The ships had a normal capacity of of coal, though at full load they could carry up to . At a cruising speed of , the ships could steam for ; increasing speed to reduced their range to , and at their radius of action fell significantly, to . While steaming at , the ships could steam for . In 1915, the boilers were fitted with supplementary oil firing, along with storage for of fuel oil; this allowed oil to be sprayed on the coal to improve combustion rates.