During the thermal launch operation of offshore launch platforms/ships, they will be subjected to the combined effects of rocket impact, wind, waves, and currents. Due to different arrangements of mooring systems, the motion response and mooring stress state of offshore launch platforms/ships are affected, which in turn affects the safety of the platform/ship-arrow. Therefore, this article explores the mooring arrangement of offshore launch ships under the coupling of multiple factors, including the arrangement of mooring point positions and changes in mooring line lengths, and their effects on the motion response and mooring stress state of offshore launch ships. Research has found that placing the mooring point below the waterline of the launch vessel and appropriately increasing the length of the mooring line will be more conducive to the conduct of offshore launch operations, providing technical references for the future layout of offshore launch vessel mooring systems.

Polar heavy icebreaker is the key supporting equipment for polar merchant shipping, rescue support, scientific investigation and resource exploitation. The polar heavy breaker deserves special consideration in the application of high-strength steel and other special materials, the structural safety assessment under ice load and the hull structural layout, due to the high ice load compared with the medium and low ice class polar ships/icebreakers. The previous structural design experience for medium and low ice class polar ships cannot be arbitrarily applied to the polar heavy icebreaker. The structural design and evaluating experience of a PC2 polar heavy icebreaker that was developed by Marine Design & Research Institute of China (MARIC) are summarized. It focuses on the application of high strength steel for the ice belt structure, the application requirements and characteristics of composite steel plate for the ice belt outer plate, the impact of the non-linear evaluation technology on the ice belt scantlings, and the distribution of the ice-induced shear/bending moment and its influence on the structure in non-ice-belt regions, such as the inner platform of the main ship and the side hull of the bridge. It presents the structural design characteristics of the polar heavy icebreaker and the main differences between the polar heavy icebreaker and the medium and low ice class polar ships/icebreakers in terms of the overall structural layout and the design and evaluation of the ice belt structure. With the increase of the ice class, it is believed that the ice load not only affects the outer plate and its attached components in the ice belt region, but also has significant impact on the material selection of the ice belt structure and the overall structural layout and design of the whole ship.

The offshore launch platform considering the thermal launch of a rocket at sea has been studied. The Realizable k-ε turbulence model and the three-dimensional potential flow theory are used to study the time-domain motion response of the platform under the impact load of the rocket wake and the combined loads of the wind, wave and current. The heave, roll, pitch and yaw of the launch platform during offshore launching under two sea states are compared and analyzed. The analysis and calculation show that one sea state is more beneficial to the two-way safety of the rocket and the launch platform than the other, and the launch platform should avoid offshore thermal launching in beam waves. In addition, a simple calculation method of the wake impact under offshore launch condition is proposed to obtain the pressure time history of the gas wake impact for single Laval tube, providing theoretical and engineering foundation for the subsequent study of the structure and motion performance of the launch platform.

According to the increasingly stringent environmental protection requirements and the implementation of the mandatory emission reduction regulations in the world, energy saving and emission reduction becomes popular in the development of the shipbuilding industry, and thus the application of the new energy in ships has attracted the continuous concern. The current research presents the application of the common new energy sources, such as wind energy, solar energy, new power batteries, nuclear energy and wave energy, on ships, and analyzes the current status of the application of the new energy ships at home and abroad. The existing technical shortcomings and development directions are proposed by comparing the advantages and disadvantages of the various new energy ships. The development trend of the new energy ships has been prospected according to the current level of the scientific research: the intelligent and environment-friendly ships powered by the various new energy sources will gradually replace the traditional diesel ships, and the new energy ships will also enter the stage of the rapid development in the future.

Air compressor is an important equipment for ships. The capacity and quantity of the air compressor must match the capacity of the relevant air reservoir and the gas consumption of the main engine and auxiliary engine, and meet the requirement of the inflation time and the start-ups of the main engine and the auxiliary engine, thus to be approved by the classification societies. The rational selection of the capacity and quantity of the air compressor can greatly save the procurement cost and the energy cost by reducing the frequent start-ups of the air compressor. It analyzes the advantages and disadvantages, optimization and redundancy of the selection of the air compressor for several container ships. It can provide reference for the ship design in future.