USS R-25 (SS-102), also known as "Submarine No. 102", was an R-21-class coastal and harbor defense submarines of the United States Navy commissioned after the end of World War I.
Design
The R-boats built by the Lake Torpedo Boat Company, through , are sometimes considered a separate class, R-21-class, from those built by the Fore River Shipbuilding Company, through , and the Union Iron Works, through , R-1-class.
The submarines had a length of overall, a beam of , and a mean draft of . They displaced on the surface and submerged. The R-21-class submarines had a crew of 3 officers and 23 enlisted men. They had a diving depth of .
For surface running, the boats were powered by two Busch-Sulzer diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a Diehl Manufacture Company electric motor. They could reach on the surface and underwater. On the surface, the R-21-class had a range of at , or if fuel was loaded into their main ballast tanks.
The boats were armed with four American 21-inch torpedo| torpedo tubes in the bow. They carried four reloads, for a total of eight torpedoes. The R-21-class submarines were also armed with a single /50 caliber deck gun.
Construction
thumb|USS R-25 in Bridgeport during 1919
R-25s keel was laid down on 26 April 1917, by the Lake Torpedo Boat Company, in Bridgeport, Connecticut. She was launched on 15 May 1919, sponsored by Mrs. Rosalinda Robinson, and commissioned on 23 October 1919 with future Vice Admiral and Commander, Submarines, Southwest Pacific (COMSUBSOWESPAC), Lieutenant Commander Charles A. Lockwood, Jr., in command.
Service record
At the end of November, R-25 got underway for her homeport, Coco Solo, in the Panama Canal Zone, arriving 11 January 1920.
When the US Navy adopted its hull classification system on 17 July 1920, she received the hull number SS-102.
Except for overhaul periods at Balboa, and on the East Coast, R-25 operated in the waters off the Panama Canal Zone, until the fall of 1923.
Fate
In November of that year she arrived at the Philadelphia Navy Yard, and underwent inactivation overhaul. On 21 June 1924, she was decommissioned after just over four-and-a-half years of service. She was laid up at League Island, until she was struck from the Naval Vessel Register on 9 May 1930, and sold for scrap on 30 July 1930.