China’s CMES-Tech achieves DNV’s Type Approval for 35m Tilting Wind Assisted Rotor System (WAPS)
Shanghai, China – December 4, 2025 – The Chinese maritime technology sector has reached a landmark achievement in wind-assisted propulsion, as DNV, the world’s leading classification society, granted a Type Approval Design Certificate (TADC) to CSSC Shanghai Marine Energy Saving Technology Co., Ltd. (CMES-Tech) for its new 5m x 35m Tilting Type Wind Assisted Rotor System.
This certification is highly significant, as it makes the CMES-Tech system the first domestically developed rotor sail in China to achieve recognition under DNV’s robust WAPS rules (ST-0511). The TADC confirms the system’s design maturity, safety, and readiness for installation on DNV-classed commercial vessels globally.
Adaptive Design for Operational Flexibility
The global demand for reliable Wind-Assisted Propulsion Systems (WAPS) is accelerating, driven by mounting fuel costs and tightening emissions regulations like the CII and EEXI. The CMES-Tech design directly addresses a key challenge of deploying WAPS on working vessels: operational compatibility.
The innovative rotor sail features a retractable and adjustable design that allows the rotor to:
- Tilt to adapt to varying air draft and clearance requirements.
- Retract during cargo operations to prevent interference with deck/hatch operations or port infrastructure.
Furthermore, the system incorporates intelligent sensing and automatic control to adjust rotor operation based on real-time wind conditions, maximizing wind propulsion efficiency and ensuring continuous safety.
Validation of Maturity and Structural Integrity
The TADC was officially presented at Marintec 2025 in Shanghai, celebrating the culmination of a thorough review process. DNV’s classification experts reviewed all mechanical, structural, and electrical documentation to assess the system’s suitability for shipboard application under realistic operational and environmental conditions.
“Receiving the DNV TADC is a landmark for China’s green-shipping industry and a strong validation of our design’s maturity, structural integrity and operational practicality,” said Dr. Huang Guofu, General Manager of CMES-Tech. “It demonstrates that our 5m x 35m tilting rotor design meets the highest classification and validates our commitment to driving maritime efficiency.”
Reinforcing the design’s robustness, the prototype successfully passed a rigorous 120% overload structural test, demonstrating its ability to withstand extreme loads far beyond normal operating conditions.
Mr. Chen Keng, DNV Vice President and Area Manager China South, highlighted the importance of adding another vetted technology to the WAPS portfolio. “WAPS technologies offer immediate, tangible benefits to shipowners. The awarding of this TADC to CMES-Tech means we add another option to the growing portfolio of WAPS systems that have been assessed to the industry’s leading rule set, building further confidence in their readiness for real-world use.”
CMES-Tech is now moving forward with detailed installation planning and subsequent sea-trials to fully validate the in-service fuel-saving performance and prepare the system for commercial deployment worldwide.
About DNV
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Source: DNV Maritime