 Carnot was the second member of a group of five battleships built to a broadly similar design , but different enough to be considered unique vessels . The first ship was Charles Martel , which formed the basis for Carnot and three other ships . Design specifications were identical for each of the ships , but different engineers designed each vessel . The ships were based on the previous battleship Brennus , but instead of mounting the main battery all on the centerline , the ships used the lozenge arrangement of the earlier vessel Magenta , which moved two of the main battery guns to single turrets on the wings . The five ships were built in response to the British Royal Sovereign @-@ class battleships . 
