Tambor-class submarine

Tambor-class submarine
USS Tambor (SS-198)
Class overview
Builders:	Electric Boat Company, Portsmouth Naval Shipyard, Mare Island Naval Shipyard
Operators:	United States Navy
Preceded by:	Sargo class
Succeeded by:	Gato class
Built:	1939–1941
In commission:	1940–1946
Completed:	12
Active:	0
Lost:	7
Retired:	5
Preserved:	0
General characteristics
Type:	Diesel-electric submarine
Displacement:	1,475 long tons (1,499 t) standard, surfaced 2,370 long tons (2,410 t) submerged
Length:	307 ft 2 in (93.62 m)
Beam:	27 ft 3 in (8.31 m)
Draft:	14 ft 7 1⁄2 in (4.458 m)
Propulsion:	4 × diesel engines driving electrical generators (Fairbanks-Morse or General Motors) 2 × 126-cell Sargo batteries 4 × high-speed General Electric electric motors with reduction gears two shafts 5,400 shp (4.0 MW) surfaced 2,740 shp (2.0 MW) submerged
Speed:	20.4 knots (38 km/h) surfaced 8.75 knots (16 km/h) submerged
Range:	11,000 nautical miles (20,000 km) at 10 knots (19 km/h)
Endurance:	48 hours at 2 knots (3.7 km/h) submerged
Test depth:	250 ft (76 m)
Complement:	6 officers, 54 enlisted
Armament:	10 × 21-inch (533 mm) torpedo tubes 6 forward, 4 aft 24 torpedoes 1 × 3-inch (76 mm) / 50 caliber deck gun Bofors 40 mm and Oerlikon 20 mm cannon

The Tambor-class submarine was a United States Navy submarine design, used primarily during World War II. It was the USN's first practical fleet submarine and formed the core of the United States Pacific submarine fleet at the time of the US entry into World War II.

Design history

Preliminary designs

Early U.S. submarine designs of World War I assigned to escort shipping revealed that they had minimal ability to deter an aggressive threat. Despite the fact that German U-boats proved beyond a doubt that no navy could be a world sea power without submarines, the role played by U.S. submarines in the defense of the Pacific would have to be rethought, or else flat out discarded, by Navy planners.

Following the armistice, and after testing the capabilities of German design, the U.S. Navy began to see the potential for extended offensive submarine operations. Submarine operations with the fleet required boats with both a large cruising radius and a relatively high speed so that they could intercept and stay with their prey. The huge advancement in American technology required to fill that role with "a new all-purpose fleet submarine" also became apparent.

After the fiasco of submarine design experienced in the late 1920s, Navy designers finally produced plans for a practical fleet submarine. The lineage of what was to become the fleet submarine actually began with the Porpoise or "P"-class and Salmon / Sargo or "S"-class submarines, laid down in 1933 and 1935. These were smaller, more maneuverable boats than some of the varied and earlier V series boats. While these newer P-class and S-class boats were a step in the right direction, they were found to be lacking in speed, reliability and firepower.

Tambor class proposal

In the fall of 1937 a proposal for a true fleet submarine (a submarine intended to operate as part of a larger fleet) was finally put forward by the team of officers put together by then Commander Charles A. Lockwood (later admiral and Commander Submarine Fleet Pacific), Lt. Cmdr. Andrew I. McKee, planning officer at Portsmouth Navy Yard, and Lt. Armand M. Morgan, head of the Navy's submarine design section. It was to be large (1,500 tons), and carry the latest diesel engines, ten torpedo tubes, a 5-inch (127 mm) gun, and a new Torpedo Data Computer. Habitability would be increased by the addition of fresh water distillation units and air conditioning.

However, the design concepts faced opposition from Admiral Thomas Hart, Chairman of the General Board. Hart stubbornly defended the building of small, coastal defense boats (without "luxuries" like air conditioning). Through determination and skilled political maneuvering, the design of Lockwood's team prevailed (though Hart would only consent to a 3-inch (76 mm) gun). This design was finally adopted by the Navy's General Board and the Submarine Officers' Conference for the 1939 program.

