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Part 7: WTC 7 Fire and Column Failure

Editor’s Note: This is Part 7 (see Part 6) of an extensive report by 9/11 researcher Adam Taylor that exposes the fallacies and flaws in the arguments made by the editors of Popular Mechanics (PM) in the latest edition of their book Debunking 9/11 Myths. We encourage you to submit your own reviews of the book at Amazon.com and other places where it is sold.

(Quotes from PM’s book are shown in red and with page numbers.)

building7-closeup-burning.pngAlthough Popular Mechanics states the office fires in Building 7 reached temperatures of 1,100°F, both critics and supporters of the official story with technical expertise have pointed out that there is no evidence for fires that hot.

The Popular Mechanics chapter regarding the mysterious collapse of WTC 7 shows itself to be no more promising than its previous chapter on the Twin Towers. PM begins this section by summarizing the history of the controversy surrounding Building 7 and the numerous investigations carried out regarding its collapse. PM correctly notes that many agencies were located in the building as tenants, including the Secret Service, Central Intelligence Agency, Department of Defense, Internal Revenue Service, Securities and Exchange Commission, and New York City’s Office of Emergency Management. i The chapter discusses the initial FEMA investigation and how, after FEMA failed to provide an explanation for Building 7’s collapse, the task was then handed over to NIST. PM touts the NIST report on Building 7 as having finally proved the building was not destroyed with explosives. Contrary to PM’s assertion that the reason for WTC7’s collapse is “ less complicated and even more remarkable” (pg 66) than controlled demolition, it is apparent that the cause of collapse is still demolition, and that the NIST WTC7 report utterly fails to provide a reasonable explanation of what actually caused the collapse of the building.

The first section of PM’s WTC7 chapter mainly discusses the fire and damage to Building 7 and how this supposedly caused the building to collapse. Here is a summary of what NIST claims caused the collapse of WTC7:

  • The fires caused sufficient thermal expansion in the steel beams on the east side of WTC 7 to force the steel girder connecting Columns 44 and 79 to lose its connection with the latter, and to damage the floor framing on floors near Column 79
  • The loss of that girder’s connection to Column 79, along with fire– induced damage to the floor systems around Column 79, caused Floor 13 to collapse.
  • The collapse of Floor 13 caused all the floors below it down to Floor 5 to collapse.
  • Column 79, being left with inadequate lateral support, buckled between Floors 5 and 14.
  • This buckling caused the downward movement of Column 79 (which caused the collapse of the east penthouse).
  • Columns 80 and 81, having also lost support, buckled, causing all the floors on the east side of WTC7, which had been weakened by the fire, to collapse..)
  • All the other interior columns then failed, leaving the building a hollow shell.
  • After most of the collapse had already occurred in the building’s interior, where it could not be seen from the outside, the exterior columns failed, completing the collapse. ii

However, each of these points in this fantastic scenario is problematic:

  • Though PM claims that the fires in WTC7 reached temperatures ranging from 299°C (570°F) to 593°C (1,100°F), scientists on both sides of the argument have concluded that the fires could not have become this hot and could not have reached the temperatures claimed by NIST:
    • [R]aising those five floor beams to a temperature of 600°C would require an enormous amount of energy, far more than was available from the burning of the office furnishings underneath the floor beams. —Kevin Ryan iii
    • NIST’s collapse initiation hypothesis requires that structural steel temperatures on floors 12/13 significantly exceeded 300°C (570°F) – a condition that could never have been realized with NIST’s postulated 32 kg/m2 fuel loading. –Dr. Frank Greening iv

  • The fire that NIST claims started the collapse (via thermal expansion of long-span beams) had actually burned out in the area of the collapse more than an hour before the collapse. It could not, therefore, have caused the collapse at 5:20 p.m., as NIST claims:
    • Around 4:45 p.m., a photograph showed fires on Floors 7, 8, 9, and 11 near the middle of the north face; Floor 12 was [entirely] burned out by this time. v

    Examination of the photographs in the Final Report shows that the fire had burned out in the area of the collapse more than an hour before the collapse.

  • NIST arbitrarily added 10% to the result of their Fire Dynamics Simulator (FDS). This is simply not done in a scientific analysis:
    • Case A used the temperature data as obtained from the FDS simulation. Case B increased the Case A gas temperatures by 10%. vi
    • Only the fire-induced damage produced by Case B temperatures was carried forward as the initial condition for the building collapse analysis. vii

  • NIST applied this arbitrarily increased temperature for 4 hours of heating, ignoring their statement that the fires lasted only 20 to 30 minutes in any location. :
    • The building response is examined at 3.5 h and 4.0 h of heating. At 3.5 h, the floor systems had fire–induced damage and failures of some connections, beams, and girders. After 4.0 h of heating, substantially more damage and failures had occurred in the WTC7 structural floor system, particularly in the northeast region surrounding Column 79. viii

wtc7-column-76.pngPopular Mechanics repeats NIST’s claim that the failure of column 79 caused the collapse of the entire building, even though the scientific evidence contradicts this theory.

