|Builders:||Portsmouth Naval Shipyard
Electric Boat Company
|Operators:||United States Navy|
|Preceded by:||Tench-class submarine|
|Succeeded by:||USS Nautilus (SSN-571)
USS Seawolf (SSN-575)
|Displacement:||1,560–2,050 long tons (1,585–2,083 t) surfaced
2,260–2,700 long tons (2,296–2,743 t) submerged
|Length:||268 ft (82 m), extended to 287 ft (87 m), then to 302 ft (92 m)|
|Beam:||27 ft (8.2 m)|
|Draft:||17 ft (5.2 m)|
|Propulsion:||three GM 16-338 "pancake" diesel engines (3,400 shp (2,500 kW) total), replaced by three Fairbanks 38D8-1/8 opposed piston engines (4,800 shp (3,600 kW) total),
two electric motors (4,700 shp (3,500 kW)),
four 126-cell batteries,
|Speed:||15.5 knots (17.8 mph; 28.7 km/h) surfaced
18.3 knots (21.1 mph; 33.9 km/h) submerged
|Range:||11,500 nmi (21,300 km) at 10 kn (12 mph; 19 km/h) surfaced|
|Endurance:||1 hour at 17.5 kn (32.4 km/h) on battery|
|Test depth:||700 ft (210 m)|
|Complement:||8 officers, 75 men|
|Armament:||8 × 21 in (533 mm) torpedo tubes (6 forward, 2 aft), 26 torpedoes|
The Tang class submarines were developed from the Greater Underwater Propulsion Power Program (GUPPY) conversion program for World War II submarines, which incorporated German Type XXI U-boat technology into the United States Navy's submarine design. They comprised the state of the art in post-World War II conventionally powered submarine design; some of their features were incorporated into the nuclear-powered submarines that replaced them in the 1950s and beyond.
Probably the most important innovation of the Tangs, and their primary advantage over contemporary GUPPY conversions, was an increase in test depth from 400 ft (120 m) to 700 ft (210 m), achieved with HY-42 (42,000 psi (290 MPa) yield strength) steel. The improved HY-75 steel would not appear until the middle 1950s. This allowed the class to take advantage of deeper ocean conditions to evade sonar, as well as maneuver more safely at moderate depths.
An unsuccessful innovation of the Tang design was the General Motors 16-338 lightweight, compact, high-speed "pancake" engine. Very different from the classic diesel engines that nearly all preceding submarines used, which were laid out with a horizontal crankshaft, this new engine had a vertical crankshaft, and the cylinders were arranged radially like an aircraft engine. Three of these 13½-foot-tall (4.1 m), 4-foot-wide (1.2 m), eight-ton engines could be installed in a single engine room, thus deleting an entire compartment from the submarine's design. The goal was to reduce overall length, as testing had shown that shorter submarines were more maneuverable, especially in depth. Four compact Guppy-type 126-cell lead–acid batteries were installed to provide a high sustained submerged speed. The overall design allowed for a 25 kn (46 km/h) top speed and possible future propulsion replacement with a Type XVII U-boat-derived hydrogen peroxide turbine, closed-cycle diesel system, or even a nuclear power plant. However, attempts to develop the first two systems were unsuccessful, and nuclear power plants proved too large to be accommodated in the Tang-class hull.
When the boats went to sea in the early 1950s, the new engines did not work well. Their compact design made them difficult to maintain, and they tended to leak oil into their generators. In 1956, the Navy decided to replace the "pancake" engines with ten-cylinder Fairbanks-Morse opposed-piston 38D 8-1/8 diesels. These were similar to those of late-war World War II boats, but uprated from 1,350 shp (1,010 kW) to 1,600 shp (1,200 kW) each. To accommodate the larger engines, the boats had to be lengthened some nine feet in the engine room, and even then, only three could be installed. Accordingly, in 1957 and 1958, the first four Tangs were lengthened, while Gudgeon and Harder, still on the ways, were built to the new length, with the new engines. This propulsion plant was used for almost all subsequent US conventional submarines.
