Optimization of integrated accurate ride-tide planning and vessel scheduling in multi-functional ports with long channels

Driven by economic globalization and the reduction of transport costs, “large-scale vessels” and “multi-functional ports” have emerged as the new paradigm in marine transportation. Within this context, traditional ride-tide planning and common rule-based vessel scheduling methods sometimes become ineffective in optimizing navigational potential, leading to serious waiting problems for large-scale vessels and increasing port congestion. This paper aims to develop a new point-by-point ship ride-tide (PSRT) approach to address accurate ride-tide planning and vessel scheduling issues for a long channel in a multi-functional port. The method is developed based on coupling the vessel’s speed change and tidal level variation to determine accurate ride-tide planning for large-scale vessels. A mixed integer linear programming (MILP) model is presented, in which the vessel’s accurate tide ride, dynamic sailing speeds, and vessel scheduling priority are explicitly considered. Due to the computational inefficiency of the MILP model in large-scale scenarios, we decompose it into a master problem and several subproblems and develop an improved branch-and-price (B&P) algorithm with three enhanced methods to solve this model. Computational experiments for Huanghua Port show that the PSRT method extends available tidal time windows (ATTWs) for large-scale vessels by an average of 20% compared to the traditional single-point tide-ride approach for the same under keel clearance. Moreover, the proposed improved B&P algorithm significantly outperforms existing methods such as column generation, branch and bound, and an improved genetic algorithm as well as the port scheduling schemes adopted in reality. This study has effectively unlocked the navigational potential of long channels, making new contributions to enabling ports to accommodate and serve a greater number of large and ultra-large vessels.