Merged New video! Architects and Engineers - Solving the Mystery of Building 7

[MIKILLINI]

Yes. You do realize that "symmetrical" and "perfectly symmetrical" mean tIt's the same thing, right?

That is like saying "perfectly the same".

Or same difference.

 

[grandmastershek]

Has MM provided a source on CD's and "enar symmetry yet?

The NIST claimed that the collapse was a direct result of the migrating office furnishings fires and their amazing ability to force the failure of the northeast column 79 over 6 floors.

And how does that prove all supports must have been removed simultaneously to result in FFA?


The several seconds of east penthouse pre-collapse.

Inside the 47-storey WTC7, over a football field-sized area, interior support columns anchored to floor trusses which were anchored to exterior columns, were all failing simultaneously.

Anyone notice how he just admitted the EMP collapsing prior but then still contends the supports failed simultaneously. Mental gymnastics in action!

How did these 8 seconds of incredibly powerful pull-in forces appear to the outside world?

We can;t say since we can't observe the entire building and in detail at that.

Ahh..well..the east penthouse drop...and some window breakage on the upper northeast face.

Its called cause and effect look it up.

And what did the Mr. NIST, Dr. Shyam Sundar himself reluctantly admit was the necessary requirement for making a building go into freefall?

No reluctance. Your goalpost moving isn't convincing except to the intellectually dim. How does no support =all supports must be removed simultaneously? Source please.

But at that time, after 7 years no less, he offered numbers for the draft report, that denied that any freefall occurred.

Please quote where they denied any FFA.

3 months later after receiving debunking submissions, the NIST in their final report acknowledged new numbers revealing that 8 storeys of freefall had occurred.

Please explain what kind of fire instantly removed 8 storeys of structural components below the point of freefall that even Dr. Sundar admitted had to occur?

MM

Simply repeating yourself isn't helping.

 

[000063]

Is there an echo in here?

Sorry, sleep deprivation. I meant to finish with "cannot cause a structural steel building to fail under any circumstances whatsoever? Or does that apply only to office furnishings?"

Thinking something is not the same as proving something.

They didn't need to "prove" anything. They just needed to know the risk was high enough not to send firefighters in. I don't walk across a busy freeway blindfolded, because I know that I will likely be seriously injured and/or die. I don't see where it was the FDNY's job to "prove" anything in the first place.

Not at all.

I am well aware that the FDNY placed a transit on WTC7 during the day. I'm sure the NIST after 7 years of exhaustive research, were also well aware of this. I'm also certain that if the transit had revealed that WTC7 was in fact leaning, the NIST would have leapt at the opportunity to report it.

So suddenly the NIST report is the only source of information about such things? There have been dozens of papers and several investigations into 9/11, but if it's not in the NIST paper, it don't count, says MM.

You said "visual evidence". You said nothing about where it came from, and it is kind of sophist to expect signs of structural failure before the building actually failed. Indications of probable failure, such as measured by the FDNY, yes. Put down the goal posts.

"perfectly symmetrical"...really?

Yes, they do. And then when they find that it's not, they move to "mostly symmetrical" or suchlike. As demonstrated by you, for instance.

You are really grasping at straws here. If you want to believe what was observed was actually a staggered, lopsided 47-storey collapse, than go ahead and enjoy that fantasy. I refuse to entertain such a stupid notion.

Not actually answering my question about your falsifiability questions, responding instead with a passive-aggressive Ad-Hom. You've no more logical weight then, well, a mirage.

Dr. Shyam Sundar, the main spokesperson for the NIST, speaking about the NIST Final Report on the Collapse of WTC7 provided all the argument necessary to support atavism's point.

What unsourced quote?

I summarized an observation made in the Final NIST Report on the Collapse of WTC7.

I intended no mystery surrounding Sundar's NIST status position.

And I did provide the context for his statement; "From the Aug.26, 2008 NIST Technical Briefing". If you are unable to do some simple research, that is not my problem.

I admit, I misread that part of the post. Sleep deprivation again, whoops.

However, you seemed all gung-ho about what was or wasn't in NIST's report proper a few points ago. Why is quoting a single man from a technical briefing suddenly sufficient?

Well tell that to engineers who specialize in controlled demolitions using support removal to create building implosions.

Excellent idea. While I'm there, I'll ask them whether buildings undergoing CD fall at free fall. I'm pretty sure they don't, and free-fall is not necessarily indicative of CD even if it was present.

And of course there was a point where the speed of collapse was effected by the growing debris pile below.

You really haven't been doing your homework.

MM

"Effect" how, pray tell?

1. I believe if the portion measured hit the debris pile on the ground, then it would, you know, stop moving.
2. You are hypothesizing that there was resistance, then all resistance was removed (by explosives), then it encountered resistance again (from the debris pile).

 

[Clayton Moore]

And writing insults on an internet forum isn't going to change that behavior. It's not worth getting yourself into trouble over something where the other individual does his own damage to his credibility. I'm not complaining to you to be an ass or anything; I just don't think it's worth it to get yourself in trouble over something trivial.


