Have You Actually READ the NIST Report on Building 7?

Mick West

Administrator
Staff member
Source: https://www.youtube.com/watch?v=SxntZh8FcNo


The full NIST report on the fires and collapse of World Trade Center Building 7, NCSTAR 1-9, is nearly 800 pages long. Lots of people in the 9/11 Truth community dismiss it, but very few have even skimmed through it, let alone read the pertinent parts.

Here I do the skimming through part. I do this to give you an idea of just how large and comprehensive it it. Even in this rapid-fire overview you can see the hundred pages they spend on precisely mapping the spread of the fires, and the hundreds more on investigating the possible causes of collapse via simulations. Feel free to pause at any point. All the pages are there.

If you are going to form an intellectually honest opinion on the collapse of World Trade Center Building 7 then by all means read the information provided by Architects and Engineers for 9/11 Truth, and others. But intellectual honesty requires knowledge of other positions before you can reject them. At the very least you should start with the NIST WTC7 FAQ:
https://www.nist.gov/el/faqs-nist-wtc-7-investigation

And then watch the description of how they conducted the investigation
Source: https://www.youtube.com/watch?v=PK_iBYSqEsc


Then you will probably have questions. Be intellectually honest and unafraid. Do your own research. Read the NIST report:
http://ws680.nist.gov/publication/get_pdf.cfm?pub_id=861611
 
Thanks for the link, Mick!

Since the Husley thread, I've been thinking I should read it, but thus far I'd been too lazy to look for it.

Now I've got no excuse.
 

FFTR

New Member
Yes, I have read the NIST report. The finding of fire as the probable cause of the collapse seems reasonable to me.
 

Mick West

Administrator
Staff member
A word of caution, it seems some people who think they have read the NIST report on WTC7 have actually only read the "Draft for Public Comments" version which was released on August 1 2008. The actual report has both volumes combined into one file, and was released on November 20th, 2008. Both versions are still available on the NIST site, but some other 9/11 related sites only have the older version.

There are a few differences, but of particular note is section 12.5.3, the analysis of the collapse progression. This is quite a bit more detailed in the final version.

So:

20170928-144156-lrioj.jpg
 

Mick West

Administrator
Staff member
One difference is in the diagrams showing the ANSYS damage output. The draft has a vector image, in the final this is replaced with a lower resolution bitmap which is harder to read, but also has the buckled beams differentiated from the "loss of vertical support" beams.
Move slider to compare.

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Paul Edward

New Member
Can anybody give me a version history of the NIST WTC7 report?

I've seen Truthers whining about NIST constantly changing their story. They say when the few seconds of freefall was pointed to them they hastily revised the report to downplay this, blah, blah.....

I've downloaded the final version of the report from the NIST website. Were there interim versions? If so what changed? Is there a detailed version history record?
 

Oystein

Senior Member
Note that they also published several "Errata" - corrections of errors - subsequent to the final report on WTC7:
https://www.nist.gov/publications/e...-1-9a-federal-building-and-fire?pub_id=901225

Those Errata were dated "(January 2009, April 2012, and June 2012)".
The June 2012 Erratum corrected typographical errors - the text as printed in the report contained wrong numbers, but these wrong numbers were not actually used in the analysis the text describes, the correct values were used.
Some truthers have made some wind about this, suspecting that NIST flat out lies and used the wrong, rather than right, values in the underlying analysis.
 

Oystein

Senior Member
Long doesn’t necessarily mean comprehensive. I could prove gravity doesn’t exist with pseudo science as well.
So: Have you actually read the NIST report on WTC7?
Do you claim it's not comrehensive, and if so, what do you base that claim on? If not, why do you bring it up?
Do you claim the NIST report is pseudo science? What do you base this on?

Do the intellectually honest thing - read the NIST report, know its structure, content, scope, method - and then point out any bunk you might think there is by properly citing it and providing reasons why you think it's bunk.

What you wrote there could be applied to any video DVD by AE911Truth or other Truthers, could be said about those just so, without watching even a single second. It's cheap rethoric, empty of actionable information. It's intellectually dishonest to dismis the report without actually reading it.
 

tavis

New Member
The final report is NCSTAR 1A and is 88 pages long. It is titled "Final Report on the Collapse of World Trade Center Building 7" and I have read my printed copy of it cover to cover several times. The publication you referenced NCSTAR 1-9 is actually the technical documentation which is summarized in the Final Report. It's interesting to dive into if you really want to get into the nitty-gritty of something specific, but NCSTAR 1A is much more realistic to digest. NCSTAR 1A is the document that's meant to be read, and it summarizes NIST's methodologies and findings in much greater depth than the FAQ.
 

