from Screw Loose Change
This response to “On the Physics of High Rise Building Collapses“, is not thorough or scholarly, is shot through with basic errors (the type of plane that hit the towers for one), but it is so far the only response we have found that isn’t simply ad hominem or ridicule, and we’re publishing it in the interests of presenting opposing views. Is there a serious rebuttal to be made of Jones et al? Is this the best that can be done to refute the case for controlled demolition? We would very much like to see a better one of it can be found. And if it can’t – well that speaks for itself. And if anyone wants to reply to this we’ll be happy to publish any cogent responses
In terms of our usual metric, TTFLMO (time to first lie, mistake or omission) this one actually does pretty well; it is almost three paragraphs into the article. Talking about why high-rise buildings usually do not collapse due to fires, they write:
2) Most high-rises have fire suppression systems (water sprinklers), which further prevent a fire from releasing sufficient energy to heat the steel to a critical failure state;
True enough as far as it goes, but it omits one critical detail: when WTC-2 (the South Tower) collapsed, it took the water mains with it, and thus there were no sprinklers running in WTC-1 and WTC-7 to prevent the fires from spreading. As a practical matter, I suspect that the sprinklers in WTC-1 and WTC-2 were already not functioning after the plane impacts, but even if they were they would have been insufficient to put out the massive fires in those two buildings.
But after that, the errors and omissions abound. Next paragraph:
3) Structural members are protected by fireproofing materials, which are designed to prevent them from reaching failure temperatures within specified time periods; and
Ignores the obvious, which is that the impact of the plane debris stripped away a good deal of the fireproofing. This is the usual Truther nonsense of focusing solely on the fires and not considering the enormous energy released by the two 757s(sic) when they hit the two towers.
4) Steel-framed high-rises are designed to be highly redundant structural systems. Thus, if a localized failure occurs, it does not result in a disproportionate collapse of the entire structure.
Which ignores the unusual tube-in-tube design of the towers, which were not as capable of shifting the enormous loads they encountered on 9-11 as conventional skyscrapers.
The total collapse of WTC 7 at 5:20 PM on 9/11, shown in Fig. 2, is remarkable because it exemplified all the signature features of an implosion: The building dropped in absolute free fall for the first 2.25 seconds of its descent over a distance of 32 meters or eight stories . Its transition from stasis to free fall was sudden, occurring in approximately one-half second. It fell symmetrically straight down. Its steel frame was almost entirely dismembered and deposited mostly inside the building’s footprint, while most of its concrete was pulverized into tiny particles. Finally, the collapse was rapid, occurring in less than seven seconds.
All the signature features of an implosion? Sorry, Dr Jones, but I have watched quite a few controlled demolition implosions of buildings before and there were several missing from WTC-7’s collapse on 9-11:
1. No deafening explosions of the shaped charges which (Jones admits) are usually used in controlled demolitions.[see here for claims of eyewitness testimony of explosions – OffG ed]
2. No prior removal of the glass and other materials which might impede the collapse (not to mention the belongings inside the buiding.
3. No miles of detonation cord as is commonly used to ensure the simultaneous (or nearly) loss of load-bearing supports to the building.
And of course, when it comes to the towers, the usual focus on why the NIST report didn’t go past the moment that collapse became inevitable:
Whereas NIST did attempt to analyze and model the collapse of WTC 7, it did not do so in the case of the Twin Towers. In NIST’s own words, “The focus of the investigation was on the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower….this sequence is referred to as the ‘probable collapsesequence,’ although it includes little analysis of the structural behaviour of the tower after the conditions for collapse initiation were reached and collapse became inevitable.”
Gee, I don’t know, maybe it’s because the collapse became, you know, inevitable? After that, there are too many variables to really measure, but it doesn’t really matter.
Thus, the definitive report on the collapse of the Twin Towers contains no analysis of why the lower sections failed to arrest or even slow the descent of the upper sections—which NIST acknowledges “came down essentially in free fall” [5-6]—nor does it explain the various other phenomena observed during the collapses. When a group of petitioners filed a formal Request for Correction asking NIST to perform such analysis, NIST replied thatit was “unable to provide a full explanation of the total collapse” because “the computer models [were] not able to converge on a solution.”
If NIST really acknowledges that the Twin Towers came down “essentially in free fall” then bad on them. As for why the lower sections failed to arrest (they did slow) the descent of the upper floors, it is blindingly obvious: The floors were connected to the exterior and central columns of the building. As the weight from above collapsed on each floor, it pulled in on the connections until they snapped on the exterior. Very quickly the exterior portions of the building peeled away from the floors, leaving nothing to support them. This is why you can see, in aerial photographs of the devastation, large sections of the exterior walls virtually intact.
The references section contains four footnotes from JONES, and one from the ridiculous Bentham paper. I hope that there will be some vigorous pushback on this article from the magazine’s subscribers.