Anemoi completes Rotor Sail installation on NS United bulk carrier

(Posted on 15/11/25)

Anemoi Marine Technologies, the UK-based leading designer of Rotor Sails for wind-assisted ship propulsion, has completed the retrofit on another of the largest vessels in the world after installing five 35m-tall units on the 400,000 DWT ore carrier NSU TUBARAO. The vessel, owned by bulk owner/operator NS United Kaiun Kaisha, Ltd. (NSU) and chartered by mining giant Vale International, is expected to reduce fuel consumption by 6-12% annually using the wind-assisted propulsion system. This marks the fourth VLOC installation of Anemoi Rotor Sails on vessels chartered by Vale*.

The completion of this installation means Anemoi has surpassed 1.6million DWT of vessel tonnage installed with Anemoi Rotor Sails.

The Rotor Sail installation on the five-year-old vessel, currently operating under a long-term charter to transport iron ore for Vale, was completed during scheduled drydocking in October in Zhoushan Xinya Shipyard Co.,Ltd, China. The Rotor Sails are deployed using a folding (tilting) mechanism for flexibility during cargo handling.

NSU has taken an industry-leading approach by combining Rotor Sails with advanced digital solutions that optimise power usage and vessel routing, enhancing fuel efficiency on NSU TUBARAO and maximising the use of wind energy. Manta’s FuelOpt offers flexibility to the owner for power management of the main engine, including optimisation of fuel saved by the Rotor Sails. Coupled with NAPA’s Voyage Optimisation toolbox for voyage planning to maximise the benefits of favourable winds without compromising departure or arrival times.

During the scheduled special survey, NSU TUBARAO was also equipped with a new shaft generator designed to enhance the efficiency of the vessel. This upgrade not only improves the vessel’s own energy performance but also optimises fuel consumption when operating Anemoi’s Rotor Sails. Anemoi successfully integrated its Rotor Sail technology with the vessel’s shaft generator through advanced control system integration, ensuring seamless coordination between wind propulsion and onboard power supply. NSU’s forward-thinking approach to sustainable innovation means this installation stands among the most efficient wind propulsion retrofit projects to date.

“The scale of this project shows the market’s growing confidence in wind power as a crucial enabler of lower emission shipping. Working with progressive partners like NSU, Vale and Class NK, we are able to advance Rotor Sail technology and show how optimising propulsion integration and navigation for wind assistance can deliver even greater benefits.” - Clare Urmston, CEO of Anemoi.

“At NSU we aim to support our stakeholders with the world’s most efficient ships. The Rotor Sails on NSU TUBARAO, and the advanced systems that will help maximise its fuel-saving potential, are a perfect example of those efforts. We are pleased to have completed this successful installation, within the scheduled drydock, by strong collaboration of both Anemoi and the NSU team.” – Toru Fujita, Director, Managing Executive Officer of NSU.