 The ships of the Mackensen class were equipped with four sets of marine @-@ type turbine engines , each of which drove a three @-@ bladed screw propeller that was 4 @.@ 2 m ( 13 ft 9 in ) in diameter . The turbines mounted in Fürst Bismarck were equipped with Föttinger fluid transmission , while those on the other three ships were two sets of direct @-@ coupled turbines with geared transmissions . The ships had 24 coal @-@ fired marine @-@ type single ended boilers and eight oil @-@ fired marine @-@ type boilers . The power plants were designed to provide 88 @,@ 769 shaft horsepower ( 66 @,@ 195 kW ) and 295 revolutions per minute . Maximum speed was rated at 28 knots ( 52 km / h ; 32 mph ) . The ships were equipped with a pair of rudders mounted side by side , as opposed to the tandem rudders used on the Derfflinger @-@ class ships . 
