Continuation: 'What about building 7?'

[GlennB]

Chris, it may seem so if you have been paying attention to the non-sense from your forum buddies, but you are certainly not citing NIST, which said there was one big gash in the south west corner section,

No, they really didn't. They also mentioned and mapped this one, but your stubborn refusal to view or comment on many previous postings of the same image makes me wonder about your motives here -

 

[beachnut]

... are certainly not citing NIST,...

The obsession with NIST is not going to make the idiotic CD fantasy come true.

Where is the evidence for you theory? Where is the magical store to buy silent explosives which don't cook off in fire? Who is dumb enough to set explosives and murder thousands in your fantasy world of evil doers? In your scenario which you can't and refuse to explain, how does the CD of WTC 7 dove tail with the actions of 19 terrorists who really did 911? How can you fit 19 terrorists who did 911 into your fantasy CD of WTC which you can't explain past bashing NIST and Chris. Why are you attacking Chris when you can't explain one aspect of your fantasy CD BS scenario? The Chris and NIST obsession only makes your CD fantasy dumber.

How much explosives in pounds did you CD fantasy use? Who are the suspects, and why did they make it look like CD? Are you stuck on NIST? A true BASHNISTIAN. At least you have the super support, some engineers signed a petition for Gage pushes, at less than 0.1 percent of all engineers. Guess you failed to check with engineers outside of the fantasy world of 911 truth, and learn there is no support for your CD theory.

Did you survey thousands of engineers outside of 911 truth? No, you fell for nonsense spread on the Internet, where everything has to be right. Out of the hundreds of engineers I went to school with, I can't find one who supports 911 truth lies of CD, and some inside job you can't define.

What is your theory, please stop playing the Chris card, and bashing NIST. Present your evidence. Darn, that ends your presentation, you have nothing to present.

 

[chrismohr]

7 collapse

It has do to with how one visualizes the structural behavior of perimeter. You can do it in any of several ways, and each way sets up a different expectation for how the building collapse should look.

Imagine one of those lightweight plastic structural grids like you often see as part of trade-show booths. Now imagine a large sheet of paper attached to the front of a fairly broad expanse of it. Think of the paper attached by little rolled up loops of tape joining the paper to the grid at various points, just enough to hold it up and keep it flat.

Now go in and judiciously cut enough of the plastic grid pieces so that half the structure supporting your facade collapses while the other half stays standing. What happens to the paper? You might be able to imagine several things. The paper might tear, in which case the portion that was connected to the failed structure will fall with it, leaving the other part still attached to the still-standing structure. Or the failing structure might pull the whole sheet of paper away, severing the connections between the paper and the still-standing structure. Or at the opposite extreme, the failing structure may tear its little tape wads away, leaving the paper intact, still stuck eccentrically to the surviving structure, and roughly in its previous shape, if otherwise crinkled and now waving in the breeze.

The Truther proposition seems to be a scenario along the lines of the first two, where the perimeter should fail in a way that reveals any asymmetric nature of interior failure. The debunker proposition is more like the latter, where the perimeter stays intact but deformed and poorly supported. To understand how those can legitimately differ, imagine the thickness of the paper in the scenario varying between tissue paper and cardstock. Those are kinds of paper that would have different mechanical properties in this toy example. The tissue paper would be less likely to stay in place and more likely to follow the falling plastic grid. The cardstock would be more apt to hold its shape and stay in place even if much of the structure behind it had failed.

So I think it may be fair to say that the expectations regarding the perimeter wall vary according to how people intuitively envision the specific strength of the wall itself.

Really Ziggi, I've given up on even exploring further the ideas that 1) Building 7 fires could NOT have been caused by the collapse of the Tower and 2) fires could NOT have spread from floor to floor via the gash. It makes no sense at all, based on both common sense and the excerpts from the NIST Report that are flying at you.

