The €2bn project, to transfer Norway’s zero carbon hydro energy to the UK, has now passed the halfway stage.
North Sea Link, a cable connecting the UK and Norwegian electricity grids, is a joint venture project between the UK’s National Grid and Norwegian system operator Statnett.
For part of the job, through a Norwegian lake, regular cable laying vessels were too big and so material had to be transported piece by piece to build a custom-made floating platform. This operation in Suldalsvatnet marks the start of the cable laying on the Norwegian side.
Working at depths of up to 210 metres, the laying of the 2.8km parallel subsea cables was executed from a 43-metre x 15-metre platform.
The equipment required to lay the cable was then installed on the platform, and within 12 hours, 150 tonnes of cable was loaded on board. The platform held all the necessary equipment that is usually found on offshore cable laying vessels.
Construction director Nigel Williams said: “The engineering that has taken place to lay high-voltage cables below the seabed is remarkable. The difficult terrain, the depth of the waters, and all in amidst of operating during a pandemic has made it extremely challenging. Nevertheless, we have powered through and remained on track with our project timelines.”
The next milestone is to lay the cable out from the fjords in Suldal to the North Sea. This work will be carried out throughout the remainder of the year, and by 2021 the two parallel 720km cables between Cambois in Northumberland and Kvilldal in Norway will have been completed to make North Sea Link the longest subsea power cable interconnector in the world.