Reply To: Engineering Prof releases draft report on 9/11 collapse of WTC Bldg 7 in NYC


Home Forums Discussion Forum Engineering Prof releases draft report on 9/11 collapse of WTC Bldg 7 in NYC Reply To: Engineering Prof releases draft report on 9/11 collapse of WTC Bldg 7 in NYC

#46944
Clark

Yes, I’m saying that an emergency demolition was performed on WTC7, on the day of 9/11.

I stress emergency, not “controlled”. A civilian demolition is “controlled” in the sense that the company guarantees to limit the adjacent damage, and will pay compensation should damage exceed those limits. None of this applied post-collapse of WTCs 1 and 2; saving lives became the priority. The fire-fighters were on the verge of mutiny, prevented from searching for their lost comrades in the WTC7 exclusion zone.

Military engineers have repeatedly brought down structures in a matter of hours, behind enemy lines. Similar to 9/11, adjacent damage is not going to spark compensation claims and “control” is not the primary objective. It is true that WTC7 came down pretty symmetrically. Considerable asymmetry in fact occurred, but it was only clear from one of the camera angles, and all the more commonly seen shots make the fall look more symmetrical than it was. The fall also damaged two adjacent buildings; though most of the debris did end up in the building’s footprint, it would have been considered an expensive failure as a controlled demolition.

I think the remarkable symmetry of collapse was a combination of skill, luck, and WTC7’s unusual truss arrangement straddling a pre-existing electricity transformer substation; the “bridge” upon which the core was constructed acted as a convenient way of dropping the core.