The Rubis class (formerly SNA 72 and Provence class) is a class of six French 1st generation nuclear attack submarines. They replace the Agosta-class diesel-electric submarines. Rubis class SNAs are in service with the French Navy. They are the most compact military nuclear submarines in the world. This class is designed for deep underwater warfare, convoy surveillance and electronic intelligence.
History
With the commissioning of SSBNs in the French Navy in the 1970s, it was decided for submarine forces to build a class of SNA using the same propulsion technology, but taking up, for cost reasons, the hull shape of the Agosta class. This "nuclear-powered Agosta" was first known as SNA 72 then Provence class (the next two buildings being called Bretagne and Bourgogne), before being renamed under the chairmanship of Valéry Giscard d'Estaing.
They are the most compact SNAs in the world, which caused some difficulties for the integration of the K 48 pressurized water reactor.
The first was delivered in 1983 and took on the name of its illustrious predecessor, the Rubis, which was part of the FNFL and was made Compagnon de la Liberation. The 3rd in the series does not bear the name of a precious stone but takes up that of the Casabianca, a 1,500-tonne submarine which escaped the scuttling of Toulon and distinguished itself in the Mediterranean during the Second World War.
Occupied mainly, but not exclusively, by anti-submarine warfare operations for the benefit of deterrence, since the creation of the strategic oceanic force, the range of employment of attack submarines has widened since the mid-1990s with the upgrading of nuclear attack submarines which can now act for the benefit of carrier battle groups or maritime action.
The presence of a French SNA off the Bay of Kotor inhibited the Yugoslav navy during the Kosovo war in 1999. During Operation Harmattan in 2011 off Libya, 3 SNA took turns for intelligence missions.
Redesign
The hull shape of the Rubies, which is not profiled enough, leads to noise disturbances which disturb the sonar at high speeds. It is therefore decided to redesign called AMETHYSTE (HYdrodynamic Tactical Improvement, Silence Transmission, Listening) from the 5th building. The first four were recast to this standard in 1989 and 1995, which included a "yellowfin tuna" shaped hull, wraparound bridge deck and streamlined sonar dome.
List of ships
Although it was possible, at the start of the program, to build up to 8 ships, only 6 were actually built, delivered and fitted out:
Ruby S 601 February 23, 1983
Sapphire S 602 July 6, 1984
Casabianca S 603 May 13, 1987
Emerald S 604 September 15 1988
Amethyst S 605 March 20, 1992
Pearl S 606 July 7, 1993
Turquoise S 607 Canceled in 1992
Diamant S 608 Canceled in 1992
Features
Nuclear submarines have two crews (blue and red) who take turns every four months or so. The total number of crews which is 10 temporarily increased to 9 in the 2000s
Their "80 HLES" steel hulls with high elastic limit allow a maximum immersion of more than 300 m. The sonar dome and the solid are made of composite materials.
Equipped with a “TITAC” computerized combat system centralizing underwater detection, information processing and weapon launching (launch direction “DLA”); a “SEAO/OPSMER” command support system; a “Syracuse 2” satellite transmission system, an integrated navigation system with two Sagem “Minicin” inertial units.
The propulsion apparatus includes:
A “K 48” nuclear boiler plant with 48 thermal MW, consisting of a reactor-exchanger unit supplying steam to two turbo-alternators. This boiler room can also provide significant power, corresponding to the usual speeds, in natural primary circulation, thus adding discretion to the long-term energy autonomy that it gives to the building;
an electric motor main;
a 650 hp (480 kW) "SEMPT Pielstick 8 PA 4 V 185 SM" diesel-generator set with a 500 kW auxiliary electric motor, providing emergency propulsion in case of unavailability of the nuclear boiler room.
Amethyste is not only the name of the fifth French nuclear attack submarine, on the model of which the first four were redesigned, between 1989 and 1995, but also an acronym meaning "Tactical improvement, hydrodynamics, silence, transmission, listen”.
The expected lifespan is 25 years, and work should make them last another ten years. a new class, the Suffren class, should replace them from 2017, the second copy being in 2013 announced in 2020, the 5 Rubies remaining at this date being over 30 years old.
Availability
A report by the French National Assembly notes that "in 2008, the availability of French Navy ships remained generally good", except for the Rubis class SNAs, "which are beginning to show a high age". The availability rate thus fell from 55.5% in 2006 to 47.9% in 2007 and then to 39.7% in 20085. In 2012, the availability rate was 55%.
Of the six buildings, two are immobilized in repair, more or less long; two are dedicated to the protection of SSBNs in the context of deterrence. Only two submarines remain to carry out conventional missions, including the protection of the carrier battle group.
Export
In 1987, the Canadian Defense White Paper called for the acquisition under technology transfer over the next 20 years of a fleet of 10 to 12 Ruby-class or British Trafalgar-class nuclear attack submarines. The plan aims to establish a navy capable of maneuvering in the three oceans and, in particular, to establish Canadian territorial claims on the waters and the subsoil of the Arctic. The project, which had to be confirmed before the summer of 1988 by the choice of the type of building, was finally abandoned during the vote on the budget in April 1989.
Ruby Class
Technical features
Type Nuclear attack submarine
Length 73.60 m
Maître-bau 7.60 m
Draft 6.40 m
Displacement 2,385 t (surface), 2,670 t (diving)
Propulsion 1 K 48 pressurized water reactor, 1 electric propulsion motor, 1 propeller
Power 7,000 kW
Speed 25 knots diving
Depth> 300 m
Military specifications
Armament 4x 533mm torpedo tubes with 14x F 17 torpedoes and 2x SM-39 Exocet missiles
Other features
Electronics 1 DRUA 33 surface surveillance radar
1 DMUX 20 multifunction sonar
1 ETBF DSUV 62 C passive sonar
1 DSUV microphone array 62 C
TITAC computerized combat system
link 14
1 ARUR 13 radar detector
Crew 68 men
Manufacturers DCN, Cherbourg
Served in French Navy
Construction period December 11, 1976 - 1993
Period of service February 23, 1983 - underway
Ships built 6
Cancelled ships 2
Ships in operation 6