NEAT Lötschberg Base Tunnel, Power Traction Supply 132 kV and 15 kV 16.7 Hz

Power traction supply ensures electrical energy supply to trains. This is provided by two feed-in points in Mitholz (33 MVA) and at Lötschen junction (20 MVA, from Gampel-Steg substation), as well as the connection with the 15 kV networks of BLS in Frutigen and SBB in Raron. In the first operation phase a 1x1000 MVA connection at 132 kV level will be created between the BKW converter unit in Wimmis and the SBB substation in Gampel-Steg. In addition, a new substation will be erected in the Mitholz access gallery with a 132 kV GIS in the cavern (Mitholz substation) as well as a 33 MVA transformer in front of the portal of the access tunnel.

Power supply for the catenary will be ensured from the feed-in points at Mitholz and Lötschen as well as the network connections in Frutigen and Raron. Furthermore, switch posts are planned in Ferden and in the relay room at 30 km.

A complex and selective protection system ensures the safety of the new 50 kA switchgear. Facultative catenary protection sections will be moni-tored for synchronicity with neighbouring sections and will be communicated to the train driver via stationary signals in Frutigen and Raron as well as cab signalling in the tunnel.

All switchgear can be operated manually on-site or electrically in the respective operating centre. All switching conditions, measurements and alarms are transmitted to the operations control centres, local control centres (HV management system) and the main traction power supply control centre in Spiez. Operation takes place primarily from the superordinate control centre.



BLS AlpTransit AG


IUB Engineering AG

Construction period


Construction costs

CHF 26 million

Scope of services

Planning of the power traction supply (switch gear, transformer, protection and control systems)

  • Preparation of the preliminary design study
  • Preparation of a detailed concept
  • Tendering, evaluation of bids
  • Monitoring of detailed design
  • Construction supervision