AFIK the biggest conventional bomb was the WW2 T12, one of which (no
HE!) stands sentry at the front door to the office of the Aberdeen
proving Gorund Museum. 43,000 pounds, ready to drop. My brother in law
was a USAF Sgt working on the things out at Muroc (Edwards AFB) at the
end of WW2. He kept us in stitches one night telling us about the
troubles they had just getting the things off the train and to the
ramp. He told us about a tug driver pulling up to a hangar and then the
tug, him and the bomb on its trailer sliding through the hangar wall
because the brake system was unable to cope with 100,000 pounds worth
of inertia. When the static drop test was conducted (prior to flight)
the B29's tires left the ground due to the rebound of suddenly
releasing 21.5 tons. The bomb was dropped from just over 20,000 because
teh B29 couldn't get it any higher. it hit the salt flats and made a
hole about 90 feet across and the same dapth - and it was loaded with
just concrete for ballast - no HE at all. You can google 'Very Heavy
Bombs' for more info. Oh, yes, he was the tug driver mentioned above.
He retired about twenty years ago from his job as senior scientist for
Hughes Aircraft. Walt