Being simply power-converting, rather than power-generating, devices, electric locomotives have several advantages. They can draw on the resources of the central power plant to develop power greatly in excess of their nominal ratings to start a heavy train or to surmount a steep grade at high speed.Sustainability Locomotive rebuilds can help the railway industry meet ecological challenges while still providing transportation services. High power High power electric locomotives are used for long-distance passenger trains and trunk line freight. Heavy freight Multi-section electric locomotives with extremely high power can haul heavy freight. Locomotives can generate power through a variety of methods, including: Diesel Diesel locomotives have their own fuel supply and use a mechanical, electric, or hydraulic transmission to power the wheels. Electricity Electric locomotives are used in China for long-distance passenger trains and trunk line freight. One disadvantage of locomotives is that poor coordination between the train schedule and the locomotive schedule can lead to inefficiencies.