Optimization Of Containership Sailing Speed And Fleet Deployment For Ocean Container Liner Shipping

Shipping is the most important mode of transportation in international trade,and container shipping is the main body of international trade in industrial goods.Especially for the world's three major trading regions such as East Asia,North America and Europe,ocean container liner shipping plays an irreplaceable role.In the ocean container liner shipping,the fleet deployment problem is an important decision problem faced by liner companies.This problem 1s not only the implementation of the strategic decision such as liner route network design and fleet size and mix problem,but also the basis of operation decision such as container stowage and slot allocation.Meanwhile,fleet deployment has a close relationship with containership sailing speed,different sailing speeds determine different number of deployed containerships.It is noteworthy that ocean container liner shipping has the characteristics of large volume of containers,high value of cargoes,long distance of voyages,large number and capacity of containerships.Due to the above characteristics,the containership sailing speed and fleet deployment decisions are not only directly related to the economic benefits of liner companies,but also affect the interests and satisfaction of customers.Therefore,the optimization of containership sailing speed and fleet deployment for ocean container liner shipping has become an important issue for liner companies.After systematically summarizing and analyzing the research of fleet deployment problem,sailing speed adjustment problem and the joint optimization problem of sailing speed and fleet deployment,it is found that many research models and methods are difficult to meet the realistic background requirements as the current market environment changes.In particular,in view of the present dramatic changes in the container demand,the high fuel prices for containerships,the severe situation of energy conservation and emission reduction,and the improvement of customer transportation service requirements,the existing research is still relatively scarce,Therefore,this dissertation takes the ocean container liner shipping as the research object,and takes the containership sailing speed and fleet deployment as the main research content.In view of several kinds of realistic situations existing in the current container liner shipping market,the research work is summarized as follows:Firstly,some ocean routes have the problem of cabotage restriction.Based on the characteristics of container cargo OD flow on ocean route,the relationship between container loading capacity on each leg and the OD flow of container cargo in relevant port pairs is analyzed.The containerships' apacity constraint of each leg is determined,and a nonlinear programming model is established to optimize containership sailing speed and fleet deployment on oeean routes.A stepwise approximation algorithm combining enumeration is designed to solve this model.Secondly,for some ocean routes,there exist carbon emissions restrictions or carbon emissions control area problems.Combined with carbon tax policy and cap-and-trade programme,carbon emussions are converted into carbon costs and added to the objective function,and the carbon emissions caps of containerships are introduced into constraints as a hard one.The nonlinear programming model of containership sailing speed and fleet deployment considering carbon emissions factors is established.Then a discretization algorithm for model preprocessing is designed to solve this model.Afterwards,for some ocean routes,the value of container cargoes is high and the customer is sensitive to the time value of container cargoes.The impact of containership sailing speed changes on cargo transportation time of two long legs is analyzed,and the differential pricing function with sailing speed is constructed.Then,a nonlinear programming model for both single-route and multi-route are established to maximize total profit of liner companies,and the discretization algorithm is designed for both models.Finally,in view of some ocean route,there is a large difference in carinteger nonlinear programming model aiming at minimizing total operating costs is established for containership sailing speed and fleet deployment considering the fuel replenishment strategy.Then a piecewise linear approximation algorithm is designed to solve this model.Experiment results show that on the ocean routes with cabotage restriction,the optimization of containership sailing speed and the reasonable number and types of containerships on different routes can significantly reduce total operating costs of liner companies.Considering the severe fluctuations in fuel price,liner companies should timely choose the strategy of "adding containership to slow down its sailing speed" or "reducing containership to accelerate its sailing speed",which can effectively improve their economic benefits.On some ocean routes where there are restrictions on carbon emissions or control area of carbon emissions,the increase in carbon taxes and the reduction in carbon caps will lead to a sharp decline in the sailing speed of containerships and an increase in the number of containerships.Besides,it will lead to a significant increase in total operating costs and a sharp decline in carbon emissions.On some ocean routes where the container cargo value is high and the cargo owners' requirements for transit time are relatively high,the optimization results of containership sailing speed and fleet deployment considering earo time value can not only reduce container cargo time costs for customers,but also significantly increase total profit for liner companies.In addition,for those ocean routes with large difference fuel prices at the fuel ports,it is more economical and reasonable for liner companies to adopt different sailing speeds on different legs than to adopt a uniform one for the whole ocean route.In the case of sluggish demand in shipping market,containerships are more likely to adopt lower sailing speeds.Besides,taking flexible bunkering port selection and relaxing time window restrictions can effectively reduce total operating costs.Theoretically,this dissertation has significant importance to promote the theory and method of containership sailing speed and fleet deployment on ocean routes.Practically,it provides guidance significance to improve the profit for both liner companies and customers.