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WTC7a
Comment		Issue:
	1	Listing of Contributors
	2	Reference to weather
	3	Analysis of the buckling is substantially incomplete.
	4	Failure due to thermal expansion in buildings does not happen at low temperatures. To suggest this disregards the known properties of materials.
	5	Limiting the analysis to properties of the soundtracks to hypothetical blast events is fraudulent
	6	Building structure as given in the document(s) is incomplete – therefore the analysis is incomplete.
	7	Dimensions and weights of beams must be provided.
	8	Aspect ratio of beams
	9	Causes for the destruction other than fire and thermal expansion must be properly considered, using all available data.
	10	Analysis for the fate of the fuel is incomplete.
	11	Incomplete analysis of what was heard.
	12	It would be like raining dump trucks.
	13	No mention of fire, heat or smoke on floors 4,5,6 casts doubt on NIST's analysis of fire immediately above those floors.
	14	Spontaneous disintegration
	15	Failure to include magnetometer and failure to properly use seismic data.
	16	Analysis is incomplete; sound analysis omitted.
	17	242-foot drop?!
	18	Incongruence in Collapse time calculation.
	19	Selective use of audible data. The analysis of sound is incomplete.

WTC7b
Comment		Issue:
	20	Eliminating Controlled Demolition through false choice.
	21	Need to explain "disintegration."
	22	Effects on WTC7 compared with effects on Bankers Trust
	23	Modeling a disintegrating structure

WTC7c
Comment		Issue:
	24	How was this possible?
	25	A building turns to mud?
	26	Incorrect description of Bar/Beam shape
	27	Stress-strain curves are shown for tension, but according to the text, the beams were loaded in compression.
	28	Observed fuming pattern not properly defined or explained
	29	Models given do not match enough of observed phenomena, nor to they explain resulting state of WTC 7

-- Click on figures to enlarge. --

DR. JUDY WOOD
202 Mulberry Ave.
Clemson, SC 29631
864-654-8271

lisajudy@nctv.com

September 14, 2008

WTC Technical Information Repository
Attention: Mr. Stephen Cauffman
National Institute of Standards and Technology
Stop 8610
Gaithersburg, MD 20899-8610
Email: wtc@nist.gov

Re: Comments

Dear Mr. Stephen Cauffman:

Set forth below are comments on the "Final Report on the Collapse of World Trade Center Building 7 Draft for Public Comment" dated August 21, 2008 (NCSTAR 1A). The source of the said NCSTAR 1, meaning the point at which it can be and has been accessed, is: http://wtc.nist.gov/

First, the comment period provides insufficient time for comprehensive comment. That period should be extended for a minimum of ninety (90) additional days. Further, and as seen below, several of the comments that are made herein indicate that NCSTAR 1-A is misleading to the point of being fraudulent.

NIST should also publish all comments received in their entirety. If NIST does not do so, then NIST should at least acknowledge that one commentator, Dr. Judy Wood, requested that NIST do so and NIST should then explain that such comments can be obtained by the public upon request and should further indicate the reason for not publishing all comments it received.

I am represented in connection with these comments by Attorney Jerry V. Leaphart whose contact information is set out at the end of the comments. If you have any questions, please contact either me or my counsel.

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Comment 1

Issue: Listing of Contributors

Location: page 8-10 of 115 of pdf, (labeled page vi-viii of report) http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

NIST CONTRACTORS

Siemens

Steven Shamash

John Farrington

Robert Salamone

U.S. Securities and Exchange Commission

Al Basile

Robert DeLeonardus

Ray Ferrari

Richard Lee

COOPERATING ORGANIZATIONS

Siemens Corporation

Steven R. Shamash

Bob Salamone

U.S. Securities and Exchange Commission

Richard D. Lee

Robert DeLeonardis

Figure 1. page 9-10 of 115 of pdf, (labeled page vii-viii of report) http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

General Services Administration

Mary Guida

GSA

Maria Guida

Figure 2. page 10 of 115 of pdf (labeled page viii of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: The listings are inconsistent with individuals being listed as paid contractors and cooperating organizations. This should be clarified. Mary Guida is listed twice (GSA is listed twice).

Suggestion for Revision: Delete or modify as necessary.

Comment 2

Issue: Reference to weather

Location: Beginning of Section 2.1 pg. 51, paragraph 1,. page 51 of 115 of pdf (labeled page 13 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Chapter 2 The Account of WTC 7?13

2.1 Introduction?13

2.1 INTRODUCTION

Shortly before 9:00 a.m. on Tuesday, September 11, 2001, about 4,000 people were at work in WTC 7. This was about half of the roughly 8,000 people who worked there. It was the first day of school for many local children, and it also was a primary election day in New York. The weather was clear and comfortable, so some had taken time to do early morning errands.

