Diesel locomotive Dv12s. In the 21st century series production standard gauge diesel–hydraulic designs include the Voith Gravita, ordered by Deutsche Bahn, and the Vossloh G2000, G1206 and G1700 designs, all manufactured in Germany for freight use. Steam-diesel hybrid locomotives can use steam generated from a boiler or diesel to power a piston engine. The "Cristiani Compressed Steam System" used a diesel engine to power a compressor to drive and recirculate steam produced by a boiler; effectively using steam as the power transmission medium, with the diesel engine being the prime mover The diesel-pneumatic locomotive was of interest in the 1930s because it
Diesel locomotive 1970s onwards diesel–electric transmission has dominated. The earliest recorded example of the use of an internal combustion engine in a railway locomotive is the prototype designed by William Dent Priestman, which was examined by Sir William Thomson in 1888 who described it as a ""[Priestman oil engine] mounted upon a truck which is worked on a temporary line of rails to show the adaptation of a petroleum engine for locomotive purposes."". In 1894, a two axle machine built by Priestman Brothers was used on the Hull Docks. In 1896 an oil-engined railway locomotive was built for the Royal Arsenal, Woolwich,