torpedo

Cigar-shaped, self-propelled underwater missile, launched from a submarine, surface vessel, or airplane and designed to explode on contact with the hulls of surface vessels and submarines. It contains devices to control depth and direction as well as a detonator for the explosive-filled warhead. Originally the word referred to any explosive charge, including the weapon now known as a submarine mine. The first modern torpedo (1866) carried an 18-lb (8-kg) charge of dynamite in its nose and was powered by a compressed-air engine driving a single propeller; its range was 200–700 yards (180–640 m). Torpedoes were used successfully by submarines in both world wars, when many merchant ships were sunk, mostly by German U-boats. Torpedoes are now usually propelled by battery-powered electric motors.