USS S-20 (SS-125)

USS "S-20" (SS-125) was a first-group ("S-1" or "Holland") "S"-class submarine of the United States Navy. Her keel was laid down on 15 August 1918 by the Bethlehem Shipbuilding Corporation in Quincy, Massachusetts. She was launched on 9 June 1920 sponsored by Miss Anne Claggett Zell, and commissioned on 22 November 1922 with Lieutenant John A. Brownell in command.

In addition to duty in northeastern points out of New London, Connecticut, from 1922 into 1929, the new submarine visited Coco Solo in the Panama Canal Zone, in March 1923; served at Saint Thomas, United States Virgin Islands, in February 1924; and operated in the Panama Canal area from January through April 1926. "S-20" visited Kingston, Jamaica, from 20 March to 28 March 1927, and served again in the Panama Canal area from 17 April 1929 into November 1930. Departing Coco Solo on 7 November, "S-20" arrived at Pearl Harbor on 7 December that year. Following duty there, she sailed on 20 February 1932 and, from March of that year into April 1933, served at Mare Island. Later, she operated mainly at San Diego, California, into 1934. Departing San Diego on 15 March, "S-20" returned to New London on 28 October. From then into December 1941, she operated there as part of a test and evaluation division. During this period, she visited Guantanamo in February and March 1938; served in the Panama Canal area from January into March 1939; and visited Guantanamo again in February 1940.

From December 1941 into July 1945, "S-20" continued to operate from New London. Her operations were off New England and often included training activities at Casco Bay, Maine. Departing New London on 2 July 1945, "S-20" was decommissioned on 16 July at Philadelphia, Pennsylvania. Her name was struck from the Naval Vessel Register on 25 July. She was sold on 22 January 1946 to North American Smelting Company, Philadelphia, for scrapping.

Modifications

"S-20" was rebuilt in 1924, with a larger bow (similar to that of the "V-1" class) to improve seakeeping and blisters on the upper hull to hold more fuel, but this modification was not repeated on any other members of the class."U.S. Submarines Through 1945" pp. 132] "U.S. Submarines Through 1945" pp. 137] "U.S. Submarines Through 1945" pp. 138] She was also used as an experimental engine test vessel, with a new high-speed geared-drive convert|600|hp|adj=on MAN diesel replacing her starboard engine in 1931.

In 1932, this new engine was replaced by a prototype diesel-electric plant. This was a MAN-type convert|635|hp|adj=on 16-cylinder engine running at even higher speed, driving an electrical generator, built by Electric Boat and designated 16VM1. Electricity produced by the generator was used to drive a high-speed electric motor geared to the shaft; there was no direct connection between the diesel engine and the shaft. Diesel-electric propulsion was then adopted for many U.S. submarines through World War II, starting with the 1932 "Porpoise" class; other navies did not follow suit until after the war."U.S. Submarines Through 1945" p. 198] "U.S. Submarines Through 1945" p. 259–261] "U.S. Submarines Through 1945" p. 359]

References