Baltic Cable Repair

• Turnkey repair operation, including mobilization/demobilization
• Assisted the client with pinpointing the fault location, deburial of the cable and cut-and-seal operations
• Project management and repair planning
• Loading and installation of spare cable and jointing
• Offshore operation with own vessel NKT Victoria

The Baltic Cable HVDC (high-voltage direct-current) link relies on a 250-km-long submarine cable. Running between the cities of Lübeck (GER) and Trelleborg (SWE), it has been connecting the power grids of Germany and Sweden since 1994. It makes it possible to pool electrical resources in both countries and thereby complement and optimize existing capacities in both grids. It enables a more efficient use of the existing power plants on both sides of the sea.

NKT was informed by the owner and operator Baltic Cable AB that a cable section had been damaged. Baltic Cable AB handed over the fault localization, de-burial and cut-and-seal operation as well as the repair operation to NKT, who had previously brought the cable back into operation after it had been damaged in 2018.

Spare cable could immediately be retrieved from the customer's warehouse in Karlshamn (SWE). This was essential for a quick repair operation, as lead times for producing new spare parts are often too long and would have significantly extended the time required to restore the link.

The project was performed in an extremely efficient way. As soon as NKT had been informed about the damage by Baltic Cable AB, NKT staff and equipment were quickly made available for the initial operation. After the fault location had been detected, NKT staff deburied the cable and carried out the cut-and-seal operation aboard a subcontracted vessel provided by JD Contractor. Within five days, this initial operation was completed and the cable was prepared for the repair. After efficient preparations, the final repair operation was completed on our vessel NKT Victoria, and within just 29 days the Baltic Cable was back in operation.

By bringing the Baltic Cable back into operation in less than a month, we once again showcased our speed in offshore repairs. In addition to the short resource mobilization time and the availability of our own repair vessel NKT Victoria, our ability to efficiently cooperate with customers and subcontractors contributed to a quick repair.

Operational success was ensured through efficient execution by all parties involved, minimizing the outage time and bringing the important interconnector back into operation. The operations also showed the importance of having a pre-negotiated repair contract and a sufficient and updated stock of spare cable parts in place to ensure quick mobilization and execution.