Nexans, in partnership with Swissgrid, is to install an 18km-long high-voltage line in the Gotthard Tunnel’s second tube.
The new 220kV line, which will be installed by 2030, will replace the existing overhead line across the pass. The new connection will play a critical role in electricity transmission along Switzerland’s north–south corridor.
Nexans says it is the first time a European road tunnel will be used 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 used. Combining infrastructures often contributes to landscape preservation and more efficient land use.
Nexans will supply a total of 57km of extra-high voltage cablefor the 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 will take place from 2025-2028, works are due to start in 2028 and be completed in 2030.
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. The dismantling operation will contribute to reducing environmental and landscape impact in this sensitive natural area.
Valued at approximately €50m, the project is the largest contract ever signed by Nexans Switzerland.
The new Gotthard Tunnel will supplement the existing 16.9km tunnel between Göschenen in the Swiss canton of Uri and Airolo in the canton of Ticino. The 45-year-old tunnel needs repair so the Swiss Federal Roads Office (ASTRA) has commissioned the construction of a second, parallel tube to ensure that traffic can continue to flow during the renovation and closure of the tunnel. Once work on both tubes has been completed, one tunnel with one lane (plus emergency lane) will be available for southbound and one for northbound traffic.