I do want to look further into the issue of the perimeter wall collapsing pretty much as a unit. I've attached a diagram of what was supposedly going on inside the building. With this kind of chaos, I would think that Jay Utah's explanation is inadequate. For a 47-story unit to hold up for even six seconds with all these supports cascading away requires that the perimeter wall be a strong structural unit. And then it has to have very rapid-fire column failure. Because it is a structural unit and strongly tied together, I can see the possibility of the west side of the wall holding up the east side of the wall for a few seconds before the rapid-fire column failure begins. And I can see those failures happeningh fast at the welded connections, where the steel would be more brittle. And once the welded connections fail, the columns would slip off to the side, into open office space, and start falling really fast, with remnants of the interior still yanking them down maybe even fasster. The paper/cardboard analogy doesn't work for me because I think the perimeter wall MUST have had some real structural strength. But the way the analogy CAN work is to imagine that the paper or cardboard from the west side could briefly hold up the unsupported east side for at least awhile. Thoughts?

 

[JayUtah]

The paper/cardboard analogy doesn't work for me because I think the perimeter wall MUST have had some real structural strength.

The proposition that the perimeter wall had some strength of its own is the essence of the analogy, so you got the idea I intended even if it was via a different route.

 

[Oystein]

...I've attached a diagram of what was supposedly going on inside the building. With this kind of chaos, I would think that Jay Utah's explanation is inadequate. For a 47-story unit to hold up for even six seconds with all these supports cascading away requires that the perimeter wall be a strong structural unit. ...

A nitpick: I think the figure you attached (Fig 2-2 of NCSTAR 1A, page 22) is a bit too early to demonstrate the problem. At this time, col 79 has only just begun to buckle as a result of floors 13 down to 6 collapsing. At that point in time, floors 14 and up are largely intact and served to brace the east perimeter.

This Fig. 2-2 appears to be the same as Fig 12-43 in NCSTAR 1-9, which has a note "Snapshot at -0.5 (15.5) s"; which I think means half a second before NIST's t₀ of global collapse (descent of EPH?). A second later, at +0.5 s (Fig 12-48), the floors above 14 are coming undone as 79 descends. At 1.5 s they are shown entirely detached.

Fig. 12-67 and 12-68 on pages 592f, although pertaining to the collapse model without debris impact damage, illustrate nicely how the entire east core disintegrates. They don't show perimeter and floors, but I think it's an easy step to imagine the "hollow shell" that was the east side after t=0.5 s.

 

[jaydeehess]

NIST found no evidence of the pathway the fire took to reach the north face, nor when it arrived at this face

Paraphrase from the bottom of page 244. Sorry if its not verbatim, my tablet won't allow copy/paste from the PDF nor can I view two windows at once.

Point is that Ziggi et al have been trying to tell us that when NIST says it found no evidence that it means they are saying it did not occur. This sentence illustrates the true contextual meaning. NIST is obviously not saying there was no path for 11th floor flames to reach the north face, nor is it saying that the fire did not reach the north face. It is describing to gap in information and nothing more.

When NIST says it found no evidence that burning debris from WTC1 started the fires in the streets or WTC7, it is not it claiming it did not happen. It is instead saying no direct imagery could be found to positively identify that mechanism. The report DOES go on to state that it is "highly likely" that is the cause of the fires. There was no video in which a burning piece of debris is observed to land inside WTC7 and ignite materials there. Unsurprising since cameras were largely trained on the towers themselves, as they collapsed.

Of course reading comprehension on this matter seems to be a big problem for some truthers.

 

[Crazy Chainsaw]

Really Ziggi, I've given up on even exploring further the ideas that 1) Building 7 fires could NOT have been caused by the collapse of the Tower and 2) fires could NOT have spread from floor to floor via the gash. It makes no sense at all, based on both common sense and the excerpts from the NIST Report that are flying at you.

