Diesel traction in Europe and North America

The European railway network is the densest one in the world and features the highest percentage of electrification with nearly 70 %. On the electrified part of the network about 80% of the total transport volume (Passenger + Freight) is hauled.  
The main lines in Western Europe that have been or will be partly turned into highspeed lines are operated by electric traction exclusively. For lines in rural areas and in the Eastern European countries Diesel traction still plays an important role. Further the use of diesel locomotives hauling freight trains avoids time-consuming traction changes at the national borders. Diesel traction in Europe hauls only~ 15-20 % of the railway transport volume whereas Diesel traction in North America covers more than 90% of the total railway transport volume. In North America the market share of the total freight transport volume hauled by rail is ~ 40 % is whereas in Europe it less than 15 %.

  The environmental benefit demonstrated by the railways over the modes of transport is a vital precondition in ensuring social and political support for this mode of transport. The railways have shown that on specific consumption of resources and specific emissions of carbon dioxide their values are lower than those obtained by their main competitors on the road (in particular due to the higher passenger densities achieved by railways).
Among surface transport modes the road transport and international waterway navigation have the highest pollutant emissions (NOx, PM). Waterway navigation emission increased between 1990 and 2001, whilst road emissions decreased.

Rail’s share of emissions is comparatively small (1-3%), but emissions generated locally by individual diesel vehicles may be perceived by the population living nearby; this is to be particularly considered since increasing attention on air quality is paid by public authorities to air quality limits being exceeded in various European hot spots.

Diesel will continue to be America’s major propulsion for the rail sector as the percentage of the electrification will not increase significantly. Although the importance of diesel traction varies from country to country across Europe, diesel will continue to have an important role in providing rail services for the future.  


UIC, UNIFE and MTU aim to apply the near zero emissions HD diesel engine, under development by the GREEN project, to locomotives on non-electrified tracks for the railway sector. In order to apply the future HD engine to diesel locomotives and multiple units UIC & UNIFE have drafted a list of rail specifications:

Specifications of the Railway sector

  • Fitment space engine + periphery < 110%
  • Weight of engine + periphery < 110%
  • Purchase cost of all traction equipment incl. engine + periphery and transmission < 110%
  • Purchase cost of the engine incl. additional components, cooling equipment, auxiliary equipment and exhaust post-emission treatment < 120%
  • Operating costs incl. maintenance < 105%
  • Costs of operating substances (fuel, oil, coolant, reducing agent, etc.) < 100%
  • Engine + periphery overhaul intervals (DMU traction unit < 600kW) > 800 Tkm
  • Engine + periphery overhaul intervals (locomotive traction > 600 kW) > 1.2 million km
  • Transmission overhaul intervals (DMU traction unit < 350kW) > 800 Tkm
  • Transmission overhaul intervals (DMU traction unit > 350kW) > 1.6 million km
  • Transmission overhaul intervals (locomotive traction > 600kW) > 2.4 million km
  • No second operational fluid
  • No restrictions regarding suitability for rail sector use (idling, non-stationary load profiles, ambient temperatures, vibrations, etc.)
  • Approval in accordance with UIC Leaflet 623