Did You Know High Strength Steel Gives No Resistance to a Medium-Sized Aluminum Plane Going 450 MPH?
“Because of their unique design and the use of the so called “steel bearing wall” tube structural system, which as far as we know has never been used before or after its application in the WTC towers, the buildings essentially showed no resistance to the impact of a medium-sized plane flying into them at about 450miles per hour.”
He also noted that designers chose to fabricate many of the building columns out of very high strength steel [90 ksi steel as opposed to the more typical 36-65 ksi steel]. “This is not allowed by the structural design codes then and is still notallowed in current codes,” he stressed. “But the World Trade Center did not need to obtain a permit from City Hall. Because of special status as Port Authority of New York and New Jersey, they could make such choices outside the prevailing codes.”
This choice, he argued, allowed builders to use less steel in the columns [two to three times thinner than typical columns] presumably to save cost.
But by using high strength steel and thin cross sections, he pointed out, on impact the plane was able to cut through the outside steel bearing wall and enter the building...
What will those wacky engineers come up with next???