In any engineering investigation you have unkowns; that's absolutely no excuse to ignore the penthouse collapse or the window breakage along the exterior that followed before the exterior facade collapsed. The WTC 7 structural details and blueprints are available and provide information about the internal structure, whilst the available data of the exterior provides a rough estimate of both the location, and progression of the collapse. By ignoring even the external indicators, you are by definition excluding critical information that pieces together an approximate narrative of the collapse. This is basic in any engineering investigation, you use whatever information you have.


You're missing a major difference between steel framed construction where most concrete is used as part of the floor systems adding lateral stability, and reinforced concrete construction that used higher strength concrete to carry gravity loads. The two construction approaches result in very different fire resistance ratings and structural dynamics, which is why buildings like the Chinese Mandarin Oriental Hotel, and the Madrid Windsor tower were never under any threat of total collapse, whereas the steel framed building of WTC7 was more vulnarable.

You of course have other facts which play in, such as the construction methods used in assembling the structural frame, for example unlike say, the Murrah Building which was not only reinforced concrete, but also built on a traditional grid layout, whereas the WTC had long spanning floor members and a non-standard column layout due to it being built on top of a substation. Things which drastically affect the expected behavior of the buildings, when compared with one another.

Steel is used because it has high tensile and compressive capabilities without the need to add additional reinforcement. Concrete has a very high compression strength but an extremely poor tensile performance (hence rebar reinforcement).



I'm not ignoring it, I'm fully aware of what the fireproofing does for the building and how it works. Firstly, the ratings for fireproofing are done under controlled conditions and they refer to full building assemblies, not individual structural members. Secondly the testing that establishes ratings does not necessarily model every real life scenario that you can expect the assembly to encounter. Thirdly, you're ignoring that the fires still produced heated gases within the enclosed space, exposing elements to elevated temperatures. Finally, you're ignoring unique properties of WTC 7's construction that may have made the assembly more vulnerable to a large scale progressive failure.

None of this requires the steel to be "pre-damaged"


Thermal expansion/contraction from high temperature differentials introduces shear stresses on the bolts that join column and floor beam together. The expansion or contraction of the beam pushes/pulls on the bolt and causes it to fail. These aren't novel concepts; If you want to advance a case against that and call it "fantastical", then offer a quantitative analysis of why it can't have happened. I've seen none of that from Gage's group which allegedly professes to have done the full structural analyses.


And it can be a feature of any collapse under the right set of circumstances. Once again, how a building falls is directly impacted by:
- The make up of the structural assembly
- The Location of the initiating failures
- The sequence of failures.

Implosion based controlled demolitions are no different than any other collapse in this respect; they engineer where to induce the failures, to ensure that the building falls in a premeditated path to avoid damage to other buildings.


In any other collapse it is whatever the engineering investigation finds. Yet again, the path of the collapse is affected not by explosives, but by where the failure occurs (independently of the cause), how it it progresses, and how the construction factors into the progression. Some buildings are more vulnerable to collapse than others. Implosions are not a catch all as you unrealistically believe.


None of the collapses were "controlled". If you're appealing to the "unconventional demolition" answer then you might as well be arguing that the destruction of the buildings resembled the 1999 attack on the US embassy in Kenya:

[qimg]http://img18.imageshack.us/img18/1350/galosamadead16.jpg[/qimg]

Which used explosives in an effort to destroy the building, and the attackers had absolutely no concern over the collateral both in terms of property and life.



No integrity and no resistance are one in the same. When a structure has undergone any failure mechanism, such as buckling, there is no way for the structure to provide the "resistance" you're saying it should. Sunder understands this, you don't.


For the penthouse to have collapsed, there had to have been a failure inside the building to initiate it; there's no disputing it. The window breakage progresses downward in the same region as the penthouse and shows that there was enough of a deflection on that part of the facade to cause them to break. Clearly something was already happening inside the building and it progressed to a point where the rest of the building failed. Again, whether or not you see the internals, is no excuse to cast to the sidelines because you think it's irrelevant. In an engineering investigation, to ignore something like that would be downright incompetent, which is BTW what AE911 does, they ignore it.



The "sudden" collapse of the roofline only occurs after a preceding sequence of failures, AKA the penthouse collapse and any associated progressive collapse occurring inside. You're ignoring cause, and effect, which pieces together the collapse narrative.

It's boggling that after 10 years people can perpetuate such an obvious lie so eagerly and verbosely. The reward for lying must be tremendous. The penalty will be devastating.

 

[NoahFence]

The penalty will be devastating.

LOL

Insignificant threat.

 

[Grizzly Bear]

Clayton, this is a discussion for adults, if you have any serious feedback to any one of the points I laid out you are most certainly free to offer. Tell me, would you care to explain what points I've laid out are lies? I will offer my undivided attention just for you. Or is simply calling me a paid shill your only way to respond?

 

[Miragememories]

"An observed fact, supported by video recordings of the collapse. If you choose to remain ignorant of a detail that 9/11 truth never wants to address, it's not my problem."

"The all-important internal facts that are supposed to provide credance to the theory, were unobserved."

