Deployment strategies of double-rail-mounted gantry crane systems for loading outbound containers in container terminals

Double-rail-mounted gantry (DRMG) crane system is an emerging container-handling technology that was recently introduced in Europe. The system consists of two rail-mounted gantry (RMG) cranes of different height and width. Intuitively, this special feature will help to increase the productivity of the two cranes since they can pass through each other during their movement along a container block. This paper focuses on providing an efficient operation strategy for the DRMG systems to load outbound containers. An integer programming model is developed to formulate the problem. A greedy heuristic algorithm, a simulated annealing (SA) algorithm and a combined DRMG scheduling heuristic (CDSH) are designed to solve the proposed problem. Computational experiments show that the CDSH outperforms the other two approaches. Since the CDSH performs well and is easy to implement, it has a high potential to be used in scheduling DRMG systems in real operation.