Lot 154
A wooden model of The Grand Slam Bomb (medium capacity) 22,000 LB (10,000 kilogrammes earthquake bomb) raised on a turned wooden stand 17cm x 7cm. The Grand Slam was the second bomb Wallis designed after the success of the bouncing bomb. The bomb was even larger than the Tallboy and there was still no aircraft capable of lifting it to its optimal altitude. Like the Tallboy it could be dropped from a lower height and would enter the earth at near supersonic speed, penetrating to a depth of up to 20m before exploding. The Grand Slam was also used on strategic German targets such as V-2 rocket launch sites, the V-3 supergun bunker, submarine pens and the battleship Tirpitz, as well as large civil constructions such as viaducts and bridges.  £400-600