Critical Errors and Omissions in WTC7 Report Uncovered

[qed]

It is not possible for the beams to have expanded much more than 4.67 inches though. And NIST said that when they got to 5.5 inches the girder failed. But then they found that was a 'typo' when challenged and changed it to 6.25 inches, which is impossible as they say that steel sags at over 600C. So what we have learnt here is that NIST are not very good at reading structural drawings, doing math, or citing correct initiating events., amongst other things.

How does NIST calculate 6.25 inches expansion. If they fixed a "typo" from 5.5in did they change the calculation?

 

[Representative Press]

The sources are the structural drawings for WTC7. Go to the first post in this thread and look at the 4 videos if you need a more in depth analysis of NISTs collapse initiation hypothesis. You need to watch the videos, and also have a clue about NISTs report as a whole.

NIST NCSTAR 1-9, WTC Investigation p349 says "Based on fabrication shop drawings (Frankel 1985)"

It does not appear that the video is talking about the same drawings because it says "source Frankel 1091" @ 1m59s into your video:

Why don't you tell us the specific page numbers of the specific NIST reports you are talking about so we don't have to hunt around guessing what it is you are referring to? What you are doing isn't research science paper caliber. I shouldn't have to hunt around guessing what you are citing. Just cite the specific place you are getting the information you are disputing.

 

[gerrycan]

How does NIST calculate 6.25 inches expansion. If they fixed a "typo" from 5.5in did they change the calculation?

No, they just said that they got the initial 5.5 wrong, but they do not address the consequences of the new 6.25" walk distance required. They initially got the 5.5" from the fact that they said that the plate (pf) in the drawing was 11" wide. So they supposed that the girder would fail when it got half way. As you can see though the plate is actually 12" according to the structural drawings themselves.

 

[gerrycan]

NIST NCSTAR 1-9, WTC Investigation p349 says "Based on fabrication shop drawings (Frankel 1985)"

It does not appear that the video is talking about the same drawings because it says "source Frankel 1091" @ 1m59s into your video:

Why don't you tell us the specific page numbers of the specific NIST reports you are talking about so we don't have to hunt around guessing what it is you are referring to? What you are doing isn't research science paper caliber. I shouldn't have to hunt around guessing what you are citing. Just cite the specific place you are getting the information you are disputing.

These elements that make up the connection are cited on more than one drawing. Structural drawings differ depending on what they are there to show. Some are floor framing plans eg E12/13, some are Connection details like 1091. You should note that 1985 refers to the year, NOT the drawing number.

 

[qed]

No, they just said that they got the initial 5.5 wrong, but they do not address the consequences of the new 6.25" walk distance required. They initially got the 5.5" from the fact that they said that the plate (pf) in the drawing was 11" wide. So they supposed that the girder would fail when it got half way. As you can see though the plate is actually 12" according to the structural drawings themselves.

But surely at some point there must be a calculation of girder expansion at 600 degrees that yields 5.5'' or 6.25''? Or am I missing the point?

 

[Jazzy]

Then why didn't their simulation account for the whole floor accurately?

Compared with your standards, NIST's accuracy was perfect. In fact it was as reasonably perfect as one might expect from truly talented programmers operating brilliant equipment. It would be unreasonable to expect greater precision (unless I managed that operation). But I waste my time talking to you about it.

A third problem is that NIST's claim that steel beams expanded enough to cause such damage is dependent on a finding of its computer simulation, according to which the shear studs connecting the steel beams to the concrete floor slabs failed because the steel beams expanded further and more quickly than the concrete slabs. This was a surprising
result, given the fact that steel and concrete, when heated, expand virtually the same amount. The result becomes less surprising, however, when we learn that NIST, while running its simulation, "heated" only the simulated steel, not also the simulated concrete, even though an actual fire in the real building would have heated the actual concrete as well as the actual steel. It was only through this chicanery, evidently, that the simulation predicted the failure of the shear studs.

Not too surprising, actually, that that worked to reveal the the studding weakness. Steel does pick up heat faster than concrete does. And, hey, they didn't do what you said in the final test.