Figure 3. [emphasis added]
page 51 of 115 of pdf (labeled page 13 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: The reference is casual and is based on commonly held assumptions, but is not sufficient for a comprehensive and detailed report. Because of the magnitude of the destruction that NIST itself describes as "disproportionate" it is necessary to have a proper understanding of the precise weather mechanism that may have impacted upon the unprecedented destructive events that occurred.

Suggestion for Revision: It is not commonly known or appreciated that a massive Category 3 hurricane was located offshore New York on 9/11/01. That was Hurricane Erin, as seen here:

Hurricane Erin on 9/11/01


Figure 4. (9/11/01) Source:, (9/11/01) Original Image:	Figure 5. (9/11/01) Source:

Figure 6. (9/11/01) Source: 010911_wtc_terra1_cbc.jpg


Figure 7. Weather at Newark International Airport, Newark, NJ, on 9/11/01. Source	Figure 8. Weather at Laguardia International Airport, New York, on 9/11/01. Source	Figure 9. Weather at J.F. Kennedy International Airport, New York, on 9/11/01. Source

Locations where rain and thunder were recorded.

Figure 10. " Figure 5–3. Map of the lower portion of Manhattan showing the location of the WTC complex relative to the island."
Page 138 of 404 of pdf (labeled page 94 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_Vol1_for_public_comment.pdf

NHC Data (9/9/01 - 9/12/01)

Figure 11. Source: nhc


Figure 12. Best track for Hurricane Erin, September 2001. Track during the extratropical stage is based on analyses from the NOAA Marine Prediction Center. (9/16/01) source:	Figure 13. Hurricane Erin track (atl.ec.gc.ca). According to the Canadian Hurricane Centre (CHC), Hurricane Erin entered the "Response Zone." A hurricane in this zone should presumably trigger a "response." (9/15/01) Source:


Figure 14. Hurricane Erin, September 11, 2001, at about 37.4°N, 65.6°W, which corresponds to abut 10:15AM (EDT). source:	Figure 15. . Best track of Hurricane Erin, September 1-17, 2001 source:, website

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Comment 3

Issue: Analysis of the buckling is substantially incomplete.

Location: page 34 of 115 of pdf, (labeled page xxxii of report), paragraph 2 http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

PRINCIPAL FINDINGS OF THE INVESTIGATION

Eventually, the fires reached the northeast of the building. The probable collapse sequence that caused the global collapse of WTC 7 was initiated by the buckling of a critical interior column in that vicinity. This column had become unsupported over nine stories after initial local fire-induced damage led to a cascade of local floor failures. The buckling of this column led to a vertical progression of floor failures up to the roof and to the buckling of adjacent interior columns to the south of the critical column. An east-to-west horizontal progression of interior column buckling followed, due to loss of lateral support to adjacent columns, forces exerted by falling debris, and load redistribution from other buckled columns. The exterior columns then buckled as the failed building core moved downward, redistributing its loads to the exterior columns. Global collapse occurred as the entire building above the buckled region moved downward as a single unit. This was a fire-induced progressive collapse, also known as disproportionate collapse, which is defined as the spread of local damage, from an initiating event, from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it.

Figure 16. [emphasis added]
page 34 of 115 of pdf, (labeled page xxxii of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: Analysis explaining exactly how an interior progressive collapse and complete unit global collapse occurred. The likelihood of asymmetry converting to symmetry is highly unlikely and without detailed engineering descriptions, borders on incredible.
Suggestion for Revision: Crucial to the viability of the probable collapse sequence articulated in this report is that the [dimensions] column would have had to become unsupported over nine stories. We also note that we relied on the soundtracks of available video to refute hypothetical blast events as a causal factor. We did not engage in an analysis of the soundtracks to determine whether the audible sounds could be deemed to be consistent with a [dimension] column becoming unsupported. We have no explanation for why we did not engage in that analysis.

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Comment 4

Issue: Failure due to thermal expansion in buildings does not happen at low temperatures. To suggest this disregards the known properties of materials.

Location: First use at Pg. 34 (pdf) Executive Summary, plus, comment pertains to all 37 uses of that term throughout NCSTAR 1-A, paragraph 3

PRINCIPAL FINDINGS OF THE INVESTIGATION

Factors contributing to the building failure were: thermal expansion occurring at temperatures hundreds of degrees below those typically considered in design practice for establishing structural fire resistance ratings; significant magnification of thermal expansion effects due to the long-span floors, which are common in office buildings in widespread use; connections that were designed to resist gravity loads, but not thermally induced lateral loads; and a structural system that was not designed to prevent fire-induced progressive collapse.

