The ''T-1''-class submarines were a pair of submarines designed by the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

and built in the early 1950s for use in training submarine personnel and testing submarine equipment. Both submarines of the class served in these roles for over 19 years.

Design and construction

Except for the first 25 early development pre-

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submarines, the ''T-1'' class were among the smallest operational submarines ever built for the

. The first unit was planned under project SCB 68 as an experimental auxiliary submarine with

hull number Hull number is a serial identification number given to a boat or ship. For the military, a lower number implies an older vessel. For civilian use, the HIN is used to trace the boat's history. The precise usage varies by country and type. United S ...

AGSS-570, but instead was built as the training submarine USS ''T-1'' with hull number SST-1. Her

sister ship A sister ship is a ship of the same class or of virtually identical design to another ship. Such vessels share a nearly identical hull and superstructure layout, similar size, and roughly comparable features and equipment. They often share a ...

, USS ''T-2'', was planned as SST-2 from the beginning. The ''T-1'' class were built to resemble the 160-ton, 16-crew s, of which over 100 were in service in 1950. It was thought the M class would be effective in restricted waters such as the

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and parts of the

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. The ''T-1'' class were built to train

anti-submarine warfare Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typi ...

(ASW) forces in countering small submarines. Both submarines were constructed by the

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Division of the

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Corporation at

Groton Groton may refer to: Places England *Groton, Suffolk ** Groton Wood United States *Groton, Connecticut, a town ** Groton (city), Connecticut, within the town * Groton, Massachusetts, a town ** Groton (CDP), Massachusetts, the main village in the ...

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, in 1952–1953.

Service history

Both submarines entered service in 1953 and were renamed in 1956, ''T-1'' becoming USS ''Mackerel'' (SST-1) and ''T-2'' becoming USS ''Marlin'' (SST-2). Both operated primarily in

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and Caribbean waters to train submarine personnel, serve as targets for

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on ...

and

antisubmarine An anti-submarine weapon (ASW) is any one of a number of devices that are intended to act against a submarine and its crew, to destroy (sink) the vessel or reduce its capability as a weapon of war. In its simplest sense, an anti-submarine weapo ...

warfare training, and test submarine equipment. They were decommissioned simultaneously in a combined ceremony in 1973.

Ships

USS ''Mackerel'' (SST-1), ex-USS ''T-1'', ex-AGSS-570

, planned as AGSS-570, was commissioned as ''T-1'' (SST-1) in October 1953 and decommissioned in January 1973. A highlight of her career was testing of equipment for the

NR-1 Deep Submergence Craft Deep Submergence Vessel ''NR-1'' was a unique United States Navy (USN) nuclear-powered ocean engineering and research submarine, built by the Electric Boat Division of General Dynamics at Groton, Connecticut. ''NR-1'' was launched on 25 Januar ...

in 1966–1967. ''Mackerel'' was sunk as a target in 1978.

USS ''Marlin'' (SST-2), ex-USS ''T-2''

was commissioned as USS ''T-2'' (SST-2) in November 1953 and decommissioned in January 1973. Donated as a

museum ship A museum ship, also called a memorial ship, is a ship that has been preserved and converted into a museum open to the public for educational or memorial purposes. Some are also used for training and recruitment purposes, mostly for the small num ...

in August 1973, she was assigned on 20 August 1974 to go on display at

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in Omaha,

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References

NavSource Online: Submarine Photo Archive Mackerel (AGSS-570) T-1 (SST-1) / Mackerel (SST-1)
* for USS ''Mackerel (SST-1) * for USS ''Marlin'' (SST-2) * Gardiner, Robert and Chumbley, Stephen, ''Conway's All the World's Fighting Ships 1947–1995'', p. 603 London: Conway Maritime Press, 1995. .

External links

"Midget Submarines Play Targets For Killers."
''Popular Mechanics'', July 1954, pp. 84–89/240. {{US submarine classes after 1945 Submarine classes T-1 class