Lloyd’s Register has granted Approval in Principle to Rondal for its Aero Wing Sail concept after completing a concept-level assessment under the classification society’s 2025 Guidance Notes on Wind Assisted Propulsion Systems, LR said in a news release.
The approval was presented at Metstrade 2025 in Amsterdam. The Aero Wing Sail is a rigid wing-sail intended for large yachts and multihull platforms, designed to deliver wind-assisted propulsion while allowing integration within existing vessel layouts.
According to the announcement, the AiP confirms that safety, structural, mechanical and aerodynamic aspects of the concept have been reviewed. The evaluation covered Computational Fluid Dynamics analysis, structural design review and mechanical system assessment to identify operational and integration-related risks. LR also made recommendations for further refinement.
Tom Wolodarsky, Senior Surveyor and Lead Specialist WASP at LR, said: “This Approval in Principle reflects Lloyd’s Register’s commitment to enabling innovative technologies that support decarbonisation and operational efficiency. Wind-assisted propulsion is a vital step toward reducing emissions, and we are proud to collaborate with Rondal in bringing this solution closer to market readiness.”
Hermen de Jong, Innovation Manager at Rondal, said: “This Approval in Principle is an important achievement for Rondal. It demonstrates the maturity of the Aero Wing Sail and that we are ready for application in new yacht projects.”
LR noted that the AiP aligns with its broader work on the safe and scalable adoption of wind-assisted propulsion technologies. The classification society referenced its report Applying wind-assisted propulsion to ships, part of the LR Retrofit Research Programme.
Lloyd’s Register is an international classification society and engineering services organisation that provides technical standards, compliance services and risk management support for the maritime sector and other industries. It operates as an independent entity overseen by the Lloyd’s Register Foundation, a charitable body that funds research and safety initiatives.
Rondal is a Netherlands-based manufacturer operating as a specialist supplier to the superyacht and multihull sectors. The company designs and produces high-performance composite structures, rigging solutions and related mechanical systems for large yacht applications, working with shipyards and naval architects on custom and series-build projects.
