Normandie-class battleship

In December 1911, the French Navy's Technical Committee () issued a report that examined the design of the that had been ordered for 1912. They concluded that the amidships gun turret was an unsatisfactory choice, based on experiences from the 1880s with blast damage on battleships from their own guns. This position influenced the construction of the next class of dreadnought battleships, for which design work began shortly thereafter. The French Navy's design staff () submitted the first draft of the new dreadnought design in February 1912. The size of French shipyard facilities significantly affected the design. Length was limited to , beam to , and draft to approximately . These dimensions limited the design to a displacement of around and a speed of , depending on the armament arrangement. The design staff presented three armament alternatives, all armed with a secondary armament of twenty guns in a new twin-gun casemate mounting. The first was a design with the same ten 340 mm guns as the s, but with a top speed greater than 21 knots. The second was for a ship with a dozen 340 mm guns arranged in two quadruple-gun turrets fore and aft of the superstructure with superfiring twin-gun turrets and a speed of 20 knots. The last proposal was a ship that was armed with sixteen guns in four quadruple turrets and a speed of 20 knots. The staff also prepared two design options for the propulsion system. One used two sets of direct-drive steam turbines, as in the class; the one ultimately selected was a hybrid system that used one set of direct-drive turbines on the two inner propeller shafts, and two vertical triple-expansion steam engines (VTE) on the outer shafts for low-speed cruising. This was intended to reduce coal consumption at cruising speeds, as direct-drive turbines are very inefficient at moderate to low speeds. The fifth ship, , was instead equipped with two sets of turbines to allow her to match the fuel consumption rate of the turbine-equipped class. The General Staff decided in March 1912 to retain the 340 mm gun of the class and favored the all-turbine design. They chose the new quadruple turret and preferred an armament of twelve guns in two quadruple and two double turrets. The following month, the Naval Supreme Council () could not reach a decision on the quadruple turret as it was still being developed, but wished to revisit the issue once it was further along. The council rejected the twin-gun casemate mounting proposed for the secondary armament and proposed a mixture of eighteen 138.6 mm and a dozen guns. It accepted the hybrid propulsion system, and the armor layout of the class was to be retained, with an increase in the thickness of the main belt if possible. Théophile Delcassé, the Naval Minister (), accepted the council's recommendations with the proviso that the -class arrangement of five twin turrets, including one amidships, would be substituted if the quadruple turrets were not ready in time. The Technical Department prepared two new designs, A7, which incorporated the five twin turrets, and A7bis, with three quadruple turrets. The A7bis design was some lighter than the A7 design, and on 6 April the Navy accepted a quadruple-gun-turret design submitted by Saint-Chamond. On 22 May it realized that the 100 mm gun would not ne ready by the time construction was scheduled to begin, so the design reverted to the 138.6 mm gun. Further work revealed that two additional guns could be accommodated, and the Naval Supreme Council accepted the design with twenty-four 138.6 mm guns on 8 July. == Description ==

The -class ships were long at the waterline, and long overall. They had a beam of and a mean draft of at full load. They were intended to displace at normal load and at deep load. The ships were subdivided by transverse bulkheads into 21 watertight compartments. The first four ships were equipped with one set of steam turbines driving the inner pair of four-bladed, propellers. and had license-built Parsons turbines, had turbines by Rateau-Bretagne, and s turbines were built by Schneider-Zoelly. The four ships had a pair of four-cylinder vertical triple-expansion engines that drove the two outer three-bladed, propellers for steaming astern or cruising at low speed. The last ship, , was equipped with two sets of Parsons turbines, each driving a pair of three-bladed, 3.34 m propellers. and were fitted with 21 Guyot-du Temple-Normand small-tube boilers, and were equipped with 28 Belleville large-tube boilers, while had 28 Niclausse boilers. All of the boilers operated at a pressure of . The ships' engines were rated at and were designed to give them a speed of , although use of forced draft was intended to increase their output to and the maximum speed to . The ships were designed to carry of coal and of fuel oil, but up to of coal could be stored in the hull. At a cruising speed of , the ships could steam for ; at , the range fell to , and at top speed, it dropped to . The ships would have had a crew of 44 officers and 1,160 enlisted men when serving as a flagship. Armament The main battery of the class consisted of a dozen 45-caliber Canon de 340 mm Modèle 1912M guns mounted in three quadruple turrets. One turret was placed forward, one amidships, and one aft, all on the centerline. The turrets weighed , and were electrically