Machinery and bow units for a hard-to-handle carrier

Graf Zeppelin’s main plant used ultra-high-pressure boilers related to those fitted in Admiral Hipper-class cruisers, whose machinery demanded heavy maintenance. Designers also knew the high-freeboard carrier would be difficult to control below eight knots, especially in gusts while passing through the Kiel Canal. Retractable Voith Schneider units in the bow were intended to berth the ship, steer it below twelve knots, or move it at about four knots in calm water if the main engines failed. Those units added another vulnerable mechanism whose shafts, retraction gear, and watertight covers would have to survive combat and saltwater service. The later Atlantic bow lengthened the hull by 5.2 metres to improve seakeeping. Both low-speed control and open-water behaviour needed additional remedies.