 The ships ' main armament was composed of twelve 340mm / 45 Modèle 1912 guns in three quadruple turrets , the same as in the contemporary French battleships of the Normandie class . One turret was placed forward , and the other two were placed in a superfiring pair , all on the centerline . The guns had a range of 16 @,@ 000 m ( 17 @,@ 000 yd ) and had a rate of fire of two rounds per minute . The shells were 540 @-@ kilogram ( 1 @,@ 190 lb ) armor @-@ piercing rounds and were fired with a muzzle velocity of 800 meters per second ( 2 @,@ 600 ft / s ) . A secondary battery of twenty @-@ four 138 @.@ 6 mm / 55 Modèle 1910 guns mounted in casemates was planned for defense against torpedo boats . These guns fired a 36 @.@ 5 kg ( 80 lb ) shell at a muzzle velocity of 830 m / s ( 2 @,@ 700 ft / s ) . The armament was rounded out by six torpedo tubes of undetermined diameter , all submerged in the ships ' hulls . 
