Step-wise stowage planning of roll-on roll-off ships transporting dangerous goods

Planning stowage with the presence of dangerous goods is critical to ensure safety at sea. In this paper, we propose a step-wise stowage planning approach to generate optimal stowage plans for roll-on roll-off ships transporting trailers (some containing dangerous cargo) between two ports. The planning approach consists of three steps, where Step 1 maximizes the number of dangerous cargo units to transport while adhering to the International Maritime Dangerous Goods regulations. Step 2, which is optional, maximizes the safety distance among the dangerous cargo units found in the first step. Finally, in Step 3, the ballast water intake needed to ensure stability of the ship is minimized, as this has a significant effect on the fuel consumption. Computational results on instances generated based on real data from a shipping company show that the proposed planning approach might both reduce the ballast water intake (and hence reduce the fuel consumption) and increase the safety distance among dangerous cargo units