A fourth problem involves a second instance of fraud involving shear studs. NIST's finding in its computer simulation that the girder connecting Columns 44 and 79 failed is dependent on its claim that, although shear studs were used to connect the beams to the floor slabs, they were not also used to connect the girders to the slabs. But NIST's Interim Report on WTC 7, released back in 2004, stated that shear studs were used to connect the girders (as well as the beams) to the floor slabs. Once we are aware of this and the previous three problems in NIST's theory of how the global collapse of WTC 7 began, we can see that it is completely unworthy of credence. (The Mysterious Collapse of World Trade Center 7: Why the Final Official Report about 9/11 is Unscientific and False (Kindle Locations 3241-3250)
Griffin, David Ray (2012-12-30))[/ex]

The studs weren't the major problem by a long walk.

Apparently by your own standards, it's unrealistic to fail to consider the whole floor.

It's true. It's one of several scenarios they created which I disagree with.

I believe it - There is that.

There is indeed. It's still the most credible version I have met.

 

[gerrycan]

But surely at some point there must be a calculation of girder expansion at 600 degrees that yields 5.5'' or 6.25''? Or am I missing the point?

You would have thought they would have calculated this, but in fact they did not. In their initial calculation, they used the equation for unrestrained expansion, they didn't take into account ambient temp, and still they were struggling to get anything like 5.5". They really blew it when they admitted it would take 6.25" though, because the stiffener plates on the girder (which they also omitted from their analysis), would extend the walk off distance to somewhere nearer 9 inches. They are refusing to respond now or even acknowledge that the stiffener plates exist.

 

[Representative Press]

These elements that make up the connection are cited on more than one drawing. Structural drawings differ depending on what they are there to show. Some are floor framing plans eg E12/13, some are Connection details like 1091. You should note that 1985 refers to the year, NOT the drawing number.

What page number of what report are you taking information from? Is that a difficult question to answer? I'm doing a search for "1091" of the NIST reports I have and find nothing, maybe I am not looking in the right place? If Richard Gage can repeatedly point to the wrong computer model, I don't think I should assume the people who put the info together for your video did good research. Citing the page number of the report you are disputing is bare minimum if you want people to take your "technical level" videos seriously and be able to evaluate them accurately.

 

[Jazzy]

Is there somewhere in the NIST report that actually claims a longer expansion?

While the summary of the damages in case C, listed of NCSTAR 1-9 do say that
(Page 514, pdf 580)
https://www.metabunk.org/files/NCSTAR_1-9_WTC7_unlocked.pdf

Summary. After 4.0 h of heating, Column 81 had lost lateral support in the north-south direction at Floor
13, due to failure of the girders framing into Column 81. The girders between Columns 26 and 81 and
Columns 80 and 81 had buckled and the girder between Columns 79 and 44 had walked off the seated
connection at Column 79. In addition, all 4 bolts had failed at the seated connection at Column 79 on
Floor 14. Approximately one-half to three-quarters of the east floor beams had a connection damage
level of 0.75 to 1.0 on Floors 11, 12, and 14. All of the east floor beams, except for one, had failed on
Floor 13.

They give a lot more detailed description of this later in chapter 8, and the unseating the the 79->44 girder is attributed to the buckling failure of the beams after the initial failure of the shear studs. NOT the expansion of the beams, which only is required to break the shear studs.

