Comprehensive Optimisation Study of Train Formation Plans at Loading Stations Considering Multi-Shipment Direct Trains

railway loading station train formation plan multi-shipment direct train 0-1 programming model

Authors

  • Chao HE School of Traffic and Transportation, Lanzhou Jiaotong University, Lanzhou, China
  • Hai jun LI
    lihaijun@mail.lzjtu.cn
    Key Laboratory of Railway Industry on Plateau Railway Transportation Intelligent Management and Control, School of Traffic and Transportation, Lanzhou Jiaotong University, Lanzhou, China
  • Ru Hu GAO Key Laboratory of Railway Industry on Plateau Railway Transportation Intelligent Management and Control, School of Traffic and Transportation, Lanzhou Jiaotong University, Lanzhou, China

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This paper analyses the situation where the car flows at loading stations are small and concentrated, and based on existing literature, proposes an optimisation model for multi-modal transportation in loading station train formation plans. This model transports small car flows by adding two types of multi-shipment direct trains. Based on this, an optimised train formation plan model for loading stations, considering multi-shipment direct trains, was designed. This model is a nonlinear 0-1 integer programming model that satisfies constraints such as the uniqueness of car flow organisation, reclassification capacity constraints at technical stations, conditions for operating direct trains from the loading station and small car flow organisation constraints. The objective is to minimise the costs associated with loading, unloading and reclassification during transportation. To enable the use of commercial solvers for solving the model, linearisation techniques were applied to convert the model into a linear form. Finally, the model is solved using Gurobi, with the example of the Northern Passage of Xinjiang Coal Transportation. According to the results, 6 multi-shipment direct trains are organised from the loading station to the unloading station, 3 multi-shipment direct trains are sent to the technical station en route, 2 groups of car flows are sent to the first technical station by local trains, and 10 other groups of car flows are organised into direct trains from the loading station to the technical station. The total cost is 28,922.6 train hours. Additionally, comparing the experimental results with the scheme that only uses local or detachable trains to transport small car flows demonstrates the effectiveness of the proposed model, As a result, the total train-hour consumption was reduced by 9.273% compared to the formation plan without considering multi-shipment direct trains. The utilisation rates of reclassification capacity at the two technical stations decreased by 100% and 25.57%, respectively. The case study fully demonstrates the effectiveness of the proposed model.