A hybrid SA-based model for integrated routing and 3D stowage of inter-continental RoRo ships with mixed pickup-delivery and stability constraints

Abstract

Integrated voyage and stowage planning for Roll-on/Roll-off (RoRo) ships involves optimizing port sequences and managing simultaneous loading/unloading operations. While most existing research on RoRo Ship Routing and Stowage Problems (RSRSP) addresses simplified routing scenarios, this study proposes a more realistic model termed 3L-MPD-RSRSP. It incorporates intercontinental routing, 3D stowage constraints, and operational complexities such as simultaneous loading/unloading at ports and adjustable deck heights for high & heavy cargo. To solve this, we propose a hybrid algorithm based on simulated annealing. The framework is used to generate high-quality initial route plans. Then, a newly developed heuristic, RSP, is applied to stowage planning. RSP prioritizes cargo placement through rule-based logic, including cargo classification and location ranking. It works in conjunction with a simulation engine that evaluates 3D stowage feasibility, ship stability, Last-In-First-Out constraints, and cargo profitability. Experimental results demonstrate that the proposed algorithm outperforms conventional methods in both solution quality and operational robustness, offering a more realistic and effective framework for RoRo voyage and stowage planning.