"In any engineering investigation you have unkowns; that's absolutely no excuse to ignore the penthouse collapse or the window breakage along the exterior that followed before the exterior facade collapsed. The WTC 7 structural details and blueprints are available and provide information about the internal structure, whilst the available data of the exterior provides a rough estimate of both the location, and progression of the collapse. By ignoring even the external indicators, you are by definition excluding critical information that pieces together an approximate narrative of the collapse. This is basic in any engineering investigation, you use whatever information you have. "

Of course there are always some remaining unknowns expected in major engineering investigations. You are merely stating the obvious.

But I am perplexed about your assertion that the penthouse collapse or the window breakage along the exterior that followed before the exterior facade collapsed were ignored?

By whom?

You are creating a "strawman" by referring to all this engineering data that I have in no way suggested was ignored by anyone.

"WTC7 was a concrete and steel building over-engineered to allow for tenant modifications and to protect against potential damage to the Con Edison substation which it was built over.

Of course the concrete in the floors added to the rigidity and thus the overall strength of the structure."

"You're missing a major difference between steel framed construction where most concrete is used as part of the floor systems adding lateral stability, and reinforced concrete construction that used higher strength concrete to carry gravity loads. The two construction approaches result in very different fire resistance ratings and structural dynamics, which is why buildings like the Chinese Mandarin Oriental Hotel, and the Madrid Windsor tower were never under any threat of total collapse, whereas the steel framed building of WTC7 was more vulnarable.

You of course have other facts which play in, such as the construction methods used in assembling the structural frame, for example unlike say, the Murrah Building which was not only reinforced concrete, but also built on a traditional grid layout, whereas the WTC had long spanning floor members and a non-standard column layout due to it being built on top of a substation. Things which drastically affect the expected behavior of the buildings, when compared with one another.

Steel is used because it has high tensile and compressive capabilities without the need to add additional reinforcement. Concrete has a very high compression strength but an extremely poor tensile performance (hence rebar reinforcement)."

You wasted a lot of words with few of them actually addressing the significance of the specific concrete flooring in WTC7.

Re: the WTC7 Floor System, the floor slabs were reinforced concrete of varying thickness. Floors 8 through 47 had a concrete slab 5.5" thick (on floor 7 it was 8". The concrete on most floors was poured on a 3" corrugated metal deck.

Unquestionably the floors offered significant lateral stability and fire protection to the WTC7 structure.

I offer no argument to your point that different building constructions offered different structural characteristics.

"You are also ignoring the fact that the steel was undamaged and fully fire-proofed and the NIST estimated localized office furnishings fires as peaking after 20-30 minutes."

"I'm not ignoring it, I'm fully aware of what the fireproofing does for the building and how it works. Firstly, the ratings for fireproofing are done under controlled conditions and they refer to full building assemblies, not individual structural members."

Again, like your previous comment, you are padding your answer with a general lecture which does not address anything specific.

"Secondly the testing that establishes ratings does not necessarily model every real life scenario that you can expect the assembly to encounter."

But the tests must have validity or they would be providing meaningless test data.

Office furnishings fires were what the NIST stated caused the steel failure, and I'm sure the test methods used for structural steel assemblies must have, at the very least, allowed for burning office furnishings.

"Thirdly, you're ignoring that the fires still produced heated gases within the enclosed space, exposing elements to elevated temperatures."

No I am not ignoring that fires produce heated gases.

What I would question is your suggestion that the heated gases would be so confined, and for so long, that they established prolonged significantly elevated temperatures.

The NIST argued that the fires were started on the south face as a result of debris damage.

Clearly, that damage also provided an outlet for the heated gases produced by the fires started there and those that migrated inward.

Also, high gas temperatures would be expected to cause window breakage which would also vent and reduce hot gas buildup. That kind of window breakage was evident along the fire path on the north face of WTC7.

You have said nothing about the undamaged fireproofing?

According to FEMA; "A sprayed fire-resistive material (SFRM) was used to protect the structural steel of WTC 7 from a fire. Instructions to bidders for WTC 7 recommended using a 3 hour fire rating requirement for columns and a 2 hour fire rating requirement for beams. This requirement was more stringent than the required fire ratings provided by the NYCBC for Type 1C Construction. Private inspections concluded that the thicknesses of applied SFRM were consistent with the recommended values by designers."

So for your concerns to have any validity, those extra hot gases would have to be maintained around column 79 for an inordinately long time.

"Finally, you're ignoring unique properties of WTC 7's construction that may have made the assembly more vulnerable to a large scale progressive failure.

None of this requires the steel to be "pre-damaged"

emphasis mine

Or may not have.

"According to the NIST fantastical hypothesis, office fires caused this column to lose support on 6 sequential floors and then buckle.

"

"Thermal expansion/contraction from high temperature differentials introduces shear stresses on the bolts that join column and floor beam together. The expansion or contraction of the beam pushes/pulls on the bolt and causes it to fail. These aren't novel concepts; If you want to advance a case against that and call it "fantastical", then offer a quantitative analysis of why it can't have happened. I've seen none of that from Gage's group which allegedly professes to have done the full structural analyses."

You are merely regurgitating the NIST theory as to what lead to the column 79 failure. A theory based on little or no empiric evidence.

A theory that requires an enormous amount of targeted heat focused on column 79 over 6 floors. A theory that even the NIST's own thermal model and external photography fail to support.

