The class were fast battleships built for the French Navy between the 1930s and 1950s. Initially two ships were ordered in 1935 in response to Italian orders for the s the previous year. The s were based on the preceding , but scaled up to accommodate more powerful guns and armor to protect them from guns of the same caliber. To keep the ships within the displacement limits imposed by the Washington Naval Treaty, they featured the same concentrated arrangement as the s for the main battery: two quadruple gun turrets placed forward. They also incorporated new, more compact boilers that allowed for a shorter hull (which required less heavy armor) for the desired top speed. After Germany ordered two s, France responded with another pair of s, to be built to modified designs. The first, , would have received modified secondary and anti-aircraft batteries, while would have had her superfiring main battery turret shifted aft, along with other changes. was never completed, and was never laid down. The s were the last battleships built for the French Navy.
Neither of the two completed members of the class had been completed by the outbreak of World War II. was finished shortly before the French defeat in the Battle of France, while was hurriedly prepared to be ready to go to sea during the campaign. Both vessels fled to French colonies in Africa: steamed to Dakar and went to Casablanca. Work on and stopped after the Germans occupied France. In mid-1940, was attacked twice and damaged by British forces attempting to coerce the crew to defect to Free France, while was badly damaged by American forces during Operation Torch in November 1942. After the French African colonies shifted to Free French control, was taken to the United States to be repaired and modernized, while was not completed. saw active service with the British Home Fleet in early 1944 before being transferred to the Eastern Fleet later that year. There, she took part in numerous operations against Japanese forces in the Indian Ocean. She was present for the Japanese surrender of Singapore at the end of the war.
After the war, took part in the initial campaign to restore control of French Indochina before returning to France, where she saw limited activity into the early 1950s. During this period, the French Navy discussed proposals to complete or convert her into an aircraft carrier, ultimately settling on the former. was finally commissioned in 1955, thereafter taking part in the French intervention in the Suez Crisis in November 1956. Her career proved to be a short one, and she was placed in reserve in 1957. Both vessels were used as training and barracks ships into the 1960s; was sold to ship breakers in 1968 and followed her in 1970.
Design
In the early 1930s, the French Navy began construction of the two small s in response to the German s. The Italian (Royal Navy)—France's other major naval rival—announced on 11 June 1935 that it would begin building two battleships of the in response to the s. The Italian ships were to be armed with nine guns, significantly more powerful than the eight guns of the French ships. In order to maintain parity, the French realized that similar vessels would be required to counter the new Italian ships. At the time, battleship construction was governed by the Washington Naval Treaty, which limited displacement to 35,000 tons and gun armament to .
The French naval command issued specifications for a new battleship design in response to the s on 24 July, less than two weeks after the Italian ships were announced. The new ships would be built to the maximum Washington limits: 35,000 tons displacement and a battery of eight guns of either 380 mm or 406 mm. The vessels would also carry a secondary battery of dual-purpose guns, be capable of a speed of , and carry belt armor that was thick. (Vice Admiral) Georges Durand-Viel, the Chief of Staff of the French Navy, favored using the basic design, scaled up to account for the increases in displacement, armament, and armor, to reduce the amount of time needed to design the ship. The s had adopted an unusual arrangement of the main battery that grouped all eight guns in a pair of four-gun turrets placed forward of the superstructure in a superfiring pair.
Initial studies by the design staff quickly demonstrated that a battery of 406 mm guns would be impossible if the other characteristics would be fulfilled within the allotted displacement. Six proposals were submitted on 27 November. The first, Project 1, was a scaled up , while Project 2, 3, and 4 were variations on that design with main battery arrangements based on the British , mounting three turrets forward of the superstructure. Project 2 used one twin and two triple turrets, Project 3 incorporated one quadruple and two twin turrets, while Project 4 used three triple turrets. Two related variants, Project 5 and 5 bis adopted an even more unusual arrangement featuring two quadruple turrets placed amidships between fore and aft superstructures inspired by the ideas of the Italian admiral Vincenzo De Feo. Secondary armament for the designs amounted to twelve guns in quadruple turrets as on the s. All six designs were overweight and the last two were quickly rejected since their layout significantly limited the firing arc of the main battery.
