 The <unk> @-@ class ships had two sets of direct @-@ drive steam turbines , each of which drove two propeller shafts with 3 @.@ <unk> @-@ metre ( 11 ft 3 in ) propellers . The high @-@ pressure turbines drove the wing shafts while the low @-@ pressure turbines drove the inner shafts . The turbines were designed to produce a total of 40 @,@ 000 or 45 @,@ 000 shaft horsepower ( 30 @,@ 000 or 34 @,@ 000 kW ) ( <unk> and <unk> respectively ) , using steam provided by 24 <unk> <unk> <unk> water @-@ tube boilers at working pressures of 13 – 16 @.@ 9 kg / <unk> ( 1 @,@ 275 – 1 @,@ <unk> <unk> ; 185 – 240 <unk> ) . Both ships comfortably exceeded their designed speed of 23 knots ( 43 km / h ; 26 mph ) during their sea trials ; <unk> reached 23 @.@ 6 knots ( 43 @.@ 7 km / h ; 27 @.@ 2 mph ) from 56 @,@ <unk> shp ( 42 @,@ 131 kW ) and <unk> exceeded that with 24 knots ( 44 km / h ; 28 mph ) from 63 @,@ <unk> shp ( 47 @,@ 136 kW ) . Each of the boilers consumed a mixture of coal and oil and the ships had a stowage capacity of 4 @,@ <unk> long tons ( 4 @,@ <unk> t ) of coal and 1 @,@ <unk> long tons ( 1 @,@ <unk> t ) of fuel oil , which gave them a range of 9 @,@ 680 nautical miles ( 17 @,@ 930 km ; 11 @,@ 140 mi ) at a speed of 14 knots ( 26 km / h ; 16 mph ) . <unk> and <unk> had three generators of 150 <unk> ( 200 hp ) capacity and two 250 @-@ <unk> ( 340 hp ) <unk> generators at 225 volts . 