NCSTAR 1-9 Page 352 (pdf 396)
View attachment 4130

The predicted response of the system is summarized in Table 8–2. The first failures observed were of the
shear studs, which were produced by axial expansion of the floor beams, and which began to occur at
fairly low beam temperature of 103 °C. Axial expansion of the girder then led to shear failure of the bolts
at the connection to Column 79; and, at a girder temperature of 164 °C, all four erection bolts had failed,
leaving that end of the girder essentially unrestrained against rotation. Continued axial expansion of the
floor beams pushed the girder laterally at Column 79, as shown in Figure 8–26, in which failed shear
studs and bolts were evident. When the beam temperatures had reached 300 °C, all but three shear studs
in the model had failed due to axial expansion of the beams, leaving the top flanges of the beams
essentially unrestrained laterally. Continued axial expansion of the girder caused it to bear against the face
of Column 79, generating large axial forces that led to failure of the bolts connecting the girder to Column
44. When the girder temperature had reached 398 °C, all four erection bolts at Column 44 had
failed, leaving the girder essentially unrestrained against rotation at both ends. After failure of the erection
bolts in the seat at Column 44, continued axial expansion of the floor beams pushed the girder laterally,
where it came to bear against the inside of the column flange. Axial compression then increased in the
floor beams, and at a beam temperature of 436 °C, the northmost beam began to buckle laterally.
Buckling of other floor beams followed as shown in Figure 8–27 (a), leading to collapse of the floor
system, and rocking of the girder off its seat at Column 79 as shown in Figure 8–27 (b). The collapse
process took time to occur in the LS-DYNA analysis, during which the temperatures had ramped up to
their maximum values in the simulation.

So where is the long expansion needed?

Frankly, Mick, I haven't a clue. It seems to me that when you consider everything that was going on at that particular time, that anyone made sense of what occurred is a marvel.

That others make nonsense of it is hardly surprising. It is surprising, however, that they produce it within Metabunk.

 

[gerrycan]

What page number of what report are you taking information from? Is that a difficult question to answer? I'm doing a search for "1091" of the NIST reports I have and find nothing, maybe I am not looking in the right place? If Richard Gage can repeatedly point to the wrong computer model, I don't think I should assume the people who put the info together for your video did good research. Citing the page number of the report you are disputing is bare minimum if you want people to take your "technical level" videos seriously and be able to evaluate them accurately.

Ok, I will remain polite here. 1091 is the number of a structural drawing, not a page number. and just in case you didn't notice frankel 1985 refers to the year that set of drawings was released. Again, you are not debating Gage here, you are debating me, or trying to.

 

[gerrycan]

Frankly, Mick, I haven't a clue. It seems to me that when you consider everything that was going on at that particular time, that anyone made sense of what occurred is a marvel.

That others make nonsense of it is hardly surprising. It is surprising, however, that they produce it within Metabunk.

I agree with one sentence in there. NIST actually used the reference for column 81 to model 79 for some strange reason, so you will need to look again jazz. Guess what size the seat plate is for column 81? 11 inches.

 

[Representative Press]

Ok, I will remain polite here. 1091 is the number of a structural drawing, not a page number. and just in case you didn't notice frankel 1985 refers to the year that set of drawings was released. Again, you are not debating Gage here, you are debating me, or trying to.

And I have no evidence that the particular drawing was used in the final construction or in the NIST report. Presumably you are disputing something NIST claims, then you should be able to point to where those claims are made. Not every drawing is the final drawing, and a particular drawing may not even be the one used in the final design. If you are so familiar with this topic, then why can't you just say "on this page of this report NIST claims such and such." If this is so "technical" then act like it and provide the sources.

 

[gerrycan]

And I have no evidence that the particular drawing was used in the final construction or in the NIST report. Presumably you are disputing something NIST claims, then you should be able to point to where those claims are made. Not every drawing is the final drawing, and a particular drawing may not even be the one used in the final design. If you are so familiar with this topic, then why can't you just say "on this page of this report NIST claims such and such." If this is so "technical" then act like it and provide the sources.

I think we are done here rep to be honest. The drawings that NIST used are the ones that I use, and they came from NIST. If you think I am just making stuff up, you need to go and substantiate that and bring some evidence. If you want to defend NISTs report, you have to read it, and if you want to dispute what is in the drawings that I cite and are clear enough on the screen in the 4 previous videos, then go and get the drawings for yourself and look at them.

 

[qed]

The drawings that NIST used are the ones that I use, and they came from NIST. If you think I am just making stuff up,

How did you get them?
Do you have copies on you to reproduce for us?

 

[qed]

Mike [edit Mick], is this satisfactory? For a moment there I wasn't sure what the response would be.

 

[gerrycan]

Mike, is this satisfactory? For a moment there I wasn't sure what the response would be.