Figure 17.
page 34-5 of 115 of pdf, (labeled page xxxii - xxxii of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: The term "thermal expansion" does not appear to have any clearly articulated scientific basis in reality; nor does NCSTAR 1-A adequately explain how the concept of thermal expansion, as articulated, could have arisen in connection with steel columns, girders, and beams that were fire proofed.

December 18, 2007 NCST meeting

Charlie Thornton: Let me ask another question. How long does a 4 pound per square foot combustible office building fire generally last?

Shyam Sunder: The rule of thumb for 10 pounds per square feet is one hour. Four pounds is 20 minutes.

Charlie Thornton: So again, why would these fires have burned for as long as they did in order to take out this rather well fireproofed heavy robust structure?

Shyam Sunder: Charlie, what I’m saying – I guess I’m not communicating well what I’m saying, which is that the fire at any one location is consumed in 20 minutes where the fire front is, but then it moves to the next place where there’s more combustibles.

Charlie Thornton: But if you’re saying that beams sagged and buckled and pulled,
O K, that had to be exposed to the fire for more than 20 minutes.

Shyam Sunder: Well, the temperatures at which the beams are exposed, that is the critical issue here, not how long they were exposed to that temperature, and of course beams and slabs and any fireproofing – concrete slab - the metal deck may have some. The beams are much more slender elements in terms of thermal mass and of course the fireproofing on the beams, the floor beams, are much less than the fireproofing on the girders and of course the columns. And so when you go through the analysis for these fires which are moving around from location to location, on those particular floor beams, you see a considerable amount of temperature increases. In fact, you’ll see temperatures getting up in to …in certain regions to 5 600 degrees. Now what also compounds this is you have these heating elements in very large spans in the northeast side of the building. As we said before, there were 2000 square feet large spans, floor areas ... for those columns. So those spans were in fact sagging and we’re seeing evidence through our analysis of these very large magnitude of sag.

[There is a loud hammering/knocking sound at this part of the recording as though carpenters were hammering on something in the room. This made Charlie’s next remark difficult to hear.]

Charlie Thornton: I mean it sounds to me, it sounds to me like between the words here you’re questioning the use of _?_ fireproofing for a two-hour rating on a W 21 wide flange beam as an effective fireproofing in the absence of sprinkler systems.

Bill Gross: Can I add two things to Shyam’s [remarks]. Charlie, you can have an ignition event quite early in the process in which the fire does not burn robustly but smolders and, you know, is barely maintained. And unlike the Towers where you had so much fuel distributed in which the fires spread very quickly, you could have a fire ignited and not grow very fast. It reaches then a certain critical size and then it begins moving as Shyam described. That’s one thing.

The second, this would have to be literally a matter of an hour or two where it could be burning at a very slow rate and then burst out in to a full fledged floor fire.

The second thing is don’t forget that once the fire front passes, you still a lot of amount of heat there, so the cool-down period following the consumption of most of the fuel – it’s still very very hot and will last for a couple of hours, so that adds to the heating of the structure.

Shyam Sunder:Yes, that’s a very good point, Bill. The fire front moves but the heated elements don’t cool down.

Bob ____: Shyam, this is Bob. I ran down the same question that Charlie did some time ago

Shyam Sunder: O K

Bob: The same concern. The basic point is that this was a bank fire, and we did the temperature study by using the model, the fire dynamic simulator model, and the temperature… it was more like a series of burners coming on at 20-minute intervals, and as you said, pumping heat into the building, losing some through the vents, having other sink into the material, and the model gave us the fire that they are using. We transferred all of the temperatures on the back side of the fireproofing and then compared those to the properties of the steel or the concrete as the case may be and fed in to the structural model these changes in qualities.

Shyam Sunder: Yes, I think that that is an important point that, Charlie, we aren’t making any assumptions in this thing. The models are very detailed, so the fire dynamics model gives us the information on the gas temperatures. The thermal model, which is using also LS-DYNA, which is not the structural model, the model, the fireproofing and the structural elements, the seal (?) elements there. So basically, the gas temperatures actually predicting the rise of the temperature in the steel through the fireproofing, and that is done with considerable detail, and then at that point, the structural model comes in to play.

Charlie Thornton: I’m not questioning what you’re doing. I’m questioning the way that American architects and structural engineers design buildings with spray-on fireproofing. I think you’re basically coming out with a conclusion that maybe it doesn’t work.

Shyam Sunder: I think I will hold off on making a recommendation at this point. Your input is certainly very meaningful to us and as we go forward here, you know, at the end of the day when all of this analysis is finished and we can conclude definitively what we have actually accomplished. At that point I think we will in a position to make a statement about design practices."

The foregoing exchange clearly questions the efficacy of reliance on an unexplained concept of "thermal expansion" as a causal factor in the destruction of WTC 7.

