Classification society DNV has approved a new rotor sail design developed by CMES-Tech, making it the first Chinese-designed tilting rotor sail system to meet the class society’s rules.

The type approval confirms the system is ready for installation on DNV-classed ships, DNV said in an emailed statement on Thursday.

A rotor sail is a wind propulsion system that consists of a tall spinning cylinder using wind to help push a ship forward, reducing bunker use and emissions.

CMES-Tech’s rotor sail design can tilt or retract so it does not get in the way during cargo operations or when a ship passes under low structures. It also has sensors and automatic controls to adjust how it works depending on the wind.

“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,” Dr. Huang Guofu, General Manager of CMES-Tech, said.

DNV engineers checked the design’s strength, safety and electrical systems before granting approval.