Dutch heavy lifting company Mammoet has completed a major phase in the assembly of next-generation floating offshore wind turbines at Port-la-Nouvelle in France.
The company provided lifting and transport services for the Eoliennes flottantes du Golfe du Lion (EFGL) wind farm, a joint venture between Ocean Winds and Banque des Territoires.
Engineers managed the marshalling and assembly of the three turbines at the port, working in weather conditions where wind speeds can reach 10m/s.
Mammoet joined the project in the planning phase, advising on crane selection and logistics for moving components arriving from the Netherlands and For-sur-Mer.
To reduce the impact of wind delays all turbine components were delivered to the port before assembly began.
A large crawler crane, the CC8800-1, was used for the main lifts, while two 200t mobile cranes assisted to carry out tailing operations.
Mammoet France managing director Yan Billard said: “With jobs like this, you must use a powerful crane with a big outreach capacity, because the foundations are moored next to the quayside.”
The project team reinforced a 40m² area of the quay to withstand loads of up to 30t/m², using layers of wooden mats over gravel to prepare the ground.
Mammoet deployed self-propelled modular transporters (SPMTs) to transfer the turbine parts across the port, from the quayside to dedicated laydown areas and onwards for assembly.
Foundation components for the turbines arrived from For-sur-Mer after a one-day tow, while other parts came from the Netherlands and deliveries started in summer 2024.
The assembly process began with the three tower sections, positioning the bottom section upright near the main crane, then placing the remaining sections, followed by the nacelle, which weighed 380t, and finally, the three blades.
Once assembled, the turbine was towed to another part of the quay for final mechanical and electrical completion.
The process included storing the lower tower sections upright due to internal electrical installations, while the assembly team used cranes to manoeuvre and tail the sections safely.
The strategy of pre-positioning all equipment and turbine components at the site in advance reduced downtime and allowed the project team to maintain schedule despite variable weather conditions.
The use of heavy cranes and tailored ground reinforcement at the port addressed the demands linked with rising turbine sizes and challenging wind conditions.
In March, Mammoet completed the weighing, transport, and loadout of 24 PAU and PAR modules for a major gas development project.
