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 80% reduction in nitrogen oxide emissions. "See" List of low emissions locomotives. Other technologies that are being deployed to reduce locomotive emissions and fuel consumption include "Genset" switching locomotives and hybrid Green Goat designs. Genset locomotives use multiple smaller high-speed diesel engines and generators (generator sets), rather than a single medium-speed diesel engine and a single generator. Because of the cost of developing clean engines, these smaller high-speed engines are based on already developed truck engines. Green Goats are a type of hybrid switching locomotive utilizing a small diesel engine and a large bank of rechargeable batteries. Switching locomotives are