The torpedo tubes were also redesigned. The six forward tubes now used air-powered piston ejection pumps, which forced a slug of water through a slide valve behind the torpedo to push it out, rather than the pulse of air used in previous designs. Because this design is somewhat quieter and does not release an air bubble every time a torpedo is fired, it has been used in all subsequent submarine designs throughout the world. The four stern tubes of previous classes were reduced to two shorter, simpler tubes that could not accommodate the longer anti-ship torpedoes and had no capability to actively eject torpedoes. Rather, they were designed for the Mark 27 and planned Mark 37 swim-out torpedoes.
Ships in class
In October 1946, the first two boats were ordered. USS Tang (SS-563) was built at Portsmouth Naval Shipyard; USS Trigger (SS-564) at the Electric Boat yard in Groton, Connecticut. In 1947, contracts were awarded to Portsmouth for USS Wahoo (SS-565) and to Electric Boat for USS Trout (SS-566). Then in 1948, a similar pair of contracts were awarded for USS Gudgeon (SS-567) and USS Harder (SS-568). They are named for six US submarines lost during World War II, of which most of their commanding officers were killed in action while combating Japanese surface vessels: Gudgeon, Wahoo, Trout, Trigger, Harder and Tang.
|Name||Hull number||Builder||Laid Down||Launched||Commissioned||Fate|
|Tang||SS-563||Portsmouth Naval Shipyard||18 April 1949||19 June 1951||25 October 1951||Transferred to Turkey 6 August 1987, decommissioned 2004, preserved as a museum|
|Trigger||SS-564||Electric Boat||24 February 1949||14 June 1951||31 March 1952||Transferred to Italy 10 July 1973, decommissioned 28 February 1986|
|Wahoo||SS-565||Portsmouth Naval Shipyard||24 October 1949||16 October 1951||30 May 1952||Decommissioned 27 June 1980, scrapped 1984|
|Trout||SS-566||Electric Boat||1 December 1949||21 August 1951||27 June 1952||Transferred to Iran 19 December 1978, transfer rescinded March 1979, in limbo 1979-92, USN sonar testbed 1994-2007, scrapped 2008|
|Gudgeon||SS-567||Portsmouth Naval Shipyard||20 May 1950||11 June 1952||21 November 1952||Transferred to Turkey 1983, decommissioned 2004, preserved as a museum|
|Harder||SS-568||Electric Boat||30 June 1950||3 December 1951||19 August 1952||Transferred to Italy 18 August 1974, decommissioned and scrapped 1988|
In 1967, Tang, Wahoo, Gudgeon, and Harder received an additional 15- or 18-foot (4.6 or 5.5 m) section to accommodate the BQG-4 Passive Underwater Fire Control Feasibility Study (PUFFS) passive sonar installation, with three tall domes added topside. The extension accommodated additional fire control equipment that enabled the use of the Mark 45 nuclear torpedo. This left the boats very similar in size and capability to the GUPPY III conversions.
Two boats of this class, TCG Pirireis (ex-Tang) and TCG Hizirreis (ex-Gudgeon), are preserved as museum ships in Turkey. Ex-Tang is at the İnciraltı Sea Museum, in İzmir, and ex-Gudgeon is at the Kocaeli Museum Ships Command in Izmit.
|Wikimedia Commons has media related to Tang class submarines.|
- Friedman, Norman (1994). U.S. Submarines Since 1945: An Illustrated Design History. Annapolis, Maryland: United States Naval Institute. pp. 16–28, 242. ISBN 1-55750-260-9.
- Friedman, Norman (1984). Submarine Design and Development. Annapolis, Maryland: United States Naval Institute. p. 61. ISBN 0-87021-954-5.
- Friedman since 1945, pp. 46-48
- Gardiner and Chumbley, p. 603
- Friedman since 1945, p. 43
- Kocaeli Museum Ships Command
- Gardiner, Robert and Chumbley, Stephen, Conway's all the world's fighting ships 1947-1995, London: Conway Maritime Press, 1995. ISBN 1-55750-132-7.
- NavSource.org Postwar Diesel Submarines photo gallery index
- This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.