The first French Georges Leygues Class Frigates was launched in 1978 with displacement of 3830 tons and a crew of 218. It was powered by two Rolls-Royce Olympus TM3B gas turbines rated at 46200 bhp and two SEMT- Pielstick 16PA6 CV280 diesels rated at 10400 bhp providing the vessel with a top speed of 30 knots(21 knots using the diesel engines), and a range, of 13,600 km at a speed of 18 knots. Armaments consisted of four Aerospatiale MM 38 Exocet anti-ship missiles; a Thomson-CSF Crotale Navale EDIR octuple anti-aircraft launcher with twenty-six missiles; one 100 mm/55 Mod 68 CADAM automatic dual purpose gun; two Oerlikon 20 mm guns; four M2HB 12.7 mm machine guns; two fixed torpedo launchers and ten ECAN L5 anti-submarine torpedoes; twelve Honeywell Mk 46 torpedoes for use with helicopters are also carried for the ship' s two dual-purpose, anti-submarine and anti-ship Lynx helicopters.
Initial planning called for the construction of a large number of the TOURVILLE-class ships. However, due to their complex construction and high costs, only three ships were of that class were built before attention was shifted to a more simplified DDG project: the Georges Leygues-class, which reflected the French Naval staff's modern views on the use of a DDG as the basis of their service fleet for the rest of the 20th century and beyond.
The project's plan called for the development of two variants (a strong ASW and a strong AAW capability in a single ship). Depending on the variant, the fundamental tasks of the DDG would be either ASW or air defense of the carriers. Initial plans called for building 7 ships designated for ASW and 4 for AAW. By 1986, four ships of the first variant were in service while the lead ship of the second variant had been launched and was to join the fleet.
Designated Fregates (Frigates) or Escourteurs d'Escadre, these vessels were originally known as the C-70 Fregates anti-sousmarines (antisubmarine frigates) when laid down in the mid-1970s. The French classifications express their purpose better than the catch-all phrase 'destroyer', though they are larger than most ships classed as frigate and the authoritative Jane's Fighting Ships rates them as destroyers. With two Lynx helicopters able to carry AS12 anti-ship missiles or anti-submarine torpedoes and a comprehensive weapon fit themselves, the 'Georges Leygues' class are versatile warships. They are also large enough to accept new weapons systems in due course; OTO-Melara Matra anti-submarine missiles were planned to be eventually added. The last three ships of the seven ship series have towed arrays, and the others were thought possible candidate to receive them as well in mid-life refits.
Georges Leyguesis a completely steel hulled ship, divided by watertight compartments into 17 segments, fore-and-aft framing, webbed frames and a dual-sectioned steel superstructure. The latter, however, is not considered as part of the ship's longitudinal integrity. The superstructures were built to optimize resistance from nuclear explosions' blast. For a considerable portion of its length, the hull has a double bottom. The ship's ventilation system, equipped with filters, is a supercharged system of internal compartmentation, water screen and a deactivation position. The particulars of the hull show several unusual stern designs, with a large stern counter and a small cruiser stern. The full length of the waterline is maintained almost to the very stern, turning into a side V-shaped stern feature. Such a shape favorably affects its seakeeping qualities. The absence of a submerged stern decreases to a certain degree the wetted surface, thanks to which hydrodynamic resistance at low and moderate speeds is reduced. The bulbous bow with its sonar transducer does not extend beyond the limits of the stempost.
The DD has a rather low freeboard, there is a slight curve in its bow section (up to -5°), there is an upper deck and a stern recess for installation of the towed sonar array equipment. As in the majority of European ships, the interdeck height is about 2.6 m in contrast to U.S. Navy ships where it is 2.9 m. Direct transit for the length of the ship is arranged on the 2nd deck, except for the area of the smoke-stack installation, where it zigs to the port side. The Combat Information Center directly abuts the pilot bridge, which experience from the Falkland Islands conflict showed, is considered essentially unsatisfactory as it reduces survivability. Owing to the large size of the towed antenna array, the helo landing pad is less displaced in the stern as in DDs of other classes.
The program was designed taking into account modern requirements for stability under attack. Hull architecture, integrity, speed and endurance were considered under normal displacement, which presupposed the presence on the ship of half its expendable supplies. According to habitability standards, the arrangements for the crew differ to a better degree from that in other ships, including the U.S. Navy. Enlisted personnel have 3-tiered bunks, in 9 to 18-person compartments, separated by partitions from the adjoining ones for comfort; petty officers are in 2-tiered bunks in 2 to 12-man compartments or cabins; and officers live in 1 to 4-man cabins. Living and administrative spaces have also been increased. Georges Leygues DDGs are equipped with active roll dampers, in the form of two side control rudders and a pair of side keels.
In contrast to the first four ships of the class, the later three ships had their pilot bridges placed higher by one deck and displaced somewhat toward the stern, so as to avoid overflowing from waves in bad weather. Ships of the first and second variant (except for their armament inventory) differ from each other in the basic type of power plant used and in the superstructure (made of aluminum alloy and therefore of less weight). On ships with greater ASW capability, in contrast with accepted practice in French shipbuilding to equip destroyers with steam turbine power plants, a combination diesel-gas turbine is used with two OLYMPUS TM3B gas turbines of 21,000 horsepower each for full speed, and two SEMT 16PA6 CV280, cruising diesels of 500 hp each, operating through reduction gears with two variable pitch propellors. In the electrical plant, there are four diesel-generators of 850 KW each.
