The Ocean class constructed in the 1870s were the first of the barbette ships made by the French navy , she was basically a box battery warship with 4 barbettes fitted on her main deck to provide more end on fire . The class consisted of Ocean, Marengo and Suffren .
Friedland was originally laid down as an Ocean class ironclad but was much modified in her building . She mounted 8 heavy guns , 6 in a box battery amidships with a further two mounted in barbettes on deck .
Richelieu was similar in layout as the earlier Ocean class warships in that she carried 6 x 10.8 inch heavy cannon in a box battery sited amidships with 4 lighter 9.4 inch cannon in barbettes on the main deck at each corner of the main battery but she also had a fifth 9.4 inch cannon positioned in the bow.
The Redoutable of 1878 represented a departure from earlier French designs, she mounted 8 x 10.8 inch cannon, four sited in an overhanging lower deck battery providing end on fire with two more en-barbette above the main battery and another pair mounted in the stern and after positions. The vessel also had a considerable tumblehome that was a signature of French designed vessels to come.
Although these vessels were actually launched in 1882 their design originated from the Redoutable of 1878. The main battery contained 4 x 13.4 inch cannons with 4 x 10.8 inch cannon mounted on the upper deck as in the earlier class. The ships in this class included Devastation and the Courbet