Saint-Gotthard road tunnel: Nexans to install Switzerland’s longest high-voltage underground line

SAINT-GOTTHARD ROAD TUNNEL: NEXANS TO INSTALL SWITZERLAND’S LONGEST HIGH-VOLTAGE UNDERGROUND LINE

  

_PRESS RELEASE _ 

• Nexans, in partnership with Swissgrid, will install a high-voltage line in a road tunnel, a pioneering project in Europe.
• Works will begin in 2028 and be completed in 2030.

Paris, May 14, 2025 – Nexans, in partnership with Swissgrid, Switzerland’s national grid operator, will install a high-voltage line in the Saint-Gotthard Road tunnel.

The Saint-Gotthard Road tunnel’s second tube will feature a first: by 2030, it will house an 18 km long high-voltage line, which will replace the existing overhead line across the pass. This new connection will play a critical role in electricity transmission along Switzerland’s north–south corridor.

The 220 kV high-voltage line is a pioneering project. It marks a first of major significance in Europe: using a road tunnel for cable installation. On behalf of the federal government, Swissgrid evaluates every grid project to determine whether synergies with other infrastructure—such as rail or road tunnels—can be leveraged. Combining infrastructures often contributes to landscape preservation and more efficient land use. Nexans will supply a total of 57 km of extra-high voltage cable for this operation, working with its bases in Charleroi (Belgium), which will manufacture the cable, and in Cortaillod (Switzerland), which will handle the project engineering and installation as well as supply accessories. The preparatory phase is set to unfold from 2025 to 2028, and works are due to start in 2028 and be completed in 2030.

Nexans relied on a longstanding partnership with Swissgrid, as well as the success of several previous projects. This experience has enabled the company to acquire in-depth knowledge of the Swiss market, along with a reputation for excellence in reliability and installation solutions. Valued at approximately €50 million, this project represents the largest contract ever signed by Nexans Switzerland, making it a historic milestone for the company.

Marco Spinelli, CEO PWR-Grid Central Europe at Nexans, remarks, “This project illustrates our aim to remain a top-tier partner for Swissgrid, leveraging our ability to devise novel and dependable cable-laying solutions in complex environments. It also reflects our commitment to supporting the energy transition while playing an active part in protecting landscapes.”

Once the new line is operational, the overhead cables crossing the Gotthard Pass will be dismantled. However, four pylons near the summit will remain active but be reduced in size, to continue supporting a high-voltage connection for Swiss Federal Railways (SBB). The dismantling operation will contribute to reducing environmental and landscape impact in this sensitive natural area.

About Nexans

For over a century, Nexans has played a crucial role in the electrification of the planet and is committed to electrifying the future. With approximately 28,500 people in 41 countries, the Group is paving the way to a new world of safe, sustainable and decarbonized electricity that is accessible to everyone. In 2024, Nexans generated €7.1 billion in standard sales. The Group is a leader in the design and manufacturing of cable systems and services across four main business areas: PWR-Transmission, PWR-Grid, PWR-Connect and Industry & Solutions. Nexans was the first company in its industry to create a Foundation supporting sustainable initiatives, bringing access to energy to disadvantaged communities worldwide. The Group is recognized as a global leader on climate action and has committed to Net-Zero emissions by 2050 aligned with the Science Based Targets initiative (SBTi).

Nexans. Electrify the Future.

Nexans is listed on Euronext Paris, compartment A.

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