Saint-Nazaire Offshore wind farm
Saint-Nazaire Offshore Wind Farm
For the Saint-Nazaire Offshore Wind Farm project, the Type 183 heavy lift vessel MV Svenja was deployed to transport a total of 80 monopiles and 80 transition pieces. The transition pieces reached weights of up to approximately 496 metric tons and exceeded 30 metres in height, while the monopiles weighed up to around 979 metric tons. The transport route ran from the port of loading in Rotterdam, the Netherlands, to the port of discharge in La Rochelle, France. In total, 20 voyages were carried out, each combining four monopiles and four transition pieces per shipment. Due to the significant height of the transition pieces, a customised lifting and guidance system was developed, based on a detailed step-by-step analysis of the entire lifting path. As a result, the project required not only a suitable heavy-lift vessel but also a tailored engineering approach to ensure the safe and efficient handling of the oversized components.
Project Context & Significance
With several thousand kilometres of coastline along the North Sea, the English Channel, the Atlantic and the Mediterranean, France is among the world’s most promising growth markets for offshore wind energy. The Saint-Nazaire Offshore Wind Farm represents one of the country’s first major offshore installations and an important milestone in the French energy transition. SAL Heavy Lift supported DEME Offshore with the transport of the foundation structures, continuing a long-standing partnership that has already proven successful on previous large-scale offshore wind projects. Immediately after completing the Hornsea 2 monopile campaign, MV Svenja was redeployed to Eemshaven and mobilised for this next assignment – further demonstrating SAL’s operational continuity and expertise in the offshore wind sector.
Engineering Approach & Vessel Capabilities
The scope of work involved transporting monopiles of up to 62 metres in length and 979 tons in weight, alongside 30-metre-high transition pieces weighing up to 496 tons. One decisive factor in the project award was SAL’s ability to ship four monopiles and four transition pieces simultaneously. Detailed feasibility studies confirmed that MV Svenja could meet the operational and stability requirements, while also offering the transit speed needed to maintain full scheduling flexibility for the client.
A comprehensive lifting and securing concept was developed, including bespoke bumpers and guide systems adapted to the height of the transition pieces. All TPs were loaded without the use of the vessel’s stability pontoon. Existing seafastening grillages were structurally reassessed and modified to match the new cargo dimension envelope, with engineering calculations based on defined weather limits and open-hatch transport conditions. The result was a fully documented, technically robust solution aligned with DEME Offshore’s requirements.
Project Execution & Client Feedback
MV Svenja commenced the first voyage in February 2021 and completed the final shipment in October 2021. The successful execution of all 20 voyages further strengthened SAL Heavy Lift’s position in the offshore wind supply chain – a market that continues to grow rapidly and in which SAL is strategically committed to long-term participation.