The wind farm, located 11 kilometres from the island of Yeu and 16 kilometres from the island of Noirmoutier, is the fifth offshore wind farm to be commissioned in France by 2025, requiring an investment of more than 2.5 billion euros. With a generating capacity of 496 MW, it will be able to supply more than 800,000 homes with renewable energy, equivalent to the entire population of the Vendée. The wind farm represents a major step forward in France's efforts to increase its renewable energy generation capacity and thus reduce its dependence on fossil fuels.
Specialists in heavy lifting, engineered transport and crane rental services, Sarens, is working with DEME Offshore in the port of La Rochelle on the load-in, onshore storage and load-out of 61 monopiles with maximum weights of 1200 tons and 62 metres in length, and 61 transition pieces of up to 400 tons and 35 metres high.
To carry out this operation, the Sarens engineering team commissioned Charier, a local groundworks company, to prepare seven pairs of dunes for the storage of the monopiles. In order to handle these pieces, weighing around 1200 tons, the company has deployed 45 axle lines of Kamag K24 SPMTs (Self-Propelled Modular Trailers) to the site. The monopiles are arriving at the quayside via marine shipments from China with the Boskalis Blue and Black Marvin vessels, and are stored onshore via 24/7 load-ins over link spans with the SPMTs.
The transition pieces, meanwhile, have been arriving at the port in 16 shipments with the UHL Fresh vessel from Vlissingnen in the Netherlands, to be lifted onto the quayside and picked up for storage using a total of 24 axle lines Cometto SPMTs with a TP Handler. Over 100 units of 500 mm elephant feet (stools) have specifically been created for the storage of the transition pieces.
The Sarens TP Handler has proved to be a crucial tool for this work, as the transition pieces to be moved have a higher height to diameter ratio than usual, making logistical tasks more complicated and sensitive. Therefore, the Sarens engineering team, after a thorough preliminary study, must ensure at all times that the maximum speed, the inclination and even the wind during the movements are significantly lower than usual.
“Our company has a great deal of experience acquired in similar projects” said Abderahim Bouazza, Project Manager at Sarens. “In fact, we already knew the La Rochelle port facilities very well from our involvement in the Saint-Nazaire wind farm, so it was easier to adapt to it and anticipate our client's needs in terms of machinery, thus reducing downtime to practically zero. We thank DEME Offshore for their confidence in our work, and we look forward to continuing to work with them on strategic projects to help achieve France's environmental goals in terms of greenhouse gas reduction.”
Sarens has extensive international experience in the assembly and maintenance of wind farms. It has participated in various installations in France such as Fécamp, Saint Nazaire, Provence Grand Large and in the lifting and transport work for the foundation bases of the new offshore wind farm in Saint Brieuc, located off the Brittany coast.
During this project, Sarens successfully transported loads weighing over 1150 tons. More recently, Sarens has been actively involved in the reception and loading operations of monopiles and transition pieces for 176 turbines for the Coastal Virginia Offshore wind farm in the US and the marshalling and installation of 62 monopiles in the Moray West offshore wind farm, each weighing up to 2000 tons, the largest and heaviest XXL monopiles ever to be handled in the UK.
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