Mark 17 torpedo
The Mark 17 torpedo was a long-range, high-speed torpedo developed by the Naval Torpedo Station in Newport, Rhode Island and the Naval Research Laboratory in 1940. Development efforts on the Mark 17 were halted in 1941 in favor of producing Mark 13 and Mark 15 torpedoes during World War II; development resumed in 1944. Production of the Mark 17 began before development was complete and though 450 units were manufactured before the war was over, none of these were used in combat.
The Mark 17 was discontinued about 1950.