At China Classification Society (CCS), there is a technical team that cracks the code of green transformation by taking wind as a medium when the shipping industry is seeking a breakthrough in the wave of environmental protection; when the traditional ship power system encounters a bottleneck in emissions reduction, they add green power to large ships based on nature power by taking their intelligence as a sail; when the industry urgently needs to be reshaped in technological changes, they take standards as a guide to help global shipping sail towards new paths —— this is the “WindMastery” team of CCS, who are creating a green future for the shipping industry based on technological innovation. 

II. Cracking the Technical Code of Marine Wind-assisted Propulsion Technology for the Industry

In recent years, the CCS “WindMastery” team has gathered the advantageous resources of the entire CCS system to carry out research on wind-assisted propulsion technology, providing strong technical support for subsequent full-scale ship projects.

In terms of the arrangement of sail and the design and survey technology of sail devices, the team has not only conducted in-depth research on various forms of wind-assisted propulsion technology, such as wind sail, kite sail, hard wing sail, and rotor sail, but also systematically studied their aerodynamic performance, structural design, and integrated optimization with ship power systems. At the same time, it is committed to developing intelligent wind control systems to achieve efficient utilization of wind resources and precise control of ship navigation. It has broken through the inversion of internal and external environmental conditions involved in wind-assisted propulsion system, wind load and aerodynamic forecasting methods, inertial load calculation methods, ice and snow load calculation methods, main structure strength and ship longitudinal and local strength evaluation methods for installing wind-assisted propulsion systems, as well as the optimization design methods for the connection structure between navigation assistance system and ship hull, as well as key technical difficulties such as hull structure optimization and lightweight methods. It has formed a multi-objective refined solution, established a contribution evaluation and verification method for wind-assisted propulsion technology to EEDI/EEXI. Internationally, it has taken the lead in researching and formulating corresponding technical standards, constructed a wind environment database, and established specialized service capabilities for ship wind-assisted propulsion devices including rotor sails, kite sails and hard wing sails. 

Some members of the team have collaborated with Dalian Shipbuilding Industry Co., Ltd. (DSIC) to jointly participate in the national projects “Technical Demonstration, Application and Development of Wind Sails (Wind Sail Phase I)” and “Research on Engineering Application of Wing Sail-assisted Propulsion System” (Wind Sail Phase II).

Among them, in the Phase I project, the ship “New Vitality” has broken through many key technologies including the design and construction of wing sail prototypes, the overall design of the “ship-sail” interface, the development of sail control strategy and control system, the evaluation of structural safety, etc. In terms of strength calculation of the novel sail structure, it has comprehensively considered the theory of large deflection calculation, innovatively determined the appropriate contact element mode, solved the convergence problem of the calculation model and provided key technical support for the successful implementation of the project.

In the progress of the ship “New Aden” in the Phase II project, the project team has comprehensively optimized it based on the perfect combination of the Phase  I project. It has adopted new technologies including carbon fiber composite material skin, etc. to achieve the formulation of lightweight standards for the sail structure, filling the gap in the application of composite materials in sails in China. Under the EEDI computing framework, the team has revised relevant international conventions and standards, and made breakthroughs in the survey techniques and verification methods for new technologies in wind sail-assisted propulsion. At the same time, the team has also established a safety technical standards verification system for the application of sail device to reduce the design costs and promote the application of sail devices on ships. 

Another important point is that based on years of research results and full-scale ship experience, the team has provided strong technical support for the compilation of the “Guidelines for Evaluation and Inspection of Marine Hard Wing Sails”, the “Guidelines for Survey of Marine Wind-Rotor Assisted Propulsion System”, and the “Guidelines for Survey and Verification of Wind Rotors-assisted Propulsion”. These documents have played a crucial role in the commercial application of wind-assisted propulsion technology on ships, creating good economic benefits for clients.

III. Important Projects and Honors

In recent years, the CCS “WindMastery” team has carried out extensive and in-depth cooperation with multiple units and achieved significant results. 

From January 2015 to the end of 2019, CCS collaborated with Dalian Shipbuilding Industry Co., Ltd. (DSIC) on a national level project “Technical Demonstration, Application and Development of Wind Sails”, which was successfully applied onboard the “New Vitality” of China Merchants Shipping Co., Ltd. After more than 5 years of use verification, its energy-saving effect is significant, reaching about 5%, accumulating valuable experience for subsequent project R&D.

On November 13, 2018, the world’s first VLCC “NEW VITALITY” equipped with a sail device was successfully delivered, and CCS participated in its research and survey. This ship is the world’s first VLCC equipped with a wind sail-assisted propulsion device for testing purpose. It is a demonstration ship of a national key scientific research project led by DSIC, with CCS getting involved in its research and survey. It has filled the international gap, and is a major innovative technological achievement jointly developed by relevant research units in the domestic shipbuilding and shipping industries.

From January 2020 to the end of 2022, CCS collaborated with Dalian Shipbuilding Industry Co., Ltd. (DSIC) on a national level project “Research on Engineering Application of Wing-shaped Sail-assisted Propulsion System”, which successfully applied onboard the ship “New Aden” of China Merchants Shipping Co., Ltd., with an energy-saving effect of about 9%.

On June 17, 2023, after three years of theoretical research, prototype development and testing, engineering prototype design, manufacturing, installation, and commissioning, the marine wind rotor-assisted propulsion project  “Changhang Shenghai” successfully completed onboard installation and survey, with CCS participating in its R&D.  

CCS has collaborated with Dealfeng New Energy Technology (Tianjin) Co., Ltd. (Dealfeng) and Offshore Oil Engineering Co., Ltd. (COOEC) to retrofit the wind-assisted propulsion system of the in-service deck carrier “Hai Yang Shi You 226”. After being retrofitted and installed with a rotor sail, its annual fuel saving rate is about 11%. 

On November 29, 2023, the ship “Jun Bai 56” with CCS participating in its R&D was successfully launched as the first new energy powered vessel in China to be equipped with an approved wind-rotor assisted propulsion system. 

The retrofitting project of a wind-assisted propulsion system for the bulk carrier “Yue Dian 83” that was jointly carried out by CCS, CSIC Shanghai Marine Energy Saving Technology Development Co., Ltd (CMES-Tech) and Chaokang Energy Transportation Co., Ltd. will be completed by October 2025. According to calculations, the ship can achieve an energy-saving effect of 5% to 8% depending on the route after being installed with two sets of rotor sails. It is expected to save about 2 tons of fuel per day and reduce greenhouse gas emissions by 1600t annually, achieving a win-win situation in both economic and social values. 

The series of collaborative projects conducted by CCS have not only demonstrated the strong capabilities of the CCS “WindMastery team in technology R&D and application, but also provide practical and feasible solutions for the green transition of the shipping industry, winning wide recognition and praise from the industry.