HMS Cyclops (F31) was a Royal Navy vessel originally constructed as a passenger liner named Indrabarah, built by Laing for the Indra Line Ltd. Launched on 27 October 1905, she measured 460 feet (140.2 meters) between perpendiculars and 476 feet (145.1 meters) overall, with a beam of 55 feet (16.8 meters). Her design included facilities such as a distillation plant for fresh water, and she was equipped with machinery, carpenters' and blacksmiths' shops, as well as coppersmiths', iron, and brass foundries, reflecting her original purpose as a passenger liner. During the First World War, Cyclops was repurposed as a repair ship, serving the Grand Fleet from her base at Scapa Flow for the duration of the conflict. After the war, she was paid off on 1 April 1919 and subsequently assigned to White Sea duties at Archangel. Returning to Chatham in October 1919, she was refitted and converted into a submarine depot ship, officially commissioning for the 1st Submarine Flotilla of the Atlantic Fleet on 21 December 1922. Between the wars, Cyclops served primarily in Malta, and she was in reserve at the start of the Second World War. She was reactivated in late 1939 to serve as the depot ship for the Royal Navy's 7th Submarine Flotilla based in Rothesay. From November 1939 to May 1940, she supported the 3rd Submarine Flotilla at Parkeston Quay, Harwich Harbour, where her submarines engaged in reconnaissance and raiding missions in the Heligoland Bight and off Denmark. During this period, she earned the nickname "Cycle Box" and notably used her 4-inch guns to fend off a German seaplane attacking the harbor in December 1939. Throughout her service, Cyclops was involved in various operations, including practice attacks on convoys in 1942, and she was commanded by notable officers such as Cdr. Benjamin Bryant during her later wartime years. She was equipped with extensive facilities to support submarine operations, including water distillation and repair shops. HMS Cyclops was ultimately sold for scrap to John Cashmore Ltd and dismantled at Newport in July 1947, marking the end of her distinguished maritime career.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.