Anemoi, Hafnia, GSI and DNV team up to unlock full potential of rotor sails on MR tankers

UK-based wind-assisted propulsion provider Anemoi Marine Technologies, Singapore-based tanker owner Hafnia, China-based shipbuilder Guangzhou Shipyard International (GSI), and Norwegian class society DNV have embarked on a collaboration to develop the integration design of rotor sails suitable for installation on 50,000 dwt medium-range (MR) tankers.

The companies recently signed a joint development project (JDP) to develop a new generation of environmentally friendly rotor sail vessel designs to increase the efficiency of MR tankers within the wider global fleet.

As part of the project, Anemoi and Hafnia will undertake several engineering studies to establish specifications related to how rotor sails can be efficiently installed on the deck of MR tankers, alongside additional electrical and control system layouts for these vessels.

In addition, the studies will include calculations to examine how rotor sails can improve the Energy Efficiency Design Index (EEDI) and Energy Efficiency Existing Ship Index (EEXI) values of existing and future MR tankers.

GSI will apply its naval architecture and marine engineering principles to develop essential technical documentation for the new rotor sail’s design integration, while DNV will undertake an approval in principle (AiP) assessment to ensure that the design is feasible and verifies that no significant obstacles exist to prevent the design from being realized based on current and foreseeable regulatory and class requirements.

“Participating in this joint development project allows us to collaborate with industry partners to unlock the full potential of rotor sails on MR tankers. It supports Hafnia’s decarbonisation strategy to assess and embrace the potential of innovative technologies to improve fuel efficiency and reduce vessel emissions,” Jesper Kristiansen, Hafnia’s General Manager Technical, commented.

In December last year, Hafnia revealed it was exploring the installation of wind-assisted propulsion systems (WAPS) on its new vessels. In 2023, Hafnia ordered several dual-fuel methanol MR tankers from GSI.

Earlier this year, the company welcomed the 49,800 dwt Ecomar Gascogne, its first methanol dual-fuel chemical IMOII MR tanker, to the fleet.

“WAPS, like rotor sails, are spreading throughout the industry, enabled by new materials, data and software, and evolving rules and regulations. Across all segments, we still have room to improve vessel energy efficiency and WAPS have emerged as one of the most attractive tools for shipping to make immediate, impactful gains in this area. DNV is very pleased to be part of this forward-looking group, and build on a cooperation with Anemoi, Hafnia and GSI that is driving shipping’s journey towards a more sustainable future,” Shao Guang Chi, Station Manager of Guangzhou Station at DNV Maritime, said.

“With new regulations driving the need for lower emissions, the time is right to adopt highly efficient ship designs. Integrating rotor sails into MR tankers is a necessary step, and together with our partners, we’re committed to delivering vessels that meet both environmental and commercial demands,” said Huang Jun, Deputy Chief Engineer at GSI, highlighted.

“There is growing interest within the tanker sector for novel technology that can help reduce the carbon footprint of their vessels and increase their value, particularly as the MR tanker fleet is expected to grow in the coming years. Our partnership with Hafnia, alongside GSI and DNV, will ensure a new generation of MR tankers that utilises rotor sails to improve their efficiency and sustainability credentials hits the water in the not-too-distant future,” Nick Contopoulos, Chief Production and Partnerships Officer of Anemoi, noted.

Rotor sails, also known as Flettner rotors, are vertical cylinders that harness the renewable power of the wind to provide additional forward thrust and improve the energy efficiency of the vessel.

This energy-saving technology is increasingly being sought after by shipowners and operators as a cost-effective and immediate solution to reduce the carbon emissions and fuel consumption of their vessels, as well as helping meet international emission reduction targets.