A mathematical model to evaluate different train loading and stacking policies in a container terminal

A container terminal is devoted to transfer containers from sea to land and vice versa in the most efficient way. The main objective of a container terminal is to optimize, in terms of times and costs, the activities related to container handling and forwarding. As regards the hinterland side, a crucial activity is represented by train loading/unloading, considering also the increasing importance assumed by rail transportation in allowing the move of large volumes of goods in/out of the logistic transportation nodes. This article pursues the modelling and comparison of different train loading policies by varying the storage area strategies in order to evaluate them and determine the most effective policy for ensuring quickness and efficiency in the terminal. With respect to the train loading policies, all the possible configurations are taken into account, starting from a pure sequential loading by the rail overhead travelling crane, which consequently implies some rehandling operations in the yard, up to the opposite situation in which non-sequential loading operations are allowed in order to avoid rehandling activities. These loading policies are analysed by varying the stacking strategies adopted in the yard where containers can be stored taking into consideration different factors (commercial priorities, weights, and so on). By using real data in relation to the physical characteristics of containers, trains and wagons, a proper experimental campaign has been performed in order to test the effectiveness of the different scenarios described above.