The LEB major project in three construction phases.

A building site has given rise to an impressive structure. The LEB tunnel in the heart of Lausanne was opened on 14 May 2022. Comparison of the pictures from June and November 2021 and March 2022 give an idea of the many different tasks cablex assumed in this project as well as showing the tunnel construction's rapid progress.

Author Carolin Rabea Primerova

LEB stands for the rail route Lausanne-Echallens-Bercher and the tunnel for a major project that makes the infrastructure in the very busy traffic of the city centre smoother and safer. As part of the IGCS consortium, cablex was responsible for the overall project management in terms of electrical installations and carried out implementation of the railway engineering work package.

The LEB major project in three construction phases.

The background.

The overloading of the Avenue d'Echallens in Lausanne resulted in repeated accidents. Pedestrians, motorists, cyclists, buses and trains were travelling at the same time and produced a confusing and dangerous overall situation.

To make the traffic infrastructure safer and more convenient, construction of the 1.7 km LEB tunnel began in summer 2017. It has been in two-lane operation in an 8 m wide and 15 to 30 m deep underpass below the Avenue d'Echallens since 14 May 2022.

Another reference for cablex.

cablex assumed responsibility for the overall project management in the person of Philippe Wuillemin as well as for the project management of the train technology in the LEB tunnel construction project. cablex can point to many outstanding references in the infrastructure segment with tunnel projects such as the Ceneri base tunnel, Bözberg, CEVA or maintenance work in the Gotthard tunnel. The successful conclusion of the LEB project once again showed that cablex is not only a reliable and expert partner in network construction and service, but also puts in a convincing performance in road and rail transport with professionalism, experience and quality.

The following work will be performed by cablex in connection with the LEB project:

  • Electrical distribution from different entry points in the tunnel and engineering spaces
  • Installation of all low-voltage devices: lighting with KNX control system, service sockets, emergency lighting, inverters for emergency grid.
  • Installation of low-intensity current for key safety components: fire detection, access control (door monitoring and infrared light curtain), video surveillance, valve control for fire management, Genephone communication systems for firefighters.
  • Installation of cable troughs for distribution along the length of the tunnel, feeding of cables into a battery of tubes on platforms on each side of the route with feed-through chamber every 50m.
  • Earthing/equipotential bonding with isolation of various earthing systems using an isolation transformer (rail earth and construction work earth)
  • Handrail along the length of the tunnel on both sides (2×1.6 kilometres)
  • Installation of lighting in the tunnel (service lighting) and emergency lighting beneath the handrail
  • Wiring of fibre optics for communication and for tunnel control (installation of racks in the engineering spaces)
  • Installation of electrical equipment in the emergency recesses (control panel for maintenance work, communication intercom)
  • Installation of signage for escape routes and emergency exits in the tunnel
  • Performance documentation (more than 150 technical reports) 

cablex will also perform the following installations on behalf of Siemens:

  • Installation of five ventilators on the tunnel ceiling (500 kilograms per unit)
  • Installation of compressor fan in the emergency exits
  • Wiring of three Axiaux fans (250 kW) for smoke extraction in the tunnel
  • Wiring for ventilation control between engineering spaces and firefighter access points
  • Wiring of centralised technical management with control station at Echallens 
  • Support with construction management and coordination 

cablex will also perform the following installations for the GCF company:

  • Installation of power cables in the tunnel from the train traction cable (1500VDC)
  • Installation of cables in the tunnel between two substations of the traction cable (1500VDC)
  • Installation of rail earth cables in the tunnel bench
  • Various equipotential bonding connections between the devices on the traction cable.

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