Foundation installation under way at Saint-Brieuc offshore France

May 3, 2021
Van Oord’s upgraded jackup vessel Aeolus has started installing the first of 62 jacket foundations for the Saint-Brieuc offshore wind farm.

Offshore staff

ROTTERDAM, the Netherlands Van Oord’s upgraded jackup vessel Aeolus has started installing the first of 62 jacket foundations for the Saint-Brieuc offshore wind farm in France.

Iberdrola’s 496-MW wind farm is 16.3 km (10.1 mi) off the coast of Brittany in the Bay of Saint-Brieuc.

Van Oord is responsible for the transport and installation of 62 jacket foundations for the wind turbines (three pin piles each) and the four foundation pin piles for the offshore substation. A total of 190 pin piles will be installed.

The Aeolus was put into service in 2014. The main crane has a lifting capacity of more than 1,600 metric tons (1,764 tons). Its four-legged jacking system allows the vessel to be jacked up and to work in waters of up to 45 m (148 ft) deep.

Due to the geotechnical circumstances in the Bay of Saint-Brieuc, harsh weather conditions combined with extremely strong currents, heavy Atlantic swell and high waves, offshore operations are possible only between March and October, the company said.

To ensure that the Aeolus can be safely jacked up above sea level the lifting spuds were modified with a flex-pin construction. For drilling, new hydraulic drills were engineered and built to handle all types of soil and rock conditions. A newly designed and created drilling template will function as a positioning and holding-tool to ensure the precise placement of the pin piles.

The company said it will also deploy several other vessels on the project in the next months for the removal of boulders, installation of scour protection, transport of pin piles, etc. The installation campaign for the pin piles will be executed in 2021 and 2022. The jackets will be installed in 2022.

Van Oord will use the port of Cherbourg as the pin pile marshalling port. The pin piles, coming from Spain, will be stored in France before installation offshore.

05/03/2021