Driven by China’s booming natural gas consumption market, LNG (Liquified Natural Gas) shipping import has grown rapidly. To facilitate scientific and efficient decision making on LNG shipping fleet deployment and the development of the LNG shipping industry, this article proposes an optimization model to minimize annual fleet operating costs, including voyage cost, running cost, and capital cost. Under the consideration of the mixed factors of self-owned and time charter vessels, epidemic prevention and control, port congestion, transportation time cost, and evaporation loss, as well as navigation security and emergency situations, the validity and optimality of the model are demonstrated by the empirical example and the cost comparison between the conventional and optimized solution. The results show that this optimization model can reduce the total cost by 9.87%. Then, through sensitivity analysis, various significant factors affecting the operating costs of LNG shipping enterprises and their degrees of influence are determined. Based on the analysis of the relevant causes, some actionable countermeasures are recommended, including establishing a shipping price reciprocity mechanism and full chain investment planning, optimizing the inbound link to reduce invalid berthing time, strengthening the construction competitiveness and economy of scale of larger LNG ships, and building a combined dual resource pool transportation mode. This paper contributes to improving transregional maritime energy transport and management capacity, while further enhancing the energy security and development of port cities and their economic hinterlands.

With the advantages of large volume, low unit transportation costs, as well as sustainable and stable transport capacity, China in recent years has actively promoted the innovative pilot of double-stack container sea-rail intermodal transport in the Ningbo-Zhoushan port. In this study, a new synchronous handling technology is proposed to improve the handling efficiency of double-stack container trains at sea-rail intermodal terminals. This research primarily focuses on the design of an LDAGV (Automatic Guided Vehicle with Loading and Discharging Function) and a new special articulated flat car for double-stack container trains, while also optimizing the overall layout of the container terminal yard. It then evaluates nine double-stack container stacking forms based on the requirements of transport gauge and center of gravity height. Finally, using data from the Ningbo Beilun No. 3 container terminal, a cost-benefit analysis is performed to compare the traditional handling scheme for common double-stack container trains and the new synchronous handling scheme for double-stack container trains with new special articulated flat car. The results show that the application of new synchronous handling technology has obvious advantages in terms of reducing the handling time and operation cost of double-stack container trains in sea-rail intermodal container terminals, as well as enriching the stacking forms of double-tier containers on the new special articulated flat car, thus reducing the difficulty of collecting cargoes and the organization of container source.

The authors would like to make the following corrections to the published paper