Wärtsilä Vasa

The Wärtsilä Vasa is a series of medium-speed diesel engines built by Wärtsilä and named after Vaasa in Finland, where they were produced. Wikipedia dates its release to 1977 and the end of production to 2010. The series has three models, the Vasa 22, 32 and 46, whose numbers give the cylinder bore in tens of millimetres, so the bores are 220, 320 and 460 millimetres, and each could be ordered in inline or V form, with up to nine cylinders in line and up to eighteen in a V. The engines are turbocharged, non-reversible and use direct fuel injection, and they were designed to run continuously on heavy fuel oil once it is pre-heated to the right viscosity. Because they cannot reverse they were used mainly for electricity generation and diesel-electric propulsion rather than as direct propulsion engines, and Wikipedia names Wilmer Wahlstedt as lead designer of the first engine.