Lyon - class battleship The " Lyon " class was a proposed type of battleship which was planned for the French Navy in 1913 , with construction scheduled to begin in 1915 . The class was to have comprised four ships : " Lyon " , " Lille " , " Duquesne " , and " Tourville " . The first two were named for cities in France , while the rest honored French admirals Abraham Duquesne and Anne Hilarion de Tourville . The design was an improvement on the previous , and mounted a fourth quadruple gun turret , for a total of sixteen guns . Construction was cancelled due to the outbreak of World War I in August 1914 before any of the ships could be laid down . Design . Starting in 1910 , the French Navy began a dreadnought battleship construction program , starting with the four ships of the that year . The three - ship was authorized the next year , and five s followed in 1912 . Design work began in 1912 ; the design staff submitted several proposals for the new battleships . Displacements ranged from to ; the various designs featured a main battery of fourteen or sixteen guns , eight or ten guns , or twenty guns , in a mix of quadruple or twin gun turret s . In 1913 , the Navy authorized a fourth class of battleships , " Lyon " , which was scheduled for 1915 . The design staff determined the 38 cm gun would take too long to design , so the proposals that incorporated these weapons were cancelled . The design staff settled on one of the two 34 cm proposals . The first proposal , which mounted fourteen guns , was a ship long . On 24 November 1913 , the design staff instead chose the slightly larger second design , armed with sixteen guns in four quadruple turrets . The first two ships , " Lyon " and " Lille " , were scheduled to be ordered on 1 January 1915 , and " Duquesne " and " Tourville " would have followed on 1 April 1915 . World War I broke out in August 1914 , however , and shifting military requirements , particularly for the army , forced the cancellation of the class . Characteristics . The ships would have been long between perpendiculars and long overall . They would have had a beam of and a draft of . Their full load displacement was estimated at . The propulsion system had not been settled by the time the class was cancelled ; the design staff proposed either the mixed steam turbine and triple expansion engine system used in the first four ships of the preceding " Normandie " class or the all - turbine system used in the last ship of the previous class , " Béarn " . They also considered new geared turbines that had proved satisfactory in the new destroyer " Enseigne Gabolde " . The final design called for a propulsion system rated at with a top speed of . An unknown number of boilers were trunked into two funnels amidships . Sixteen 340mm / 45 Modèle 1912 gun s mounted in four quadruple turrets comprised the main battery . The turrets , which were equipped with electric - hydraulic training and elevation gear , were all mounted on the centerline , though the arrangement is not clear . According to " Conway ' s All the World ' s Fighting Ships " , one turret was placed forward , one amidships , and two in a superfiring pair aft . The contemporary " Journal of United States Artillery " , however , suggests the turrets would have been mounted in two superfiring pairs , forward and aft . The turrets weighed , and were electrically trained and hydraulically elevated . The guns were divided into pairs and mounted in twin cradles ; a thick bulkhead divided the turrets . Each pair of guns had its own ammunition hoist and magazine . They could be fired simultaneously or independently . The guns had a range of and had a rate of fire of two rounds per minute . The shells were armor - piercing rounds and were fired with a muzzle velocity of . The secondary battery was to consist of twenty - four guns , either the 138 . 6 mm / 55 Modèle 1910 or a new automatic model , each singly - mounted in casemates in the hull . The M1910 guns fired a shell at a muzzle velocity of . The ships would also have been equipped with an unknown number of or anti - aircraft guns and six torpedo tube s of unknown size , submerged in the hull . The ships would have been protected with a variation of the armor layout of the previous " Normandie " class . The primary alterations were slightly thinner casemate armor and upper deck plating to compensate for improved armor below the waterline .