The center of the upper right quadrant is where column 79 is located. From 4:00 p.m. to the 5:20 p.m. global collapse time, the thermal activity was continually declining around column 79.

"Freefall, close-to-symmetrical collapses are the common signature of implosion-based controlled demolition collapses."

"And it can be a feature of any collapse under the right set of circumstances. Once again, how a building falls is directly impacted by:
- The make up of the structural assembly
- The Location of the initiating failures
- The sequence of failures.

Implosion based controlled demolitions are no different than any other collapse in this respect; they engineer where to induce the failures, to ensure that the building falls in a premeditated path to avoid damage to other buildings."

OMG. I can't believe you would say that.

First of all, must I remind you that 9/11 represented a day where for the first time in history concrete and steel buildings totally collapsed supposedly, from the finalizing effects of fire? That in the case of WTC7, the NIST determined, after 7 years of investigation, that office furnishings fires were the sole cause behind the collapse?

You honestly believe that random un-fought fires in a modern concrete and steel office tower could set up the same series of synchronized failures that professional engineers would require to achieve a freefall, close-to-symmetrical collapse?

Your belief that such an incredible freak of circumstances could occur in reality is absolutely incomprehensible. Especially given all the fire data that contradicts even the remotest possibility of that happening.

"Freefall, close-to-symmetrical collapses are the common signature of implosion-based controlled demolition collapses. The mechanism is implosion, and the commercially used trigger is explosives. With a pre-rigged demolition, the designers have a complete expectation of what is going to happen, including where and when."

"In any other collapse it is whatever the engineering investigation finds. Yet again, the path of the collapse is affected not by explosives, but by where the failure occurs (independently of the cause), how it it progresses, and how the construction factors into the progression. Some buildings are more vulnerable to collapse than others. Implosions are not a catch all as you unrealistically believe."

Sigh.

Most engineering investigations of building collapses don't require 7 years to reach a determination of cause. Before and after 9/11, no comparable (concrete and steel) building has non-deliberately collapsed. The deliberately collapsed ones were imploded. Carefully engineered to avoid toppling, staggering, piecemeal, incomplete and unsymmetrical collapses.

If WTC7's collapse had been the consequence of random failures caused by mindless migrating fires, a reasonable expectation would have been partial collapse at the first location where structural support integrity was lost.

"Of course, not being a legally-sanctioned commercial demolition, WTC7 utilized something more exotic than RDX."

"None of the collapses were "controlled". If you're appealing to the "unconventional demolition" answer then you might as well be arguing that the destruction of the buildings resembled the 1999 attack on the US embassy in Kenya: Which used explosives in an effort to destroy the building, and the attackers had absolutely no concern over the collateral both in terms of property and life."

You cannot make something true just because you state it as a fact.

"You mean this short version;"

"...a free fall time would be an object that has no...uh... structural components below it..."

"Not just "no structural integrity", no structural resistance."

"No integrity and no resistance are one in the same. When a structure has undergone any failure mechanism, such as buckling, there is no way for the structure to provide the "resistance" you're saying it should. Sunder understands this, you don't."

Wrong.

No structural integrity means that it is structurally impaired and no longer stable or reliable.

No structural resistance means that there is zero structural support.

Anything above relying on this support, has to immediately drop under the force of gravity.

Yes indeed, Sundar understood this. Which is why he provided numbers in the draft report that did not support freefall
in the observed collapse of WTC7.

"If you observe the global collapse video, for a few seconds after the east penthouse drops through the roof, other than some broken windows on the upper northeast face the whole structure remains visibly unaffected."

"For the penthouse to have collapsed, there had to have been a failure inside the building to initiate it; there's no disputing it. The window breakage progresses downward in the same region as the penthouse and shows that there was enough of a deflection on that part of the facade to cause them to break. Clearly something was already happening inside the building and it progressed to a point where the rest of the building failed. Again, whether or not you see the internals, is no excuse to cast to the sidelines because you think it's irrelevant. In an engineering investigation, to ignore something like that would be downright incompetent, which is BTW what AE911 does, they ignore it."

Of course there is no dispute that obviously the penthouse could not have collapsed unless it lost the structural support immediately below it.

The window breakage does indicate an internal structural disruption.

From here, it is a major leap of faith to believe the official explanation for what followed.

"Then, and unlike what is observed in the NIST computer simulated collapse video, the whole roofline suddenly, yes suddenly, begins a rapid descent which included 8 storeys of freefall."

"The "sudden" collapse of the roofline only occurs after a preceding sequence of failures, AKA the penthouse collapse and any associated progressive collapse occurring inside. You're ignoring cause, and effect, which pieces together the collapse narrative."

Inside the 47-storey WTC7, over a football field-sized area, interior support columns anchored to floor trusses which were anchored to exterior columns, were all supposedly failing simultaneously due to their connectivity to column 79.

Major perimeter pull-in forces that apparently didn't.

MM

 

[beachnut]

It's boggling that after 10 years people can perpetuate such an obvious lie so eagerly and verbosely. The reward for lying must be tremendous. The penalty will be devastating.

