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
TU10 diesel locomotive used, although most of them have been replaced by TU7 diesel locomotives or TU7A diesel locomotives. The production of narrow gauge locomotives was discontinued in the 2000s because of the demise in narrow gauge railways in Russia, such as forest railways, peat railways and industrial railways, and this led to a lack of suitable new or second-hand locomotives for the children's railways. The Kambarka Engineering Works began in 2008 with the development of a modern diesel locomotive especially for use at children's railways. Based on the experience with older models, the following innovations were implemented: The locomotives have two equal