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
TU2 diesel locomotive the Ways and Communications. The tests were successful, so the TU2 was taken into production. The only factory that produced the TU2 was Kaluga machine factory. The first three locomotives were tested again, in Panevėžys, (Lithuania) and Pärnu, (Estonia). During the tests, the locomotive could run as fast as . But due to the poor tracks on most of the country's narrow gauge railways, the highest allowed speed during normal operation was . TU2 diesel locomotives were produced till 1959; 281 locomotives were built. The locomotives were used on many narrow gauge railways to haul cargo as well as passenger