I guess i probably should have checked, these links start a torrent, providing you have bit torrent or similar to get them. Mick ? This is the main page of the site, from which you can navigate to the structural drawings torrent links. http://911datasets.org/index.php/Main_Page
I deleted the last post containing the direct links, if anyone needs help getting to the drawings, let me know and I will try to help.

 

[Representative Press]

I think we are done here rep to be honest. The drawings that NIST used are the ones that I use, and they came from NIST.

You came on here claiming technical videos. What you are doing is rude. It is not too much to ask in the slightest bit to ask you to provide a source for what it is you are specifically disputing which you claim NIST says. Scientists don't behave the way your are behaving, you should be able to cite your sources, it is you that posted this thread making claims, the first two of which I debunked. When technical research is put together, scientists don't respond with "I think we are done here" when they are asked for the sources. Considering your reaction to the debunking of your first two specific claims ("fell so rapidly and symmetrically") I guess I shouldn't be surprised.

BTW, I am able to give people sources for what I post and what I put in my videos.

 

[qed]

@Representative Press

Do you accept the evidence provided?

 

[gerrycan]

You came on here claiming technical videos. What you are doing is rude. It is not too much to ask in the slightest bit to ask you to provide a source for what it is you are specifically disputing which you claim NIST says. Scientists don't behave the way your are behaving, you should be able to cite your sources, it is you that posted this thread making claims, the first two of which I debunked. When technical research is put together, scientists don't respond with "I think we are done here" when they are asked for the sources. Considering your reaction to the debunking of your first two specific claims ("fell so rapidly and symmetrically") I guess I shouldn't be surprised.

BTW, I am able to give people sources for what I post and what I put in my videos.

See above for link to the set of released structural drawings for WTC7, and for NISTs report go to NISTs site. You clearly don't trust me, why would you ask me to do your research for you? As for WTC7 i think it did fall too rapidly and too symmetrically, not perfectly symmetrically, just TOO symmetrically.

 

[Representative Press]

@Representative Press

Do you accept the evidence provided?

I don't know why I am expected to go on wild goose chases, why can't a specific page of a specific document be cited? How are you guys construing it as too much to ask, I am not going to hunt down sources for claims you guys make. cite the evidence of specifically what you claim NIST says and what you think disputes that. If you guys are so into this, then what I ask shouldn't be a problem. Frankly, the fact that those videos have all the clips starting after the actual start of the collapse is a tip off to just how credible they are. I doubt the claims made in the video are accurate.

"
I don't believe that the presence of studs in the girder would have changed the analysis results to any significant degree, as suggested by Fig. 11-9 of NCSTAR1-9 pg. 476 (Vol 2., pdf pg 138), which shows the location of the modeled studs. Note the proximity of shear studs on the ends of the floor beams to the girder. Those studs tie the concrete to the floor beams, which are tied to the girder. Ergo, in the model, the concrete is still proximally tied to the girder thru the beams.

Until the expansion causes the studs to shear. If present, studs in the girder would have sheared in the girder (or pulled out of the concrete) at a very low temperature. (See section 8.7.4 & the calculation (4) on page 347.)

IMHO, their presence in the girder could have caused the girder to roll about its long axis prior to shearing. Possibly causing the girder to fall off of its seat at a lower temperature than NIST predicted."
" http://www.internationalskeptics.com/forums/showthread.php?postid=6416225#post6416225

 

[Representative Press]

LOL @ you "debunking" anything when you clearly demonstrated that you didn't even have a basic understanding of what was being discussed. Throwing straws about penthouse and secret agents and claiming to have debunked something. You only made yourself look like a fool.

Tangled Webs NIST and WTC7 @ 4:31 the video deceptively asks people to compare WTC5 to WTC7 and it gives the false impression that no steel failed and collapsed within WTC5. I would say that these videos are unscientific. The videos in the playlist continually omit the penthouse collapsing and give a false collapse time. I can't see why you are impressed with these video's accuracy.