  • NIST applied the 4 hours of heating in 1–½ seconds over the entire northeast part of the floor, again creating an unrealistic situation and result:
    • Ramping up the temperatures for the beams and the girder then commenced at 1.1 s, leveling off at temperatures of 600°C for the beams and 500°C for the girder at 2.6 s. These temperature histories were prescribed uniformly for all nodes of the beams and the girder, respectively. ix

  • NIST heated the steel beams, but not the concrete slab above, and then claimed that the temperature differential caused the shear studs to fail. In reality, the fire would have heated them both nearly uniformly – without significant differential expansion.
    • No thermal expansion or material degradation was considered for the concrete slab. x

    Concrete expands at 85% the rate of steel. Leaving this expansion out of the calculations in order to show failure of the shear studs is both unscientific and fraudulent.

Certainty of impending collapse

David Ray Griffin noted in The Mysterious Collapse of WTC Seven: Why NIST’s Final 9“11 Report is Unscientific and False: The Mysterious Collapse of WTC Seven: Why NIST’s Final 9/11 Report is Unscientific and False:

  • f NIST did engage in fraudulent science, this would not be particularly surprising. NIST is an agency of the US Department of Commerce. During the years it was writing its World Trade Center reports, therefore, it was an agency of the Bush-Cheney administration. In 2004, the Union of Concerned Scientists put out a document charging this administration with “distortion of scientific knowledge for partisan political ends.” By the end of the Bush administration, this document had been signed by over 15,000 scientists, including 52 Nobel Laureates and 63 recipients of the National Medal of Science.
  • Moreover, a scientist who formerly worked for NIST has reported that it has been “fully hijacked from the scientific into the political realm,” with the result that scientists work ng for NIST “lost [their] scientific independence, and became little more than ‘hired guns.’” Referring in particular to NIST’s work on the World Trade Center, he said everything had to be approved by the Department of Commerce, the National Security Agency, and the Office of Management and Budget–“an arm of the Executive Office of the President,” which “had a policy person specifically delegated to provide oversight on [NIST’s] work.”

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Debunking the Real 9/11 Myths: Why Popular Mechanics Can't Face up to Reality - Part 3 Written by Adam Taylor Wednesday, 25 April 2012 16:07

Collapse Times of the Twin Towers

Editor’s note: This is Part 3 (see Part 2) of an extensive report by 9/11 researcher Adam Taylor that exposes the fallacies and flaws in the arguments made by the editors of Popular Mechanics (PM) in the latest edition of Debunking 9/11 Myths. We encourage you to submit your own reviews of the book at Amazon.com and other places where it is sold.

(Quotes from Popular Mechanics’ book are shown in red and with page numbers.)

Rapid Destruction of The Twin Towers While citing several experts who support their assertion that the collapse rates of the Towers were nothing unusual, PM failed to acknowledge numerous other experts who say that the collapse rates clearly violated the laws of physics.

In Popular Mechanics’ next section, they discuss the rate at which the Twin Towers were destroyed. PM begins by correctly pointing out that it is difficult to determine exactly how long it took each Tower to collapse, being that much of the destruction was blocked from view by the huge clouds of pulverized debris. However, it is quite evident that PM has again misrepresented the characteristics of the buildings’ destruction.

PM continues by naming off a few people who have said the Twin Towers collapsed too quickly, but they evidently cherry-picked the individuals to quote on this topic. For example, PM quotes talk show host Rosie O’Donnell as saying that the Towers each collapsed in nine seconds. They also quote 9/11 truth advocate Andrew Johnson as saying that the South and North Towers collapsed in eight seconds and ten seconds, respectively. However, neither of these individuals is an engineer or a scientist with relevant expertise who can give an expert opinion. To be sure, PM does quote engineers that say the collapse times of the Towers were not remarkable at all, but omits the opinions of the hundreds of architects and engineers who reviewed the Towers’ destruction and stated the collapses happened too quickly to have been caused by fire. Here are just a few expert opinions that could have been included in PM’s book: Paul W. Mason is among over 1600 credentialed architects and engineers who have challenged the official explanation for the Twin Towers’ collapse

The collapse of the three WTC buildings would seem to defy the laws of mechanics, conservation of energy and known structural failure behavior. The case for the destruction of the three WTC buildings by means of "controlled demolition" is overwhelming.
, civil engineer with 45+ years of experience

