Optimization of transshipment points seaport — railway

Due to the growth volumes of multimodal transportation, Russian Railways requires a more efficient use of available resources. Because of the large international cargo turnover, today the most popular type of international delivery is sea transport, followed by transshipment onto the railroad for delivery to the destination on the mainland. This article proposes a complex mathematical model that includes two subtasks: the berth assignment problem (BAP) and the task of forming trains. The joint solution of these interrelated tasks allows us to take into account all the constraints in the solution process and find a solution that is optimal both from the point of view of optimizing the seaport and the technical features of the railway. The proposed model makes it possible to obtain effective solutions for the combined task of a transshipment point. The Gurobi optimizer was used to carry out computational experiments. The choice of the Gurobi optimizer is due to the fact that it allows obtaining a better-quality solution compared to heuristic algorithms, although it works longer on average. The increase in the efficiency of the port, associated with a better-built schedule, is in priority over a longer computation time. For the experiments, pseudo-real data were generated corresponding to the infrastructure of the Far Eastern Railway, with dimensions of up to 15 berths and 12 ships. Calculations were carried out with a time limit of 60 minutes, in which for some of test examples it was possible to find the optimal solution, and for the rest of test examples, the error estimate of the obtained value of the objective function is less than 10%.