Since the outbreak of COVID-19, a large number of passengers infected on multiple cruise ships have exposed the shortcomings of existing ship design methods in epidemic prevention functions. This paper proposes a risk analysis method based on people flow simulation to address the risk of infectious diseases caused by flow of people on board. The internal spatial characteristics and people flow simulation model of a ship with medical function are constructed in the current study. The people flow under specified operation conditions is then simulated based on the cellular automata method. The risk level of various places within the ship’s space are obtained by combining with the infection probability model of a specific virus strain. The analysis results show that the overall layout design of the target ship based on the principle of zoning management can control the risk of infection transmission to a certain extent, but it is still necessary to further optimize the details of the cabin passage layout and daily management. The analysis methods and examples used in the current study can provide references for the epidemic prevention design of the general arrangement of ships and give suggestions for the management of the onboard people flow under the epidemic situation.

The positioning speed of the life buoys equipped on the ship in case of a shipwreck plays a great role in the efficiency and even the success rate of rescue. It is important to grasp the hydrodynamic characteristics of life buoys in waves for the positioning speed of the life saving. In this paper, in order to improve the navigation speed of life buoys, the hydrodynamic characteristics of self-develped integral self-propelled buoys are investigated with different trim angle and navigation speed under the still water and regular waves by numerical method. It is found that the drag force on self-propelled floats in still water and regular waves increases nearly linearly with the increase of sailing speed, and the drag force on regular waves is generally larger than that in still water. The motion response of a self-propelled float is further induced by the increase of the high-pressure region, the emergence of the low-pressure region, and the alternation of high- and low-pressure regions around the float by wave action. The motion response of the self-propelled floats is greatly affected by the draft, and the longitudinal oscillatory motion of the floats is more pronounced at smaller and larger initial drafts, while the vertical oscillatory motion of the self-propelled floats is more and more pronounced as the draft increases. The conclusions of the study can provide the necessary data support for the research and development of self-propelled floats.

The feasibility of offshore tandem lifting test for the semi-submersible lifting and disassembling unit has been discussed based on the procedure of the offshore tandem lifting with a 2 000 t crane, combining with the performance properties of the crane and the actual experiment environment. The operation of each segment in the procedure of the tandem lifting can be safe and reliable according to the characteristics of the unit. It can provide a theoretical basis for the later offshore tandem lifting test of the semi-submersible lifting and disassembling unit. The analysis results show that the tandem lifting procedures that meet the requirements of feasibility and safety can be tested at sea.

The digital and intelligent technology is continuously developing for ships. An innovative three-dimensional (3D) modeling method based on the 3DExperience (3DE) platform driven by two-dimensional (2D) layout of AutoCAD is explored by combing the advantages of AutoCAD and the advantages of 3DE in digital design. The secondary development of the 3DE platform based on the Component Application Architecture (CAA) implements abilities of the batch creation and attribute extension of the equipment nodes and the automatic call of equipment modeling. The 3D layout modeling of the machinery space in a cargo vessel is generated through reading the data table that is generated from 2D layout by using the secondary development tool, in order to verify the feasibility of this method. The full-scale trial results show that the efficiency of the 3D modeling of the 3DE platform can be greatly improved by using this method. It can provide the specific development methods and the technical routes for the efficient 3D modeling of ships.