Straight-12 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.
Land use.
A straight-12 is a very long engine, and therefore straight-12 engines are extremely rare in automobiles, the first recorded being the Corona made available in France in 1920. It displaced , but it is not known if any were sold. Packard also experimented with an automobile powered by an inline 12 in 1929. The straight-12 has also been used for large military trucks.
Marine use.
Some Russian firms built straight-12s for use in ships in the 1960s and 1970s. MAN Diesel & Turbo 12K98ME and 12S90ME-C and the Wärtsilä-Sulzer RTA96-C are examples of contemporary marine engines in L-12-cylinder configuration. These are popular for propulsion in container ships. Wärtsilä-Sulzer has even made the world's so far only L-14 configuration.