Bureau Veritas Approvals Boost Confidence in Rotor Sails

Bureau Veritas Expands Certification of Anemoi Rotor Sails

According to a report published by The Maritime Executive, Anemoi Marine Technologies has received new design assessment certificates from classification society Bureau Veritas covering multiple configurations of its Rotor Sail wind-assisted propulsion system. The move adds another layer of third-party validation to a technology that shipowners are increasingly evaluating as a fuel-saving and emissions-reduction measure.

What the New Approvals Cover

The latest Bureau Veritas certificates apply to Anemoi’s fixed and rail-mounted 3.5m x 24.5m Rotor Sails, including explosion-proof (EX-rated) versions and shorter units designed for vessels with restricted air draft. The company is also pursuing further approvals for its fixed and folding 5m x 35m Rotor Sail models, suggesting the certification programme will continue to broaden in scope as larger installations move through development.

With this round of approvals, Anemoi’s entire Rotor Sail product range is now covered by certificates from four major classification societies: Bureau Veritas, Lloyd’s Register, DNV, and ClassNK. That breadth of class coverage means owners working with different class societies across their fleets no longer face a mismatch between their preferred class provider and available rotor sail certification.

Why Multi-Class Coverage Matters for Owners

Classification approval is meant to confirm that equipment can be built, fitted and operated safely in line with recognised standards. For a retrofit or newbuild project, having that assurance already in place cuts down the amount of project-specific testing and verification an owner would otherwise need to arrange. Anemoi has framed the approvals as a way of lowering barriers to adoption for both new construction and retrofit projects, and of reducing overall project risk.

The company also points out that its rotor sails are already operating on vessels classed by several different societies, which it says demonstrates performance across varied ship types and operating conditions, beyond the paper certification itself.

Clare Urmston, CEO of Anemoi Marine Technologies, said the approvals reflect both the technical maturity of the product and the scale at which it is now being deployed, adding that class verification remains central to building market confidence in wind-assisted propulsion and crediting the company’s engineering team for meeting the technical requirements needed to secure approvals from multiple societies in a short period.

An Operational and Survey Perspective

For technical managers and superintendents, broadening class approval across Bureau Veritas, Lloyd’s Register, DNV and ClassNK removes one of the practical obstacles to fitting rotor sails: the need to align equipment certification with a vessel’s existing class society. That said, certification of the equipment itself is only part of the picture. Once a rotor sail is installed, it becomes part of the vessel’s structure and machinery footprint — adding weight, deck loading, and air draft considerations that need to be accounted for in stability calculations, cargo hold access, and periodic condition surveys. Owners retrofitting rotor sails should expect surveyors to pay closer attention to structural reinforcement points, foundation integrity, and any impact on cargo operations or crane sightlines during subsequent condition and pre-purchase surveys. As wind-assisted propulsion moves from pilot projects to fleet-wide adoption, verifying that these installations remain structurally sound and properly maintained over time will become a routine part of vessel inspection, not just a one-off classification exercise at fitting.

Looking Ahead

As more classification societies certify a wider range of rotor sail configurations, the technology is likely to see faster uptake among owners seeking to cut fuel consumption and comply with tightening efficiency regulations. Whether that uptake translates into measurable, verified fuel savings across diverse trades and vessel types will remain an area worth tracking as more vessels enter service with the technology installed.

Reviewed by Ibrahim Halil Ceylan, Marine Surveyor at Apeks Marine.