TBM Ready To Bore

The 450 tonne shield of our Tunnel Boring Machine (TBM) has been successfully positioned in front of the Mt Eden tunnel portal - where it will be attached to the rest of the TBM before beginning its nine-month journey underground to build the first of two CRL tunnels.

Getting the shield, or front section, into place was no easy feat. The 500-metre-long drive from where it was originally stationed took one-and-a half hours to complete. 

The shield was moved from the western edge of the Mt Eden site along a specially built road by a truck towing a hydraulic trailer fitted with 15 axles and 250 wheels to safely carry the shield’s weight.

Over the next week the team will be working to position the shield inside the first 50 metres of the CRL tunnel and connect the shield to the TBM’s ‘factory’ – the 11 sections or gantries that 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 TBM is scheduled to launch at the end of April, when it will start boring the first of two tunnels to Karangahape Station and then on to the Aotea Station in the central city where it will join with the tunnels already built from the Britomart Station and under the lower end of Albert Street.