I do want to look further into the issue of the perimeter wall collapsing pretty much as a unit. I've attached a diagram of what was supposedly going on inside the building. With this kind of chaos, I would think that Jay Utah's explanation is inadequate. For a 47-story unit to hold up for even six seconds with all these supports cascading away requires that the perimeter wall be a strong structural unit. And then it has to have very rapid-fire column failure. Because it is a structural unit and strongly tied together, I can see the possibility of the west side of the wall holding up the east side of the wall for a few seconds before the rapid-fire column failure begins. And I can see those failures happeningh fast at the welded connections, where the steel would be more brittle. And once the welded connections fail, the columns would slip off to the side, into open office space, and start falling really fast, with remnants of the interior still yanking them down maybe even fasster. The paper/cardboard analogy doesn't work for me because I think the perimeter wall MUST have had some real structural strength. But the way the analogy CAN work is to imagine that the paper or cardboard from the west side could briefly hold up the unsupported east side for at least awhile. Thoughts?

Chris, here is a small passage on weld failure.

"When a member develops a cross sectional fracture other than that associated with the
whole tensile cross section, the member is said to fail by “block shear” or “patterned tear
out.” These failures generally precipitate as a combination of shearing and tensile ruptures
that are usually initiated in tension; this failure can have a strong interaction with eccentric
effects. This mode is important because as the length of a connection increases there is a
transition to the “shear lag” mode. When a member fails through the net tensile area, at less
than the full section tensile strength, it is generally the result of “shear lag;” the member
geometry could not develop the full tensile ultimate strength and has suffered a shear lag
reduction. “Shear lag” will also interact with eccentricity if it is large."

S7-3-Humphries.PDF.

 

[chrismohr]

Chris, here is a small passage on weld failure.

"When a member develops a cross sectional fracture other than that associated with the
whole tensile cross section, the member is said to fail by “block shear” or “patterned tear
out.” These failures generally precipitate as a combination of shearing and tensile ruptures
that are usually initiated in tension; this failure can have a strong interaction with eccentric
effects. This mode is important because as the length of a connection increases there is a
transition to the “shear lag” mode. When a member fails through the net tensile area, at less
than the full section tensile strength, it is generally the result of “shear lag;” the member
geometry could not develop the full tensile ultimate strength and has suffered a shear lag
reduction. “Shear lag” will also interact with eccentricity if it is large."

S7-3-Humphries.PDF.

Thanks C Chainsaw,
Do you anything about the speed with which progressive failure of columns can happen in this scenario, and if there is any evidence from the debris that this is how the failure occurred? If I recall, all NIST said was that the failures occurred at the welded connections. The speed of the progressive column failures is important, because if "Shear lag" refers to a "lag time," there ain't much of that in Building 7's collapse at all.

 

[Crazy Chainsaw]

Thanks C Chainsaw,
Do you anything about the speed with which progressive failure of columns can happen in this scenario, and if there is any evidence from the debris that this is how the failure occurred? If I recall, all NIST said was that the failures occurred at the welded connections. The speed of the progressive column failures is important, because if "Shear lag" refers to a "lag time," there ain't much of that in Building 7's collapse at all.

Shear lag can occur at 5100 meters per second, it refers to failure that is faster than tensile strength bending.
The speed and energy must occur faster than the metal crystals can deform, bend in tension. Tension deformation steel crystal realinement is a time dependant phenomenon.
If the shock is fast enough the metal does not have time for it's structure to reform streach
In tension so the crystals shear.

Tony had the argument, backwards!

Shear Lag and weld embrittlement are undoubtedly the main failure modes, as I pointed
out to Dr. Benson in 2008 after searching every available picture of the steel, and
experimentally inducing it on a welded specimen in my back yard.

 

[JSanderO]

Really Ziggi, I've given up on even exploring further the ideas that 1) Building 7 fires could NOT have been caused by the collapse of the Tower and 2) fires could NOT have spread from floor to floor via the gash. It makes no sense at all, based on both common sense and the excerpts from the NIST Report that are flying at you.

