Tunnel fit-out and track laying

Tunnel fit-out is an essential part of the project and includes installation of rail infrastructure and electrical, mechanical, hydraulic, safety and communications systems.

Early fit-out of the tunnels and preparation works for rail began mid-2019. The tunnel boring machines completed their work in April 2020, paving the way for track laying and other fit-out works.

For rail within the tunnels, a fixed track slab method is used with rail fastening systems affixed to embedded sleepers and infill concrete.

The construction is completed in three stages:

  • Installation of rail and sleepers
  • Setting the track to line and level
  • Concrete placement and finishing

Track located outside the tunnels and dive structures is placed on a bed of crushed stones, referred to as ballast.

Once the track laying process is underway, work will begin on the installation of overhead line equipment to power the trains, as well as associated rail systems.

Watch a video about the start of track laying within the tunnels or view the tunnel fit-out and track laying fact sheet.


The total length of rail strings


The number of sleepers used within the tunnels