Emergency risk assessment provides a basis for offshore operators to identify hazards, reduce risks to an appropriate level and protect people from the impact of accidents. The aquaculture vessel will be affected by adverse natural conditions during navigation and operations, not only facing risks such as collision and grounding, but also encountering additional emergencies arising from engineering operations such as mooring operations and aquaculture farming. It is therefore necessary to carry out risk assessment for the emergencies it faces. Firstly, the characteristics of the aquaculture vessel is analyzed. Subsequently, the types, probabilities, causes, processes, and severity of potential emergencies throughout the whole process of the navigation and operation of the aquaculture vessel are examined based on these characteristics. Finally, a risk assessment of the emergencies faced by the aquaculture vessel is conducted to develop a FMEA worksheet by using the failure mode and effects analysis (FMEA) method. It provides valuable date decision support for emergency decision-making and emergency management system construction.

Environmental friendly dual-fuel propelled ships are becoming popular for new shipbuilding. In order to maximize the capacity utilization and take into account the scantlings of the container hold, the type C LNG fuel tanks are transversely arranged below the superstructure in the large dual-fuel container ships. Compared with the LNG carrier, the safety of the traditional saddle structure becomes insufficient due to the significant changes of the load acted on the hull. The optimized arrangement plan and structure design of the saddle are proposed in the current study. The strength and fatigue of the saddle and its supporting structure are analyzed by using the finite element method, and compared with those of traditional saddle design. The results show that the optimized saddle structure can significantly improve the stress distribution and increase the fatigue life. It can provide references for the structure design of the saddle for large container ships with type C LNG fuel tanks.