Figure 18. from Transcript of NCST December 18, 2007 meeting. (transcript courtesy of Archie)

NIST's use of a thermal expansion, occurring at "low temperature" is insufficiently elaborated. Clearly, NIST is trying to navigate a very narrow factor of plausibility here, and that is the most that can be said about it. On the one hand, thermal expansion might, in very generous theoretical terms be said to result in certain effects. However, if the temperature is too high, then a softening of material occurs, which would negate the necessary strength needed to cause expansion. Accordingly, absent a detailed indication of what temperature is low enough to cause expansion, while simultaneously not causing loss of strength is crucial. It may well be that there is no such temperature. In any event, NIST must, at a minimum specify what temperature it has reason to believe was achieved and how the conditions known could have resulted in that temperature. We understand, as well, that there are some who will question the validity of the use of this concept and who may claim that NCSTAR 1-A is fraudulent.

Suggestion for Revision: NIST data show that ____ temperature was achieved and documents that following conditions occurred at that temperature [details]. NIST also acknowledges, in this respect that there are some who will question the validity of the use of this concept and who may claim that NCSTAR 1-A is fraudulent.

Comment 5

Issue: Limiting the analysis to properties of the soundtracks to hypothetical blast events is fraudulent

Location: page 34 of 115 of pdf, (labeled page xxxii of report), paragraph 5 http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

PRINCIPAL FINDINGS OF THE INVESTIGATION

Hypothetical blast events did not play a role in the collapse of WTC 7. NIST concluded that blast events did not occur, and found no evidence whose explanation required invocation of a blast event. Blast from the smallest charge capable of failing the critical column would have resulted in a sound level of 130 dB to 140 dB at a distance of at least half a mile. There were no witness reports of such a loud noise, nor was such a noise heard on the audio tracks of video recordings of the WTC 7 collapse.

Figure 19. [emphasis added]
page 34 of 115 of pdf, (labeled page xxxii of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: NIST's acknowledgment that the soundtracks from available videos were used in connection with the analysis of hypothetical blast events requires, for sake of consistency of analysis, that such soundtracks also be used to substantiate (or refute) the findings that NIST made in connection with its other findings. The failure to do so is consistent with fraud.

Suggestion for Revision: We understand, as well, that there are some who will question the validity of limiting our analysis of the properties of the soundtracks to hypothetical blast events. We have no explanation for doing so and if there are those who wish to assert that our failure in this respect is fraudulent, then they may do so. We acknowledge being placed on notice of this claim of fraud in comments received from Dr. Judy Wood.

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Comment 6

Issue: Building structure as given in the document(s) is incomplete – therefore the analysis is incomplete.

Location: page 43 of 115 of pdf, (labeled page 5 of report), 2^nd paragraph from bottom http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Chapter 1 The New York City World Trade Center Building 7?1

1.1 The World Trade Center Complex?1

1.2 WTC 7?1

1.2.1 The Edifice?1

1.2.2 The Con Edison Substation?3

1.2.3 The Structure?5

From the 7^th floor to the 47^th floor, WTC 7 was supported by 24 interior columns and 58 perimeter columns (numbered 1 through 57, plus 14A, which was located near the south end of the west face) (Figure 1 5). Twenty one of the interior columns (numbered 58 through 78) formed a rectangular building core, which was offset toward the west of the building. The remaining three interior columns (79, 80, and 81) were particularly large, as they provided support for the long floor spans on the east side of the building.

Figure 20. [emphasis added]
page 43 of 115 of pdf, (labeled page 5 of report)
http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: Use of generic, non-specific language – "three interior columns (79, 80, and 81) were particularly large" is unsatisfactory for a report that must comply with the standards of the Information Quality Act. The dimensions of those columns must be specific. Full drawings and material specifications related to the building must be available in the report.

Suggestion for Revision:
The three interior columns (79, 80, and 81) were of the following dimensions: [provide length, width, breadth and weight]. NIST could not confirm via the available soundtracks that columns of that dimension could be heard crashing down.

[Or, in the alternative]

NIST correlated the sound of crashing of columns in the soundtracks for videos taken at sites __, ___.

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Comment 7

Issue: Dimensions and weights of beams must be provided.

