Inch Cape Monopile Foundation Installation Complete

Inch Cape has now successfully installed all the project’s 54 giant monopiles in the North Sea off the Scottish coast.

Since the first installation in December, Jan De Nul’s heavy lift vessel Les Alizés has been transiting to and from the new purpose-built berth at the Port of Leith in Edinburgh collecting five monopiles per voyage and steadily installing them across the site.

Inch Cape Project Director John Hill said: “The installation of all our monopiles is a huge achievement for the Inch Cape team and confirmation of the project’s momentum as we continue an extremely busy period of offshore construction activity.

“The scale of Inch Cape’s monopiles is leading-edge for the industry and to reach this milestone the project has overcome significant challenges. These are amongst the largest ever monopiles to be installed for an offshore wind farm – they have diameters of 11.5 metres, are up to 102 metres in length and weigh around 2300 tonnes.

“This milestone is the culmination of extraordinary efforts by many contractors including SLPE for the engineering design, monopile suppliers CWHI and Dajin for the fabrication and delivery and Forth Projects for its offloading and marshalling work.”

Les Alizés utilised a 5,000-tonne crane that reaches 160 metres at full height, along with a specially designed IQIP pile lifting tool as well as an IQIP hydraulic impact hammer to drive the monopiles into the seabed.

The installation engineering of these latest generation heavy monopiles in complex ground conditions required extensive analysis to mitigate risks, which was provided by the geotechnical teams at Geowynd and supported by Cathie.

To ensure the protection of marine mammals, mitigations including the use of acoustic deterrent devices and soft start to the piling were put in place, and a noise monitoring programme was also undertaken.

As well as 54 monopiles with transition pieces, Inch Cape will comprise 18 jacket foundations with 54 pin piles to support its 72 Vestas 15MW turbines. A team of around 100 continues to work at the Port of Leith, where all the remaining components are being loaded out for installation after completion works, supported by Global Energy Solutions.

Jan De Nul’s Les Alizés has been on long-term charter to RWE, which leased the vessel to Inch Cape in a period between its own construction projects.

The offshore construction activity to come this year will include the installation of transition pieces and jacket foundations along with the remaining sections of the second export cable, the first array cables and the first turbines. The project is on track for first power in late-2026 and full commercial operations in 2027.

Inch Cape is owned in a 50/50 equal joint venture by ESB and Red Rock Renewables.