A 1905 Wolseley
straight-12, 360 hp, petrol or oil marine engine
A straight-12 engine or inline-12 engine is a twelve-cylinder internal combustion engine with all twelve cylinders mounted in a straight line along the crankcase.
A straight-12 is a very long engine, and therefore straight-12 engines are not common in automobiles, but it has been used for large military trucks.
Some Russian firms built straight-12s for use in ships in the 1960s and 1970s. The Wärtsilä-Sulzer RTA96-C is offered in 12-cylinder configuration.