There is no penalty for Gage spreading lies and you falling for them. Being knowledge free on 911 issues and supporting the delusions Gage pushes, is not a crime. You will have no reward for supporting Gage. Gage pulls in over 300k a year, your penalty for believing Gage's nonsense is priceless.

Let's get our America back, the America with knowledge. Back from the anti-intellectual cult movements of idiotic conspiracy theories and other nuts like Gage.

 

[Clayton Moore]

Well Clayton, would you care to explain what points I've laid out are lies? If not, please let the adults continue having their discussion.

Your entire premise that those three huge buildings were SO damaged that they were completely destroyed by their own WEIGHT is a LIE.

Anything you say in support of that basic lie is a lie.

 

[LSSBB]

Your entire premise that those three huge buildings were SO damaged that they were completely destroyed by their own WEIGHT is a LIE.

Anything you say in support of that basic lie is a lie.

So, anything he says that you fail to believe is a lie, even if you can't prove that it is wrong?

 

[Grizzly Bear]

Your entire premise that those three huge buildings were SO damaged that they were completely destroyed by their own WEIGHT is a LIE.

Now support that claim by demonstrating to me some knowledge and study on the engineering that explains why the buildings should not have collapsed. It's easy as hell to ridicule, showing you actually know the material, that ought to be interesting. Show me what you've studied; as I said earlier I will offer you my full, undivided attention if you put some thought into your responses.

MM, I will address you as soon as I have the opportunity.

 

[Xero]

Your entire premise that those three huge buildings were SO damaged that they were completely destroyed by their own WEIGHT is a LIE.

Anything you say in support of that basic lie is a lie.

And yet, you've failed to show any even resembling convincing evidence of your claims. Just repeating things does not make them true.

One set of claims is backed by facts, and much investigation by bodies with a great deal of knowledge and experience in their relevant fields. And the other ... is not.

 

[grandmastershek]

LOL

Insignificant threat.

Come on...the storm twoofers need something to latch on to. Christians have the rapture these guys have their imaginary court sentences. Its justt the regular unwitting admission that dissent will not be tolerated.

Has MM:

Provided a source on "near symmetry".
Refuted the FDNY's testimony on sounds and visual confirmation of structural weakening.
Demonstrated FFA requires simultaneous failures of all the supports.

Or demonstrated any of the other parts of the laundry list of fallacious arguments, and thin air facts he's wished into reality?

 

[NoahFence]

The center of the upper right quadrant is where column 79 is located. From 4:00 p.m. to the 5:20 p.m. global collapse time, the thermal activity was continually declining around column 79.

Yes or no, MM. Just once. Give it a try! It's fun:

Yes or no -

The damaged sustained by the fire at Column 79 remained after the fire had moved on.

Yes or no?

 

[triforcharity]

Yes or no, MM. Just once. Give it a try! It's fun:

Yes or no -

The damaged sustained by the fire at Column 79 remained after the fire had moved on.

Yes or no?

My guess is this will not be answered. He drives a 2500 Dodge Ram after all. With the 5.7L Hemi I might add.

 

[twinstead]

Wake up sheeple! Column 79 repaired itself after the fire had moved on.

 

[tfk]

The all-important internal facts that are supposed to provide credance to the theory, were unobserved.

Of course they were "unobserved".

So were the "all important internal facts" that caused the breakup of the Challenger & Columbia.

So were the "all important internal facts" that caused virtually every airplane crash.

Didn't stop engineers from figuring out the reasons for the failures.

But, based on your ridiculous requirement for observation, NO theory can be justified. Including CDs.

… time for everyone to go home now?

WTC7 was a concrete and steel building over-engineered to allow for tenant modifications and to protect against potential damage to the Con Edison substation which it was built over.

You don't know squat about structures.

It was over-engineered for loads applied in one direction only.

Sorry, the loads associated with the fires & progressive collapse were unlike any loads considered in the engineering.

Freefall, close-to-symmetrical collapses are the common signature of implosion-based controlled demolition collapses.

Wrong.

There's that "structures" thing again…

For a building composed of a square, rectangular or rhomobohedral lattice array of support columns, a "close-to-symmetrical collapse" is the signature of EITHER a very carefully planned CD OR any sort of natural collapse.

These buildings can not "tip over" or fall significantly different from "straight down", except (possibly) by one mechanism. They might be made to fall to one side (non-symmetrically) by carefully planned CD that instantly took out a giant "V" shaped group of columns, simultaneously cutting the bottom & top of the V. I doubt that, even with this action, the building would tilt more than about 5 degrees, before buckling the un-blown columns & falling straight down.

(That's the only way that I can think of, anyway. I'll happily listen to your speculation as to how to make that happen otherwise.)

The mechanism is implosion, and the commercially used trigger is explosives.

Of course, not being a legally-sanctioned commercial demolition, WTC7 utilized something more exotic than RDX.

No "bang".
No explosives.
No exotic explosives.
No RDX.

If you observe the global collapse video, for a few seconds after the east penthouse drops through the roof, other than some broken windows on the upper northeast face the whole structure remains visibly unaffected.

Wow.

Three paragraphs ago, you CORRECTLY stated that "The all-important internal facts that are supposed to provide credance to the theory, [i.e., the internal structure of the building] were unobserved."

Now you're saying that you can see "the whole structure".

