Iberdrola-owned company Ailes Marines says Van Oord has installed the first foundation at the Saint-Brieuc offshore wind farm off France.
Installation took places in three stages, the developer said.
The jacket foundation was lifted from its barge and then lowered by crane into its location.
The points of the three legs of the trellis were inserted inside the three piles previously installed on the seabed.
The sealing of the lower parts of the legs to the piles will soon be carried out by the North Sea Giant vessel.
Installation work of the second foundation, also positioned on the northern part of the park, has now started, Ailes Marines said.
Each jacket foundation weighs 1150 tonnes, is 75 metres high and 25 metres square and will be fixed to the seabed by three 18-47-metre long piles, previously installed by the Aeolus.
The developer added that at the same time as foundation installation operations, Van Oord is continuing drilling and anchoring work for the piles of the remaining foundations with the Aeolus vessel.
To date, more than a quarter of the wind farm foundation positions have been drilled and equipped with piles. All of this work will continue until 2023.