W4d5Y
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This is exagerated, a fair amount of concrete, which equaled 780,000 metric tons, together with 200,000 metric tons of steel, was pulverized in mid-air and would therefore reduce the mass the building would build up during the collapse and therefore decrease the mechanical energy (or kinetic, people always vary with the description) which would require a steady supply of mass in order to have the two towers crush themselves completely due to gravity and Newton's laws.
Once the top section and a section beneath equal in mass are consumed in the collapse and leave only dust and an amount of steel which is lighter in mass, I do not understand where (apart from loose steelbeams) the steady supply of mass came from to deliver the energy necessary to continue the collapse.
And why the hell did the outer wall of the lobby survive the collapse, yet not the mighty core collumns?
I usually do not bother consulting engineers for matters of collapse mechanics, although of course you are the ones you have the best idea of what a building can stand and what not.
(ps: Showing that the towers could indeed have collapsed in on themselves however does not disprove that secondary devices might have been involved.)
But let's ask some engineers just this time:
pretty short here, sadly.
Once the top section and a section beneath equal in mass are consumed in the collapse and leave only dust and an amount of steel which is lighter in mass, I do not understand where (apart from loose steelbeams) the steady supply of mass came from to deliver the energy necessary to continue the collapse.
And why the hell did the outer wall of the lobby survive the collapse, yet not the mighty core collumns?
I usually do not bother consulting engineers for matters of collapse mechanics, although of course you are the ones you have the best idea of what a building can stand and what not.
(ps: Showing that the towers could indeed have collapsed in on themselves however does not disprove that secondary devices might have been involved.)
But let's ask some engineers just this time:
-Scott C. Grainger, BS CE, PE – Licensed Professional Civil Engineer and/or Fire Protection Engineer in the States of Arizona, California, Colorado, Nevada, New Mexico, New York, Utah, Virginia, Washington, and Wyoming. Owner of Grainger Consulting, Inc., a fire protection engineering firm (23 years). Former Chairman, Arizona State Fire Code Committee. Former President of the Arizona Chapter of the Society of Fire Protection Engineers. Current Member of the Forensic Sciences Committee and the Fire Standards Committee of ASTM International (formerly American Society for Testing and Materials ). Senior Member, National Academy of Forensic Engineers."Approximately 50% of my work is forensic. I am licensed in 9 States. In addition to my forensic work, a good portion of my work is in the design of structural fireproofing systems.
All three [WTC] collapses were very uniform in nature. Natural collapses due to unplanned events are not uniform."
pretty short here, sadly.
- Eric Douglas – Registered Architect in New York and California.The NIST investigation of the WTC building failures was extensive, but NIST did not substantiate its conclusions experimentally. On the contrary, many of NIST’s tests contradicted its conclusions. Furthermore, there are several examples in which NIST chose to manipulate input data, and then certify its findings based upon the inevitable conclusions that derive from the manipulated input. One finds little acknowledgement on the part of NIST that uncertainties in its simulations translate into uncertainties in its findings.
NIST’s physical tests were inadequate. Their ASTM E119 tests and their workstation burn tests were improperly modeled. Further, the former produced results that contradicted NIST’s conclusions and the latter fell far short of testing the performance of realistic steel members in the actual fire conditions. The workstation burn tests showed that the temperatures were generally too low, especially in the ventilation-controlled WTC environments. The ASTM E119 tests showed that the WTC floor trusses should have easily withstood the fires they experienced on 9/11.
There were also flaws in NIST’s computer simulations, including its impact simulation, its fire loading simulation, its temperature mapping simulation, its thermal/structural component simulations, and its global simulation. The LS-DYNA simulation showed that the aircraft would have done much less damage than NIST assumes, and NIST’s subsequent "scenario pruning" was confused and unsubstantiated. The decision to exclude the hat truss from the structural/thermal response simulations was a significant omission. The sequence of failed truss seats leading to pull-in forces on the exterior columns is central to NIST’s theory but not explained or supported by simulation.
This paper will conclude that the findings of the NIST investigation, although not necessarily incorrect, are not inherently linked to the reality of the failure mechanisms that took place in WTC buildings 1 and 2. The author calls on NIST to explain the discrepancies in its reports, admit the level of uncertainty in its findings, broaden the scope of its investigation, and make its raw data available to other researchers.
