Améthyste (French: [ametist]; "Amethyst") is a nuclear-powered attack submarine of the French Navy, the fifth of the Rubis class. Her hull number is S605. The boat's name is a pun on the precious stone amethyst and the acronym AMÉTHYSTE — AMÉlioration Tactique, HYdrodynamique, Silence, Transmission, Écoute ("Tactical, Hydrodynamic, Silence, Transmission, and Listening Improvements"). She represents a major upgrade over the initial Rubis-class design, and earlier units were later refitted to her standards. With the decommissioning of her sister boat Perle in 2026, she is the last vessel of her class in active service.
Design and construction
Améthyste was laid down on 31 October 1983, launched on 14 May 1988, and commissioned on 3 March 1992. She is 73.6 m (241 ft 6 in) long, with a beam of 7.6 m (24 ft 11 in) and a draught of 6.4 m (21 ft 0 in). Displacement is 2,400 tonnes surfaced and 2,600 tonnes submerged. The submarine is powered by a pressurised-water K48 nuclear reactor (48 MW, using 7% low-enriched uranium) driving turbo-alternators and a single electric motor (7 MW) for a single propeller. Speed exceeds 25 knots (46 km/h; 29 mph), with a range of 8,500 nautical miles (15,700 km) and an endurance of 60 days. Test depth is over 300 m (980 ft). The crew complement is 68 (8 officers, 52 warrant officers, 8 petty officers).
The Améthyste silencing program reshaped the hull, lengthened it compared to the first four boats, and introduced a superstructure and external bow made of glass-reinforced plastic. Machinery was given flexible mountings to reduce noise emissions. Sensor upgrades included the DMUX 20 multifunction sonar suite, ETBF DSUV 62C towed passive array, DSUV 22 microphone system, and DRUA 33 radar. Armament consists of four 533 mm (21 in) torpedo tubes with a mixed load of 14 weapons, including F17 Mod 2 torpedoes and SM39 Exocet anti-ship missiles, and the ability to lay mines.
Service history
Améthyste took part in Operation Allied Force (1999), the NATO bombing campaign over Yugoslavia, where she protected the NATO aeronaval group and, together with Rubis, interdicted the Kotor straits to prevent sorties by the Serbian Navy. She also gathered intelligence for the coalition.
In October 2010, Améthyste deployed as part of the French naval task group led by the aircraft carrier Charles de Gaulle for a four-month mission in the Mediterranean Sea, Red Sea, Indian Ocean, and Persian Gulf. The group conducted anti-piracy operations off Somalia, supported NATO operations in Afghanistan, and participated in the bilateral exercise Varuna 10 with the Indian Navy in January 2011.
Améthyste is home-ported at Toulon. She is projected to be withdrawn from service in 2027.
Decorations
- Croix de guerre des théâtres d'opérations extérieures with 1 bronze star
- Cross for Military Valour with 1 palm
