| Nous sommes désolés, il n'existe pas de traduction de ce texte pour le moment. 
 
	DEBUNKING THE REAL 9/11 MYTHS:
Written by Adam Taylor WHY POPULAR MECHANICS CANT FACE UP TO REALITY
Part 7: WTC 7 Fire and Column Failure
Editors 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 PMs book are shown in red and with page numbers.)
	
 
	
		
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			| Although 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 7s	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
	PMs assertion that	the reason for WTC7s 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 PMs 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 79The 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 buildings
		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 NISTs 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 NISTs 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 fireinduced 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 
		
			
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				| Popular 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 1½ 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 NISTs Final 911 Report is
	Unscientific and False: The Mysterious Collapse of WTC Seven: Why NISTs Final 9/11 Report is
	Unscientific and False:
 
	[I]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 NISTs 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
		Budgetan arm of the Executive Office of the President, which had a policy person
		specifically delegated to provide oversight on [NISTs] work. 
 
	 ↑ For the full list of WTC7 tenants, see:	http://wtc7.net/background.html
	 ↑ Summary adapted from The Mysterious Collapse of World Trade	Center 7,
		by David Ray Griffin, pg 210211
	 ↑ Quoted from: http://911review.com/articles/ryan/NIST_WTC7.html
		
	 ↑ Quoted from: http://www.coolplaces.0catch.com/911/
		GreeningCommentsNCSTAR1-9.pdf
	 ↑ NIST L pg 26 [pdf pg 30]
	 ↑ NIST NCSTAR 1A pg 32 [pdf pg 74] http://www.nist.gov/customcf/
		get_pdf.cfm?pub_id=861610
	 ↑ NIST NCSTAR 1A pg 36 [pdf pg 78] ↑ NIST  NCSTAR 19 Vol. 2 pg 493 [pdf pg 155]:http://wtc7.net/background.html
	 ↑ NIST NCSTAR 19 Vol. 1 pg 352 [pdf pg 396]
	 ↑ NIST NCSTAR 19 Vol. 1 pg 352 [pdf pg 396]
	 
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