page_title: French battleship Jean Bart (1940)
section_title: Design
hierarchical_section_title: French battleship Jean Bart (1940) / Design
context_page_description: Jean Bart was a French fast battleship, the second and final member of the Richelieu class. Built as a response to the Italian Littorio class, the Richelieus were based on their immediate predecessors of the Dunkerque class with the same unconventional arrangement that grouped their main battery forward in two quadruple gun turrets. They were scaled up to accommodate a much more powerful main battery of eight 380 mm guns, with increased armor to protect them from guns of the same caliber. Jean Bart was laid down in 1936 and was launched in 1940, following the outbreak of World War II in Europe. The ship was not complete by the time Germany won the Battle of France, and Jean Bart was rushed to Casablanca to escape advancing German troops. She had only one of her main turrets installed, along with a handful of anti-aircraft guns.
  While in Casablanca, the French attempted to prepare the ship for action as much as was possible in light of limited infrastructure and the necessary parts to complete the vessel. Her anti-aircraft armament was slowly strengthened as guns became available and a search radar was fitted in 1942.
context_section_description: When in 1934 Italy announced that it would begin building two Littorio-class battleships armed with 380 mm (15 in) guns, the French Navy immediately began preparations to counter them. The small Dunkerque-class battleships that had been ordered provided the template for the next French battleship design, but it needed to be scaled up to match the new Italian vessels, both in terms of offensive and defensive characteristics. The design staff considered 380 and 406 mm (16 in) guns, but the latter could not be incorporated in a design that remained within the 35,000 long tons (35,560 t) limit imposed by the Washington Naval Treaty and was quickly discarded. The Dunkerques carried their armament in two quadruple gun turrets arrayed in a superfiring pair forward of the superstructure, and the designers experimented with other arrangements, including combinations of triple and twin turrets, but the need to minimize the length of the armor belt (and thus its weight) necessitated a repetition of the Dunkerque layout.
  Jean Bart displaced 37,250 long tons (37,850 t) standard and 43,992 long tons (44,698 t) fully loaded, with an overall length of 247.85 m (813 ft 2 in), a beam of 33.08 m (108 ft 6 in) and a maximum draft of 9.9 m (32 ft 6 in). She was powered by four Parsons geared steam turbines and six oil-fired Sural water-tube boilers, which developed a total of 155,000 shaft horsepower (116,000 kW) and yielded a maximum speed of 32 knots (59 km/h; 37 mph). At a cruising speed of 15 knots (28 km/h; 17 mph), the ship could steam for 9,500 nautical miles (17,600 km; 10,900 mi). Her crew numbered 1,569 officers and men. The ship carried four Loire 130 seaplanes on the fantail, and the aircraft facilities consisted of a steam catapult and a crane to handle the floatplanes.
  She was armed with eight 380 mm/45 Modèle (Mle) 1935 guns arranged in two quadruple gun turrets, both of which were placed in a superfiring pair forward of the superstructure. Her secondary armament consisted of nine 152 mm (6 in) /55 Mle 1930 guns mounted in three triple turrets, arranged on the rear superstructure. Heavy anti-aircraft (AA) defense consisted of twelve 100 mm (3.9 in) /45 Mle 1930 anti-aircraft guns in twin turrets. Close range anti-aircraft defense was provided by a battery of eight 37 mm (1.5 in) guns in twin mounts and twenty 13.2 mm (0.52 in) machine guns in four quadruple and two twin mounts. The ship's belt armor was 330 mm (13 in) thick amidships, and the main battery turrets were protected by 430 mm (17 in) of armor plate on the faces. The main armored deck was 170 mm (6.7 in) thick, and the conning tower had 340 mm (13 in) thick sides.
caption: Recognition drawing of Jean Bart's sister Richelieu in her designed configuration
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