Tench-class submarine

USS Toro shown post-war, after removal of her deck guns, c. 1947.[1]
Class overview
Builders	Portsmouth Naval Shipyard Electric Boat Company Boston Navy Yard[3]
Operators	United States Navy  Republic of China Navy  Turkish Navy  Hellenic Navy  Peruvian Navy  Pakistan Navy  Maritime Command  Italian Navy  Brazilian Navy  Bolivarian Navy of Venezuela
Preceded by	Balao class
Succeeded by	Barracuda class
Subclasses	Corsair class
Built	1944–1951[2]
In commission	1944–present[2]
Completed	29[3]
Cancelled	51[3]
Active	1[3][needs update]
Lost	1[3]
Retired	27[3]
Preserved	3
General characteristics
Type	Diesel-electric submarine
Displacement	1,570 tons (1,595 t) surfaced[3] 2,416–2,429 tons (2,455–2468 t) submerged[3]
Length	311 ft 8 in – 311 ft 9 in (95.0 m)[3]
Beam	27 ft 3 in – 27 ft 4 in (8.3 m)[3]
Draft	17 ft (5.2 m) maximum[3]
Propulsion	4 × diesel engines driving electrical generators (Fairbanks-Morse or General Motors (Corsair only))[3] 2 × 126-cell Sargo batteries[5] 2 × low-speed direct drive electric motors (Elliott Company, General Electric, or Westinghouse)[3] two propellers[3] 5,400 shp (4,000 kW) surfaced[3] 2,740 shp (2,040 kW) submerged[3]
Speed	20.25 knots (38 km/h) surfaced[5] 8.75 knots (16 km/h) submerged[5]
Range	11,000 nautical miles (20,000 km) surfaced at 10 knots (19 km/h)[4]
Endurance	48 hours at 2 knots (3.7 km/h) submerged[5] 75 days on patrol
Test depth	400 ft (120 m)[5]
Complement	10 officers, 71 enlisted[5]
Armament	10 × 21-inch (533 mm) torpedo tubes 6 forward, 4 aft) 28 torpedoes[6] 1 × 5-inch (127 mm) / 25 caliber deck gun[6] Bofors 40 mm and Oerlikon 20 mm cannon[3][5][7]

Tench-class submarines were a type of submarine built for the United States Navy (USN) between 1944 and 1951. They were an improvement over the Gato and Balao classes, only about 35 to 40 tons larger, but more strongly built and with a slightly improved internal layout. One of the ballast tanks was converted to carry fuel, increasing range from 11,000 nautical miles (20,000 km; 13,000 mi) to 16,000 nautical miles (30,000 km; 18,000 mi). This improvement was also made on some boats of the previous two classes.^[4] Further improvements were made beginning with SS-435, which are sometimes referred to as the Corsair class. Initial plans called for 80 to be built, but 51 were cancelled in 1944 and 1945 when it became apparent that they would not be needed to defeat Japan. The remaining 29 were commissioned between October 1944 (Tench) and February 1951 (Grenadier). The last submarine of the Tench class, as well as the last submarine which served during World War II, remaining in service with the U.S. Navy was USS Tigrone (AGSS-419) which was decommissioned on 27 June 1975.