T-12 Cloudmaker

The T-12 (also known as Cloudmaker) earthquake bomb was developed by the United States from 1944 to 1948 and deployed until the withdrawal of the Convair B-36 Peacemaker bomber aircraft in 1958.

It achieved this by having an extremely thick, hardened nose section designed to penetrate deeply into the earth before exploding and then damage the target by the resulting shock wave.

The T-12 was a further development of the concept initiated with the United Kingdom's Tallboy and Grand Slam weapons developed by British aeronautical engineer Barnes Wallis during the Second World War: a hardened, highly aerodynamic bomb of the greatest possible weight designed to be dropped from the highest possible altitude.

Originally designed to meet a 42,000 lb (19,000 kg) target weight (one half of the maximum payload for the Convair B-36 "Peacemaker" bomber), with its hardened case was slightly less than 43,000 lb (19,500 kg).

This was twice the size of the United States' previous largest bomb, the 22,000 lb (10,000 kg) M110 (T-14), the American-built version of the British Grand Slam.