 The Mackensen @-@ class ships were 223 m ( 731 ft 8 in ) long and had a beam of 30 @.@ 4 m ( 99 ft 9 in ) and a draft of 9 @.@ 3 m ( 30 ft 6 in ) forward and 8 @.@ 4 m ( 27 ft 7 in ) aft . The ships were designed to displace 31 @,@ 000 t ( 30 @,@ 510 long tons ) on a standard load , and up to 35 @,@ 300 t ( 34 @,@ 742 long tons ) fully laden . The Mackensens ' hulls were composed of longitudinal steel frames , over which the outer hull plates were riveted . This was the same type of construction as in the preceding Derfflinger @-@ class battlecruisers , and was intended to save weight compared to the traditional method of construction , which incorporated both longitudinal and transverse frames . The ships ' hulls contained 18 watertight compartments and a double bottom that ran for 92 percent of the length of the hull . This was significantly greater than the older Derfflinger @-@ class ships , which had a double bottom for only 65 percent of the length of the hull . 
