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
Rigid-framed electric locomotive reluctant single prototype, built for comparison with the articulated 2′B+B1′ , which had themselves been a reaction to the poor performance of the 1912 1′D1′ . A rare example of the 2′D2′ layout was the unique British diesel-mechanical of 1955. Rigid-framed electric locomotive Rigid-framed electric locomotives were some of the first generations of design. When these began the s of these early locomotives, particularly with AC motors, were too large and heavy to be mounted directly to the axles and so were carried on the frame. One of the initial simplest wheel arrangements for a mainline electric locomotive, from around