United States R-class submarine

The R-class submarines were a class of United States Navy submarines active from 1918 until 1945.

The R-1 thru R-20 boats built by Fore River Shipyard and Union Iron Works were known as the "R-1 class" subs. These single-hull submarines were structurally very similar to the preceding O-class, but with the addition of 21-inch torpedo tubes and a fixed (rather than retractable) gun mount.

Boats R-21 to R-27, which were slightly smaller and faster than the R-1s, were built by Lake Torpedo Boat and are sometimes regarded as a separate class, the "R-21 class." These featured a double-hull and had their diving planes more conventionally positioned fore and aft, but retained the characteristic wide stern and 18-inch torpedo tubes.

Electric Boat built four boats for the Peruvian Navy (R-1 to R-4). Built after World War I using materials assembled from cancelled S-class submarines, they were refitted in 1935–36 and 1955–56, and renamed Islay, Casma, Pacocha, and Arica in 1957. They were discarded in 1960.

Ships

 * USS R-1 (SS-78) - Commissioned 1918, scrapped 1946
 * USS R-2 (SS-79) - Commissioned 1919, scrapped 1945
 * USS R-3 (SS-80) - Commissioned 1919, scrapped 1948
 * USS R-4 (SS-81) - Commissioned 1919, scrapped 1946
 * USS R-5 (SS-82) - Commissioned 1919, scrapped 1946
 * USS R-6 (SS-83) - Commissioned 1919, scrapped 1946
 * USS R-7 (SS-84) - Commissioned 1919, scrapped 1946
 * USS R-8 (SS-85) - Commissioned 1919, sunk as target, 1936
 * USS R-9 (SS-86) - Commissioned 1919, scrapped 1946
 * USS R-10 (SS-87) - Commissioned 1919, scrapped 1946
 * USS R-11 (SS-88) - Commissioned 1919, scrapped 1946
 * USS R-12 (SS-89) - Commissioned 1919, lost June 1943 in a training accident off Key West, Florida
 * USS R-13 (SS-90) - Commissioned 1919, scrapped 1946
 * USS R-14 (SS-91) - Commissioned 1919, scrapped 1945
 * USS R-15 (SS-92) - Commissioned 1919, scrapped 1946
 * USS R-16 (SS-93) - Commissioned 1919, scrapped 1946
 * USS R-17 (SS-94) - Commissioned 1918, scrapped 1945
 * USS R-18 (SS-95) - Commissioned 1918, scrapped 1946
 * USS R-19 (SS-96) - Commissioned 1918, transferred to United Kingdom May 1942, lost in collision June 1942
 * USS R-20 (SS-97) - Commissioned 1919, scrapped 1946
 * USS R-21 (SS-98) - Commissioned 1919, scrapped 1930
 * USS R-22 (SS-99) - Commissioned 1919, scrapped 1930
 * USS R-23 (SS-100) - Commissioned 1919, scrapped 1930
 * USS R-24 (SS-101) - Commissioned 1919, scrapped 1930
 * USS R-25 (SS-102) - Commissioned 1919, scrapped 1930
 * USS R-26 (SS-103) - Commissioned 1919, scrapped 1930
 * USS R-27 (SS-104) - Commissioned 1919, scrapped 1930