The tunnel-boring machine Alice has now excavated 630m of the 2.4km second tunnel. PHOTO/SUPPLIED
The tunnel-boring machine Alice is now a quarter of the way into drilling the second motorway tunnel of the Waterview Connection in Auckland.
The machine has now excavated 630m of the 2.4km second tunnel. NZTA highways manager Brett Gliddon said the work was on track to break through at Owairaka
in mid-spring.
Alice, the world's 10th largest tunnel boring machine, began the second tunnel after a complex operation to turn the machine around.
The cutter head was turned first to excavate the first 250m to make room for the rest of the machine.
"Worldwide, very few TBMs are turned to complete a second run underground and the project's extraordinary innovation to achieve this manoeuvre, with just millimetres to spare at times, is now fully complete.
