeed evidence of a sufficient fire, given that the intensity (wattage per square meter) need not have been all that high. The relative lack of recovered material will not help, that is for certain. However, the delay doesn't surprise me, as I noted on the first page of this thread. The report shows clear signs of scope creep throughout its development. That always creates delays.
 
I am intoxicated, forgive me.

Mackey.

In one sentence, make me believe 9-11 is as it is said to be. ie, in one sentence, why should i believe the official hypothesis?

One sentence.....

I am a man of reason. Give me reason using one sentence....
 
Sizzler said:
I am intoxicated, forgive me.

Mackey.

In one sentence, make me believe 9-11 is as it is said to be. ie, in one sentence, why should i believe the official hypothesis?

One sentence.....

I am a man of reason. Give me reason using one sentence....
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You should believe because nobody in the world has been able to construct a plausible alternate hypothesis.

This is why I pushed you to try to come up with one of your own.
 
Can I play too?

Because all of the governments and organisations that most want to believe in the conspiracy theories, like China, Iran, Cuba, Venezuela, North Korea, MEND, FARC, the Taliban, Al-Qaeda, and so forth, don't, and between them they're much smarter than you, or me, or R. Mackey.
 
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you include Venezuela? and Iran?

oh missreaded it,

you include AQ? i heard they was upset about Iran for spreading woo.

ETA3:
not missread, its a totaly strange sentence....


and why would China want to belive them?
 
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R.Mackey said:
You should believe because nobody in the world has been able to construct a plausible alternate hypothesis.

This is why I pushed you to try to come up with one of your own.
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i agree that noone has presented a complete and plausible alternate hypothesis to WTC7 nor for the complete 9/11 atack.
i also find the not alternate one not very plausible nor complete.
 
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