Many senior officers in the navy envisioned using the Bismarck class in the Atlantic Ocean, which would require a long cruising range.[12] The naval constructors examined diesel engines, steam turbines, and turbo-electric drive engines; the last system was the preferred choice, as it had been extremely successful in the two American Lexington-class aircraft carriers and the French passenger ship Normandie.[8] The design staff were also required to provide sufficient range to the new battleships; they would have to make long voyages from German ports to reach the Atlantic, and Germany had no overseas bases where the ships could refuel.[13] Raeder ordered the turbo-electric engines for the new ships, but the contracting manufacturer, Siemens-Schuckert, could not meet the navy's requirements and removed itself from the project less than a month before construction on Bismarck began, forcing the navy to revert to high-pressure steam turbines.[14]