"Of particular concern are the effects of thermal expansion in buildings with one or more of the following characteristics: long-span floor systems, connections that cannot accommodate thermal effects, floor framing that induces asymmetric forces on girders, and composite floor systems, whose shear studs could fail due to differential thermal expansion (i.e., heat-induced expansion of material at different rates). Engineers should be able to design cost-effective fixes to address any areas of concern identified by such evaluations." -NIST Questions and Answers about the NIST WTC 7 Investigation

I think it makes more sense to assume NIST knows what they are talking about rather than those responsible for the video and its promotion.

 

[gerrycan]

Tangled Webs NIST and WTC7 @ 4:31 the video deceptively asks people to compare WTC5 to WTC7 and it gives the false impression that no steel failed and collapsed in WTC5. I would say that these videos are unscientific. The videos in the playlist continually omit the penthouse and give a false collapse time. I can't see why you are impressed with these video's accuracy.

The video shows both buildings and says that there were serious fires in wtc7 as well, it goes on to show the two buildings afterwards, one of which is still standing. You are free to draw your own conclusions. Have you seen the drawings for either?

I think it makes more sense to assume NIST knows what they are talking about rather than those responsible for the video and its promotion.

You should be able to assume this and trust NIST, I agree. But you cannot. These are the people who cannot tell the difference between 11" and 12" on a bill of materials. NIST also missed out vital structural elements at that column and made glaring errors like getting 5.5 mixed up with 6.25. This is pretty basic stuff that is addressed in the videos, and you can also see the erratum statement that NIST were forced to release. Does this sound like an agency you can trust? Very dangerous assumption you got there rep, and one that has been proved to be in error. Watch the rest of the videos.

 

[xenon]

All this talk of girders, flanges and slippage is fascinating but can everyone agree that WTC7 fell at free fall speed for close to 5 seconds? That's what NIST says.

How can that happen if a beam or girder slips?

 

[Representative Press]

"The 5.5 in. dimension was the length of the girder bearing on the seat connection that had to slide off the seat axially to the girder. The 6.25 in. dimension accounted for the length from the flange tip to the far side of the web, so that the web was no longer supported on the bearing plate. This change corrects a typographical error which showed a lateral displacement of 5.5 in. instead of the correct value of 6.25 in., which was used in the analyses."

"The 16-story model of WTC 7 used a 12 in. bearing plate on the north side of Column 79, consistent with Frankel drawing 1091. The 5.5 in. dimension was incorrectly cited, as the 6.25 in. dimension accounted for the lateral walk-off distance. These changes correct typographical errors. The dimensions and lateral displacements used in the analyses were correct."

Why exactly is this supposed to be a smoking gun?

 

[gerrycan]

All this talk of girders, flanges and slippage is fascinating but can everyone agree that WTC7 fell at free fall speed for close to 5 seconds? That's what NIST says.

How can that happen if a beam or girder slips?

This thread is really about the initiation of collapse, but yes, the building accelerated at the rate of gravity for at least 2.25s. The issues re the girder etc are crucial to NISTs story and represent the evidence that really scares NIST. If freefall scared them, they wouldn't have admitted it so easily.

 

[gerrycan]

"The 5.5 in. dimension was the length of the girder bearing on the seat connection that had to slide off the seat axially to the girder. The 6.25 in. dimension accounted for the length from the flange tip to the far side of the web, so that the web was no longer supported on the bearing plate. This change corrects a typographical error which showed a lateral displacement of 5.5 in. instead of the correct value of 6.25 in., which was used in the analyses."

"The 16-story model of WTC 7 used a 12 in. bearing plate on the north side of Column 79, consistent with Frankel drawing 1091. The 5.5 in. dimension was incorrectly cited, as the 6.25 in. dimension accounted for the lateral walk-off distance. These changes correct typographical errors. The dimensions and lateral displacements used in the analyses were correct."

Why exactly is this supposed to be a smoking gun?

The fact that the expansion of 6.25" in the beams would take a temperature above that which NIST said existed, and also a temperature at which they said themselves would cause the beams to sag and not push. Also, had the 2 stiffener plates been included in their analysis the required distance for the walk off would be at least 9". With respect, you really need to watch the whole lot, then get back to me.

