ClassNK has issued an Approval in Principle to OceanWings for two wingsail configurations, the Rigid Fixed (RF) and the Rigid Tiltable (RT), the classification society and the developer announced in a report published on 4 September 2026. The approval was presented during an official ceremony at SMM in Hamburg on 2 September 2026 and, according to the report, confirms the technology’s scalability across a broad range of vessel sizes and shipping segments.
The AiP covers both OceanWings designs by name, identifying the RF and RT wingsails as the subjects of the classification assessment. The report supplied to this paper states that ClassNK’s approval expands the formal recognition of OceanWings’ concept beyond earlier assessments, signalling regulatory acceptance of the two specific configurations.
What the approval covers
ClassNK’s Approval in Principle applies explicitly to OceanWings’ Rigid Fixed and Rigid Tiltable wingsail designs, the report says, and was conferred in a formal presentation at SMM in Hamburg on 2 September 2026. The company and class society framed the decision as an expansion of the scope of prior approvals, and the published account records that the certificate confirms the two designs’ suitability for further development and verification.
The designation RF is given to the Rigid Fixed wingsail and RT to the Rigid Tiltable wingsail in the material provided, ensuring clarity about which configurations received the AiP. No technical specifications or vessel lists accompanied the published summary, which focuses on the formal outcome of the class assessment and the ceremony at SMM.
Industry implications noted in the announcement
The report underlines that the AiP “confirms the scalability” of the OceanWings systems across a wide range of vessel sizes and shipping segments, a formulation supplied in the original account. The statement in the published item frames the approval as an enabling step for OceanWings to pursue demonstration and further design integration with different types of merchant tonnage.
The published account does not set out a schedule for installations, retrofits or test programmes, nor does it include direct quotations or technical drawings. It records the formal conferment of the AiP at SMM on 2 September 2026 and the subsequent publication of the news item on 4 September 2026 by reports.
OceanWings and ClassNK are identified as the parties to the announcement in the source material supplied to this paper, which describes the event as an official ceremony at the Hamburg trade gathering. The report presents the AiP as an expanded endorsement of the two wingsail variants, but it does not specify particular shipowners, ship types or the next steps in certification beyond the AiP itself.
The announcement represents a formal milestone reported on 4 September 2026, but the published material limits its scope to the AiP outcome, the two designs named and the presentation at SMM on 2 September 2026. Observers will look for subsequent technical approvals, installation notices or sea trials to establish how the wingsail concepts are applied in practice, none of which were detailed in the account provided to this paper.
In sum, the ClassNK Approval in Principle for OceanWings’ RF and RT wingsail designs was publicly presented at SMM in Hamburg on 2 September 2026 and reported two days later; the published summary frames the decision as an extension of formal recognition that confirms the designs’ scalability across vessel sizes and shipping segments. The article of 4 September 2026 in reports supplied these facts and serves as the basis for this report.