Rail tunnels can now be built at Mt Eden as part of Auckland’s City Rail Link, after a massive new stormwater main was built under the project’s first complete contract.
The NZ$16.5 million contract built a 423-metre stormwater main, 17 metres below ground, then connected new and old mains, to allow for the removal of the existing stormwater main obstructing the planned path for the rail tunnels.
The new main was bored by a micro-tunnel boring machine called Jeffie, which took just 7 weeks to do the work expected to take 15.
CRL Ltd chief executive Dr Sean Sweeney said the completion of the relatively small contract was a significant step for the NZ$4.4 billion passenger rail project.
“The contract was a small but important step and its completion marks the start of huge strides we’re about to take as our main work ramps up to deliver CRL for Auckland in 2024,” Sweeney said.
“Jeffie went superbly well and did a fantastic job for us building the new main.”
Jeffie used technology not seen before in New Zealand during its boring journey.
In order to navigate a tight underground curve around some hard volcanic rock, hydraulic joints were used to spread the pressure evenly between each segment, to avoid damaging the pipes around the curve.
Jeffie has since moved on to Ecuador for a new tunnelling project.
CRL is to be a 3.45-kilometre, twin-tunnel underground rail link at depths of up to 42 metres below Auckland’s city centre. The new rail link will connect Britomart to the existing Western Line at a re-developed Mt Eden station, to ‘complete the loop’ for passenger rail in New Zealand’s most populous city.