trained and hydraulically elevated. The guns were divided into pairs and moved together in twin cradles; a -thick bulkhead divided the turrets in half. Each pair of guns had its own ammunition hoist and magazine. They could be fired simultaneously or independently. Had the ships been completed, these would have been the first quadruple turrets in the world. The guns had a range of and a rate of fire of two rounds per minute. The shells were armor-piercing rounds and were fired with a muzzle velocity of . Each gun was to have been supplied with 100 rounds of ammunition. Five rangefinders provided fire-control for the main battery. Two of the rangefinders were mounted on the conning tower and the other three were placed atop each of the turrets. The turrets also had auxiliary gunnery-control stations. The ships would also have been armed with a secondary battery of twenty-four 55-caliber 138.6 mm Modèle 1910 guns, each singly mounted in casemates near the main-gun turrets. These guns fired a shell at a muzzle velocity of . These guns would have been supplied with 275 rounds of ammunition each. Six Canon de Modèle 1902 anti-aircraft guns, which were converted from low-angle guns, would also have been carried by the ships. The ships also would have been equipped with six underwater torpedo tubes, three on each broadside, and carried 36 torpedoes. Protection , 1916 The armor belt of the -class ships was made from Krupp cemented armor and extended almost the entire length of the hull (), save at the stern. The belt consisted of two rows of plates that were a total of high, of which was below the waterline. The thickest portion of the armor protected the hull between the barbettes of the end turrets and was thick. Each of the upper plates was tapered to a thickness of at its top edge and the lower plates were tapered to at their bottom edge. From No. 1 barbette to the bow, the plates progressively reduced in thickness from at the bow; the upper edges also progressively reduced from while the bottom edge of these plates was thick. Aft of the rear turret, the armor plates were progressively reduced in thickness from 260 millimeters to 140 millimeters. Their upper edges also progressively thinned from , and their lower edges were the same 80 millimeters in thickness as their forward equivalents. The aft belt terminated in a transverse bulkhead. Above the waterline belt was an upper strake of 160-millimeter armor that extended between the fore and aft groups of casemates for the secondary armament. The portions of the barbettes that extended outside the upper armor were protected by plates, while the interior surfaces were only thick to save weight. The turrets were protected with an armor thickness of 300 millimeters on their faces, on the sides, and 100 millimeters on the roof. The sides of the conning tower were thick and its roof was also 100 millimeters thick. The lower armored deck consisted of a single plate of mild steel for a width of along the centerline, and another layer of the same thickness was added outboard of that. The deck sloped downwards to meet the bottom of the waterline belt, and a plate of armor steel reinforced the sloped portion of the deck to give a total thickness of . Two layers of plating made up the center of the upper armored deck, which was reinforced to a total of along the edges and above the magazine. The hull of the s had a double bottom deep. Their propulsion machinery spaces and magazines were protected by a torpedo bulkhead that consisted of two layers of nickel-chrome steel plates. The outer side of the bulkhead was lined with a 10-millimeter plate of corrugated flexible steel intended to absorb the force of a torpedo detonation. Another measure intended to dissipate the force were tubes that extended from the double bottom to the upper armored deck, intended to divert the gases of a detonation away from the torpedo bulkhead. Concerned about the possibility of capsizing after asymmetric flooding, the design incorporated empty compartments below the waterline and outboard of the fore and aft 34-centimeter magazines, the engine rooms and the midships 138.6-millimeter magazines that were intended to be flooded if necessary to correct any list. == Ships ==

== Construction and cancellation ==

Named after provinces of France, and were ordered on 18 April 1913, although neither was formally authorized until the enabling finance bill () was passed on 30 July, and and on that same day. had been planned to be ordered on 1 October 1914, but it was brought forward to 1 January; the five ships would permit the creation of two four-ship divisions with the three -class dreadnoughts then under construction. Work on the class was suspended at the outbreak of World War I, as all resources were needed for the Army. The mobilization in July greatly impeded construction as workmen who were in the reserves were called up for military service, and work was effectively halted later that month. The labor force available to work on the s was further reduced by conscription and orders for munitions for the Army. In light of such constraints, the navy decided that only those ships that could be completed quickly, such as the s, would be worked upon, although sufficient construction of the first four s was authorized to clear the slipways for other purposes. Construction of