The naval command quickly settled on Project 1, as it had the most balanced combination of speed and combat power—offensively and defensively—that could realistically be achieved within the displacement constraints imposed by the Washington Treaty (and the existing French shipyard facilities). But concerns over the perceived lightness of the secondary battery compared to foreign capital ships led the command to request studies for a new secondary battery, despite this precluding the use of dual-purpose guns. The designers submitted two options: five triple or four triple turrets, with a heavy anti-aircraft battery of guns; the five turret variant would include six of the 75 mm guns, while the four turret version would add two of the 75 mm weapons. These proposals presented several problems: first, the anti-aircraft guns were sensitive to blast effects from the main and secondary batteries, which would require additional space that was not available, and second, the Project 1 design was already overweight, and the added guns would increase displacement even further. The naval command ultimately decided on 14 April 1935 that new dual-purpose mounts for the 152 mm guns would have to be developed.
The weight problem was solved by adopting a new type of boiler, designated "Sural" (short for [pressure-fired]); these boilers were much more compact than the type used in the class and the s had a wider beam (allowing three boilers side-by-side instead of just two), so the boiler rooms could be reduced from three to two, with the total machinery space shortened considerably. Since the machinery spaces required heavy armor protection, this reduced the length of the hull that needed to be covered by the armor belt by almost . The belt was also decreased in thickness from 360 mm to 330 mm (though the angle of inclination was increased to compensate for the reduction); coupled with minor reductions in armor elsewhere in the ship, these changes offset the weight of the 152 mm battery and brought the displacement within Washington limits. Work on the design proceeded quickly, and on 14 August, the navy placed orders for the first two ships, and .
Despite both vessels adhering to the displacement limits, when construction of began in October, France had violated the Washington Treaty. The treaty had included a moratorium on new battleship construction that was extended by the London Naval Treaty of 1930 (which France had signed but not ratified), though France and Italy had secured an exception to allow them to build up to of new battleships as their fleets were older than those of the other signatories. Combined with the two s, brought the total French construction program to , and when was laid down in December 1936, the total rose to . Britain objected to the construction program, but France dismissed them by pointing out that Britain had unilaterally signed the Anglo-German Naval Agreement earlier in 1935, effectively abrogating the disarmament clauses of the Treaty of Versailles that had severely constrained the size and effectiveness of the German fleet. From the French perspective, if Britain would cavalierly strengthen France's enemy, the French would similarly disregard their own treaty obligations in favor of self defense.
General characteristics
By the time the first vessel was completed, the -class ships displaced standard and fully loaded. They were long between perpendiculars and were long overall. They had a beam of and a maximum draft of . Because the compact Sural boilers allowed the machinery spaces to be shortened, the ships featured a very compact superstructure. This in turn allowed for a long forecastle that significantly improved seakeeping and helped to keep the bow dry in heavier seas. The ships' superstructure was fairly minimal; it featured a single tower mast directly behind the armored conning tower, along with a small deck house directly aft of the funnel.
Their crew numbered 1,569 officers and men, though this changed considerably over the course of their careers, particularly as their anti-aircraft batteries were revised. They carried a number of small boats, including eight motor boats, a pair of motor launches, three motor pinnaces, two whale boats, two dinghies, and two small flat-bottomed boats. The compact superstructure also allowed for the aviation facilities of the ships to be expanded compared to the s. A long quarterdeck housed a pair of catapults and a long hangar that could accommodate two Loire 130 seaplanes with their wings folded, with a third carried on top of the hangar; two more aircraft would be carried, ready to launch, on the catapults. The catapults were offset en echelon, with the starboard mount further forward than that on the port side. A large crane was used to recover the aircraft after they landed in the sea near the ship, and when not in use, it could be folded flat.
Machinery
The -class ships were powered by four Parsons geared steam turbines and six oil-fired Sural forced-circulation boilers manufactured by Indret for and by Penhoët and AC de la Loire for . The Sural boilers were experimental, and were thus a major risk to take with what were to be the most powerful capital ships of the French fleet; they nevertheless proved to be generally reliable in service. Like the s, the s used the unit system of machinery for their propulsion system, which split the machinery into two separate systems. Three boilers were placed in one boiler room, followed by the forward engine room that housed the pair of turbines that drove the outer pair of propellers. Next astern was a second boiler room, followed by a second engine room, which powered the inner pair of screws. The arrangement offered improved damage resistance, since one system could be disabled due to battle damage and the other could remain in operation. All four screws had four blades and were in diameter. The boilers were ducted into a single funnel.