 The main gun turrets had faces 495 mm ( 19 @.@ 5 in ) thick with sides and roofs 230 mm ( 9 @.@ 1 in ) thick . 180 @-@ millimeter ( 7 @.@ 1 in ) thick plates protected the gun ports and 60 @-@ millimeter ( 2 @.@ 4 in ) bulkheads separated each gun . The barbettes were 425 mm ( 16 @.@ 7 in ) thick above the upper deck . The MK @-@ 4 turrets had 100 mm faces and 65 mm sides . Their barbettes were 100 mm in thickness , but reduced to 65 mm on their <unk> sides . 100 mm of armor protected the faces , sides and backs of the <unk> @-@ 14 turrets for the 100 mm guns , but their roofs and barbettes were 100 mm thick . The forward conning tower had walls 425 mm thick while the rear conning tower had only 220 mm ( 8 @.@ 7 in ) . The flag bridge in the tower @-@ mast had 75 mm ( 3 @.@ 0 in ) of protection . 
