Ship allocation considering energy type and transportation preference: A variational inequality approach

Abstract

When devising ship allocations, the holistic impact of ship energy supply types, cargo preferences, and Emission Control Areas (ECAs) is frequently disregarded. This paper introduces a variational inequality model to address the intrinsic correlation between time and economic costs in ship allocation along routes. It considers both the ship’s energy supply type and cargo transportation preferences within the transport fleet to optimize shipping costs across diverse routes. An improved diagonal algorithm is designed to precisely solve the model. The results show that factors such as energy prices, port handling capacity, and port service fees all influence the distribution of ships within the shipping network. Cargo transportation preferences further affect the allocation of ships to specific routes within the network. When transportation demand remains constant, disparate allocations are made for cost-preferred cargo and time-preferred cargo within the same type of energy-supply ship for the voyage segment. Ship allocation for time-preferred cargo tends to favor routes with fewer transit ports.