Tang-class submarine

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USS Gudgeon
USS Gudgeon
Class overview
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)
Built: 1949–1952
In commission: 1951–1983
Completed: 6
Retired: 6
Preserved: 2
General characteristics
Type: Submarine
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,
two shafts[1]
Speed: 15.5 knots (17.8 mph; 28.7 km/h) surfaced
18.3 knots (21.1 mph; 33.9 km/h) submerged[1]
Range: 11,500 nmi (21,300 km) at 10 kn (12 mph; 19 km/h) surfaced[1]
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[1]

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.[2]

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.[1] 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.[3][4]

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.[1]

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[edit]

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.[1][5]

Museum Ships[edit]

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.[6]


  1. ^ a b c d e f g 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. 
  2. ^ Friedman, Norman (1984). Submarine Design and Development. Annapolis, Maryland: United States Naval Institute. p. 61. ISBN 0-87021-954-5. 
  3. ^ Friedman since 1945, pp. 46-48
  4. ^ Gardiner and Chumbley, p. 603
  5. ^ Friedman since 1945, p. 43
  6. ^ Kocaeli Museum Ships Command