Empty container repositioning in liner shipping1

The efficient and effective management of empty containers is an important problem in the shipping industry. Not only does it have an economic effect, but it also has an environmental and sustainability impact, since the reduction of empty container movements will reduce fuel consumption and reduce congestion and emissions. The purposes of this paper are: to identify critical factors that affect empty container movements; to quantify the scale of empty container repositioning in major shipping routes; and to evaluate and contrast different strategies that shipping lines, and container operators, could adopt to reduce their empty container repositioning costs. The critical factors that affect empty container repositioning are identified through a review of the literature and observations of industrial practice. Taking three major routes (Trans-Pacific, Trans-Atlantic, Europe--Asia) as examples, with the assumption that trade demands could be balanced among the whole network regardless the identities of individual shipping lines, the most optimistic estimation of empty container movements can be calculated. This quantifies the scale of the empty repositioning problem. Depending on whether shipping lines are coordinating the container flows over different routes and whether they are willing to share container fleets, four strategies for empty container repositioning are presented. Mathematical programming is then applied to evaluate and contrast the performance of these strategies in three major routes. -super-1A preliminary version was presented in IAME Annual Conference at Dalian, China, 2--4 April 2008.