Tactical locomotive fleet sizing for freight train operations

Determination of fleet size of locomotives and of a policy to deadhead them are tactical issues that influence the level of customer service in a rail network. This paper considers a railroad system in which a priori freight train schedule does not exist. A simulation-based approach is proposed for tactical locomotive fleet sizing. The study shows that the throughput increases with the number of locomotives upto a certain level; after that the congestion caused by the movements of large number of locomotives in the capacity-constrained rail network offsets the potential benefit of a large fleet.