Contradict yourself much?

Why, yes you do.

 

[Grizzly Bear]

Of course there are always some remaining unknowns expected in major engineering investigations. You are merely stating the obvious.

But I am perplexed about your assertion that the penthouse collapse or the window breakage along the exterior that followed before the exterior facade collapsed were ignored?

By whom?

You are creating a "strawman" by referring to all this engineering data that I have in no way suggested was ignored by anyone.

You yourself said that "the all-important internal facts that are supposed to provide credance to the theory, were unobserved." Am I took to take it that this renders the collapse of the penthouse unimportant to your views? Or something otherwise? Please clarify if you believe I took your response the wrong way.

In addition, virtually every single video supporting the controlled demolition of WTC 7 and arguing that the collapse to 6 seconds ignores the collapse of the penthouse and minor exterior signs of distress. Do you agree with not including the penthouse collapse as part of the overall collapse time? If not, then why?

You wasted a lot of words with few of them actually addressing the significance of the specific concrete flooring in WTC7.

Re: the WTC7 Floor System, the floor slabs were reinforced concrete of varying thickness. Floors 8 through 47 had a concrete slab 5.5" thick (on floor 7 it was 8". The concrete on most floors was poured on a 3" corrugated metal deck.

Unquestionably the floors offered significant lateral stability and fire protection to the WTC7 structure.

No arguments with anything but the bolded. The concrete used on the floor slabs does not offer any significant, additional fire protection to the steel frame. Had WTC 7 been built more like the Madrid tower, the Mandarin oriental/CCTV, the Murrah Building, or perhaps Complejo Parque Central, you could make such a case, but not for WTC 7 as it's primary passive fire resistance consisted of SFRM, and Gypsum wall board.

This is the "big difference" you missed. The lightweight concrete doesn't perform the same role in the WTC as it does in examples like those I named, where it functions both as the vertical load bearing structure and provides substantial fire resistance without the need for additional passive measures such as Gypsum and SFRM.

I offer no argument to your point that different building constructions offered different structural characteristics.

Keep this part in mind; this is important for one of your other comments addressed below

But the tests must have validity or they would be providing meaningless test data.

Oh they certainly do, because they define benchmarks by which architects and engineers conform to code. However, it strictly refers to a measured level of performance under a specific set of criteria for testing and evaluation. It's performance under real world conditions, as stated before however, is never guaranteed to be exactly the same. This is due to quite a few factors which I'll explain below.

Office furnishings fires were what the NIST stated caused the steel failure, and I'm sure the test methods used for structural steel assemblies must have, at the very least, allowed for burning office furnishings.

There's few ways that fire proofing works:
- It limits the amount of heating that the underlying material experiences.
- When the building has enclosed spaces, it compartmentalizes the fire and heat to prevent or delay it from spreading to other parts of the building, allowing occupants more time to evacuate safely and emergency crews to respond.

The actual performance depends on some of the same factors; the building's actual design, but it's more than just whether or not the spaces were compartmentalized or not. With WTC 7, NIST argues that the failure of the fireproofing wasn't the problem, it was thermal expansion under temperatures lower than traditionally expected to cause the steel to fail. They attribute that failure to WTC 7 having longer spanning beams than typically seen in other buildings of similar construction. The longer spans magnify the degree to which the thermal expansion occurs, and it means that each column supports more floor area than a traditional framing system. When one column fails, the loads it carried had to be transferred to an adjacent column. In WTC 7, because of the longer spaces, if one column failed the adjacent assembly had to compensate more than expected in a building of more traditional construction.

What I would question is your suggestion that the heated gases would be so confined, and for so long, that they established prolonged significantly elevated temperatures.

The NIST argued that the fires were started on the south face as a result of debris damage.

Clearly, that damage also provided an outlet for the heated gases produced by the fires started there and those that migrated inward.

Also, high gas temperatures would be expected to cause window breakage which would also vent and reduce hot gas buildup. That kind of window breakage was evident along the fire path on the north face of WTC7.

The fires burned for several hours. In order to exit the building the heated air and smoke needs to traverse whatever part of the building it originates from to exit.

You have said nothing about the undamaged fireproofing?

According to FEMA; "A sprayed fire-resistive material (SFRM) was used to protect the structural steel of WTC 7 from a fire. Instructions to bidders for WTC 7 recommended using a 3 hour fire rating requirement for columns and a 2 hour fire rating requirement for beams. This requirement was more stringent than the required fire ratings provided by the NYCBC for Type 1C Construction. Private inspections concluded that the thicknesses of applied SFRM were consistent with the recommended values by designers."

The fireproofing doesn't need to be damaged to fail. I refer you back above to the response I wrote to an earlier point you made where I alluded that fire proofing makes the building more resistant to fire but it doesn't expressly grant that the assembly will not weaken or otherwise fail. Recall, that fire ratings are established using burn conditions for structural assemblies under specifc, controlled conditions. Other factors including the building's actual construction, and the actual conditions of the fire event will determine the real life performance.

In the vast majority of cases it's lead to a highly successful safety record, in the case of WTC 7 a combination of it's unique design and the failure of active fire protection (sprinklers) it didn't work out. If the sprinkler systems weren't cut off, and/or firefighters were able to fight it it's very likely the building wouldn't have collapsed and the longer floor spans wouldn't have been as big of a player.