 

[Representative Press]

but can everyone agree that WTC7 fell at free fall speed for close to 5 seconds? That's what NIST says.[/media]

No, NIST is measuring a point on the exterior of the building after the collapse has started.


If I have 2 weights tied by a rope together on a table & I push one off the side of the table, it is not strange to think that the second weight might be accelerated by the first one faster for a few seconds as the initial jerking motion of the first weight tied to the rope pulls on the second.


The exterior columns then buckled as the failed building core moved downward, redistributing its loads to the exterior columns. " NIST NCSTAR 1-9 Vol 2 pp617-618 WTC Investigation


see https://www.metabunk.org/threads/cr...-wtc7-report-uncovered.2332/page-6#post-69143

 

[xenon]

This thread is really about the initiation of collapse, but yes, the building accelerated at the rate of gravity for at least 2.25s. The issues re the girder etc are crucial to NISTs story and represent the evidence that really scares NIST. If freefall scared them, they wouldn't have admitted it so easily.

Fine but I'm just saying, how can free fall happen in the first place? The initiation of collapse is the point. Even if the initiation of the collapse happened the way NIST says how can free fall be possible?

And I'm not so sure the admission was easy. But I don't know enough about it yet. That's why I'm here.

 

[Representative Press]

The fact that the expansion of 6.25" in the beams would take a temperature above that which NIST said existed, and also a temperature at which they said themselves would cause the beams to sag and not push. Also, had the 2 stiffener plates been included in their analysis the required distance for the walk off would be at least 9". With respect, you really need to watch the whole lot, then get back to me.

where does NIST say that? What page does NIST say the temp of x made expansion go to x?

 

[gerrycan]

where does NIST say that? What page does NIST say the temp of x made expansion go to x?

I wouldn't trust NIST, better to go to the drawings, measure the elements and do the analysis yourself and produce the results. If you disagree with the figures that are clearly there on the video, or the equation, just say where you disagree and why.

 

[xenon]

No, NIST is measuring a point on the exterior of the building after the collapse has started.


If I have 2 weights tied by a rope together on a table & I push one off the side of the table, it is not strange to think that the second weight might be accelerated by the first one faster for a few seconds as the initial jerking motion of the first weight tied to the rope pulls on the second.


The exterior columns then buckled as the failed building core moved downward, redistributing its loads to the exterior columns. " NIST NCSTAR 1-9 Vol 2 pp617-618 WTC Investigation


see https://www.metabunk.org/threads/cr...-wtc7-report-uncovered.2332/page-6#post-69143

Can you point to other similar occurrences?

There should be a few, no? It's not like there haven't been other major even more serious high rise fires.

Like Torre Windsor in Spain:

Or the Beijing Television Cultural Center fire

Edit to add: Here's a list of many others.
http://en.wikipedia.org/wiki/Skyscraper_fire

 

[gerrycan]

Fine but I'm just saying, how can free fall happen in the first place? The initiation of collapse is the point. Even if the initiation of the collapse happened the way NIST says how can free fall be possible?

And I'm not so sure the admission was easy. But I don't know enough about it yet. That's why I'm here.

You're right they were kind of backed into a corner. David Chandler was the man who forced them into the statement, which is an important one. What we have found is sort of different though. We have found that they left whole elements out of the very part they said caused the building to fail, and this is provable by way of the drawings for the building, and I am keen to see what people make of this. Didn't mean to be short with ya, and well done for looking into this whole thing.
maybe this thread https://www.metabunk.org/threads/the-uniqueness-of-the-wtc7-collapse.1972/page-14#post-69275
or this one https://www.metabunk.org/threads/significance-of-wtc7.2489/
would be a better place for the freefall thing. I might well join you there.

 

[Representative Press]

I wouldn't trust NIST, better to go to the drawings, measure the elements and do the analysis yourself and produce the results. If you disagree with the figures that are clearly there on the video, or the equation, just say where you disagree and why.

What a minute, what is the basis for the claim that NIST is saying a temp of x made the expansion go to x? Where is the data for how much force the girder would have even if it is loosing strength at what ever given temp? Where are you getting this data from? Where is the source for the spread sheet in the video? I don't see why you think scientists working for NIST would feel it necessary to report anything other than what their research found. On what basis would they assume something shouldn't be revealed?