had been already halted on 23 July, and all further work on her was abandoned. In July 1915 work on the ships' armament was suspended, save the guns themselves, which could be converted for use by the Army. Four of the completed 340 mm guns were converted into railway guns for the French Army. Nine of the guns built for were also mounted on railway carriages in 1919, after the end of the war. Several of the 138.6 mm guns were also modified for service with the Army. The boilers intended for and were used to replace the worn-out boilers of various destroyers, namely the s purchased from Argentina in 1914 and the three ships seized from the Royal Hellenic Navy in late 1916. The boilers built for were installed in new anti-submarine ships. The armor-plate and turntables for s turrets had been ordered from Fives-Lille, whose factory was captured by the Germans in 1914. They were discovered in one of Krupp's factories in Germany in 1921, and returned to the Navy. In January 1918, a final wartime order specified that the ships remained suspended, but that all material that had been stockpiled for work would remain in place. By that time, some of steel plating that had been earmarked for had been taken for other uses. On 22 November, days after the Armistice with Germany, the design staff sent the General Staff a proposal to complete the first four s to a modified design. The General Staff replied that the ships would need a top speed of and a more powerful main battery. Since the dockyard facilities had not been enlarged during the war, the size of the ships could not be significantly increased. This allowed only modest improvements, particularly for the installation of anti-torpedo bulges. In February 1919, the General Staff decided that the ships would be completed anyway, because new vessels incorporating the lessons of the war could not be completed for at least six to seven years due to the lengthy design studies required. The Technical Department created a revised design that incorporated some improvements. The machinery for the four ships that had been launched during the war would be retained; increasing their speed to required a corresponding increase to , which could be obtained by building more powerful turbines. The elevation of the main guns was to be increased to 23–24 degrees, which would increase the range of the guns to to avoid being outranged by foreign battleships. The need to engage targets at longer ranges was confirmed by the examination of one of the ex-Austrian ships that had been surrendered to France at the end of the war. The main armored deck was to be increased to to increase resistance to plunging fire. The submerged 450 mm torpedo tubes were to be replaced with deck-mounted tubes, and fire-control equipment was to be improved. Equipment for handling a two-seat reconnaissance aircraft and a single-seat fighter was also to be installed. After the war, Vice Admiral Pierre Ronarc'h became Chief of the General Staff, and in July 1919 he argued that the Italian Navy was the country's primary naval rival, and that they might resume work on the s that had been suspended during the war. He suggested there were three options for the first four s: complete them as designed, increase the range of their guns and improve their armor, or lengthen their hull and install new engines to increase speed. The Technical Department determined that lengthening the hulls by could increase speed by as much as . Nevertheless, by 12 September 1919, Ronarc'h had decided that completing the ships would be too expensive for the fragile French economy. Plans for the first four ships included converting them into cargo ships, oil tankers, or passenger liners, or using them as floating oil depots, but these ideas were ultimately rejected. The ships were formally cancelled in the 1922 construction program, and were laid up in Landevennec and cannibalized for parts before being broken up in 1923–1926. Much of the salvaged material was incorporated into completing and in modernizing the battleship . Plans to complete included replacement of the coal-fired boilers with eight oil-fired Niclausse boilers and new, more powerful turbines. A new quadruple turret that allowed greater range was considered, along with twin turrets mounting guns. The battleship was launched on 15 April 1920 to clear the slipway. A temporary wooden platform was built atop the lower armored deck later that year to serve as a flight deck for aircraft landing trials. Transverse arresting wires that were weighted by sandbags were improvised, and the evaluation successfully took place off Toulon in late 1920. In 1922, the Navy instead decided to complete the ship as an aircraft carrier. Conversion work began in August 1923, and was completed by May 1927 using the hybrid propulsion system from with a dozen Normand boilers. The ship was the first carrier of the French Navy. She served in the fleet through World War II, generally being used as a ferry for aircraft; she did not see any combat as she spent most of the war in the Caribbean in the island of Martinique. In 1944, she was refitted in the United States and equipped with a battery of modern American anti-aircraft guns. She remained in service through the First Indochina War, still as an aircraft ferry. The ship was ultimately broken up for scrap in 1967. == Notes ==