The DB Class V 162 (after 1968 named DB Class 217) is a class of four-axle diesel hydraulic locomotive built as a development of the DB Class V 160 for the Deutsche Bundesbahn from 1965 to 1968. This variant has a separate diesel engine providing auxiliary power and for electric train heating, replacing the steam generator in the original V 160. The locomotives continued to be used after the formation of the Deutsche Bahn AG in 1994; the final DB Schenker unit was withdrawn in December 1997. Two of the prototypes of the class operated as internal locomotives and were for a time classified as DB Class 753. Background In the early 1960s, the then German Federal Railways (Deutsche Bundesbahn or DB) and the German railway industry developed the V 160 series (with which this class shares the majority of its design features), a diesel locomotive for use on medium-duty passenger and freight trains on main and secondary lines. These locomotives had steam heating apparatus for passenger coaches, but could not power electrically heated stock. Therefore, with the increasing use in the future of electrically heated coaches, co-commitment with the increasing electrification of the system it was necessary to produce a variant with a method of electrical power generation. Design and production Prototypes In 1963, Krupp AG was requested to develop a V160 variant with electric train heating which would have the classification code V 162. In 1965 two prototypes V 162 001 and V 162 002 were produced, and a third V 162 003 made in 1966. Each had a MTU-built (then Maybach) 16-cylinder engine of the type 16V652 TB10 producing which was entirely used for traction. Since in the mid-1960s a more powerful engine was not available, the electrical supply was powered by an auxiliary diesel engine. The inclusion of two engines in turn meant that the overall length of the machine was increased by 0.4 m in comparison to the V 160, making a total length over buffers of 16.4 meters. The auxiliary engine used by Krupp was a 12-cylinder MAN D3650 HM3U engine developing of power. Since DB required that the auxiliary power should be available for traction (for use on freight trains), the auxiliary engine was also connected to the transmission, meaning that the traction power could be increased to 1813 kW when necessary. The generators of the three prototypes were from different manufacturers: In