Naval forces chose both torpedo and dive bombers. These comprised two squadrons each of dive bombers and torpedo bombers. He later flew as a turret gunner in an Avenger torpedo bomber. Both types of torpedo bombers suffered heavy casualties. Several smaller guns were carried for defense against torpedo boats. This is the working of torpedo and naval mine warfare. These ships could also function as flagships of torpedo boat flotillas. The ships were also armed with a quadruple bank of torpedo tubes. The mine is propelled to its intended position by propulsion equipment such as a torpedo. She was also armed with a pair of submerged torpedo tubes. Samuel Colt experimented with electrical firing of the torpedo. The propulsion system was the biggest obstacle in the development of the Yu-6 torpedo. But this fire was separate from that caused by the exploding torpedo. The first boat designed to fire the self-propelled Whitehead torpedo was , completed in 1877. The base later became famous as the home base of the manned Kaiten "suicide torpedo".