Châtelard - Vernayaz: discover one of our turnkey projects

Context

The Nant de Drance pumped storage power station (Valais, Switzerland) required a 380 kV line between Châtelard and La Bâtiaz, which meant relocating the 132 kV SBB line. Part of this line is now buried through the village of Salvan and as far as Vernayaz.

Services

Nexans Switzerland carried out this turnkey project, including engineering, manufacture of cables and accessories, laying, assembly and testing. 16 km of 800 mm² Cu 150 kV cable were shipped from Cortaillod. Begun in April 2023, the 132 kV underground line was commissioned in August 2024.
 
Technical challenges

• Work in difficult terrain using specific techniques
• HV cable pulling on a 100% slope
• Unique concept of restraint, braking and clamping

 Safety

• Protocols for securing work areas
• Preventing falls and minimising fatigue
• Informing local residents and coordinating with local authorities

 Key facts

• 12 employees mobilised during the critical phases
• Route from 1,010 m to 447 m to Vernayaz
• Access to the anchoring chambers only on foot or by helicopter
• Adverse weather conditions between March and June 2024

 Key figures

• 3 junction chambers and 26 anchoring chambers
• 334 flanges
• 6 months of work

Conclusion

This project reduces the visual impact by partially burying the 132 kV line in Salvan and strengthens the power supply. It illustrates Nexans Switzerland's expertise in designing innovative solutions and managing complex turnkey projects.