I do want to look further into the issue of the perimeter wall collapsing pretty much as a unit. I've attached a diagram of what was supposedly going on inside the building. With this kind of chaos, I would think that Jay Utah's explanation is inadequate. For a 47-story unit to hold up for even six seconds with all these supports cascading away requires that the perimeter wall be a strong structural unit. And then it has to have very rapid-fire column failure. Because it is a structural unit and strongly tied together, I can see the possibility of the west side of the wall holding up the east side of the wall for a few seconds before the rapid-fire column failure begins. And I can see those failures happeningh fast at the welded connections, where the steel would be more brittle. And once the welded connections fail, the columns would slip off to the side, into open office space, and start falling really fast, with remnants of the interior still yanking them down maybe even fasster. The paper/cardboard analogy doesn't work for me because I think the perimeter wall MUST have had some real structural strength. But the way the analogy CAN work is to imagine that the paper or cardboard from the west side could briefly hold up the unsupported east side for at least awhile. Thoughts?

Chris,
NB how few columns going axially (vertically) directly beneath the 4 sides of the trapazoidal frame which was from floor 8 to flr 47.

north curtain wall/moment frame - 5 columns
east curtain wall/moment frame - 4 columns
south curtain wall/moment frame - 10 columns (unbraced for 6 stories)
east curtain wall/moment frame - 5 columns

There were 57 columns in the perimeter above floor 8 and only 26 below floor 8

Both the east and west were braced frames below floor 8... and likely folded inward as not columns but the entire braced frame which included the columns

The entire building was surrounded by a 2 story belt truss at the perimeter from floors 5-7 functioning as a sort of rigid based the the frame above

Essentially the support below the perimeter braced frame failed almost at once and the 4 sides came down together.

 

[Ziggi]

Really Ziggi, I've given up on even exploring further the ideas that 1) Building 7 fires could NOT have been caused by the collapse of the Tower and 2) fires could NOT have spread from floor to floor via the gash. It makes no sense at all, based on both common sense and the excerpts from the NIST Report that are flying at you.

Well Chris, the important thing to remember is that NIST admits it found no evidence that burning debris from the Towers started fires in WTC7, or that fires spread from floor to floor. You are free to look into the data yourself and come to a different conclusion, but when you do that you have to make sure to clearly note that your conclusion is not NISTs conclusion because it found no evidence to support it. You have a BIG problem because several of your forum buddies like to conflate their own opinions with NISTs report, giving the false idea that NIST supports what they are saying, and then you trust them and make their opinions your own.

..I do want to look further into the issue of the perimeter wall collapsing pretty much as a unit. I've attached a diagram of what was supposedly going on inside the building. With this kind of chaos, I would think that Jay Utah's explanation is inadequate. For a 47-story unit to hold up for even six seconds with all these supports cascading away requires that the perimeter wall be a strong structural unit. And then it has to have very rapid-fire column failure. Because it is a structural unit and strongly tied together, I can see the possibility of the west side of the wall holding up the east side of the wall for a few seconds before the rapid-fire column failure begins. And I can see those failures happeningh fast at the welded connections, where the steel would be more brittle. And once the welded connections fail, the columns would slip off to the side, into open office space, and start falling really fast, with remnants of the interior still yanking them down maybe even fasster. The paper/cardboard analogy doesn't work for me because I think the perimeter wall MUST have had some real structural strength. But the way the analogy CAN work is to imagine that the paper or cardboard from the west side could briefly hold up the unsupported east side for at least awhile. Thoughts?

I looks to me that you are imagining the 4 corners supporting each other with rigid perimeter frame "walls" between them. The problem is not the corners, but the 47 story high walls, which are way too tall and wide to remain rigid without support from the core. Once the floors/girder assemblies outside the core start to fail, the perimeter exterior frame starts to sag inward, and this is exactly what NISTs computer model shows, meaning it fails to support the notion that the perimeter could remain rigid while the interior collapses.

NISTs model also fails to show the free fall collapse, and NIST was on record saying free fall would be impossible, before Chandler proved it.

In the end the problem is that NISTs work did not explain the observed phenomena of the collapse, such as the symmetric free fall, which is what it was supposed to do. NIST failed big time.

Don´t you think it would be more fitting to ask for a real independent scientific investigation to find out what really happened, rather than laymen and anonymous forum posters making up imagined stories of what could have happended?

