The limpet mine (T.S.R.) was built in two specimens in the Dockyard of Venice according to a design by Major of the Naval Engineers Raffaele Rossetti.

The device was propelled by compressed air. The eight-meter long torpedo- shaped mine, with a diameter of 600 mm, had a 10 mile range at 1 MPH.

Besides, it was fitted with explosive charges designed to be fixed to the ship’s bottom by magnets. The operators, usually frogmen, used to carry the mine to the target and fix it to the enemy ships.

The most spectacular action performed using limpet mines was the sinking of the Austro-Hungarian SMS Battleship Viribus Unitis in the harbor of Pola (Trieste) on November 1, 1918.