Statement from September 13th, 2001:In my opinion the building WTC 7 was, with great probability, professionally demolished," says Hugo Bachmann, Emeritus ETH [Swiss Federal Institute of Technology] - Professor of Structural Analysis and Construction. And also J?rg Schneider, likewise emeritus ETH - Professor of Structural Analysis and Construction, interprets the few available video recordings as evidence that "the building WTC 7 was with great probability demolished."
- Hugo Bachmann, PhD – Professor Emeritus and former Chairman of the Department of Structural Dynamics and Earthquake Engineering, Swiss Federal Institute of Technology. Author and co-author of Erdbebenbemessung von Stahlbetonhochbauten (Seismic Analysis of Concrete Reinforced Structures) (1990), Vibration Problems in Structures: Practical Guidelines (1995), Biege- und Schubversuche an teilweise vorgespannten Leichtbetonbalken (Structural Analysis of Linked Concrete Beams) (1998), Hochbau f?r Ingenieure. Eine Einf?hrung (Structural Construction for Engineers. An introduction) (2001), Erdbebensicherung von Bauwerken (Earthquake-proofing Buildings) (2002).As Bachmann told the Neue Z?richer Zeitung Online on September 13, 2001, at first glance there seemed to be two possibilities in the fall of the towers. The first was the fire and its effect on the steel supports. But Bachmann had an alternative: "In the second scenario, an additional terrorist action would have caused the collapse of the buildings. In this way, according to Bachmann, buildings like the World Trade center can be destroyed without great logistical exertion." The article went on to say that "Bachmann could imagine that the perpetrators had installed explosives on key supports in a lower floor before the attack." If the perpetrators had rented office space, then these "explosive tenants" could have calmly placed explosive charges on the vulnerable parts of the building "without having anyone notice."
- David A. Johnson, B.Arch, MCP (City Planning), PhD (Regional Planning), F.AICP – Internationally recognized architect and city and regional planner. Professor Emeritus, Department of Urban and Regional Planning, University of Tennessee. Former Professor and Chair of the Planning Departments at Syracuse University and Ball State University. Elected Fellow, American Institute of Certified Planners (2004). Past President of the Fulbright Association of the United States. Recipient of five Fulbright Scholarships for continued education in Cyprus, India, Thailand, and the Soviet Union. Directed educational projects in Brazil and Portugal. Active in reconstruction efforts in Bosnia and bicommunal peace-making in Cyprus. Former professional planner on the staffs of the Washington National Capital Planning Commission and the Regional Plan Association of New York. Former editorial board member of the Journal of the American Planning Association. Author of numerous journal articles on urban and regional planning theory and history. Author of Planning the Great Metropolis (1996). Co-author of The TVA Regional Planning and Development Program (2005). Contributing author to Two Centuries of American Planning (1988).I was dubious of the official explanations from the outset. You see, as a professional city planner in New York, I knew those buildings and their design. I attended and participated in the hearings at the New York City Hall when the buildings were first proposed. I argued for the buildings on the basis that the interior core represented a way of internalizing the cost of mass transit, which in our system is almost impossible to finance through public bond issues.
So I was well aware of the strength of the core with its steel columns, surrounding the elevators, and stairwells. I should also mention that with a degree in architecture and instruction in steel design (my Yale professor had worked on the Empire State Building) I was and am no novice in structural design.
When I saw the rapid collapse of the towers, I knew that they could not come down the way they did without explosives and the severing of core columns at the base. The spewing of debris from the towers where the planes entered also could not have occurred simply with just a structural collapse. Something else was happening to make this occur.
Moreover, the symmetrical collapse is strong evidence of a controlled demolition. A building falling from asymmetrical structural failure would not collapse so neatly, nor so rapidly, as you have pointed out.
What we are faced with is a lie of such proportions that even to suggest it makes one subject to ridicule and scorn. Who could have done such a terrible thing? Certainly not our government or military. Rogue elements in the intelligence agencies? I have no idea.
But I do know that the official explanation doesn't hold water. An open, honest re-opening of the case is in order. A near majority of Americans agrees with this view. Let us keep pressing for an honest investigation.