Energy, time and longitudinal train dynamics costs using energy optimised driving strategies in heavy haul trains

There are many costs and overheads in operating a rail haulage service. Insights into how to reduce some of the operational costs can be obtained by focusing on costs that are affected by the driving strategy. Two main costs affected by the driving strategy relate to time and energy. There also exists a train dynamics cost which is influenced by longitudinal in-train forces. The cost optimisation of a heavy haul rail operation involves many factors such as train design, track design and scheduling. However an above-rail operator may only have control over the driving strategy and the train configuration with the other factors forming the operational limits. This paper investigates the train dynamics cost, energy cost and time cost of a heavy haul train using an energy efficient driving strategy. In the view of the conference theme “Rail’s Digital Revolution”, comparison is also made with operational data to provide insights into and estimations of possible cost reductions in areas of energy, time and longitudinal train dynamics. It was found that operational control strategies of empty trains exhibit minimal energy and dynamics, but reducing journey times could reduce the empty journey cost by 25%. Loaded journeys had higher possible cost reductions of up to 33%. To realise these cost reductions improvements to the track and rollingstock would be required to permit higher operational speeds. Longitudinal dynamic costs generally increased with faster journey times, but overall the longitudinal dynamics costs were low when compared to the time and energy costs. The study confirmed that energy-time efficient strategies generally produced good train handling. However in some instances, control strategies with higher energy usage produced better train handling.