Diesel locomotive set, and went into series production with other streamlined car sets in Germany starting in 1935. In the USA, diesel-electric propulsion was brought to high speed mainline passenger service in late 1934, largely through the research and development efforts of General Motors from 1930–34 and advances in lightweight carbody design by the Budd Company. The economic recovery from the Second World War saw the widespread adoption of diesel locomotives in many countries. They offered greater flexibility and performance than steam locomotives, as well as substantially lower operating and maintenance costs. Diesel–hydraulic transmissions were intrdouced in the 1950s, but from the
M62 locomotive M62 locomotive M62 is a Soviet-built diesel locomotive for heavy freight trains, exported to many Eastern Bloc countries as well as to Cuba, North Korea and Mongolia. Beside the single locomotive M62 also twin versions 2M62 and triple versions 3M62 have been built. A total number of 7164 single sections have been produced, which have been used to build 5231 locomotives. According to the Comecon directives production of heavy diesel locomotives among Eastern Bloc countries was left exclusively to Romania and the Soviet Union. The first few prototypes of this heavy freight locomotive were ready in 1964 and their first