Jan De Nul’s heavy lift vessel Les Alizés has completed installation of all 54 monopile foundations at the 1,080-MW Inch Cape offshore wind farm in the North Sea, 15 km off the Angus coast in Scotland, according to the contractor’s 10 June statement.
The campaign began in December 2025 and was completed over the following six months. Les Alizés operated from the Port of Leith in Edinburgh, carrying five monopiles per voyage to the offshore site.
The foundations will support 15-MW Vestas turbines, making Inch Cape the first offshore wind farm in the UK to use the model.
The largest monopiles installed on the project were up to 101 metres long and weighed around 2,300 tonnes.
Jan De Nul said they were the largest and heaviest monopiles it had installed and among the largest used for an offshore wind farm.
“The largest monopile was 101 metres in length, the length of a football pitch, and weighing up to 2,300 tonnes. To put that into perspective, the largest monopile we installed on a previous project was 88 metres long and weighed 1,500 tonnes,” offshore construction manager Philippe Mols said.
Inch Cape is being developed by ESB and Red Rock Renewables as a 50/50 joint venture. The project is expected to produce enough electricity for half of Scottish homes and cut carbon emissions by 2.5m tonnes a year.
Les Alizés is on long-term charter to RWE, which leased the vessel to Inch Cape between its own construction projects.
Jan De Nul is a Belgium-based maritime and offshore construction group providing dredging, offshore energy, civil engineering and environmental services.
ESB is a statutory electricity company established in Ireland, with activities in electricity generation, networks, supply and energy services.