Diesel locomotive Diesel–hydraulic locomotives have a smaller market share than those with diesel electric transmission - the main worldwide user of main-line hydraulic transmissions was the Federal Republic of Germany, with designs including the 1950s DB class V 200, and the 1960 and 1970s DB Class V 160 family. British Rail introduced a number of diesel hydraulic designs during it 1955 Modernisation Plan, initially license built versions of German designs (see ). In Spain RENFE used high power to weight ratio twin engined German designs to haul high speed trains from the 1960s to 1990s. (see RENFE Classes 340, 350, 352, 353,
Diesel locomotive made (e.g., the British Rail 10100 locomotive), although none have proved successful in the end. In a diesel–electric locomotive, the diesel engine drives either an electrical DC generator (generally, less than net for traction), or an electrical AC alternator-rectifier (generally net or more for traction), the output of which provides power to the traction motors that drive the locomotive. There is no mechanical connection between the diesel engine and the wheels. The important components of diesel–electric propulsion are the diesel engine (also known as the prime mover), the main generator/alternator-rectifier, traction motors (usually with four or six axles), and a