The plans finally drawn for a practical fleet submarine were those of the Tambor or "T"-class submarine. A fairly trim and maneuverable vessel at 300 feet (91 m) LOA (Length Over All) and 1,500 tons (compared with the 381 feet (116 m) LOA and 2,000 tons of the varied and experimental but widely disliked predecessor, the V-class), the new fleet boats provided sufficient elbow room for long war patrols.

The Gar class boats were virtually identical to the "T" class and are often listed as "T" class submarines.

Design specifications

One key to the success of the "T" class was the development of a compact diesel engine designed in concert with the American railroad industry, which enthusiastically embraced the benefits of diesel-powered locomotives (and was delighted by the Navy's willingness to fund the huge research and development costs associated with their creation). Equipped with four of the new diesel engines, the boats could reach top speeds of over 20 knots (37 km/h) and make 10,000-nautical-mile (19,000 km) cruises without suffering from the engine fragility of the compact MAN diesel designs used in some of their predecessors.

Sailor in his bunk aboard a typical wartime fleet boat.

The "T" Class boats were the last phase of development of US subs prior to the introduction of the Gato class in 1942. These two classes of submarines handled most of the combat duties during the early stages of the war, with the USS Tautog holding the scoring record in the category of "number of ships sunk" by a U.S. submarine.

Role

These boats were the core of the 56 boat U.S. Submarine Fleet Pacific when the United States entered World War II in December 1941. The "T" class design, somewhat refined in the following Gato and Balao classes, formed the backbone of the wartime US Navy submarine fleet.

Ships in class

Name	Hull number	Builder	Laid Down	Launched	Commissioned	Fate
Tambor	SS-198	Electric Boat, Groton, CT	January 16, 1939	December 20, 1939	June 3, 1940	Sold for scrap September 1, 1959
Tautog	SS-199	Electric Boat, Groton, CT	March 1, 1939	January 27, 1940	July 3, 1940	Sold for scrap 15 November 1959, to the Bultema Dock and Dredge Company of Manistee, Michigan
Thresher	SS-200	Electric Boat, Groton, CT	April 27, 1939	March 27, 1940	August 27, 1940	Sold for scrap 18 March 1948 to Max Siegel of Everett, Massachusetts
Triton	SS-201	Portsmouth Navy Yard, Kittery, Maine	July 5, 1939	March 25, 1940	August 15, 1940	Lost March 20, 1943
Trout	SS-202	Portsmouth Navy Yard, Kittery, Maine	August 8, 1939	May 21, 1940	November 15, 1940	Lost around 29 February 1944
Tuna	SS-203	Mare Island Navy Yard, Vallejo, CA	July 19, 1939	October 2, 1940	January 2, 1941	Towed out to sea and sunk, 24 September 1948

The last six of the Tambor class are often listed as "Gar class" submarines

Name	Hull number	Builder	Laid Down	Launched	Commissioned	Fate
Gar	SS-206	Electric Boat, Groton, CT	December 27, 1939	November 27, 1940	April 14, 1941	Sold for scrap 18 November 1959 to Acme Scrap Iron and Metal Company
Grampus	SS-207	Electric Boat, Groton, CT	February 14, 1940	December 23, 1940	May 23, 1941	Lost March 5, 1943
Grayback	SS-208	Portsmouth Navy Yard, Kittery, Maine	April 3, 1940	January 31, 1941	June 30, 1941	Lost February 27, 1944
Grayling	SS-209	Portsmouth Navy Yard, Kittery, Maine	December 15, 1939	November 29, 1940	March 1, 1941	Lost between September 9 and September 12, 1943
Grenadier	SS-210	Portsmouth Navy Yard, Kittery, Maine	April 2, 1940	November 29, 1940	May 1, 1941	Scuttled following enemy action April 22, 1943
Gudgeon	SS-211	Portsmouth Navy Yard, Kittery, Maine	November 22, 1939	January 25, 1941	April 21, 1941	Lost between April 7 and June 7, 1944

See also

• Unrestricted submarine warfare
• Intensified submarine warfare
• U-boat
• Torpedo
• Battle of the Atlantic (1939-1945)