 

[Crazy Chainsaw]

Well Chris, the important thing to remember is that NIST admits it found no evidence that burning debris from the Towers started fires in WTC7, or that fires spread from floor to floor. You are free to look into the data yourself and come to a different conclusion, but when you do that you have to make sure to clearly note that your conclusion is not NISTs conclusion because it found no evidence to support it. You have a BIG problem because several of your forum buddies like to conflate their own opinions with NISTs report, giving the false idea that NIST supports what they are saying, and then you trust them and make their opinions your own.




I looks to me that you are imagining the 4 corners supporting each other with rigid perimeter frame "walls" between them. The problem is not the corners, but the 47 story high walls, which are way too tall and wide to remain rigid without support from the core. Once the floors/girder assemblies outside the core start to fail, the perimeter exterior frame starts to sag inward, and this is exactly what NISTs computer model shows, meaning it fails to support the notion that the perimeter could remain rigid while the interior collapses.

NISTs model also fails to show the free fall collapse, and NIST was on record saying free fall would be impossible, before Chandler proved it.

In the end the problem is that NISTs work did not explain the observed phenomena of the collapse, such as the symmetric free fall, which is what it was supposed to do. NIST failed big time.

Don´t you think it would be more fitting to ask for a real independent scientific investigation to find out what really happened, rather than laymen and anonymous forum posters making up imagined stories of what could have happended?

I am not anonymous to Chris and seeing you and Tony had the weld shear argument totally
backwards, asking for an investigation of known engineering, is fool hardy.

If you wish to continue your CD. Fantasy, you simply have to debunk rapid weld and connection failure.

 

[ozeco41]

...If you wish to continue your CD. Fantasy, you simply have to debunk rapid weld and connection failure.

Not quite. You are being too generous.

He (they) have to prove CD.

They cannot do that which is why we see them encouraging all this circling discussion of details.

 

[chrismohr]

Well Chris, the important thing to remember is that NIST admits it found no evidence that burning debris from the Towers started fires in WTC7, or that fires spread from floor to floor. You are free to look into the data yourself and come to a different conclusion, but when you do that you have to make sure to clearly note that your conclusion is not NISTs conclusion because it found no evidence to support it. You have a BIG problem because several of your forum buddies like to conflate their own opinions with NISTs report, giving the false idea that NIST supports what they are saying, and then you trust them and make their opinions your own.




I looks to me that you are imagining the 4 corners supporting each other with rigid perimeter frame "walls" between them. The problem is not the corners, but the 47 story high walls, which are way too tall and wide to remain rigid without support from the core. Once the floors/girder assemblies outside the core start to fail, the perimeter exterior frame starts to sag inward, and this is exactly what NISTs computer model shows, meaning it fails to support the notion that the perimeter could remain rigid while the interior collapses.

NISTs model also fails to show the free fall collapse, and NIST was on record saying free fall would be impossible, before Chandler proved it.

In the end the problem is that NISTs work did not explain the observed phenomena of the collapse, such as the symmetric free fall, which is what it was supposed to do. NIST failed big time.

Don´t you think it would be more fitting to ask for a real independent scientific investigation to find out what really happened, rather than laymen and anonymous forum posters making up imagined stories of what could have happended?

