Italy sets record for world’s deepest subsea cable

Nexans has successfully completed the high-voltage subsea cable installation on the Tyrrhenian Link project in Italy, confirming a world-record installation depth of 2,150m for a 500kV high-voltage direct current (HVDC) subsea cable.

The world record was achieved during an offshore installation campaign in December 2025, as part of Nexans’ works for Terna, the Italian Transmission System Operator.

The Tyrrhenian Link is a strategic 500kV HVDC interconnection designed to strengthen Italy’s national transmission grid.

The offshore execution milestone was finalised with the successful completion of the second pull-in operation on 1 January 2026, establishing the physical connection between the cable landing points in Terra Mala (Sardinia) and Fiumetorto (Sicily).

This operation marks the completion of all high-voltage subsea cable laying activities on the project.

The western section of the Tyrrhenian Link, which falls within Nexans’ scope of work, comprises approximately 480km of deep-water subsea cable, installed over two offshore campaigns of around 200km and 280km respectively.

The Tyrrhenian Link as a whole consists of two 500kV HVDC subsea connections, each approximately 970km in length, with a total transmission capacity of 1,000MW.

“Setting a world record at 2,150m and completing the high-voltage subsea cable installation phase of the Tyrrhenian Link are defining achievements for Nexans,” said Pascal Radue, Executive Vice President, PWR-Transmission at Nexans.

“Installing a 500kV HVDC cable at such depths requires exceptional precision and discipline across engineering, manufacturing, route preparation and vessel operations.

“These milestones reflect the strength of our technology, the performance of the Nexans Aurora, and the expertise of our teams throughout the project.

“The Tyrrhenian Link has reached a depth of 2,150m, setting a world record for a submarine power cable,” said Giuseppina Di Foggia, Chief Executive Officer and General Manager, Terna.

“This milestone demonstrates Terna’s ability to manage highly complex technological challenges and deliver infrastructure that strengthens the stability, security and adequacy of Italy’s electricity system.