Risk Prediction for the Securing of Vehicles on a ROPAX Vessel

The rolling of a ship in a seaway has a significant impact on the securing of vehicles stowed on deck. To ensure the safety of the vehicle, the crew on deck should ensure that all the vehicles have been rigidly lashed and secured as per international codes. However, accidents of vehicles involving severe cargo damage and huge property loss still occur on roll-on/roll-off passenger (ROPAX) vessels occasionally. Among the reasons causing these accidents, the heavy weather encountered by the vessel is a prominent one. Actually, the critical issue is that most ROPAX vessels are not able to predict the securing condition of the vehicles onboard. To this end, this paper proposes a mathematical model to assess the securing condition of vehicles on ROPAX vessels. Firstly, a model for calculating the transverse external force caused by the rolling of a ROPAX vessel and transverse securing force of a vehicle is proposed. Then, an approach for predicting the real-time securing condition of the vehicles is established. Finally, the measures for the decision-making of mitigating the influence of heavy weather are proposed to ensure the securing safety of the vessel. Good feasibility of the novel approach is validated through a comparison between the computational results in this study and the simulation results of Maxsurf. The approach in this study can be used for avoiding the accident of the lashing wires breaking of the vehicles on a ROPAX vessel in heavy weather.