Tambor-class submarine

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.

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 in 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 in 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 ft LOA (Length Over All) and 1,500 tons (compared with the 381 ft 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 kn and make 10000 nmi cruises without suffering from the engine fragility of the compact MAN diesel designs used in some of their predecessors.



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 (SS-199) 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
The last six of the Tambor class are often listed as "Gar class" submarines