There is no doubt that there were vast quantities of extra energy applied to the structures to achieve both rapid collapses and complete destruction of their components. This energy can realistically only have come from explosive charges.
, civil/structural engineer with 35 years of experience

The speed at which the buildings fell implied that the central cores provided virtually no vertical resistance at any point during the collapses.
, civil engineer

The physics of momentum transfer in the collapse of the WTC buildings completely precludes the possibility that collapse at near free-fall speed could occur due to gravity alone.
, civil engineer

The prevailing theory would have us believe that each of the Twin Towers inexplicably collapsed upon itself crushing all 287 massive columns on each floor while maintaining a near free-fall acceleration as if the 100,000, or more, tons of supporting structural-steel framework underneath didn’t exist.
, P.E., Structural Engineer.

PM chose to omit opinions such as these from credentialed experts, preferring to only quote only those engineers who support their overall premise.

PM initially argues that the complete collapses of the buildings took longer than 10-15 seconds by quoting NIST as saying that the portions of the cores of both Towers actually remained standing after the outer structures fell. However, as noted by mechanical engineer Gordon Ross, a dimensional analysis by 9/11 researcher Muhummad Colombo shows that the cores of the Towers were attacked first in the demolition, based on dimensional analysis of the cores:

The photograph by Aman Zafar (below), previously shown and commented upon, appears to show the lower core structure still upright after the floors and perimeter columns had collapsed to ground level. However, this is not the full story. Muhammad's analysis shows that the remaining core was too narrow to be the entire core, and was in fact, the inner 23 core columns. The 24 core columns which made up the outer perimeter of the core structure and to which the floors were connected are clearly absent from the photograph. Thus we can see that the outer core columns fell in the early stages of the collapse along with the floors and perimeter walls. For this to happen, the bracing which attaches these outer core columns, both to each other and to the inner core columns, would have to be severed and each column broken into sections.

South_Tower_analysis.pngAnalysis of images of the South Tower shows that key core columns were destroyed early on in the collapse, a phenomenon that can only be caused by explosives, contradicting PM’s claims

PM claims that “professors and investigators contend it’s not surprising that [the Towers’] collapse-time estimates are close to would-be free-fall results” (pg. 44), and then proceeds to quote several of these said people. One of the people is MIT professor Dr. Thomas Eagar, who said it was not surprising that each Tower collapsed in ten seconds. PM writes:

[Eager’s] analysis explains that as exterior columns bowed and joists on the most heavily burned floors gave way, the mass of the collapsing floors created a cascade of failures
. (pg. 44)

This first thing that should be noted about PM’s citation of Dr. Eagar is that his analysis actually contradicts NIST’s analysis of the Towers’ collapses. PM cites Dr. Eagar’s paper, Why Did the World Trade Center Collapse? Science, Engineering, and Speculation, but when one actually reads what he wrote it is apparent that his analysis doesn’t promote NIST’s theory of collapse at all. In his paper, Dr. Eagar writes:

As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell.

Whereas NIST told us that the exterior columns bowed inward, Dr. Eagar’s paper asserts that the exterior columns bowed outward. By not quoting this section of his paper correctly, PM gives the impression that Dr. Eagar’s analysis is in total agreement with the NIST investigators (though Eagar’s paper currently provides a link to another article in the Journal of the Minerals, Metals and Materials Society that promotes NIST’s theory7). Instead, PM proceeds to directly quote from Eagar’s paper:

The floor below (with its 1,300 ton design capacity) could not support the roughly 45,000 tons of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an estimated speed of 200 km per hour.

However, this analysis is flawed by the fact that actual measurements of the collapse of the Towers show that the upper sections of the Towers never exerted massive forces on the lower sections, due to the fact that the upper sections accelerated through the lower section. As physicist David Chandler has shown, the upper section of the North Tower fell into the lower section, and

.9 Hence, there was no dynamic load being exerted on the lower section to cause it to collapse.

The next alleged expert PM cites is Dr. Keith Seffen, a senior lecturer in the engineering department at the University of Cambridge. They cite his paper, Progressive Collapse of the World Trade Center: A Simple Analysis, published in the Journal of Engineering Mechanics,10 as evidence that the Towers could have collapsed as quickly as they did as a result of the jet fuel and office fires. Instead of mentioning the technical refutations of Seffen’s claims, PM quotes a non-technical writer, Peter Wakefield Sault, who cites that “Dr. Seffen is an accessory after the fact to mass murder”. Dr. Keith Seffen has yet to respond to questions surrounding his defense of the official explanation for the Twin Towers’ collapse

