The Axen tunnels along the shoreline of the southern part of the Lake Lucerne (Lake Uri) are of an age of 100 years plus.

The goal of the renovation work was to safeguard another 50 years of operation, especially as northern feeder line for the Gotthard Base Tunnel. 

Project description

  • In view of the opening of the Gotthard Base Tunnel,  the Axen Tunnels were fitted up safeguarding of 50 years of remaining lifetime
  • Restoration of vault structural safety and invert serviceability
  • Elimination of deficits of railway loading gauge (clearance)
  • Production of norm conform construction parts and railway infrastructural components 
  • Installation of the latest generation equipment of railway infrastructure and improvement of self-rescue conditions
  • Constructional implementation with a minimum of restrictions to the railway operation 
  • Vault refurbishment, renewal of invert
  • Renewal of tunnel floor, tunnel drainage and self-rescue facilities 
  • Deepening niches
  • Renewal of railway infrastructure
  • Restoration of retaining walls
  • Provisional track changes
  • All restauration works to be performed under operation (partially single track operation) 
  • Restoration of construction substance
  • Supervision and coordination of all involved parties
  • Very limited access and difficult logistic conditions
  • Condition assessment 
  • Project design for all phases
  • Construction supervision and documentation
  • Client representation


Vault works under railway operation

Invert work in double track section

Limited accessibility of line sites

Engineering approach

Vault renovation and sealing work

Removal of existing pavement

Installation of provisional track changes

Technical solutions

Use of special inventory for tunnel refurbishment

Renewal of invert and drainage

Special inventory for rail construction