Liebherr crane plays key role in France’s first floating wind farm
Liebherr LR 11350 crawler crane played a crucial role in the construction of Provence Grand Large, France’s first floating offshore wind farm. The crane was used to install three 8.4 MW wind turbines onto floating platforms, which were then towed to their final location 17 kilometres offshore.
The unit was deployed to the Port-Saint-Louis-du-Rhône, just shy of 50 kilometres northwest of Marseille, in the Provence-Alpes-Côte d’Azur region. In the spring and summer of 2023, Siemens Gamesa Renewable Energy joined forces with energy providers EDF Renouvables and Enbridge to establish the first floating wind farm in the Mediterranean Sea. This saw three 8.4 MW wind turbines positioned on special floating foundations. They were then towed by tugboats out to the high seas some 17 kilometres from the shores of Port-Saint-Louis-du-Rhône, where they were fixed to the sea bed using anchor ropes for a relatively low impact.
The operators, together with the scientists and ecologists involved in the project, are anticipating that this approach will deliver important findings for the future of offshore wind energy generation that is even more efficient while also being kind to marine life and seabirds.
Right crane for the operation
On Gloria Quay in Port-Saint-Louis-du-Rhône, the LR 11350 crane extended its 168-meter-long lattice boom skyward. Equipped with a PowerBoom for this operation, its dual design allows the lattice boom to extend an additional 80 meters in parallel from the lower section. This enhancement increases the crane’s load capacity by nearly 50 per cent. The LR 11350 boasts a maximum load-bearing capacity of 1,350 tonnes and is primarily designed for loading heavy cargo in ports or for industrial applications.
The LR 11350 was dismantled into individual parts and transported directly to France from the Liebherr plant in Ehingen, Germany, using over 90 articulated lorries. Additionally, another 45 HGVs delivered extra equipment. Awaiting the crane’s arrival in the port—stabilized with specialist pads and reinforced with extra steel plates—were 15 experts from Schmidbauer’s large cranes team. Accompanied by up to four Liebherr engineers, the team took one and a half months to assemble the crawler crane for the first time.
Following load testing, the unit was straight into action lifting heavy components onto a floating platform. However, much to the disappointment of the project managers from Siemens Gamesa Renewable Energy, it was often necessary to put the crane on Gloria Quay completely into idle mode for several hours or even days at a time.
That’s because the mistral blows through the region every few weeks. The famous Rhône Valley wind often sweeps out to the Mediterranean at speeds well in excess of 100 kilometres per hour.
The offshore research field
Floating wind farms create opportunities in new regions of the open ocean. Only a limited portion of the world’s seas is shallow enough—less than 60 meters deep—for traditional offshore wind turbines that are secured to the seabed using monopiles. However, floating wind turbines can now function in areas with water depths of up to 300 meters, as they are tethered to the seabed with steel cables. This development makes them a practical option for harnessing wind energy in offshore areas globally that were previously considered unsuitable.
In addition to examining the advantages of the Provence Grand Large pilot project’s location, Liebherr’s scientific partners are also exploring the ecological and marine biological factors related to expanding offshore wind energy. This research includes an ornithological radar to monitor the flight patterns of migratory and seabirds. A radar station was set up on the Napoléon beach in Port-Saint-Louis-du-Rhône and another on one of the floating platforms. This study will, for the first time, determine whether offshore wind farms affect the natural migration routes of birds, and if so, how.