Location: page 44 of 115 of pdf, (labeled page 6 of report), paragraph 1 http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Chapter 1 The New York City World Trade Center Building 7?1

1.2 WTC 7?1

1.2.3 The Structure?5

The floor slabs were reinforced concrete of varying thickness. The 1st floor slab was 14 in. thick. The concrete on almost all of the other floors was poured on top of 3 in. deep corrugated metal decking. Floors 2, 3, 4, and 6 had a 6 in. total slab thickness; on Floor 5, the concrete was 14 in. thick; and on Floors 8 through 47, the concrete was 5.5 in. thick. On Floor 7, the south half of the floor had a poured 8 in. slab, and the north half had an 8 in. total slab thickness on a 3 in. deep metal deck. The floor slabs were supported by the structural floor framing shown in Figure 1-5. The floor beams were connected to the concrete deck by shear studs, which caused the floor beams and concrete slab to act together, or compositely. This type of floor system is thus referred to as a composite floor. The floor beams were framed into (connected to) girders with a variety of types of shear connectors2, through which the floor beams transferred gravity loads from the floors to the girders. The girders also framed into the columns with a variety of types of shear connectors and transferred the gravity loads to the columns. Interior columns were connected with splice plates, welds and bolts. The exterior frame had moment connections in each face of the building.

Figure 21. [emphasis added]
page 44 of 115 of pdf, (labeled page 6 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: Building structure as given in the document(s) is incomplete – therefore the analysis is incomplete. Location of beams alone is insufficient to make a valid assessment. Much more structural information needs to be included, with more specific details of dimensions, weights and materials involved for anything which fell to the ground.

Suggestion for Revision: NIST has determined that the dimensions of the beams referenced here are as follows: [provide dimensions]

Figure 1–5. Typical WTC 7 floor showing locations of the columns, girders, and beams.

Figure 22. page 44 of 115 of pdf (labeled page 6 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Comment 8

Issue: Aspect ratio of beams

Location: Page 346 of 382 of pdf (labeled page 684 of report), page 127 of 382 of pdf (labeled page 465 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf

Table D1. Basic wide flange column parameters. (Dimensions in in.)
Section	Web Height	Flange Width	Flange Thickness	Web Thickness
W14X730	22.4	17.9	4.91	3.07
W14X665	21.6	17.7	4.52	2.83
Figure 23. Page 346 of 382 of pdf (labeled page 684 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf


page 127 of 382 of pdf (labeled page 465 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf	The aspect ratio of the dimensions provided in Table D1 are shown above.

Reason for Comment: The aspect ratio of beam cross sections shown in the report do not have dimensions. The dimensions provided in the report describe beams with a very different aspect ratio. Dimensions and weights of beams used in this analysis must be provided so that the plausibility of NIST's theory can be properly assessed, among other things. Basically, we are led to believe that very large columns, beams and girders were all sufficiently heated by ordinary office fires that burned for no more than 20 minutes in any one area resulted in multiple, nearly simultaneous failure. That explanation is, of course, implausible, but, at a very minimum, accurate dimensions of what failed must be both provided in detail and properly diagrammed.

Because NCSTAR 1-A refers to collapsing beams, it is essential that the correct aspect ratio is depicted. Otherwise, a highly misleading report would be foisted on the public. We are already required to accept that a 47-story building could collapse in a matter of seconds. At a minimum, correct diagrams of what is said to have collapsed are required. If not, then the appearance of fraud is overwhelmingly confirmed.

Suggestion for Revision: This revision requires re-do of diagrams as exemplified above to show correct aspect ratios.

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Comment 9

Issue: Causes for the destruction other than fire and thermal expansion must be properly considered, using all available data.

Location: page 47-8 of 115 of pdf, (labeled page 9-10 of report) http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Chapter 1 The New York City World Trade Center Building 7?1

1.2.6 The Combustible Contents?9

1.2.6 The Combustible Contents

The layout of most of the floors featured clusters of workstations, or cubicles, throughout the space surrounding the building core (NIST NCSTAR 1-9, Chapter 3). Often, there were walled offices at the perimeter. The layout in Figure 1 8 is indicative of these floors. While there were almost certainly different types of workstations in the building, they were all fundamentally similar. Each cubicle typically was bounded on four sides by privacy panels, with a single entrance opening. Within the area defined by the panels was a self-contained workspace: desktop (almost always a wood product, generally with a laminated finish), file storage, bookshelves, carpeting, chair, etc. Presumably there were a variety of amounts and locations of paper, both exposed on the work surfaces and contained within the file cabinets and bookshelves.

The combustible fuel load³ for these open landscaped floors was dominated by the workstations. The architectural drawings showed densities of workstations similar to those on most of the fire floors in the WTC towers. The estimated combustible fuel load for these floors was about 20 kg/m2 (4 lb/ft2). Simulations of the fires with a higher combusted fuel load (NIST NCSTAR 19, Chapter 9) resulted in poor agreement with the observed fire spread rates.

Figure 24. [emphasis added]
page 47-8 of 115 of pdf, (labeled page 9-10 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

³ In the fire simulations, the entire combustible fuel load can be burned. In actuality, not all of, e.g., a wood desk is consumed. Thus, the combusted fuel loads estimated for these simulations are somewhat lower than the actual fuel loads in prior surveys of office buildings. (See NIST NCSTAR 15.)