Abdullah

Active Member
Yes, I have read the NIST report. But it does not seem to answer questions that are most pressing to the Metabunk user - at least not verbally. It does not explain clearly
1. How one column took down a whole building and
2. Why the building appeared to freefall for multiple storeys
The report, compared with the earlier one on the Twin Towers, strikes me as having been written by bored, exhausted people.
 
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Mick West

Administrator
Staff member

econ41

Senior Member
Yes, I have read the NIST report. But it does not seem to answer questions that are most pressing to the Metabunk user - at least not verbally. It does not explain clearly
1. How one column took down a whole building and
2. Why the building appeared to freefall for multiple storeys
The report, compared with the earlier one on the Twin Towers, strikes me as having been written by bored, exhausted people.
Be clear as to where you rank the NIST reports. For many debunkers, they are assumed to be the peak of infallible explanation. Containing ALL necessary answers and with unsurpassable accuracy. Others hold the Bazant Papers in the same degree of status. Neither of them (or any other "authority") should be given that status by a genuine sceptic - they should be as open to critique as any source. "Did xyz happen in the WTCx collapse?" is a question of fact. And a different question to "Did NIST or Bazant explain it correctly?"

Both your questions can be discussed "stand-alone" from the NIST report. OR limited to the scope of NIST. Or in debating "Is NIST's explanation correct"? I would suggest that question 2, maybe question 1, can be explained more lucidly in discussion than by limiting the explanation to the scope of the NIST report. The topic "in the wild" of online discussions has been explored far wider than what NIST says - remember that the NIST reports were the START of a lot of discussions.
 

JMartJr

Senior Member
The FAQ consists of 36 numbered questions and answers. @Abdullah asked two specific questions. Shouldn't you be as specific in your answers?
Here's what I saw, reading the FAQs looking for answers to Abdullah's two questions:

Question 1:
9. How did the fires cause WTC 7 to collapse?
The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.


According to the report's probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.


Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.

drawing
Diagram 1—Typical WTC 7 floor showing locations of columns (numbered). The buckling of Column 79 was the initiating event that led to the collapse of WTC 7. The buckling resulted from fire-induced damage to floors around column 79, failure of the girder between Columns 79 and 44, and cascading floor failures.

Credit: NIST

The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, and 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.


The probable collapse sequence is described in NIST NCSTAR Report 1A, Section 2.4 and NIST NCSTAR Report 1-9, Chapter 13.

and
31. Some people have said that a failure at one column should not have produced a symmetrical fall like this one. What is NIST's answer to those assertions?

WTC 7's collapse, viewed from the exterior (most videos were taken from the north), did appear to fall almost uniformly as a single unit. This occurred because the interior failures that took place did not cause the exterior framing to fail until the final stages of the building collapse. The interior floor framing and columns collapsed downward and pulled away from the exterior frame. There were clues that internal damage was taking place prior to the downward movement of the exterior frame, such as when the east penthouse fell downward into the building and windows broke out on the north face at the ends of the building core. The symmetric appearance of the downward fall of WTC 7 was primarily due to the greater stiffness and strength of its exterior frame relative to the interior framing.

Question 2:
32. In a video, it appears that WTC 7 is descending in free fall, something that would not occur in the structural collapse that you describe. How can NIST ignore basic laws of physics?

In the draft WTC 7 report (released Aug. 21, 2008; available at http://www.nist.gov/el/disasterstudies/wtc/wtc_draftreports.cfm), NIST stated that the north face of the building descended 18 stories (the portion of the collapse visible in the video) in 5.4 seconds, based on video analysis of the building collapse. This time period is 40 percent longer than the 3.9 seconds this process would have taken if the north face of the building had descended solely under free fall conditions. During the public comment period on the draft report, NIST was asked to confirm this time difference and define the reasons for it in greater detail.


