Lu Zhen1, Shuaian Wang 2, Kai Wang 2
1School of Management, Shanghai University, Shang Da Road 99, Shanghai 200444, China
2 Department of Logistics and Maritime Studies, The Hong Kong Polytechnic University, Kowloon, Hong Kong
Abstract:This paper investigates the method of allocating arriving vessels to the terminals in transshipment hubs. The terminal allocation decision faced by a shipping alliance has the influence on the scheduled arrival time of vessels and further affects the bunker consumption cost for the vessels. A model is formulated to minimize the bunker consumption cost as well as the transportation cost of inter-terminal transshipment flows/movements. The capacity limitation of the port resources such as quay cranes and berths is taken into account. Besides the terminal allocation, the quay crane assignment decision is also incorporated in the proposed model. A local branching based method and a particle swarm optimization based method are developed to solve the model in large-scale problem instances. Numerical experiments are also conducted to validate the effectiveness of the proposed model, which can save around 14% of the cost when compared with the ‘First Come First Served’ decision rule. Moreover, the proposed solution methods not only solve the proposed model within a reasonable computation time, but also obtain near-optimal results with about 0.1~0.7% relative gap.
Keywords:Port operations; Terminal allocation; Shipping lines; Shipping alliances; Transshipment; Bunker consumption.
1. Introduction
Due to fierce competition in the maritime transportation market as well as the existence of strong economies of scale, there have been a number of mergers and acquisitions in the liner shipping industry. Recently, COSCO and CSCL were officially merged; CMA-CGM acquired NOL; Despite these mergers and acquisitions, shipping lines still feel that they need to grow their business via other mechanisms. As a result, several shipping alliances are formed: the 2M alliance, the G6 Alliance, the Ocean Three Alliance, and the CKYHE alliance. Shipping lines in an alliance share their vessels on liner services.
A major problem associated with the deployment of megaships by shipping alliances is the transportation of containers between terminals at a mega-port. A shipping line usually operates a specific terminal at any given port. For instance, APM-Maersk has ten dedicated terminals in Europe, 13 dedicated terminals in Asia, and five dedicated terminals in North America. Ships of a given shipping line call at the line’s own terminal at a port, which can facilitate the transshipment of containers. However, shipping lines operating in vessel-sharing alliances are now deploying vessels that hold the containers of several lines, adding to the complexity of cargo handling and container delivery at many ports. Mega-ports in the world are usually multi-terminal port systems rather than single-terminal systems. For example, the port of Singapore has set up eleven terminals phase by phase, including eight container terminals; the port of Hong Kong has nine container terminals situated at Kwai Chung, Stonecutters Island and Tsing Yi; the ports of Rotterdam, Los Angeles, and Shanghai also have nine, nine, and seven container terminals, respectively. As a result, containers are often transported between terminals, even when they are very far away. This has increased considerably transportation costs. Therefore, it is an important problem for a shipping alliance to decide terminals allocation appropriately, so as to reduce the cost of the transshipment flows among different terminals in a mega-port.