Novel aspects in port rail shunting problems

In the domain of intermodal transportation, a focal point is the connection between maritime and rail transportation: this is realized in the port areas bridging the railway network and maritime terminals. This operational area encompasses a range of infrastructural components including tracks and shunting parks, and various limited resource required to operate and transfer trains. The movement of freight trains is managed by the so called shunting managers executing necessary stopovers and manoeuvres. The shunting manager schedule all the required activities in accordance with the timetables of both trains on the railway network and maritime vessels, wherein disruptions or delays within either system have a direct repercussion on shunting operations. Consequently, shunting managers face the complex task of scheduling and re-scheduling freight train transfers within the confines of the port infrastructure. In the present work the scheduling and re-scheduling of operations for the transfer of freight trains is analysed in more details for including realistic constraints related to the track lengths and details of train movements, contributing to the development of more realistic and efficient solutions within the complex landscape of intermodal transportation. The solution approaches proposed in the recent literature for these problems have been modified for including these aspects and then have been tested by using random generated instances and realistic ones. Beside the computation efficiency of the proposed approaches, the operational effectiveness has been investigated too. Results are here discussed. By including the length of tracks and trains, thus permitting to store more than one train in the same track, the shunting manager is able to increase the number of trains scheduled.