 Black Prince displaced 12 @,@ 590 long tons ( 12 @,@ 790 t ) as built and 13 @,@ 965 long tons ( 14 @,@ 189 t ) fully loaded . The ship had an overall length of 505 feet 6 inches ( 154 @.@ 1 m ) , a beam of 73 feet 6 inches ( 22 @.@ 4 m ) and a draught of 27 feet ( 8 @.@ 2 m ) . She was powered by four @-@ cylinder triple @-@ expansion steam engines , driving two shafts , which produced a total of 23 @,@ 000 indicated horsepower ( 17 @,@ 000 kW ) and gave a maximum speed of 23 knots ( 43 km / h ; 26 mph ) . The engines were powered by 20 Babcock & Wilcox water @-@ tube boilers and six cylindrical boilers . The ship carried a maximum of 2 @,@ 150 long tons ( 2 @,@ 180 t ) of coal and an additional 600 long tons ( 610 t ) of fuel oil that was <unk> on the coal to increase its burn rate . At full capacity , she could steam for 8 @,@ 130 nautical miles ( 15 @,@ 060 km ; 9 @,@ 360 mi ) at a speed of 10 knots ( 19 km / h ; 12 mph ) . The ship 's complement was 789 officers and enlisted men . 
