Container sequencing for quay cranes with internal reshuffles

Fast handling of vessels is one of the most important goals in container terminal operations planning. In recent studies, quay crane double cycling has been investigated to accelerate the service of vessels. In our paper, we show that the service process can be further accelerated by changing the treatment of so-called reshuffle containers. Reshuffle containers have to be removed from their position in the vessel only to gain access to containers stacked below them. Our approach enables to reposition reshuffle containers directly within the bay of a vessel, referred to as internal reshuffles, instead of temporarily unloading them. A mathematical problem formulation and a heuristic solution method, namely a greedy randomized adaptive search procedure, are provided for planning crane operations under internal reshuffles. Computational tests prove that the consideration of internal reshuffles leads to a further shortening of vessel handling times compared to a sole application of crane double cycling.