 

[Representative Press]

You're right they were kind of backed into a corner.

I think you don't understand what I have repeatedly explained and what is not shown in the videos clips featured in both Chandler's video and the playlist you posted. The collapse was already underway, t=0 is what Chandler assumed was the start of the collapse but that was only for a chart which NIST created to do analysis on the video clip conspiracists asked NIST to study. t=0 is not the start of the collapse and it is not odd at all that PART OF the collapse, a point measured on the exterior, could be yanked down faster as the internal elements pulled on the exterior.

 

[gerrycan]

What a minute, what is the basis fro the claim that NIST is saying a temp of x made the expansion go to x? Where is the data for how much force the girder would have even if it is loosing strength at what ever given temp? Where are you getting this data from? Where is the source for the spread sheet in the video? I don't see why you think scientists working for NIST would feel it necessary to report anything other than what their research found. On what basis would they assume something shouldn't be revealed?

Thermal expansion rates in steel are not state secrets. The data comes from the structural drawing dimensions, and accepted equations. Where do you think the spreadsheet is wrong. We have had it checked independently, what do you see as a problem with it and why? Do you want to talk to the team who did the analysis with us?

 

[gerrycan]

I think you don't understand what I have repeatedly explained and what is not shown in the videos clips featured in both Chandler's video and the playlist you posted. The collapse was already underway, t=0 is what Chandler assumed was the start of the collapse but that was only for a chart which NIST created to do analysis on the video clip conspiracists asked NIST to study. t=0 is not the start of the collapse and it is not odd at all that PART OF the collapse, a point measured on the exterior, could be yanked down faster as the internal elements pulled on the exterior.

we'll deal with freefall once we have dealt with the initiating event, let's take it one thing at a time, or maybe we could discuss this on your thread here https://www.metabunk.org/threads/significance-of-wtc7.2489/ ??

 

[gerrycan]

Sorry for not replying to this sooner..........

@gerrycan (ignoring RP and jazzy)

1. Are you saying that the NIST report does a calculation of girder expansion at 600 degrees and come up with the number 5.5in and this is just the right number for 5.5+5.5=11, where 11in is the distance needed to walk off the platform?

1. NIST, in their analysis said that the girder was at 500 and the beams were at 600. They also asserted that the underseat plate, that the girder was bolted to was 11" wide. Half of that 11" was where the 5.5 came from. They supposed the failure would occur because the load would be transferred to the bottom flange at the point once the web was no longer above the plate.

2. Are you also saying that that, because of a structural issue they overlooked, they should have used 12in for the distance needed to walk?

3. Not quite, the plate on the bill of materials on the relevant drawing is shown as 12". You can see that here, the plate is called out as 'pf' : http://i238.photobucket.com/albums/ff290/gamolon/frankelcolumn79b.png
4. That would take the halfway point to 6, so make it even less possible to have failed because the beams just can't expand that much (beyond 600 the beams would begin to sag according to NIST). About 4.7" is even an optimistic estimate. NIST were approached re the seat plate error and suddenly found that there had been a couple of typos in their analysis and suddenly the walk off distance should have been 6.25" and then released an erratum statement to that effect. This dig them into a deeper hole though as that distance is even more impossible for these beams. Then one of the guys noticed the stiffener plates. What these plates would do is to transfer the load from the bottom flange of the girder back through the web, so increasing the distance required for 'walk off' to somewhere in excess of 9". This knocked the NIST hypothesis out cold, taking it from being unlikely, via impossible, to obviously impossible by a factor of over 2. Beyond reasonable doubt. At this point NIST stopped responding to us. I wonder why.

5. Are you also saying NIST re-worked the original calculation of girder expansion to obtain 6in?

   The new distance they quoted was actually 6.25", they provided no calculations for this because if they had, they would have had to have the beam at a temp way beyond that which they said existed, and way beyond that at which they said the beam would start to sag and therefor no longer push. And even if they had contradicted themselves in this way, the stiffeners take the required walk off distance to far beyond 6.25", so they must have decided that the best policy on their part was to stop digging a hole for themselves at that point.