Figure 25. [emphasis added] Footnote 3, page 48 of 115 of pdf, (labeled page 10 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: If it was the case that: "Simulations of the fires with a higher combusted fuel load (NIST NCSTAR 1-9, Chapter 9) resulted in poor agreement with the observed fire spread rates" this means the analysis is incomplete or incorrect. Full detailed resulting data from testing of combustible fuel load should be included in the report. If data from these repeatable tests does not match up well with observed fire spread rates, then further testing is necessary.

Suggestion for Revision: Data: [Fully described, repeatable tests of combustibles within the building should be available which describe temperatures achieved (compared with materials fully documented in architectural documentation) as well as fire spread rates. These must be compared to expected heating and material failure specs of the actual materials in the building according to official architectural documents.]

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Comment 11

Issue: Incomplete analysis of what was heard.

Location: page 51 of 115 of pdf, (labeled page 13 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

2.2 ACTIVITY AT THE WTC 7 SITE

2.2.1 8:46 a.m. to 9:59 a.m. EDT

People throughout WTC 7 heard the boom of the aircraft hitting WTC 1, which was only about 110 m (350 ft) to the south. Lights flickered, the building shook, and some windows on the south side of WTC 7 were broken. However, few, if any, of the workers felt their lives were in immediate danger. This perception changed as the occupants became aware of the subsequent attacks on WTC 2 and the Pentagon, and people began using the elevators and stairs to leave the building. The elevators alone could have evacuated the building in about 20 min. The stairwells, although somewhat narrow for the maximum possible 14,000 occupants (estimated using the formula in the NYCBC), were more than adequate to evacuate roughly one third of that number in the building that morning (NIST NCSTAR 19, Chapter 7).

Figure 27. [emphasis added]
page 51 of 115 of pdf, (labeled page 13 of report) http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: Use of language is not specific enough "People throughout the building…" The description of the sound is also vague. Determine and include how many people heard the "boom". The description of the sound needs to be clearer – did it sound more like a crash, or an explosion? All subjective comments must be supported by actual statements that will verify what exactly individuals heard and how they corroborate to each other. Statistical analyses should be conducted of witness statements to ensure consistency of said statements to insure that readers of this report only hear objective data. This could then be compared with public domain analyses of eyewitness statements to ensure consistency.

Suggestion for Revision: NIST has determined with reasonable certainty the assertions concerning what was heard based on the following accounts and soundtracks [provide data]

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Comment 12

Issue: It would be like raining dump trucks.

Location: page 58 of 115 of pdf, (labeled page 20 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

The upper section of Column 79 began to descend. The cascading failures of the lower floors surrounding Column 79 led to increased unsupported length in, falling debris impact on, and loads being redistributed to adjacent columns; and Column 80 and then Column 81 buckled as well. All the floor connections to these three columns, as well as to the exterior columns, failed, and the floors fell on the east side of the building. The exterior façade on the east quarter of the building was just a hollow shell.

The failure then proceeded toward the west. Truss 2 (Figure 1-6) failed, hit by the debris from the falling floors. This caused Column 77 and Column 78 to fail, followed shortly by Column 76. Each north-south line of three core columns then buckled in succession from east to west, due to loss of lateral support from floor system failures, to the forces exerted by falling debris, which tended to push the columns westward, and to the loads redistributed to them from the buckled columns. Within seconds, the entire building core was failing.

The global collapse of WTC 7 was underway. The shell of exterior columns buckled between the 7^th and 14^th floors, as loads were redistributed to these columns due to the downward movement of the building core and the floors. The entire building above the buckled-column region then moved downward as a single unit, completing the global collapse sequence.

Figure 28.
page 58 of 115 of pdf, (labeled page 20 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: Analysis of columns 79, 80, 81, is incomplete. Much more structural information needs to be included, with more specific details of dimensions, weights and materials involved. Comprehensive re-analysis of the sound of the destruction is required – and considered in the light of the seismic readings. I.e. there was a great volume of heavy material coming down to the ground, which would have made very loud noise, but this was not observed. This must be addressed. This section describes the gravitational failure of several columns during the initiation of internal progressive collapse without including sound analysis of falling debris based on architectural documentation and material specs. Analysis of the audible recordings and sound properties of materials specified in the building should be included in the report to understand comparisons with similar weight objects as they are affected by gravity and collide with materials below.

Suggestion for Revision:
NIST realizes that the sound properties associated with the progressive collapse hypothesized in this report would have been quite pronounced. Detailed confirmation of the sound can be found in [provide data]

[Or, in the alternative]

NIST has not been able to find any soundtrack containing crashing sounds that would corroborate the theory of collapse articulated in this report. However, NIST still maintains its belief in the plausibility of its explanation even though no audible confirmation could be found.