So for your concerns to have any validity, those extra hot gases would have to be maintained around column 79 for an inordinately long time.

Again, you have a misconception of how fire resistance ratings are assigned. And anyway, fires did not need to burn exclusively around that single column. The NIST's argument doesn't require that; it argues that several floors experienced thermal expansion, and due to the length of exposure to elevated temperatures, and the length of their spans they went through more than what is typically seen. This exerted strain on the connections to the column causing them to fail; when the column lost its lateral bracing it became unstable and buckled along its unbraced length. This failure shifted loads to the adjacent supports and initiated a progressive failure of the building.

You are merely regurgitating the NIST theory as to what lead to the column 79 failure. A theory based on little or no empiric evidence.

Emphasis mine. Each of the phenomena:

- Thermal expansion/contraction
&
- Euler's formulas for column failure

Have been demonstrated in precedents already. If not adequately addressed in a building design (and even in extreme cases where they are) both can be the mechanism for either partial or complete structural failure.

Prior to deciding to evacuate the building, firefighters noticed significant structural displacement occurring in the stair enclosures. A command officer indicated that cracks large enough to place a man’s fist through developed at one point. One of the granite exterior wall panels on the east stair enclosure was dislodged by the thermal expansion of the steel framing behind it.

In this case thermal expansion exterted enough force on the stair enclosure to crack it open and displace granite panels installed in it. When NIST discusses thermal expansion in the context of WTC 7, it's the same thing, the expanding beam is restrained by the connections and has no where to go. It allows strains to increase on the bolts holding it together until they fail.

For the Euler formulas, and general info on column failure modes I'll refer you here for more details.

A theory that requires an enormous amount of targeted heat focused on column 79 over 6 floors. A theory that even the NIST's own thermal model and external photography fail to support.

Incorrect. You need to read more carefully what NIST discusses. I summarized it above.

"Freefall, close-to-symmetrical collapses are the common signature of implosion-based controlled demolition collapses."

Originally Posted by Grizzly Bear
"And it can be a feature of any collapse under the right set of circumstances. Once again, how a building falls is directly impacted by:
- The make up of the structural assembly
- The Location of the initiating failures
- The sequence of failures.

Implosion based controlled demolitions are no different than any other collapse in this respect; they engineer where to induce the failures, to ensure that the building falls in a premeditated path to avoid damage to other buildings."

OMG. I can't believe you would say that.

First of all, must I remind you that 9/11 represented a day where for the first time in history concrete and steel buildings totally collapsed supposedly, from the finalizing effects of fire? That in the case of WTC7, the NIST determined, after 7 years of investigation, that office furnishings fires were the sole cause behind the collapse?

You honestly believe that random un-fought fires in a modern concrete and steel office tower could set up the same series of synchronized failures that professional engineers would require to achieve a freefall, close-to-symmetrical collapse?

Your belief that such an incredible freak of circumstances could occur in reality is absolutely incomprehensible. Especially given all the fire data that contradicts even the remotest possibility of that happening.

I don't oversimplify.

• I've said before and I'll say it again thousands of times over; first time in history is a garbage argument. When something like the collapse of the WTC happens it is the engineering community's responsibility to find out whether the causes were:
  
  A) brought on by an unforeseen vulnerability that's not addressed in any existing code requirements
  
  or
  
  B) if it relates to a combination of criteria that goes beyond the scope of what building codes or any other design approach can feasibly account for.
  
• You're suggesting that because these are first time events that design shortfalls, regardless of likely hood shouldn't be looked at...
  
• We know about the material properties of building materials, and we know that efforts to make them more resistant to fire while effective is not a warrant to suggest they cannot still fail.
  
• We know that buildings are designed differently and that they will not conform to a specific, uniform behavior.
  
• We know their performance will depend on external factors.
  
• In light of all this, and your earlier comment of:
  
  

  I offer no argument to your point that different building constructions offered different structural characteristics

  
  I'm perplexed as to why you would be shocked for me to say that the following:
  
  - The make up of the structural assembly
  - The Location of the initiating failures
  - The sequence of failures.
  
  should be considered when investigating something like a building collapse.
  
  It was the first time in history that planes were used as an instrument of a suicide attack on a large skyscraper. It's the first modern case that I'm aware of where two buildings had fires ignited on multiple stories by thousands of gallons of accelerants 80+ stories high crippling sprinkler systems and one of only a few extremely rare instances where the fires were so far beyond the reach of firefighters to tackle. No body seems to be throwing a fit over those happening for the first time, unlikely as they seemed to be by most people's standards...

Sigh.

Most engineering investigations of building collapses don't require 7 years to reach a determination of cause.

NIST's primary focus was on the reports for WTC 1 & 2, the one for WTC 7 didn't start much until after they were completed with the first. More like 3 years.

Before and after 9/11, no comparable (concrete and steel) building has non-deliberately collapsed.