To further clarify the descent of the north face, NIST recorded the downward displacement of a point near the center of the roofline from first movement until the north face was no longer visible in the video. Numerical analyses were conducted to calculate the velocity and acceleration of the roofline point from the time-dependent displacement data. The instant at which vertical motion of the roofline first occurred was determined by tracking the numerical value of the brightness of a pixel (a single element in the video image) at the roofline. This pixel became brighter as the roofline began to descend because the color of the pixel started to change from that of the building façade to the lighter color of the sky.


The approach taken by NIST is summarized in NIST NCSTAR Report 1A, Section 3.6, and detailed in NIST NCSTAR Report 1-9, Section 12.5.3.


The analyses of the video (both the estimation of the instant the roofline began to descend and the calculated velocity and acceleration of a point on the roofline) revealed three distinct stages characterizing the 5.4 seconds of collapse:


  • Stage 1 (0 to 1.75 seconds): acceleration less than that of gravity (i.e., slower than free fall).
  • Stage 2 (1.75 to 4.0 seconds): gravitational acceleration (free fall)
  • Stage 3 (4.0 to 5.4 seconds): decreased acceleration, again less than that of gravity
This analysis showed that the 40 percent longer descent time—compared to the 3.9 second free fall time—was due primarily to Stage 1, which corresponded to the buckling of the exterior columns in the lower stories of the north face. During Stage 2, the north face descended essentially in free fall, indicating negligible support from the structure below. This is consistent with the structural analysis model, which showed the exterior columns buckling and losing their capacity to support the loads from the structure above. In Stage 3, the acceleration decreased as the upper portion of the north face encountered increased resistance from the collapsed structure and the debris pile below.
Quotes from https://www.nist.gov/world-trade-center-investigation/study-faqs/wtc-7-investigation

Hope that is of some help.
 

Thomas B

Active Member
Both your questions can be discussed "stand-alone" from the NIST report.
Here's what I saw, reading the FAQs looking for answers to Abdullah's two questions...
I also noticed something looking for answers to @Abdullah's questions:
In response to comments from the building community, NIST conducted an additional computer analysis. The goal was to see if the loss of WTC 7's Column 79—the structural component identified as the one whose failure on 9/11 started the progressive collapse—would still have led to a complete loss of the building if fire or damage from the falling debris of the nearby WTC 1 tower were not factors. The investigation team concluded that the column's failure under any circumstance would have initiated the same sequence of events.
Content from External Source
https://www.nist.gov/world-trade-center-investigation/study-faqs/wtc-7-investigation

As David Letterman said about another aspect of the events of that day, "If you live to be a thousand years old, will that make any sense to you? Will that make any goddamned sense?"

We are to imagine that "the same sequence of events" that we witnessed on 9/11 would have followed from a bomb placed at the failure point of column 79, without any other damage to the building (and no fires).

One way to understand Abdullah's question is: just exactly what is that "sequence of events"? That is, imagine the bulding on an ordinary day before 9/11 and place a demolition charge on column 79. What happens next? Go through it step by step. What is the sequence of failures that NIST is saying would lead to the "complete loss of the building" after column 79 and nothing else fails?
 
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JMartJr

Senior Member
One way to understand Abdullah's question is: just exactly what is that "sequence of events"?
My take is, in reference to the NIST report on Bldg. 7 (the topic of this thread) that sequence of events is the sequence described in Q 9 of the faqs as I quoted them above. With the answer to Q 31 as additional description. Maybe I am misunderstanding you, but honestly and without snark, it reads to me like you are asking the same question again in a different way. Which will just get the same answer.
 

econ41

Senior Member
My take is, in reference to the NIST report on Bldg. 7 (the topic of this thread) that sequence of events is the sequence described in Q 9 of the faqs as I quoted them above. With the answer to Q 31 as additional description. Maybe I am misunderstanding you, but honestly and without snark, it reads to me like you are asking the same question again in a different way. Which will just get the same answer.
Yes, the topic of THIS THREAD is "Have You Actually READ the NIST Report on Building 7?" and Abdullah's interest goes further. He specifically expresses doubt that NIST "...does not seem to answer questions". So he wants to understand what actually happened and whether or not NIST "got it right". He asks these questions:
Yes, I have read the NIST report. But it does not seem to answer questions t.......
1. How one column took down a whole building and
2. Why the building appeared to freefall for multiple storeys
Those are three questions - the two explicitly identified plus the implied third question: "Did NIST explain it correctly."
Hence my caution as to the implicit limiting assumptions that (a) NIST did explain it - sufficiently; AND (b) NIST got it right.
Because both questions have been discussed extensively since the NISTR report was released. And significant more detail has been identified in relation to at least Q2.