Figure 29. "Figure 2–2. Eastward buckling of Column 79, viewed from the southeast."
page 58 of 115 of pdf, (labeled page 20 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

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Comment 15

Issue: Failure to include magnetometer and failure to properly use seismic data

Location: page 315 of 382 of pdf, (labeled page 653 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf

B.3 PREVIOUSLY IDENTIFIED SEISMIC EVENTS AT WTC

In September 2001, researchers at LDEO analyzed seismic records from the WTC disaster and reported their findings for five major events at the WTC site (Kim et al., 2001); the event time, equivalent magnitude on the Richter scale, the dominant period of ground vibration, and the duration of the signal are shown in Table B2 for the major events. The origin times listed in column 3 of Table B2 are taken Table 53 from Kim, et al. (2001), and were also used in the FEMA report (McAllister 2002). These

Figure 32. [emphasis added]
page 315 of 382 of pdf, (labeled page 653 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf

Reason for Comment: Seismic data makes no comparisons to other comparable seismic events such as blasts related to TNT (in tons) relating to building size. Full comparisons of expected seismic activity should be made with other structures based on mass and substructure composition compared with seismic expectations of certain volumes of TNT. Any anomalies should be evaluated and determinations of these variations should be explained. If additional data, such as magnetometer data that corresponds to the onset of the events at the WTC as well as the final failure at WTC7 is available and suggests a correlation, this correlation should be included in the report and analyses conducted and findings documented.

The impact of the debris from WTC7 registered an equivalent to 0.6 on the Richter Scale. This is the magnitude of a signal that might be expected if WTC7 had lost at least 99% of its mass, evenly, over the height of the building.

Significant and important magnetometer data exists and must be included. That data consists in the following.

[See data below.]

Analysis of that data, in conjunction with seismic data results in important information that will cast doubt on the probable collapse scenario in NCSTAR 1-A. We anticipate that NIST may not use this data and that, instead, the failure to do so will have to await further proceedings, such as a Request for Correction. NIST is hereby placed on notice that the failure to include the data is inexcusable.

Suggestion for Revision:

Magnetometer + seismic + "Our seismic & magnetometer evidence"

Figure 33. North face of WFC2 shows an unusual distortion in the image.
(9/11/01) Source:

Legend:

Figure 34. Magnetometer Readings (normalized), 9/10/01-8:00 AM (EDT) - 9/12/01-8:14 PM (EDT) (data posted at one-minute intervals)
website:GIMA

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Comment 18

Issue: Incongruence in Collapse time calculation.

Location: page 79 of 115 of pdf, (labeled page 41 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

3.6 Collapse Time?................40

The theoretical time for free fall (i.e., neglecting air friction), was computed from,

where t is the descent time (s), h is the distance fallen (ft), and g is the gravitational acceleration constant, 32.2 ft/s² (9.81 m/s²). Upon substitution of h = 242 ft. in the above equation, the estimated free fall time for the top of the north face to fall 18 stories was approximately 3.9 s. The uncertainty in this value was also less than 0.1 s.

Thus, the actual time for the upper 18 stories to collapse, based on video evidence, was approximately 40 percent longer than the computed free fall time and was consistent with physical principles.

Figure 37. [emphasis added]
page 79 of 115 of pdf, (labeled page 41 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Reason for Comment: NIST arbitrarily limited its collapse time analysis to the 242-foot drop. However, even in doing that, NIST did not correlate its collapse time calculation with either an explanation of what materials dropped [columns, beams, and girders, and their dimensions] and the known audible data and seismic data.

The data presented by NIST in Table B-2 shows a dominant period lasting 0.8 seconds.

Collapse time
Duration of signal

Did the ground shake like raining dump trucks?

^aderived from signal arrival and estimated travel times from WTC site to PAL

^b based upon events observed in videos and photographs; collapse times were based on collapse initiation, not time of ground impact

^c NCSTAR 15A timing was based on downward movement of the WTC 7 roofline and not the downward movement of the east penthouse that occurred earlier.

^d Total duration of BHE PAL signal in Fig. A6, including a possible second arrival

Figure 38. "Table B2. Major seismic events previously reported."
page 316 of 382 of pdf, (labeled page 654 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf

NIST does not correlate with the seismic data noted . That data shows a seismic event lasting less than 6.4 seconds.

, where h = 650 ft(198 m), 32.2 ft/s² (9.81 m/s²),

t = 6.355 seconds, or t = 6.4 s.

T = sqrt ((2*h)/g) = sqrt ((2*650)/32.2) = 6.3539 seconds = ~ 6.4 seconds.

The collapse time for the building is not addressed. Analysis is incomplete and inconsistent with time the ground shook. Add: the sound heard should have been comparable with a fleet of dump trucks crashing to the ground (one only has to consider the noise and vibration of one that is loaded when it passes by a pedestrian on the sidewalk). In complete and should be addressed.


