Special Atomic Demolition Munition

The Special Atomic Demolition Munition (SADM) was a United States Navy and Marines project that was demonstrated as feasible in the mid-to-late 1960s, but was never used. The project, which involved a small nuclear weapon, was designed to allow one individual to parachute from any type of aircraft carrying the weapon package that would be placed in a harbor or other strategic location that could be accessed from the sea. Another parachutist without a weapon package would follow the first parachutist to provide support as needed.

The two-man team would place the weapon package in the target location, set the timer, and swim out into the ocean where they would be retrieved by a submarine or other high-speed water craft. The parachute jumps and the retrieval procedures were practiced extensively.

In the 1950s and 1960s, the United States developed several different types of lightweight nuclear devices. The main one was the Mk-54, a cylinder 40 by 60 centimetes and weighed 68 kilograms, fired by a mechanical timer it had a variable yield from 10 tons up to one kiloton. 300 SADMs were assembled and remained in the US arsenal until 1989.