CRL Tunnel Boring Machine breaks through into mined tunnel cavern

Here is the City Rail Link Dame Whina Cooper tunnel boring machine (TBM) after its most recent breakthrough – into the mined tunnel cavern at the Maungawhau Station (Mt Eden) site. It all happened only 85 metres after the TBM launched!

Before the TBM could breakthrough, significant strengthening and reinforcing works needed to take place inside the tunnel cavern. The work ensured there was no possibility the ground above could move during the breakthrough.