I guess since you're still going to have quirks with this first time in history argument let me ask you; Would you classify the Space shuttle Columbia's lift off explosion due to a faulty O-ring as impossible because it lacks an equivalent precedent? Would you classify the reentry burn up of space shuttle Columbia due to the tiles being compromised by a piece of foam that struck it on the grounds that it lacks an equivalent precedent? Do you classify the collapse of the Takoma Narrows bridge collapse due to wind and design deficiencies to be impossible on the grounds that it lacks an equivalent precedent?

Why or why not on all three?

The deliberately collapsed ones were imploded. Carefully engineered to avoid toppling, staggering, piecemeal, incomplete and unsymmetrical collapses.

In other words they were engineered to collapse in such a way as to avoid damage to adjacent structures and property... I already said that's why they're CONTROLLED!

The collapse of WTC 1 & 2 destroyed pretty much every building on the WTC property... WTC 7 damaged several buildings right next to it... one of which had to be deconstructed...

That's not controlled; not even unconventionally, period... Which perplexes me as to why you'd try to say it was in any way...

If you want deliberately destroyed... look no further than the Murrah building... McVeigh leveled the entire front half of the building and blew a crater in the parking lot with a car bomb... or Al Queda's attack on the US embassy in Kenya... again using a car bomb...

Did they care about engineering it? Why do you think, despite the fact I'd still tell you it's wrong, I suggested a closer comparative to the bombing of the US embassy in Kenya or the Murrah bombing?

If WTC7's collapse had been the consequence of random failures caused by mindless migrating fires, a reasonable expectation would have been partial collapse at the first location where structural support integrity was lost.

And hence the whole problem of the controlled demolition theory. When you don't bother to study the internal and external factors of what happened you develop premature expectations which naturally get contradicted. That's hardly surprising.

That is precisely why simplifying the things you see wrong down to barebones first time in history, it's all done in implosions, assymetrical collapse and symmetrical collapse = controlled demolition, etc will always fail, and why I don't rely on trite simplification to make my point.

"Freefall, close-to-symmetrical collapses are the common signature of implosion-based controlled demolition collapses. The mechanism is implosion, and the commercially used trigger is explosives. With a pre-rigged demolition, the designers have a complete expectation of what is going to happen, including where and when."

"None of the collapses were "controlled". If you're appealing to the "unconventional demolition" answer then you might as well be arguing that the destruction of the buildings resembled the 1999 attack on the US embassy in Kenya: Which used explosives in an effort to destroy the building, and the attackers had absolutely no concern over the collateral both in terms of property and life."

You cannot make something true just because you state it as a fact.

And I'm not saying it for that reason. Not all buildings are the same; how do you assign a consistent behavior to assemblies that you cannot realistically expect to behave in a consistent manner? There is no legally defined criteria that dictates a collapse should be symmetrical or assymetrical whether done by controlled demolition or otherwise. Such definitions are never used professionally outside of the 9/11 conspiracy theories. If you can demonstrate otherwise, fine... but you haven't...

Wrong.

No structural integrity means that it is structurally impaired and no longer stable or reliable.

No structural resistance means that there is zero structural support.

Anything above relying on this support, has to immediately drop under the force of gravity.

In any instance where a column or structure fails, either by buckling, crushing, or cutting, it's by definition sudden. If you read any literature on structures, specifically ones that comprehensively define column failure modes you get the same information. I suggest you refer to that literature. I'm more than happy to suggest a few starter books that talk about this and were required in my curriculum if you ask.

Of course there is no dispute that obviously the penthouse could not have collapsed unless it lost the structural support immediately below it.

The window breakage does indicate an internal structural disruption.

From here, it is a major leap of faith to believe the official explanation for what followed.

What followed was a progressive collapse, which has been observed on a smaller scale before and it has a legal definition in the professional environment. The likelihood of that kind of failure, is not dictated by first time events, it's dictated by the construction, which is why I continue to call the first time in history argument for what it is; an absolute oversimplification of the real world, and completely untenable.

Inside the 47-storey WTC7, over a football field-sized area, interior support columns anchored to floor trusses which were anchored to exterior columns, were all supposedly failing simultaneously due to their connectivity to column 79.

Major perimeter pull-in forces that apparently didn't.

MM

Like I said before, you made premature expectations without studying the ins and outs of the event. That the reality didn't play out like you think it should have is far from surprising. For example, the collapse was not not simultaneous, nor did it occur over 6.6 seconds. The WTC 7 collapse was by definition a progressive collapse with a single initiating event that lead to successive failure of other parts over 18 seconds...

I've made references to load paths, load capacities, construction approaches, construction vulnerabilities, internal and external factors playing into the events that lead to their collapse, and more. There's no way you can justify a statement like that (bold) in a single sentence. You're not accustomed to the complexity of building construction, and it shows like a sore thumb. It's the same for the professionals you claim have an authoritative stake in the argument, they make the exact same judgement errors. That's why I and many others criticize them.

 

[MIKILLINI]

It's boggling that after 10 years people can perpetuate such an obvious lie so eagerly and verbosely. The reward for lying must be tremendous. The penalty will be devastating.

In order to accuse someone of lying, you need to provide evidence that proves the lie. Wishful speculation doesn't qualify as evidence. Rewards for ignorance exist for truthers.

 

[NoahFence]

So no answer yet.