Dynamic group transit scheme for corridor transit

Contemporary maritime piracy around the Horn of Africa presents a serious threat to the global shipping industry. A number of countermeasures were deployed to minimize the probability of a successful hijack, one of them being the establishment of the International Recommended Transit Corridor (IRTC). Currently, all ships transiting the Gulf of Aden are strongly recommended to follow the IRTC and take part in group transit schemes-prescribed schedules stating time of arrival to the beginning of the corridor and speed at which to sail through the corridor. These schedules are fixed in advance and do not take into account speeds and constraints of arriving ships. We propose dynamic grouping schemes, customized schedules for a group of arriving ships, which take into account speeds as well as positions of arriving ships. The problem of finding optimum grouping scheme for a group of arriving ships is formulated as a bi-objective mixed integer program, weighting the delay caused by the grouping scheme and the risk taken when sailing alone. We look for a set of Pareto optimal solutions and compare the dynamic grouping scheme with currently deployed fixed scheme. Results show an improvement over current grouping scheme with respect to the number of ships grouped as well as time saved.