Scheduling Double Girder Bridge Crane with Double Cycling in Rail-Based Transfer Automated Container Terminals

In automated container terminals, rail based horizontal transfer systems are newly proposed and regarded to be more suitable to intermodal transportation [1]. However, improvements are required in operations scheduling in rail based transfer automated container terminals (RBT-ACT) to take advantage of the infrastructure improvement [2].

In this paper a double girder bridge crane (DGBC) is introduced, whose benefits can be obtained with modest investments, such as combining the existing twin 40-ft double trolley container cranes with a double girder [3]. Each girder has one independent spreader, and the two spreaders work on containers in adjacent bays simultaneously with no change to the safety distance constraints. As a result, operating costs are reduced, potential collision of QCs can be avoided and the vessel service time is reduced.

Most research in this area aims to minimizing crane cycles, not processing times [4], however is it processing time that is of ultimate interest [5]. Our objective is to minimize total processing time, and the sequence dependent setup time is considered [6]. It is well established that double cycling can greatly improve quay crane productivity [7], and we consider its performance in the scheduling strategy for DGBC.