PM’s citation of Sault’s comments highlights their obvious ploy to cherry-pick supporters of the 9/11 Truth movement to quote. Although a direct source for this quote is not provided (like most of the 9/11 Truth advocates quoted by PM), this statement is found not on the website PM provides, but on an obscure website. Sault is only commenting on a blog post about Keith Seffen.11 The fact that PM quotes from such an obscure source reveals their determination to portray anyone who questions the WTC collapses as a “crazy conspiracy theorist”. On the contrary, the study of the destruction of the Twin Towers entered the realm of laboratory research years ago with published articles in scientific and academic journals. The critique of Seffen’s WTC paper written by University of Iowa Physics Professor Dr. Crockett Grabbe points out the many unscientific arguments that Seffen made

Evidently, PM’s writers and investigative journalists somehow missed an article written by Dr. Crockett Grabbe which refutes the arguments made in Seffen’s questionable paper even though Grabbe’s article was published in the very same journal as Dr. Seffen’s paper.12 Though PM touts Dr. Seffen and his paper as providing excellent analysis of the WTC collapses, there is no mention of Grabbe’s peer-reviewed response, even though Grabbe is a credentialed scientist. Instead, PM chose to cite an inflammatory remark on an obscure internet site.

Dr. Seffen never responded to Dr. Grabbe’s discussion paper, which was published over three years ago. In addition, PM felt no need to quote Dr. Grabbe, who says on his website, “Seffen is an applied mathematician from Cambridge whose paper was on BBC News. I ripped his paper apart, and he never made any reply to my very critical comments.”13

PM finishes this section by quoting a section of NIST’s report on the collapse of the Twin Towers that discusses the rate of collapse. The section reads:

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increases, further increasing the demand of the floors below, which were unable to arrest the moving mass.

PM also quotes from NIST’s FAQ on the WTC collapses:

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2… Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.

However, engineer and 9/11 researcher Jim Hoffman addressed both of NIST’s assertions. In regards to the first point, Hoffman writes:

This does not explain either why the structure below failed to arrest the falling mass or how the structure failed to appreciably slow the falling mass. As in the preceding paragraphs, NIST begs these questions using a kind of circular argument:
The towers fell rapidly because the stories below could not resist the tremendous energy of the falling mass
. Videos clearly show that the upper section fell essentially in free-fall. Therefore the structures below offered minimal resistance to and were destroyed by the falling mass. The argument pre-supposes the conclusion that the force that overcame the resistance of the structures below was the falling mass, not some other force such as energy of explosives.

As for the second point, Hoffman writes:

To the contrary, video records, such as
, clearly establish upper boundaries on the times that it took for the vast majority of each tower to be destroyed.

While citing several experts who support their assertion that the collapse rates of the Towers were nothing unusual, PM failed to acknowledge numerous other experts who say that the collapse rates clearly violated the laws of physics. The rate in which the Towers came down cannot be explained by the combined effects of fire and gravity.

For more on the subject of the Towers’ collapse rates, the following articles are recommended:

by James Smith

, by Prof. Graeme MacQueen and Tony Szamboti

by David Chandler

by Crockett Grabbe

[in Part 4 of this monthly series, Taylor challenges Popular Mechanics’ misleading claims regarding the violent ejections of dust and building materials during the collapse of the Twin Towers. Look for Part 4 in the May edition of the Blueprint newsletter. For Part 2 click here]

1Quoted from: http://www2.ae911tru....php?uid=998501

2Quoted from: http://www2.ae911tru....php?uid=997386

3Quoted from: http://www2.ae911tru....php?uid=999894

4Quoted from: http://www2.ae911tru...php?uid=999612

5Quoted from: http://gordonssite.t...d.com/id2.html

6Quoted from: Why Did the World Trade Center Collapse? Science, Engineering, and Speculation, by Thomas W. Eagar and Christopher Musso http://www.tms.org/p...agar-0112.html

7See: http://www.tms.org/p...novic-0711.html

8Quoted from: Why Did the World Trade Center Collapse? Science, Engineering, and Speculation

9This analysis is shown in David Chandler’s paper: Destruction of the World Trade Center North Tower and Fundamental Physics http://www.journalof...ationOfWTC1.pdf (David Chandler also outlines this point in this video:)

10Seffen’s paper can be read here: http://winterpatriot...e_analysis.pdf

11See: http://laura-knight-...ecial-wtc.html

12The paper can be read here: http://www.sealane.o...ffenrevpub.pdf

13Quoted from: http://www.sealane.o.../research.html

14Quoted from: NCSTAR 1, pg. 146 http://www.nist.gov/...?pub_id=909017

15Quoted from: http://www.nist.gov/..._wtctowers.cfm

16Quoted from: http://911research.w...ist/index.html

17Quoted from: http://911research.w..._FAQ_reply.html

Edited by Steven Gaal
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