Figure 39. "Figure B9. Events identified on PAL seismogram. Refer to Table B4 for location, strength and description of event type." 329 of 382 of pdf, (labeled page 667 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf		Figure 40. page 320 of 382 of pdf, (labeled page 658 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_vol2_for_public_comment.pdf

Figure 41. reference

Suggestion for Revision: The seismic data analysis shows [add analysis] and add conclusions that follow from that data.

Comment 19

Issue: Selective use of audible data. The analysis of sound is incomplete.

Location: page 87 of 115 of pdf, (labeled page 49 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

Hypothetical blast events did not play a role in the collapse of WTC 7. NIST concluded that blast events could not have occurred, and found no evidence whose explanation required invocation of a blast event. Blast from the smallest charge capable of failing a critical column (i.e., Column 79) would have resulted in a sound level of 130 dB to 140 dB at a distance of at least half a mile if unobstructed by surrounding buildings (such as along Greenwich Street and West Broadway). This sound level is comparable to a gunshot blast, standing next to a jet plane engine, and more than 10 times louder than being in front of the speakers at a rock concert. The sound from such a blast in an urban setting would have been reflected and channeled down streets with minimum attenuation. However, the soundtracks from videos being recorded at the time of the collapse did not contain any sound as intense as would have accompanied such a blast.

Figure 42. [emphasis added]

page 87 of 115 of pdf, (labeled page 49 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf

5.7.5 Audio Characteristics Based on Video Soundtracks

Three videos in the database included soundtracks that were used to investigate the audio signature associated with the period immediately prior to and during the collapse of WTC 7. All of these cameras were located at street level at least 640 m (2100 ft) from the building. Also, there were numerous other buildings between the cameras and WTC 7.

The most usable soundtrack was recorded by Camera 3, with its West Street location. This video ran for many minutes prior to and during the collapse. Even though sound was recorded by the camera, no interviews or commentary were recorded, and the microphone tended to pick up low level street sounds, such as sirens, traffic, and distant conversations. Occasionally, the camera operators located nearby were recorded at a much louder level. Since the collapse was recorded on the video, it was possible to coordinate the sound recording with the actual WTC 7 collapse.

A careful review of the audio clip did not reveal any sounds that could be associated with WTC 7 until the global collapse began. A low level waveform for the audio signal using Aftereffects software. This video also did not reveal any features that could be associated with the collapse until after the global collapse began. In the analysis, the roughly 2 s delay in sound transmission between WTC 7 and the camera was accounted for. The amplitude of the sound signal increased while the global collapse was taking place, but there were no loud, explosive sounds when the collapse began.

The response of the camera operators provides another indication of the audio environment. Even though the east penthouse began to descend into the building 6.9 s prior to initiation of global collapse, there was no verbal response from the camera operators until 2.5 s after the global collapse began, when a loud shout of whoa, whoa, whoa, whoa was heard. There is no evidence that the operators heard something that attracted their attention prior to this time.

At the same time the Camera 3 video was being shot, a recorded street interview was being conducted a short distance away on West Street. In this video clip of the interview, WTC 7 is visible in the upper left hand corner of the frame. Even though the east penthouse can be seen disappearing into the building, neither the camera operator, interviewer, nor interviewee responded in any way until just over 3 s after the global collapse began. Again, there was no indication that sounds loud enough to attract attention or cause alarm were heard by people at the interview location prior to global collapse initiation.

Figure 43. [emphasis added]
Page 333-334 of 404 of pdf, (labeled page 289-290 of report), http://wtc.nist.gov/media/NIST_NCSTAR_1-9_Vol1_for_public_comment.pdf

Reason for Comment: The sound analysis is incomplete. It is stated that the soundtracks from the videos recording the event did not contain any sound as intense as would have accompanied such a blast, yet there is no analysis for what sound levels should accompany the sudden gravity collapse proposed. Sound is used as one of the criteria to eliminate the consideration of a blast event as causing the destruction of WTC7. But the proposed causal theory with a gravity collapse has not been tested by the same criteria.

WTC7 is approximately 200,000 tons. That's equivalent in mass to about 10,000 - 20,000 dump trucks, distributed in space over the height of the building. If those suddenly collapsed to the ground, the sound should be audible, should register seismically and must be included in NIST's analysis.

NIST acknowledges that it did not do an analysis of the soundtracks in order to verify its collapse hypothesis and, instead, only used soundtrack analysis to confirm there was no loud sound that would have been expected from a hypothetical blast event. NIST is aware that its work in this respect may be challenged as being fraudulent.

Suggestion for Revision: Soundtrack analysis data show [add data] and add conclusions that follow from that data.