SSEN Transmission and its contractors, Balfour Beatty and Siemens-BAM, recently celebrated the end of 14 months of hard work as they successfully completed and energised two new 132kV Gas Insulted Switchgear (GIS) Bays, and new underground cable circuits in Moray.
The £17.4M Keith, Macduff & Blackhillock reinforcement project included the construction of a new cable sealing end tower platform and the laying of 3.5km of underground cable into the existing Blackhillock substation. Now complete it forms an important reinforcement of the network in the area and will help to facilitate the connection of up to 150MW of new renewable generation to the grid; supporting Scotland’s and the UK’s transition to net zero emissions.
Along the way, the project has overcome many challenges in its delivery, none more so than when the underground cable route reached the A96 trunk road. Underground cables are installed primarily using an open cut trench method, where a digger will excavate a trench then cables are laid, with the trench then back filled. Doing this across the A96, one of the busiest roads in the North East, would have meant a full road closure and that simply wasn’t an option, so the team needed to find a way around this.
They did this by bringing in special tools for the job - two Horizontal Directional Drilling (HDD) Rigs. The HDD allowed the team to “tunnel” under the road for 350m, going as deep as 18m at its deepest point, so that the ducting and cable could be pulled through the small tunnels and under the road. This allowed the road to remain open throughout, keeping the traffic and the local community moving.
The reinforcement project also required upgrades at all three of the substations in the area, including an extension of the existing GIS by adding another two GIS bays inside Blackhillock substation, and remote end works at both Macduff & Keith substations.
Project Manager, Alistair McDonald said: “It’s been a fantastic project to be involved in, knowing the work myself and the team were undertaking is helping to reinforce the Transmission network today to allow more renewable generation to connect to the network in the future, playing a key role in the transition to net zero emissions.”
“The project did have its challenges to overcome but the success of completing the project ahead of time, during a very difficult period, was down to the commitment, determination and positive attitude of the project team and our contractor partners, pulling together to achieve a job well done.”
Over the coming decade SSEN Transmission plan to undertake substantial efforts to maintain, reinforce and improve the transmission network in the North East and East Coast of Scotland as it builds a network for net zero emissions. To find out more about SSEN Transmission’s East Coast reinforcement plans check out the project page here.