Currently, marine security is becoming increasingly severe, with incidents of harassment, attack, and sabotage against vessels occurring frequently. Aquaculture vessels, operating long-term in deep seas, are particularly susceptible to various forms of harassment, attack, and sabotage, which seriously threaten their safe operation. Additionally, aquaculture vessels also face significant internal security risks. It is therefore necessary to establish a complete security system for the aquaculture vessels to ensure their safe operation. The potential security risks are categorized into external risks and internal risks based on the characteristics of an aquaculture vessel. Accordingly, it constructs the external and internal risk security systems, clarifies the overall composition and workflow of the external security system, and establishes a “scenario-personnel” double closed-loop laboratory security system, as well as proposes specific security measures against violent and terrorist crimes. From the perspectives of monitoring, emergency, and supervision, an integrated security system is established to ensure the safe operation of aquaculture vessels.

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.

The scale of wind power installation units and the calculated equipment number are gradually increasing with the development of large-scale wind turbines, resulting in a very large size and weight of the selected temporary anchor equipment. This not only imposes difficulties to the arrangement of temporary anchor equipment on the ship, but also affects the strengthening of the hull structure and the operation ability of the self-elevating installation units. In order to accurately calculate the Equipment Number (EN) of the self-elevating wind turbine installation unit and reasonably configure the temporary anchor equipment, it studies the EN calculation formula and its requirements in the classification rules for the offshore unit from the classification societies. It also compares the calculation results from the rules of several classification societies. Finally, the safety factor of the anchor chain is checked by using the direct calculation method. A more reasonable EN calculation method is proposed to provide references for EN calculation of similar offshore units.

Marine crane can be used in all kinds of ships as it has various types, large lifting capacity, excellent performance and wide application. As one of the indispensable supporting equipment for modern ships, it plays an important role in the shipping industry. The principles, procedures and precautions of the selection and layout of marine cranes have been comprehensively and systematically analyzed. The simplified modelling of the crane is established to clarify the principle and the procedure of the selection and layout of the crane, as well as summarize the review points of the three-dimensional (3D) layout of the crane. The technicians can be instructed to quickly determine the location of the crane based on the layout method described in this paper, and also to quickly check the interference of the crane in 3D environment by using the 3D design software CATIA to verify the rationality of the crane location.