[Cvengr]

I disagree with you on the melting of steel. Since it seems so easy to melt steel with jet fuel or diesel, try melting your barbecue pit some time and see how successful you might be. Air flow, fuel consumption, temperature and total heat available don' t add up to melt the steel in order to cause the failures observed quantitatively. Differentials in expansion rates between the concrete and the steel would have produced far greater failing shear stress combined with the weight of the floor above at the connections of the floors to the outer walls. Additional loading on the assymetric nature of catastrophic failure from the aircraft s impact and damage to internal columns increased the catalytic nature of the initial failure of the first floors to drop, but the heating of the steal only reduced total strength. The steel didn't melt.

[Hugh Akston]

Since it seems so easy to melt steel with jet fuel or diesel, try melting your barbecue pit some time and see how successful you might be.

I doubt some charcoal would have caused the steel in the WTC to melt or buckle.

However, if you took your backyard grill, put it in a pool containing the jet fuel that a fully loaded airplane would contain, and set the pool ablaze, the grill would melt.

[Hugh Akston]

By the way- if you were trying to argue a distinction without a difference, namely that the steel did not actually "melt" but rather just had buckled, having had its ability to retain its formed shape due to the heat, then I will concede that point.