Alice, the Waterview Connection's tunnel boring machine, is lined up at the mouth of her first Mt Roskill wall, ready to dig the country's biggest roading job.
John Burden, project manager for the Well-Connected Alliance, showed how the shield or cutting face of the world's 10th-largest tunnel boring machine would soon start eating into the ground to create the first 2.4km southbound tunnel.
Alice, which can create a 14.4m diameter tunnel up to 17m long a day, not only digs the tunnel with her circular cutter head full of blades and discs but also lines the hole she has dug with concrete segments, completing the process all in one go.
"The tunnel has to be that big to get three lanes of traffic in," said Burden, aged 51, a civil engineering Auckland University graduate, who heads the project. He has worked for Fletcher Construction, one of the alliance partners, for 18 years, including on the Victoria Park tunnel.
Burden was in the successful tendering team, so has been working on the $1.4 billion Waterview job since January 2011 "and we have another 3 years to go".
Financial incentives and disincentives are built into the contract.
"The commercial organisations in the alliance work to target and get a pain or gain share," Burden said, describing financial penalties and rewards at various stages.
He cited Alice as an example, saying it had come in "very close to budget, at roughly $55 million".
"If we didn't do a good job, all the people in the alliance would be affected and get less money," Burden said.
Soil or spoil from the tunnels will be removed by a continuous conveyor belt, more than 6km long once it is linked up to the back of Alice.
Tonkin & Taylor
Source: The Well-Connected Alliance