Originally posted by ANOK
Why don't you do some calculations to show it wouldn't need explosives to laterally eject 500 ton pieces of steel.
I'll provide you with this, not that you'll understand any of it.
wtc7lies.googlepages.com...
For a worked example, Rememnikov [150] presents a typical charge of 100 kg TNT
exploding at a distance of 15 meters. A series of objects placed at this distance would
experience 272 kPa or just under 40 PSI, but would only experience the overpressure for
17.2 milliseconds, including the reflection of the blast, after which the pressure wave has
passed the objects. Let’s assume we’re discussing a section of unattached, hollow square
steel column 3 m high by 20 cm wide, with walls 4 cm thick. This object presents a
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maximum of 0.6 m2 to the blast front, so it experiences a maximum force of 272 kPa x
0.6 m2 = 163,200 N for 17.2 milliseconds, for a total impulse of 2807 Newton seconds.
It should be noted that the simplified calculation above grossly overestimates the total
impulse, because we have assumed the peak pressure is sustained for the entire duration,
when in reality a lower average value is expected. The actual expected impulse per
facing area, seen in Table 1 of Rememnikov’s paper, is a mere 955 kPa-msec, or only 573
Newton seconds imparted to our column as above. We therefore are using a very
generous estimate, almost five times higher than we actually expect. We will use our
simplified estimate rather than the lower, more accurate number to silence any doubts
that we have potentially underestimated the maximum imparted velocity.
The total impulse is equal to the mass of the object times the change in velocity. In this
case, our column contains 256 cm2 x 3 m of steel or 76,800 cm3 of steel, for a mass of
approximately 600 kg. The column would, therefore, be accelerated by 2807 N s / 600 kg
= 4.7 meters per second, or about 10 miles per hour – hardly a remarkable value
compared to the ricochet scenario described above. In order to propel this column at the
speed required, say 30 meters per second, we would need charges of at least 700 kg TNT
equivalent – very large and clearly audible explosives indeed, even accepting our
generous assumptions above.
Did you get that? To throw A 600kg piece 600' from a height of 500' would require 700kg of TNT equivalent...........
Still believe that explosives did it?
