Risk analysis of liquefied cargo shipping based on fuzzy accident tree

Due to the special characteristics of liquefiable solid bulk cargo, solid bulk ship sinking accidents happen frequently. By studying the fluidization risk of liquefiable cargo, the measures for risk factors for preventing the accidents are put forward in this paper. Firstly, the risk factors of fluidization accidents are sorted out, and the accident tree model is constructed. Secondly, Expert evaluation methods are used to rate selected risk factors, and the triangular fuzzy probability of the basic event is calculated by 3σ representation method.Finally, the median method is introduced to determine the influence degree of each basic event on the fluidization accidents. The results show that seven risk factors leading to the occurrence of fluidization accidents are ranked first, such as strong wind and waves in the sea, rain and snow, inadequate cargo protection design, excessive cargo hold capacity, lack of correct emergency measures, shipper's intention to avoid proof and ship's blind transport, indicating that these factors greatly affect the occurrence of fluidization accidents.