History
United Kingdom
Name	HMS Acheron
Builder	HM Dockyard, Chatham
Laid down	26 August 1944
Launched	25 March 1947
Commissioned	17 April 1948
Decommissioned	February 1971
Identification	P411
Fate	Sold for scrap, 1972
General characteristics
Class and type	Amphion-class submarine
Displacement	1,360/1,590 tons (surface/submerged)
Length	293 ft 6 in (89.46 m)
Beam	22 ft 4 in (6.81 m)
Draught	18 ft 1 in (5.51 m)
Propulsion	2 × 2,150 hp (1,600 kW) Admiralty ML 8-cylinder diesel engine, 2 × 625 hp (466 kW) electric motors for submergence driving two shafts
Speed	18.5 kn (34.3 km/h) surface, 8 kn (15 km/h) submerged 10,500 nmi (19,400 km) at 11 kn (20 km/h) surfaced 16 nmi (30 km) at 8 kn (15 km/h) or 90 nmi (170 km) at 3 kn (5.6 km/h) submerged
Test depth	350 ft (110 m)
Complement	60
Armament	6 × 21 inch (533 mm) (2 external) bow torpedo tubes, 4 × 21 in (2 external) stern torpedo tubes, containing a total of 20 torpedoes Mines: 26 1 × 4 in (102 mm) main deck gun, 3 × 0.303 machine gun, 1 × 20 mm AA Oerlikon 20 mm gun

HMS Acheron (P411) was an Amphion-class submarine of the Royal Navy, laid down 26 August 1944, launched 25 March 1947 and completed in 1948.

Design

Like all Amphion-class submarines, Acheron had a displacement of 1,360 tonnes (1,500 short tons) when at the surface and 1,590 tonnes (1,750 short tons) while submerged. It had a total length of 293 feet 6 inches (89.46 m), a beam of 22 feet 4 inches (6.81 m), and a draught of 18 feet 1 inch (5.51 m). The submarine was powered by two Admiralty ML eight-cylinder diesel engines generating a power of 2,150 horsepower (1,600 kW) each. It also contained four electric motors each producing 625 horsepower (466 kW) that drove two shafts.^[1] It could carry a maximum of 219 tonnes (241 short tons) of diesel, although it usually carried between 159 and 165 tonnes (175 and 182 short tons).^[1]

The submarine had a maximum surface speed of 18.5 knots (34.3 km/h; 21.3 mph) and a submerged speed of 8 knots (15 km/h; 9.2 mph).^[2] When submerged, it could operate at 3 knots (5.6 km/h; 3.5 mph) for 90 nautical miles (170 km; 100 mi) or at 8 knots (15 km/h; 9.2 mph) for 16 nautical miles (30 km; 18 mi). When surfaced, it was able to travel 15,200 nautical miles (28,200 km; 17,500 mi) at 10 knots (19 km/h; 12 mph) or 10,500 nautical miles (19,400 km; 12,100 mi) at 11 knots (20 km/h; 13 mph).^[1] Acheron was fitted with ten 21 inches (530 mm) torpedo tubes, one QF 4 inch naval gun Mk XXIII, one Oerlikon 20 mm cannon, and a .303 British Vickers machine gun. Its torpedo tubes were fitted to the bow and stern, and it could carry twenty torpedoes. Its complement was sixty-one crew members.^[1]

Service history

Acheron took part in the Coronation Review of the Fleet to celebrate the Coronation of Queen Elizabeth II in 1953.^[3] It carried out 'General Naval Service' around the UK until the end of 1964. A geomagnetic storm in February 1956, during solar cycle 19, interfered with radio communications and prompted a search for the submarine after it lost radio contact.^[4] From August to December 1959, It took part in a cruise to South Africa and Pakistan.^[5]

It was decommissioned and broken up in 1972 at the yard of J Cashmore of Newport.^[6]

Commanding officers