The turbocharger was invented in the early 20th century by Alfred Büchi, a Swiss engineer and the head of diesel engine research at the Gebrüder Sulzer engine manufacturing company. The turbocharger was originally intended to be used on diesel engines, since Büchi's patent of 1905 noted the efficiency improvements that a turbocharger could bring to diesel engines. However, it took until 1925 for the first production turbocharged engines to be manufactured— 10-cylinder turbo-diesel marine engines producing and used by the German "Preussen" and "Hansestadt Danzig" passenger ships.