The Bismarck-class ships both had three sets of geared turbine engines; Bismarck was equipped with Blohm & Voss turbines, while Tirpitz used Brown, Boveri, and Co. engines. Each set of turbines drove a 3-bladed screw that was 4.70 m (15 ft 5 in) in diameter. The three-shaft arrangement was chosen over a four-shaft system, as was typically used on foreign capital ships, since it would save weight.