HMS Acheron (P411)

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 1360 t when at the surface and 1590 t while submerged. It had a total length of 293 ft, a beam of 22 ft, and a draught of 18 ft. The submarine was powered by two Admiralty ML eight-cylinder diesel engines generating a power of 2150 hp each. It also contained four electric motors each producing 625 hp that drove two shafts. It could carry a maximum of 219 t of diesel, although it usually carried between 159 and 165 t.

The submarine had a maximum surface speed of 18.5 kn and a submerged speed of 8 kn. When submerged, it could operate at 3 kn for 90 nmi or at 8 kn for 16 nmi. When surfaced, it was able to travel 15200 nmi at 10 kn or 10500 nmi at 11 kn. Acheron was fitted with ten 21 in 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.

Service history
Acheron took part in the Coronation Review of the Fleet to celebrate the Coronation of Queen Elizabeth II in 1953. 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. From August to December 1959, It took part in a cruise to South Africa and Pakistan.

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