So the discussion risks going too far "Off Topic". The way forward is probably best served if Abdullah can clarify his interest and that will probably be best pursued in a different thread.
 
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Thomas B

Active Member
that sequence of events is the sequence described in Q 9 of the faqs as I quoted them above. With the answer to Q 31 as additional description.
Q9 is mainly about what caused column 79 to fail. Abdullah's question is addressed with these few sentences:
The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, and 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.
Content from External Source
Q31 then explains why the collapse looked symmetrical from the outside (but in fact wasn't on the inside).

I agree with you that this is basically the understanding that the FAQ provides -- handwaving at a "rapid succession" of failures from bottom to top and from inside out. I understand why Abdullah doesn't find that satisfying. If the report does a better job, I haven't been able to find it either (though it's been a while since I tried). I concur with him when he says that the report seems to have
been written by bored, exhausted people.
I generally stay away from the topic of WTC7 for this reason. I don't have a good explanation and haven't been able to find one.
 
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Abdullah

Active Member
I did not mention the FAQ initially because it was not the topic. But since you brought it up, I can say it is no better. Let us read the relevant paragraphs.

>How did the fires cause WTC 7 to collapse?​

> .....
>The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line-involving all three interior columns on the easternmost side of the building (79, 80, 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.


1. Why did failure of C79 lead to failure of 80 and 81?
2. Why did the collapse of the east lobe (with it's resultant reduction in gravity loads) lead to further column failure?



>In a video, it appears that WTC 7 is descending in free fall, something that would not occur in the structural collapse that you describe. How can you ignore basic laws of physics?​

>.....
>This analysis showed that the 40 percent longer descent time—compared to the 3.9 second free fall time—was due primarily to Stage 1, which corresponded to the buckling of the exterior columns in the lower stories of the north face. During Stage 2, the north face descended essentially in free fall, indicating negligible support from the structure below. This is consistent with the structural analysis model which showed the exterior columns buckling and losing their capacity to support the loads from the structure above. In Stage 3, the acceleration decreased as the upper portion of the north face encountered increased resistance from the collapsed structure and the debris pile below.

3. How did the columns buckle across 8 storeys steaight, given that each floor braces the columns against buckling?
 

Thomas B

Active Member
1. Why did failure of C79 lead to failure of 80 and 81?
It's been a long time since I looked at the report. Aren't there some load path diagrams that would answer this question?

As I mentioned above, according to the FAQ,
column [79]'s failure under any circumstance [i.e., no fires or other damage] would have initiated the same sequence of events.
That seems like a major design flaw. The loss of column 79 was like pulling out a card at the bottom of a cardhouse?

Like I say, it doesn't make any sense to me. But surely there is a good answer to this question for someone who has the time and expertise to understand the NIST report?

Can anyone draw the load paths for columns 79, 80, 81 and their adjacent columns in a way that makes sense of just this early sequence of failures?
 
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Jeffrey Orling

Senior Member
It's been a long time since I looked at the report. Aren't there some load path diagrams that would answer this question?

As I mentioned above, according to the FAQ,

That seems like a major design flaw. The loss of column 79 was like pulling out a card at the bottom of a cardhouse?

Like I say, it doesn't make any sense to me. But surely there is a good answer to this question for someone who has the time and expertise to understand the NIST report?

Can anyone draw the load paths for columns 79, 80, 81 and their adjacent columns in a way that makes sense of just this early sequence of failures?
it was the failure of col 79... but the failure of the beams and girders framed into it... and the floor slabs they supported.
 

econ41

Senior Member
It WAS NOT the failure of col 79... but the failure of the beams and girders framed into it... and the floor slabs they supported.
Agreed. It is one of several bits of NIST's explanations that are poorly described.

BUT the OP question is "Have you read NIST?" NOT "do you agree with NIST?" And both of @Thomas B's concerns are discussed in other threads. Viz (1) the false suggestion that Col 79 represents a "design flaw" and (2) Thomas's personal obsession with load path diagrams where they are not needed.
 
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