The construction of the 480MW Saint-Nazaire offshore wind farm, located off the Guérande Peninsula, marked a significant milestone for the French renewable energy sector. As the country's first large-scale offshore wind project, it presented unique engineering challenges—most notably the installation of 80 XL monopile foundations into a predominantly hard, rocky seabed.
Innovative installation methods
Unlike traditional projects where piles can be driven directly into the seabed, the geological conditions at Saint-Nazaire required a different approach. The density of the rock meant that most foundations had to be drilled into position, making it the first wind farm globally to utilize this specific installation method at such a scale. To manage this, IQIP provided a suite of specialized equipment designed to withstand the harsh Atlantic conditions and marine swell.
Technical solutions on site
To ensure precision and safety, several key tools were deployed:
- S-4000 Hydrohammer:Equipped with a 6.5-meter sleeve, this powerful hammer was essential for the driving phases of the operation.
- Pile Upending Tool:This tool was used to lift and position the piles vertically. By gripping the pile from the inside, it maintained the integrity of the structure while ensuring exact placement.
- Launch and Recovery Systems (LARS):IQIP supplied four LARS winches to facilitate the safe overboarding of the drilling template, even in turbulent waters.
- Modified Guiding Tools:A custom guiding tool was adapted to handle the unique weight and shape of the drilling template.
Integrated expertise for 80 foundations
Beyond the hardware, the project relied on a dedicated team of multi-skilled technicians. By sourcing a complete package of equipment and personnel from a single provider, the project benefited from streamlined workflows and optimized offshore manning. This integrated approach reduced logistical complexity and legal overhead, ensuring that the installation of all 80 foundations was successfully completed in May 2022.
