The horizontal directional drilling (HDD) works at Dounreay, Caithness have been completed. This is part of the subsea link works which will take renewable energy generated in Orkney to the Scottish Mainland and down into the UK Grid.

The HDD works for the SSEN Transmission project involved drilling and installing an 830-metre underground duct from the landfall area at Dounreay to a location beneath the seabed offshore. The duct has been designed to allow the future subsea electricity cable to be pulled ashore without the need for significant disturbance to the coastal environment.

Completion of the works means that both HDD sections at either end of the future cable route are now in place, following the successful completion of similar works at Warebeth in Orkney last year which were around 1,200m long.

Environmental specialists worked closely with the project team throughout the construction programme, helping to ensure the works could be delivered safely while minimising impacts on sensitive marine and terrestrial environments.

The project also employed innovative construction techniques, including the use of remote-operated excavators to undertake the final subsea section of drilling. This approach enhanced safety for marine construction teams while demonstrating the innovative engineering solutions being used to deliver major electricity infrastructure projects.

Ian Clark, Project Director for the Orkney Link Project at SSEN Transmission, said:

“The completion of horizontal directional drilling at Dounreay represents a huge milestone for the Orkney Link Project and is a testament to the expertise, collaboration and innovation demonstrated by everyone involved.

“This was one of the most complex construction activities on the project and required careful planning to ensure it could be delivered safely while protecting the surrounding environment.

“With both landfall HDD sections now complete, we’re another significant step closer to connecting Orkney to the national electricity transmission network, unlocking renewable energy potential and supporting our transition to a cleaner, more secure energy system  for our customers in Orkney.”

The works were delivered by Principal Contractor RJ McLeod, supported by specialist subcontractors OCU Group, Lucion, Kirkwall-based Leask Marine, and HDD specialists Peter McCormack & Sons.

The Orkney Link Project forms part of SSEN Transmission’s programme of network investment to reinforce the electricity transmission system across the north of Scotland and enable the connection of renewable generation needed to support Scotland and the UK’s net zero ambitions.