One of the two subsea cables which links Orkney to mainland Scotland, connecting up electricity distribution, has been successfully replaced by SSEN (Scottish and Southern Electricity Networks).

Teams from SSEN connected the new 37km subsea cable to the main electricity network on Thursday 5 November. This will hopefully ensure a robust and reliable supply of electricity to homes and businesses across the isles.

The £30 million cable replacement project involved significant offshore works using specialist marine vessels – the Normand Clipper and Global Symphony – working with principal contractor, Global Offshore, to successfully install and bury the 33 kilovolt (kV) cable between Murkle Bay, near Thurso and Rackwick Bay on the island of Hoy. 

Working in partnership with Aviemore-based McGowan Environmental Engineering Ltd, the installation of the new subsea cable also allowed for the removal of approximately 7km of existing overhead power lines in Rackwick, Hoy, which have now been replaced by underground cable. The existing overhead line will be dismantled in the coming weeks.

Local firms Pentland Ferries and storage and distribution specialists McAdie and Reeve played a key role in the successful delivery of the land cable works, with a bulk cargo vessel chartered to deliver 5,000 tonnes of high specification sand to Lyness harbour, and almost 30 large items of equipment and vehicles shipped from Gills Bay to Lyness under specialist charter on Pentland Ferries’ MV Pentalina.

Mark Rough, Director of Customer Operations at SSEN, said:

“The Pentland Firth East project is one of the biggest standalone projects we’ve completed in the north of Scotland and we’d like to thank our contract partners, archaeological and ecological experts, engineering teams and local suppliers for their professionalism and dedication to ensure the successful delivery of the subsea cable installation and land-based works on Hoy.

“Ensuring a safe, secure and reliable supply of electricity to our customers is our main priority at SSEN. We’d like to take this opportunity to thank the local community for their ongoing support as we worked to deliver this significant investment which will strengthen resilience of supplies to the Orkney Islands for years to come.”

Local politicians have understandably all welcomed the successful completion of the project.

James Stockan, Leader of Orkney Islands Council, said:

“The new cable will secure Orkney’s electricity supply well into the future and I am delighted this crucially important work has been completed successfully. 

“In addition, I am pleased that the onshore work at Rackwick and beyond had been carried out to a very high standard in an area renowned for its wildlife and natural beauty – a challenging task undertaken with great skill and sensitivity.”

Orkney’s Constituency MSP, Liam McArthur, commented:

“I’m pleased to hear that work to replace the Pentland Firth East cable has now been completed. 

“Last year’s cable fault resulted in serious disruption at the time and highlighted the need for a more long term solution.

“On that basis, the newly installed subsea cable should give greater confidence to households and businesses in Orkney. I’m grateful to SSEN and their partners and suppliers for working alongside local stakeholders in Orkney to deliver what has been a substantial project, particularly in the midst of such a challenging year.”

SSEN is undertaking a programme of investment to replace around 90km of submarine cables connecting Scotland’s island communities by 2023 – a fifth of the total number currently in operation.

The Pentland Firth East cable was identified for replacement after routine inspections found it was coming to the end of its operational life. In July 2019, SSEN successfully completed repairs to the cable in Rackwick Bay following a cable fault. While customer power supplies were not impacted by this fault, a long-term solution was required to maintain a safe, secure and reliable power supply to homes and businesses in Orkney