Refurbishment of 1960s transmission line complete

12th November 2015

Scottish Hydro Electric Transmission (SHE Transmission) has completed its £94m project to refurbish the 275 kilovolt (kV) overhead line on the main west to east transmission route from Beauly via Blackhillock to Kintore.

The 157km line was originally constructed in the early 1960s, spans the three local authority areas of Highland, Moray and Aberdeenshire, and is supported on 476 towers. With more renewable power generation planned for the Highland area through developers seeking connection to the transmission network in the north of Scotland, the completion of this project has allowed for an 85% increase in the capacity of the overhead line route.

Restringing and refurbishment of the line began in 2010 and at the peak of its activity was employing a workforce of 82 - some who worked on the project for its duration - to ensure the work was carried out safely, on time and to budget.

Certain elements of the work demanded robust engineering solutions, as SHE Transmission Project Manager Simon Robertson explains: In a number of locations it was necessary to temporarily divert the circuits away from the overhead line route onto new towers in order for the works to be carried out safely, all the while maintaining the transfer of power on the system. On completion of the works the line was returned to the original towers.

During the five year works the Knocknagael substation was commissioned onto the grid and connection to two wind farms were made - Berryburn in 2013 and Clashindarroch the following year - allowing for more renewable energy from these regions to be transmitted to the grid, building the strength of the network and supplies across the north of Scotland.

Simon continues: This has been a highly challenging project - from ensuring that the security of the transmission network was unaffected for the duration of the works, through the difficulties of working in the rugged terrain and all the while ensuring that disruption to the residents, the wildlife and the environment was kept to a minimum. Along the way we even came across the remains of a medieval farm building at Leylodge in Kintore, which allowed archaeologist to explore the site and log details of this areas heritage that may otherwise have lain undiscovered.

I'd also like to thank the people who live and work in the vicinity of this project, as their patience and understanding has enabled us to work safely and has given us the opportunity to use local workers and businesses wherever possible, which we hope will have long-term benefits to the area.