A two-stage weather routing strategy for container ships with container loss prevention

Abstract

Container loss accidents caused by severe weather pose a serious threat to the reputation of shipping companies and damage the marine environment. However, most existing ship weather routing strategies only focus primarily on economic performance, or ensure navigation safety based on simplified wind and wave thresholds. This study proposes a two-stage weather routing strategy for container ships to avoid container loss. In the first stage, the system investigates the causal dynamics from wave-load excitation through ship motion response to container lashing failure, and develops a rapid predictive model for container loss. In the second stage, this model is imposed as a core constraint on the route optimisation, which is then solved via a time-embedded three-dimensional dynamic programming algorithm. Case analysis results demonstrate that, in contrast to strategies that focus solely on economic performance, the routes derived from the proposed method are capable of keeping the critical structural-force demands below their corresponding control limits, thereby reducing container-loss risk within the applicability range of the proposed model.