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
ČKD T-669 diesel locomotive TE 006 traction motors are axle-mounted on the wheel sets. Located underneath the rear hood are batteries and a supply of sand. After modifications of the seating of the hood on the frame, the T 669.1 (771) and the wide-gauge version T 669.5 (770.8) were created at SMZ Dubnica. This class of locomotive, manufactured for Czechoslovak State Railways, Soviet Railways, and railways in Poland, Albania, India, Iraq and Syria numbers over 8,000 units, making it the largest series of locomotives ever manufactured in Czechoslovakia. ČKD T-669 diesel locomotive T-669.0 (770) class diesel locomotives, built by ČKD are six-axle, with two