DEME Signs Agreement for Fabrication of a Subsea Drill for XL-Monopiles

February 12, 2020 | Renewables | Energy Facts Staff Writer | 4min

DEME Offshore and Herrenknecht have signed an agreement for the fabrication of a subsea drill to be deployed at the Saint-Nazaire offshore wind farm in France. This is the first wind farm in the world to use drilled XL-monopile foundations.

In 2019, a consortium including DEME Offshore and Eiffage Métal was awarded the EPCI contract for 80 foundations for the French wind farm. The scope includes the design, fabrication, transportation and installation of the steel foundations.

The 480 MW Saint-Nazaire offshore wind farm, owned by EDF Renewables and Enbridge, will be located between 12 km and 20 km off the coast of the Guérande peninsula in western France.

The XL-monopile foundations have to be installed on a difficult rocky seabed. DEME Offshore and Herrenknecht, the global leader in tunnel boring machines, are fabricating an innovative tailormade subsea drill specifically for the project. The subsea drill will be deployed from DEME Offshore’s installation vessel ‘Innovation’.

“Installing drilled XL-monopiles is a new step forward in the offshore wind industry,” says Bart De Poorter, General Manager DEME Offshore. “With this innovative solution, developed in partnership with Herrenknecht, we ensure that the installation is performed safely and efficiently in challenging marine conditions.”

“The Offshore Foundation Drilling (OFD) enables mechanised installation of monopiles, thus providing ecological and economic advantages compared to conventional methods”, says Ulrich Schaffhauser, Member of the Board of Management of Herrenknecht AG. “We are proud, that DEME relies on Herrenknecht’s solution, expertise and know-how in the field of excavation technology. The project teams of DEME and Herrenknecht cooperated very well, now we all are looking forward to project realisation.”