Graphical data on aircraft impacts at WTC

The following graphical representations are taken from an 2002 article
in THE BRIDGE by WTC building designer Leslie Robertson. The graphs
show the relative impact energies of various aircraft types and the fuel
loads carried by them. Roberstson states the the buildings were
engineered to resist impact forces of Boeing 707 at low speed (>300 kph/
>200 mph). The fire potential of the fuel load was not considered in
calculating the building resistance.










www.nae.edu...$FILE/Bridge-v32n1.pdf?OpenElement

Les Robertson's group was only one of the engineering groups on the WTC project, and his wasn't the group that did the plane impact calculations and published them.

The firm that published information on the designs' capacity for plane impacts was Worthington, Skilling, Helle & Jackson.

This particular item of information was the 3rd point on an eleven-point white paper that firm released while the towers were being designed:

3. The buildings have been investigated and found to be safe in an assumed collision with a large jet airliner (Boeing 707-DC 8) traveling at 600 miles per hour. Analysis indicates that such collision would result in only local damage which could not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact.
[...]
--City in the Sky, p 131

stj911.org...


Note that what the above quote says must have been true because it was proven with a heavier plane (767) on 9/11. The plane impacts severed less than 15% of the columns on the impacted floors in either building. If you think that's a lot, then look up the concept of a "safety factor" in structural engineering. The fires would have had to have done at least 4x the damage of the impacts to bring the structures to the brink of collapse with a generalized safety factor of only 2 for the impacted floors.

[edit on 6-12-2007 by bsbray11]