of a high and low-pressure turbine. The turbines were manufactured by Parsons for König and Kronprinz, Vulcan AG for Grosser Kurfürst, and Bergmann for Markgraf. Each engine drove a three-bladed screw propeller that was in diameter. The high and low-pressure turbines were grouped into their own engine rooms. Steam for the turbines was provided by fifteen Schulz-Thornycroft water-tube boilers, three of which burned oil and the remainder burning coal. These were divided into three boiler rooms, the first two of which were placed between the forward and center ammunition magazines for the main battery, venting into the forward funnel. The third boiler room was located aft of the center magazine, directly ahead of the engine rooms, and venting into the smaller aft funnel. Electrical power was supplied by four turbo generators and a pair of diesel generators; total electrical output was at 225 volts. The power plant was rated at , for a top speed of , though on trials, the ships produced between . Despite significantly surpassing their intended horsepower, König and Markgraf still managed only 21 knots on their speed trials, while Grosser Kurfürst and Kronprinz reached and , respectively. This was a result of the fact that the tests were run after the start of World War I and thus had to be conducted in the safer, but shallower, waters of the western Baltic Sea. In service running under normal conditions, the Königs were faster than the Kaiser class, which averaged a top speed of . Normal fuel storage amounted to of coal and of oil, though additional voids could be used to store up to of coal and of oil. The ships' cruising radius was at a speed of , which was halved when cruising at . Armament The Königs were armed with a main battery of ten 30.5 cm SK L/50 guns in five twin turrets. Two turrets were mounted forward of the main superstructure in a superfiring pair, the third was placed on the centerline between the two funnels amidships, and the fourth and fifth turrets were arranged in another superfiring pair aft of the rear conning tower. The centerline arrangement was an improvement over the preceding Kaiser class, as all ten guns could fire on a wide arc on the broadside, and four guns could fire directly ahead, as opposed to only two on the Kaisers. The guns were supplied with 90 shells