Photo: NKT

In April 2025, one of the two export cables owned by Beatrice Transmission Capital Partners (TCP), which brings renewable electricity to around 450,000 British households, suffered an unplanned transmission outage that reduced the region’s export capacity by 50%.

The cable, which was not manufactured by NKT, was repaired using NKT’s ARSJ (Adaptive Rigid Submarine Joint) system. The key to a fast turnkey repair was the use of two such joints, which were available from NKT’s stock within a few days.

Manufacturer-independent solution

These joints are designed to work with most 110–300 kV high-voltage AC cables regardless of manufacturer, making them suitable for emergency repairs where compatible spare parts are not available or cannot be used.

“The ability to supply adaptable rigid subsea connectors off the shelf was critical to a quick repair, which allowed us to use NKT’s repair services for this asset and accelerate the repair programme ahead of other available options,” said Bruce Turner, asset manager at Transmission Capital Partners. Transmission Capital Partners is the owner of the submarine transmission system responsible for the operation and maintenance of the export cable infrastructure.

Cable repair vessel available quickly

The repair was carried out using NKT’s cable handling system, which converts conventional construction vessels into fully equipped cable repair vessels.

In this case, the system was deployed on Ocean Installer’s vessel North Sea Giant. In just six days, North Sea Giant was mobilised in Eemshaven and then loaded with the customer’s spare cable.

“It was a privilege to be part of the project team that managed to carry out such a complex repair in an exceptionally short time and complete the work several months earlier than alternative deployable repair solutions, significantly minimising downtime and reducing energy and revenue losses,” said Alanna Benians, Beatrice General Manager at SSE Renewables, operator of the offshore wind farm and one of the owners of Beatrice Offshore Windfarm Ltd.

The cable was reconnected at the end of July, just 38 days after the contract was signed, restoring the transmission grid to full export capacity.