For recent years, container traffic has been growing, especially in East and Southeast Asia. However, most liner shipping companies make an effort to select calling ports, in particular taking into account effective plans of an efficient repositioning of equipment in use based on a prediction of when and where imbalance in equipment quantities will occur. Therefore, the decision maker of a container liner company should maximize the company's profit with considering the above issue. In this paper, we propose a design method of containership routing networks as the shuttle type of the location routing problem on the set partitioning problem basis. The proposed method gives the solution as a set of calling ports, shipping routes, the number ships by ship's speed and size. An application of the problem to container transportation in Southeast Asia is presented. By numerical simulation studies, we evaluated routing alternatives of several ship sizes and examined the effect of consideration of equipment imbalance in composing the shipping routes.