“Star Performer” Preparing For Debut

Our heavy metal star – the Tunnel Boring Machine named in honour of Dame Whina Cooper - is now starting to take shape in front of the tunnel entrance at our Mt Eden site.

The first four of 11 sections, known as gantries, have been moved and aligned into position. All 11 will be in place by mid-March. The TBM’s final piece, the front section or shield, will then be connected.

When the job’s done, City Rail Link (CRL) will have a travelling factory 135 metres long ready to start excavating the first rail tunnel in late April.

The gantries provide the hydraulic, mechanical and electrical power the shield will need to excavate the tunnels, remove the excavated spoil, and install the precast concrete segments that will line the tunnels.  The gantries also carry all the ‘mod cons’ the TBM’s tunnellers will need underground - a small office, canteen, a refuge chamber if there is an emergency, and a toilet.  

A truck with a multi-wheeled hydraulic trailer moved the first gantries, each weighing 70 tonnes,  into position. 

Moving and aligning them all is a big and delicate operation at the busy Mt Eden site.  A dedicated road and ramp had to be built down to the tunnel.  Concrete slabs were poured by the entrance and rail tracks installed to position the gantries correctly.

 Once the shield and all of the gantries are connected, the completed TBM will be put through vigorous tests and commissioning to ensure it is safe to begin its journey through the first tunnel.

The TBM will be operated by the Link Alliance, which is responsible for CRL’s main contract – building the stations and tunnels and installing the systems – lighting, signals, communications and tracks - that will turn the tunnels into a railway line. 

For more information on Mt Eden works, you can email the team at mteden@linkalliance.co.nz or phone 0800 CRL TALK and press option 5 for Mt Eden works. You can also subscribe to the Mt Eden newsletter by clicking here.

The TBM’s cutter head, or shield, pictured here will be attached to the rest of the TBM last