HMS Alderney (P416/S66) was an Amphion-class submarine built by Vickers-Armstrongs at Barrow, launched on 25 June 1945. As the 12th vessel of its class, she embodied the design characteristics typical of post-WWII British submarines. The vessel measured approximately 293.5 feet (89.46 meters) in length, with a beam of 22 feet 4 inches (6.81 meters) and a draught of 18 feet 1 inch (5.51 meters). Displacing 1,360 long tons (1,380 tonnes) on the surface and 1,590 long tons (1,620 tonnes) when submerged, Alderney was powered by two Admiralty ML eight-cylinder diesel engines, each producing 2,150 horsepower, and four electric motors generating 625 horsepower each, driving two shafts. Her maximum surface speed was 18.5 knots, while submerged, she could reach 8 knots. Under submerged conditions, she could operate at 3 knots for up to 90 nautical miles or at 8 knots for 16 nautical miles. On the surface, she had an impressive range of 15,200 nautical miles at 10 knots, or 10,500 nautical miles at 11 knots, making her suitable for long patrols. Armed with ten 21-inch torpedo tubes (five bow, five stern) capable of carrying twenty torpedoes, she also featured a QF 4-inch naval gun, an Oerlikon 20 mm cannon, and a .303 British Vickers machine gun, providing versatile offensive capabilities. Alderney's operational history included three commissions between 1954 and 1963 with the 6th Submarine Squadron based in Halifax, Nova Scotia, during which she participated in exercises with the Royal Canadian Navy and Air Force. She underwent a significant modernization at Portsmouth Dockyard from 1956 to 1958. Recommissioned multiple times, she was allocated to the 1st Submarine Squadron at HMS Dolphin in 1965. Her career concluded with her decommissioning in 1966, and she was scrapped at Troon, Scotland, in 1970. Her service reflects the Cold War-era transition of the Royal Navy's submarine fleet and highlights her role within maritime defense during her active years.

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