Anonymous Ziggi,
NIST did say "it is possible that potential ignition sources entered WTC 7 through openings created in the south and west faces of the building during the collapses of the towers. ... the available data suggests that this was highly likely." Whether fires were started by the Tower collapse or arsonists is secondary to whether the whole perimeter wall coming down as a unit is evidence of CD and simultaneous destruction of columns.
I have seen the Shyam Sunder video where he said freefall of Building 7 would be impossible, and he explains why as if he were you! When NIST's final report said that these 2.25 seconds of freefall were consistent with their prior explanations, I believe that was a mistake which explanations from JREF people were unconvincing. You're right about that, in my opinion. And BTW I asked NIST about this problem and never got a satisfactory reply.
You say, "The problem is not the corners, but the 47 story high walls, which are way too tall and wide to remain rigid without support from the core." But we have the observed phenomena of the two penthouses collapsing (we don't know for sure how far down). I hypothesized that the corners would provide a few flimsy seconds of support to help keep the perimeter wall standing for a short time.
But if you believe in CD, how do you explain that it sure looks to me like a core collapse preceded the perimeter wall collapse? Seems like there is the same problem whether it's CD or natural collapse. In your CD scenario, how does the wall remain standing even after the core has at least a partial or maybe total collapse (we can't see and assert with certainty)?
BTW from the very beginning, when I debated Richard Gage in 2011, I said I was not a defender of the NIST Report, but an advocate for natural collapse of the buildings. As just one example, JSanderO has a very different collapse scenario based on his research. I won't say that his is better or worse than NIST's, because again I am no engineer. And CTBUH had its suggestions for improvements on the NIST Report. The NIST Report doesn't have to be perfect. The bar for me for wanting a new investigation would be positive evidence of CD, such as tons of thermite in the dust, or CD devices in the debris, or melted ends of the columns, or any number of things for which no evidence has been found, in my opinion. Another bar would be even one of those investigations by Purdue, Hawaii, CTBUH, or any other major organization proclaiming that the NIST Report is fatally flawed. Not one major organization anywhere has said this! Everyone agrees with the basic collapse scenario and questions only some of the details.

 

[Crazy Chainsaw]

Not quite.

He (they) have to prove CD.

They cannot do that which is why we see them encouraging all this circling discussion of details.

I agree, they seem to be propagating a lot of nonsense, maybe they could hire a qualified engineering professional to explain it to them.

Hopefully Tony and Ziggi will continue promoting 9/11 truth and never actually build anything, them building a high rise would scare the gadzoodles out of me.

 

[Dave Rogers]

Hopefully Tony and Ziggi will continue promoting 9/11 truth and never actually build anything, them building a high rise would scare the gadzoodles out of me.

Tony wouldn't actually build a high rise, he'd just post a load of opinions explaining why it isn't possible to build one. And Ziggi would show us all an empty plot and proudly tell everyone he'd built a high rise there.

Dave

 

[ozeco41]

Tony wouldn't actually build a high rise, he'd just post a load of opinions explaining why bare assertions claiming that it isn't possible to build one. And Ziggi would show us all an empty plot and proudly tell everyone he'd built a high rise there whilst gratuitously insulting everyone who knows what they are talking about and therefore disagrees with his nonsense.

Dave

FTFY Dave.

 

[Tony Szamboti]

I know Tony and Ziggi consider it impossible that the asymmetrical interior collapse could have been followed by a symmetrical perimeter collapse. I guess the one thing we have in common is incredulity. But coming back to the question I started dealing with, maybe I'm not really qualified to understand why an asymmetrical interior collapse HAS to create an asymmetrical perimeter wall collapse, and also why six seconds of so of hanging up there with no lateral support from the interior is so impossible? Especially because there was at least some lateral support from the two perimeter walls perpendicular to it. At least it wasn't completely standalone...

Chris, all one needs to do to see that what you are saying here is impossible is to look at the NIST model. The east side exterior starts to deform radically well before the west side interior has collapsed.

The 144 foot width and average 300 foot length of WTC 7 would have been too great a distance for the exterior walls to support each other without lateral support for a large number of stories.

Additionally, your notion doesn't explain no deformation while there would have been pull-in forces high in the building.

What I am saying is the complete core was dropped somewhat low in the building (probably within the non-fire floors 14 to 18, 20, 21, and 23) and it pulled the entire exterior inward at those floors, resulting in a symmetric free fall collapse of it. Unfortunately, this area of the building is not observable on video during the collapse.

 

[Tony Szamboti]

I agree, they seem to be propagating a lot of nonsense, maybe they could hire a qualified engineering professional to explain it to them.

Hopefully Tony and Ziggi will continue promoting 9/11 truth and never actually build anything, them building a high rise would scare the gadzoodles out of me.

Given that you admit you aren't an engineer it is curious that you feel qualified to say what constitutes a qualified engineering professional.

 

[Ape of Good Hope]

Chris,

Tony,