Drilling operations are now underway at Rattray Head, near Peterhead, marking a major construction milestone for SSEN Transmission's Spittal to Peterhead High Voltage Direct Current (HVDC) project.
The works, which began this month, represent the start of one of the most technically complex elements of the project, with specialist contractors carrying out Horizontal Directional Drilling (HDD) beneath the coastline to create the vital connection between onshore and offshore infrastructure.
The Rattray Head landfall HDD is expected to be one of the longest forward-drilled landfall HDD operations for power cables ever carried out, extending approximately 1.7 kilometres from the onshore landfall compound to the offshore exit point in the seabed.
Once complete, four HDD ducts will be installed beneath the coastline and nearshore environment. Three ducts will house cables required for operation of the HVDC link, while a fourth spare duct will provide additional resilience for the future.
The installation is a key component of the Spittal to Peterhead HVDC subsea link, which will help transport renewable electricity generated in the north of Scotland to homes and businesses across the country. The project forms part of a wider programme of network investment designed to support energy security and the transition to a cleaner, more resilient electricity system.
The drilling rig (in the centre) will be used to create a 1.7km long forward-drill from the landfall point in Rattray Head to the offshore exit point in the seabed.
By using HDD technology, the cables can be installed deep beneath the coastline and nearshore waters, significantly reducing surface disruption and helping to minimise impacts on local communities and environmentally sensitive coastal habitats.
Niall Macleod, Project Director for SSEN Transmission's Spittal to Peterhead HVDC subsea link, said: "The start of drilling at Rattray Head represents a significant milestone for the project. This technically complex installation will create the essential link between our onshore and offshore infrastructure, helping deliver a major reinforcement of the UK's electricity transmission network.
"Horizontal Directional Drilling allows us to install critical infrastructure beneath the coastline while minimising impacts on the surrounding environment and local communities. Reaching this milestone is testament to the extensive planning and collaboration that has gone into preparing for the execution of these works."
The specialist HDD operation will be carried out by cable supplier NKT and their sub-contractor LMR who provide specialist engineering knowledge, drilling equipment and techniques, with the works expected to take place over the next 12 months.
Once complete, the Spittal to Peterhead HVDC subsea link will play an important role in increasing the capacity of the electricity transmission network, enabling greater volumes of renewable energy to be transported to areas of demand across Great Britain.