Invited Session Tue.1.H 0111

Tuesday, 10:30 - 12:00 h, Room: H 0111

Cluster 13: Logistics, traffic, and transportation [...]

Green maritime transport logistics


Chair: Harilaos Psaraftis



Tuesday, 10:30 - 10:55 h, Room: H 0111, Talk 1

Harilaos Psaraftis
Speed optimization in a ship pickup and delivery problem: balancing economic and environmental performance

Coauthor: Christos A. Kontovas


We consider a single ship pickup and delivery problem with multiple origins and multiple destinations, in which ship speed is one of the decision variables. Each port can be visited as many times as necessary so as to pick up and deliver cargoes originating from it and destined to it. These operations can be combined in a single port stop if this is warranted. Cargoes to or from distinct ports can co-exist on the ship, so long as ship capacity is not exceeded. Cargoes cannot be split. Costs include fuel, vessel charter and in-transit cargo inventory costs. In general, different speeds can be chosen for different legs of the route, so long as they are between known lower and upper bounds. Both bounds are dictated by the maximum power and technology of the engine, and by ship payload. Fuel consumption is a known function of ship speed and ship payload. It can be shown that on each leg of the route the speed decision can be decomposed from the pickup and delivery decision. We develop algorithms that optimize the ship's route and we compare minimum cost solutions with minimum emissions solutions. Several scenarios are examined and computational experience is reported.



Tuesday, 11:00 - 11:25 h, Room: H 0111, Talk 2

Haakon Lindstad
Scheduling and environmental routing of maritime vessels in a multiobjective environment


Shipping companies must manage their fleets effectively in order to stay in business. Ship scheduling and routing which concerns the optimal assignment of available cargoes to maximize profit is a complex problem that may play an important role in this respect. Increased environmental concern due to climate change adds another dimension to the scheduling and makes it multi objective. This study has focused on developing a methodology for calculating emissions and cost as function of sea conditions and vessel characteristics. The developed methodology has been used for scheduling and optimization with multi objective voyage priorities such as minimizing voyage emissions, minimizing voyage cost and maximizing profit.



Tuesday, 11:30 - 11:55 h, Room: H 0111, Talk 3

Orestis Schinas
The cost of SOx limits to marine operators: Results from exploring marine fuel prices

Coauthor: Christos Stefanakos


Marine operators are confronted with the new air emissions regulations, that determine the limits of sulphur content in marine fuels. The low-sulphur (LS) marine fuels have a higher price, and their fluctuation is almost similar to the fluctuation of high-sulphur (HS) fuels. The price difference between HS and LS might also determine the decision of operators for alternative technical means, such as scrubbers, in order to comply with the new limits. This paper aims to provide a thorough statistical analysis of the currently available LS and HS marine fuels time series, as well as to present the analysis of the differential of the HS and LS fuel prices. Moreover, forecasting issues are discussed on the basis of the conventional analysis tools vis-a-vis a fuzzy forecasting methodology. The results of the comparison could guide the next steps of research.


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