Sorry for the long winded answer, but I hope that clears things up, and is useful for those here who haven't seen the videos yet. There's a bit more to it than this and obviously, but I think it's a fair summary.

 

[jomper]

WTC 7 did not fall... "symmetrically."

The building frame began to drop with a significant degree of symmetry to the roofline. Combined with the period of free-fall acceleration, that symmetry is significant enough to cause any reasonable person viewing the video footage of WTC 7 collapsing for the first time to ask if it was in some way an engineered event. On this basis alone your claim to have addressed gerrycan's analysis of the NIST report is tenuous at best.

If you want to quibble about this why not do it in the thread Mick has made for you to quibble in.

 

[Jazzy]

There are no stiffener plates in NISTs analysis, and also none on your diagram, thanks for making my point jazzy. This is exactly the kind of critical error by NIST that i am talking about, and exactly the kind of error that makes your assertion false on all counts.

The plates weren't in any way critical.

Your exploration is one-dimensional, bearing no relationship whatsoever to the real situation occurring in WTC7 which involved peripatetic fires wandering within it causing compression and distortion by expansion and creep.

NIST was fully aware of the complexities involved, and their description of events occurring around column 79 allows for that, and what they describe in no way allows for a description of the girder length over-run to be described as "critical". Mentioning that over-run as being the initiation of collapse was probably correct, but their representation of the state of the floor at that moment positively demonstrates that the condition of that girder wasn't essential to collapse, as the whole floor was on its way out. It would simply have torn that final connection away in moments, had it been "good".

What happens after that? Well, we know what you think - that there's no such thing as column instability, and that NIST "makes such things up", as they just have with the girder over-step.

When Floor 13 fell and took out the Floor 12 connection, Column 79 was toast. Its stability fell to one-eighteenth of its original value, and that's a figure outside its safety factor.

It seems that, now you think you have succeeded so far, we're going to enter another phase of rejection of buckling theory, refusal to accept that the collapse of the exterior face (the only part of the building standing) was not the collapse of the building, that the penthouse wasn't resting on its supporting columns, and all that balderdash.

Then there's your way of dealing with discussion...

 

[Hitstirrer]

I have followed this thread with interest and seen many members come to understand the simple point being made by gerry. I have also seen others refuse to address that simple pont being made.
All that gerry is saying is that NIST's final report specifically says that the initiation of global collapse was when a girder spanning from column 79 to column 44 on floor 13 dropped from its seat at the 79 end. They then say that the girder fell onto floor 12 causing other floor systems below to also fail, rendering column 79 unsupported laterally over many floors. NIST then says that column 79 buckled due to its lack of lateral support, and eventually that led to the global collapse.
Using basic logic it is therefore not hard to conclude that if that girder had not dropped it could not have hit floor 12. Lower floors could not have been compromised by that cascade effect. Column 79 could not have lost its lateral support over many floors. And global collapse could not occur due to that column failure.
What gerry's research appears to have uncovered is evidence that NIST reached the conclusion about the column 79 floor 13 initiation event based on incorrect data concerning the construction of that connection.
Structural Engineers who have examined gerry's evidence have said that the connection could not have failed at the temperatures admitted by NIST if the correct elements had been in place. FEA has confirmed their opinion. Gerry's videos and explanations develop his argument in support of their opinions and explain to non professionals in layman terms why the omission of 'stiffener' plates in NIST's report are of such importance.
I had hopes that serious forums such as this one would have the maturity to discuss the implications of this research and address the issues raised. What I have observed is numerous attempts to derail the thread by introducing spurious 'strawman' ploys, and then demands to be spoonfed with information. I have seen attention diverted to focus on the penthouse, and then the freefall issue. Is it asking too much to concentrate of the very specific points raised by gerry in this thread ?

There has to be a great deal of expertise available in this forum who are in a position to check gerry's work independently. If that reveals that there are real doubts about his information, rather than kneejerk reactions, concerning the true construction of that single failure connection, then we need to know that.