Earthquake bomb

Earthquake bombs were used towards the end of World War II on massively reinforced installations, such as submarine pens with concrete walls several meters thick, caverns, tunnels, and bridges.

Barnes Wallis' idea was to drop a large, heavy bomb with a hard armoured tip at supersonic speed (as fast as an artillery shell) so that it penetrated the ground like a ten-ton bullet being fired straight down.

The resulting shock wave from the explosion would then produce force equivalent to that of a 3.6 magnitude earthquake,[citation needed] destroying any nearby structures such as dams, railways, viaducts, etc.

Wallis also argued that, if the bomb penetrated deep enough, the explosion would not breach the surface of the ground and would thus produce a cavern (a camouflet) which would remove the structure's underground support, thus causing it to collapse.

Wallis foresaw that disrupting German industry would remove its ability to fight, and also understood that precision bombing was virtually impossible in the late 1930s.

The technology for precision aiming was developed during World War II, and Barnes Wallis' ideas were then shown to be successful (see for example the Bielefeld raid on 14 March 1945), considering the standards at the time.

Given the availability of nuclear weapons with surface detonating laydown delivery, there was little or no development of conventional deep penetrating bombs until the 1991 Gulf War.

In three weeks, a cooperative effort directed by the Armament Systems Division at Eglin Air Force Base in Florida developed the 5,000-pound (2,300 kg) GBU-28 that was used successfully by F-111Fs against a deep underground complex not far from Baghdad just before the end of the war.

[citation needed] The United States has developed a 30,000-pound (14,000 kg) Massive Ordnance Penetrator, designed to attack very deeply buried targets without the use of nuclear weapons with the inherent huge levels of radioactive pollution and their attendant risk of retaliation in kind.