Rotor Sails on NSU Tubarao: Breakthrough in Wind Energy for Shipping

Anemoi Marine Technologies has completed the installation of five Rotor Sails on the NSU Tubarao, a 400 000-deadweight tonne (DWT) ore carrier. The vessel is owned and operated by NS United Kaiun Kaisha (NSU) and chartered by Vale International.

The Rotor Sail retrofit was carried out during a scheduled drydocking at Zhoushan Xinya Shipyard in China this October. This marks Anemoi’s fourth such project on very large ore carriers (VLOCs) for Vale charters, bringing the total DWT equipped with Rotor Sails to over 1,6 million.

Each 35m-high and 5m-diameter Rotor Sail features a tilting mechanism for flexibility during cargo handling. Delivered in September 2020, the 361m-long and 65m-wide NSU Tubarao is one of the world’s largest bulk carriers, mainly used for iron ore transport under a long-term Vale charter. The wind-assisted propulsion technology is expected to reduce annual fuel consumption by 6 % to 12 %.

NSU Managing Executive Officer and Director Toru Fujita stated: “At NSU, we aim to support stakeholders with the world’s most efficient ships. The Rotor Sails on NSU Tubarao, along with advanced systems to maximize fuel savings, exemplify these efforts.”

In addition to the sails, the vessel now has a new shaft generator to enhance energy performance and optimize fuel use with wind systems. Anemoi has integrated its technology with the ship’s power systems for seamless coordination between wind propulsion and onboard energy management.

NSU has added digital tools like Manta’s FuelOpt for main engine power management and NAPA’s Voyage Optimisation toolbox. These adjust power and routes based on wind conditions while keeping to schedules, boosting fuel efficiency.

Anemoi CEO Clare Urmston commented: “This project’s scale reflects the market’s increasing trust in wind power as a key enabler for lower-emission shipping. Collaborating with forward-thinking partners like NSU, Vale, and Class NK allows us to advance Rotor Sail tech and demonstrate greater benefits through optimized propulsion and navigation.”

Vale reaffirmed its commitment to IMO greenhouse gas reduction goals, targeting a 15 % cut in scope 3 emissions by 2035 across its value chain, including chartered vessels. In August, Anemoi received £1,2m ($1,59m) funding from the Clean Maritime Demonstration Competition (CMDC) for a “next-generation folding sail system” designed for Kamsarmax and Panamax bulk carriers, focusing on advanced aerodynamics to improve fuel efficiency.