A single stage turbine at full power has a 28 percent thermal efficiency and a half speed, 23.2 per cent. A gas generator has a 5-stage low pressure compressor and a 7-stage high pressure one, two single stage turbines and a combustion chamber with 8 sprayer jets. The gas turbine installation appears on the ship as a single module, consisting of a gas generator, its intake and exhaust, power turbine with gas diffusing nozzles and casings. Each module is installed on shockproof supports and shock-absorber mountings. The power plant is installed in 4 compartments: in the first and third there are two diesel generators and auxiliary machinery in each; in the second, gas turbines and the reduction gears, and in the fourth, the diesels and their reduction gears.
Concerning the 2nd variant DDGs, a decision was made, unexpectedly, to equip them with diesel propulsion plants. This was explained by the fact that the air induction and the gas exhaust structures did not appear compatible with the weapons requirements, particularly the air defense ones. Four diesels (SEMT 18PA6 BTC, 10,650 hp each) drive two shafts with fixed pitch propellors. It was planned to increase the diesels' power to 11,900 horsepower. The DDGs weapons systems had a high degree of standardization according to type of system in use and are differentiated only by quantity. On all ships, starting with the Suffren-Class DDG, there is installed a CIC system (ZENIT), of various modifications, the last of which (6th) includes 6 computers, and 12 display consoles with two command posts.
Originally designed primarily to provide anti-submarine defense to a carrier battle group, anti-submarine warfare frigates have seen their above-surface action capabilities reinforced.
Georges Leygues-class DDGs (1st variant) had installed the NAVAL CROTALE SAM with dual radar and infrared homing (range, 10 km, speed, Mach 2, launch weight, 80 kg and reaction time under optimal conditions 6 seconds). All ships were equipped with the EXOCET anti-ship missile with its dual guidance systems (inertial and active radar) and subsonic speed. There are two modifications of this missile: the MM-38 (launch weight, 735 kg, range, 42 km) and the MM-40 (850 kg, 70 km).
The Georges Leygues (2nd variation) ships were armed with the TARTAR SAM and the STANDARD-1 SAM systems, with semi-active radar guidance systems (range, over 32 km; speed, Mach 2; launch weight, 635 kg; total weapon supply, 40 missiles) and the MK 13 launch system, were to be taken from the DUPETIT THOUARS-Class DDGs which were gradually being put into the Reserve Fleet. In addition, it was planned to arm them with the SARDAL self-defense SAM and the MISTRAL SAM which has infrared guidance and a rapid re-load capability, assuring target acquisition at altitudes up to 3 m.
All DDGs had a universal single-mount 100-mm Mod 68 gun battery, (range, 17 km, vertical range, up to 8,000 m in altitude and firing rate of 60 rds/min. ASW missile weapons on several of the programmed ships are the MALAFON ASW missile complex (a single launcher, launch weight of 1500 kg, range of 13 km, radio guided when in flight). The ASW missile warhead is an L4 torpedo (acoustic homing with a 30-knot speed). Among the deficiencies, according to French experts, precluding its widespread use, are its large dimensions and weight, as well as the single launcher system. Each, of the ships has 2-4 internally-installed 533-mm torpedo tubes, which fire the 15 ASW torpedo (35-knot speed), with a programmed guidance (Mod 1) or acoustic homing (Mod 4).
The armament of the TOURVILLE-and GEORGE LEYGUES-Class DDGs includes one or two LYNX Mk2 helicopters with a speed of 230 km/hr and a flight range of 590 km; a takeoff weight of 4,760 kg, and 324-mm torpedos (two each) MK 46 with active/passive sonar guidance systems (speed, 45 knots, range, 8 km, weight, 230-257 kg).
Whereas all other ships of the Georges Leygues-class were fully built at Brest, portions of the La Motte-Picquet and Latouche-Tréville frigates were constructed by DCN Brest but their final assembly and outfitting were completed at DCN Lorient.
As of March 2013, all French Navy Georges Leygues-class frigates had a mixed gender crew except for La Motte-Picquet (D 645).
For close to 20 years, the Georges Leygues (D 640) was based out of Toulon. Starting in June 1999, she became tasked in part with cadet training; a mission which she shared with the Jeanne d'Arc helicopter carrier until 2010; and since then with a projection and command vessel (BPC). In that role, she's also outfitted a conference room, a computer study room able to accomodate 36 students.
Since the multimission frigate (FREMM) Normandie headed to Egypt as part of arms contracts that was officially signed on 16 February 2015 by the Egyptian President Abdel Fattah al-Sissi and the French defense minister, Jean -Yves Le Drian, the French Navy was forced to revise its plans. The time that these vessels are brought into service, missions and continue the operational contract should be honored. Where deferral of removal from active duty (RSA) of two anti-submarine frigates (MDTF), namely the Montcalm and Jean de Vienne. These ships, which date from the early 1980s, will remain operational until 2017 and 2018 respectively. Fortunately it was decided to review the pace of job cuts in the armed frigates. Montcalm and Jean de Vienne, F-70, are actually implemented by crews of 244 sailors while only 108 personnel are needed on board a FREMM.