Rubis
On 10 June 2009 the Emeraude, a Rubis-class French nuclear submarine with advanced sonar equipment, began searching for the flight recorders of an Air France airliner that crashed into the Atlantic the previous week. The Emeraude was sent to the area to hunt the "black box" recorders, which may help explain the disaster and which are believed to lie on the ocean floor.
The first Rubis-class submarine was laid down in 1976 with torpedo and sonar systems inherited from the diesel-electric Agosta class. The first of the French SNA (Sous-marins nucléaires d'attaque - Nuclear Attack Submarine) Rubis class nuclear submarine was launched in 1988. The Rubis was an elegant design that overcame many of the faults with other nuclear submarines. With a displacement of 2,400 tons they are the most compact nuclear attack submarines to date - not significantly larger than a Scorpène-class conventional boat of up to 2,000 tons. The British Valiant, Swiftsure, and Trafalgar classes of the 1960s, '70s, and '80s displaced between 4,000 and 4,500 tons at the surface and were about 285 feet long.
France has a long history of building and operating submarines. Contrary to other countries which first of all developed nuclear powered attack submarines, the first efforts of France were directed into the building of a ballistic missile submarine. The French began gradually turning to ballistic missile submarines ("sous-marins nucléaires lanceurs d'engins", or SNLE) – with production beginning in 1964 and Le Redoutable becoming operational in 1972 – and, later, nuclear attack submarines ("sous-marins nucléaires d'attaque", or SNA), the first of which, Le Rubis, became operational in 1981. The first class of French nuclear powered attack submarines was equipped with second generation reactors.
By the early 1990s the French fleet includes five nuclear ballistic submarines (Le Redoutable and L'Inflexible classes), with two more under construction (Le Triomphant class), six nuclear attack boats (Rubis class), and several older diesel attack submarines (Agosta and Daphne classes). The overhaul of the two SSBNs and the continued construction of the Rubisclass attack submarines helped lessen the negative impact of low production when the new class of SSBNs was started. This sea-based capability, by extending the reach of France's deterrent and improving its survivability, was designed to bolster its credibility.
Budget reductions resulted in the cancellation of two Rubis-class attack submarines and a reduction in the number of new SSBNs from the original six to the current four. The seventh boat in the Rubis class, the Turquoise, was halted after the pressure hull and reactor components were completed; this boat is in storage. The eighth boat, the Diamant, was canceled.
The 5th unit, S605 Améthyste, is an upgraded version. Améthyste is not only the name of a gemstone, it's an acronym for "AMElioration Tactique, HYdrondynamique, Silence, Transmissions, Ecoute"(Tactical, hydronynamical, Silent, Transmissions and Sensors Improvement). This version is fitted with a linear towed array working on low frequencies. Automation of some tasks are also part of the improvements.
Rubis-class submarines are powered by two turbo alternators; one main motor (with an emergency electric motor); one CAS 48 pressurised water-cooled nuclear reactor rated at 48 MW; one Jeumont-Schneider auxiliary diesel electric motor, providing a top speed of 25 knots. The Rubis-class submarines 48 MW reactor needs no refuelling for 30 years. Armament consists of Aerospatiale SM 39 Exocet anti-ship missiles launched from four 533 mm torpedo tubes; ECAN L5 Mod 3 dual purpose torpedoes; or up to 32 FG 29 mines carried in lieu of torpedoes.
French SNA were designed to be able to sail for 220 days a year. Two alternating crews each of 68 personnel provide the ships compliment. In order to achived a sufficient operational availability given the reduced number of submarines at disposal, the SNAs are manned by two crews which rotate according to operational and maintenance cycles as well as, for crews, according to to deployements, training and leaves.
Beginning in 1984, new and existing vessels of this class were given improved sonar and silencing and were fitted with dive-launched Exocet antiship missiles. The first batch of Rubis class submarines was initially equipped for an anti-surface role, but since becoming the Rubis-Améthyste class they also perform anti-submarine warfare functions. As of 2006, all but the first Rubis-class had undergone modernization to the "Améthyste" standard with their military capability expandded in the areas of underwater detection, communications and acoustic discretion.
DUUX-5 Fenelon was developed to provide Rubis class submarines with panoramic search, passive acoustic rangefinding and panoramic sonar interception capability. The DUUX-5 Fenelon is an upgrade of the DUUX-2. It passively detects submarines at long ranges, making an active system necessary only for fire control. A set of six flat array panels are fitted three per side. Using at least two units per side, the submarine can determine a contact’s range by triangulation. Course and speed can be determined by TMA (Target Motion Analysis). The system is deployed on Rubis and Amethyste class SSNs, L’Inflexible and Le Redoutable class SSBNs, Spanish Agosta class SSKs and, according to some reports, Chinese Project 091 Han class SSNs, the Project 039 Song class and the Project 035 Ming class SSKs. Estimation of the unit cost of DUUX-5 is difficult since it usually forms an integrated part of a sonar suite. However, comparison with the known costs of similar systems indicates an approximate unit price of US$2 million. A sonar intercept unit records the bearing of all transmissions heard in the 2 kHz to 15 kHz band. It monitors noise near the submarine in 120-degree sectors on each side of the submarine. Four contacts can be tracked at once, one per 120-degree sector (on radiated self-noise) and one by the intercept unit (on sonar pulses).
Rubis will be replaced in 2010 by the first of a new class of submarines called "Barracuda". As of 1988 a "Post-Rubis" program anticipated the construction of at least three [later six] nuclear attack submarines which were supposed to receive — compared to the Rubis-class - a much-improved hull design and to be equipped with two reactors, instead of the previous single reactor. The launch of the program meant to replace six Rubis class nuclear submarines was delayed several times.
