SSN Rubis Amethyste Class Attack Submarine, France

The French Navy operates six Rubis Amethyste class submarines from the naval base in Toulon. The submarines, built at the Cherbourg Naval Dockyard of DCN, are the Rubis S601 commissioned in 1983, Saphir S602 (1984), Casabianca S603 (1987), Emeraude S604 (1988), Amethyste S605 (1992) and Perle S606 (1993).

The six Rubis Amethyste submarines are nuclear-powered, but DCN has developed a derivative of this class with diesel propulsion, the Turquoise, which can also be fitted with DCN's Mesma Air Independent Propulsion (AIP) system.

The first four submarines were initially equipped for an anti-surface ship role but have been re-equipped to the same standard as the later submarines for both anti-surface and anti-submarine warfare.

Rubis Amethyste Class submarines are to be replaced by the Barracuda Class nuclear powered attack submarines, which are planned to enter service from 2012.

In April 2007, DCN became DCNS. This followed an agreement in which Thales became a 25% shareholder in the new company and DCN acquired the naval business of Thales France (excluding naval equipment).

COMBAT SYSTEM

The submarine's weapon control system is the DLA 2B and DLA 3. The tactical data system is the Systeme d'Armes Tactique (SAT).

MISSILES

The torpedo tube launched Exocet SM39 anti-ship missile is manufactured by MBDA (formerly EADS Aerospatiale). Target range and bearing data is downloaded from the submarine's tactical data system and weapon control system into the Exocet's computer.

The missile approaches the target area in sea-skimming mode using inertial navigation and then active radar homing, at speeds over Mach 0.9 with a range of 50km. The Exocet's 165kg high-explosive shaped charge warhead is armed with a delayed impact and a proximity fuse.

TORPEDOES

The submarine has the capacity to carry 14 missiles and torpedoes in a mixed load. The four 533mm torpedo tubes are equipped with a pneumatic ram system for discharging torpedoes from the tubes.

The ECAN L5 Mod 3 torpedo is equipped with active and passive homing and has a range of 9.5km. The torpedo has a speed of 35 knots and delivers a 150 kg warhead to a depth of 550m. The ECAN F17 Mod 2 torpedo is a wire guided torpedo with active and passive homing to a range of 20km. The torpedo delivers a 250 kg warhead to a depth of 600m.

COUNTERMEASURES

The Thales (formerly Thomson-CSF) DR 3000U electronic support measures system is a radar warning receiver (French Navy designation ARUR-13) operating in D to K bands. The system uses a masthead antenna array with omnidirectional and monopulse directional antennas and a separate periscope warning antenna. The system provides direction finding accuracy of higher resolution than 1°.

SENSORS

The Rubis Amethyste's Type 1007 navigation radar is supplied by Kelvin Hughes and operates at I-band.

The sonar suite includes the Thales Underwater Systems (formerly Thomson Marconi Sonar) DMUX 20 multifunctional passive sonar operating at low frequency. The submarine's very low-frequency passive towed array system is the DSUV 62C.

PROPULSION

The propulsion system of the Rubis Amethyste is a nuclear-powered turbo-electric system. The Pressure Water Reactor (PWR) CAS 48 provides 48MW. A diesel-electric SEMT-Pielstick and Jeumont Schneider 8 PA4 V 185 SM provides the auxiliary propulsion. The submarine achieves a dived speed of 25 knots.

The Turquoise SSK submarine is a derivative of the Rubis Amethyste class, developed for export. Turquoise is equipped for anti-surface and anti-submarine missions and is capable of carrying out special missions, from intelligence gathering and mine laying to commando landing and recovery operations.

The diesel generators and battery capacity ensure a low indiscretion rate and a long submerged endurance. The indiscretion rate is the ratio of the time needed to remain at periscope depth to recharge the batteries and the total operating time.

The endurance of the Turquoise SSK submarine is more than 60 days, whereas that of the Rubis Amethyste is 45 days. Underwater endurance of the Turquoise can be considerably extended by the fitting of the Mesma air-independent propulsion (AIP) system, developed jointly by DCN, Air Liquide, Bertin, Izar (formerly E.N. Bazan), Framatome-Thermodyn and Technicatome.

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