The Study Of Economic Speed Of Handy-size Ships

In handy-size shipping market, large volumes of various bulk cargos are carried between the ports scatter all around the world, making it complicated to make ship’s operating plan and ship routing and scheduling for a handy-size shipping carrier. In recent years, there is sharp increase in fuel price, which is continually growing in the weak shipping market. Besides how to minimize operational costs by using economic speed same as industrial s-hipping, handy-size shipping companies try to maximize the profit of operating fleet, and this gradually attracts more attention and research.In this paper only contact cargoes are taken into account. Ship’s speed is variable within an interval adjusting according to different situation, and fuel consumption per time unit can be approximated by a cubic function of speed, so that substantial savings can be achieved by properly scheduling speed of each vessel in shipping legs. In this paper, we present the handy-size ship routing and scheduling problem with variable speed and fuel consumption subject to port time windows not violated.To solve this problem, a simulated annealing algorithm was designed due to the complexity of the problem and limitations of traditional mathematical programming approaches, especially when large-scale problems are involved. Finally through the practical case analysis, the result shows potential economic effectiveness of considering variable speed and fuel consumption in handy-size ship routing and scheduling problems. The formulated model and proposed solution scheme can help handy-size shipping companies to optimize ship’s allocation, freight assignment in routing and scheduling.From the view of economic speed formula, its value is influenced by oil price and fixed costs directly. Therefore, in this paper, on the basis of solving ship scheduling problem mathematical model, we analyzed the impact of various factors on economic speed by sensitivity analysis, providing the decision makers with microscopic theoretical basis when the external factors change.