NZTA project manager Caleb Perry at Mt Messenger bypass tunnel. Photo / RNZ
By Robin Martin of RNZ
A significant milestone has been reached in the Mt Messenger Bypass Te Ara o Te Ata project on State Highway 3 in Taranaki.
A 110 tonne excavating machine, called Hinetūparimaunga, has broken through at the northern end of the project’s 235m-long tunnel.
Hinetūparimaunga – named after the atua for mountains and cliffs – emerged to karakia from project partners Ngāti Tama and the applause of staff and assembled dignitaries braving the rain for a glimpse of history in the making.
Ngāti Tama general manager, Te Amoroa Clifton, evoked the legacy of Dame Whina Cooper when expressing the day’s significance to iwi members.
“Today as we mark the tunnel breakthrough at Te Ara o Te Ata we honour the legacy not by resisting change but by shaping it.
“With an overwhelming 82% majority Ngāti Tama uri voted in favour of the agreements with Waka Kotahi.
“We chose to allow the land needed for the bypass to be exchanged not as a surrender but as a strategic act of rangatiratanga (self-determination). This is not a contradiction of Whina Cooper’s march, it’s an evolution.”
Ngāti Tama exchanged 20ha of settlement land for a 120ha farm on nearby ancestral land, $7.7 million and a commitment from Waka Kotahi to pest control in perpetuity over 3650ha of its rohe.
The $365 million Mt Messenger Bypass aims to improve safety and resilience by replacing the existing steep and windy route which includes a narrow tunnel.
As well as the new tunnel, the bypass includes two bridges.
NZTA project manager Caleb Perry was also feeling the moment.
“This is a milestone day for Te Ara o Te Ata with the breakthrough of the 235m tunnel. We’ve been under construction for three years on this southern half and it’s really awesome to be able to connect up these two isolated parts of the project to get access into this remote central part.
“The breakthrough today enables us to get some bigger gear through into this remote central part to boost productivity for the team over summer this year.”
Workers had excavated 17,000 cubic metres of rock so far, but there was a little more tunnelling to be done.
“The team have been working day and night shift since February excavating the top header here, but the road level is about 3m below our feet, so up next the team will go back to the start and excavate the bottom bench.”
Perry, who believed the tunnel was the first to be built in Taranaki in about a century, said it would have a shotcrete finish which was a new approach.
“So, this is the first permanently lined shotcrete road tunnel in New Zealand and what that means is the shotcrete that is sprayed on during construction is the permanent lining.
“So, there’s no slip-forming to come through and no pre-casting elements to be placed in. What you see is what you get which means the quality and the checks and balances during construction has had to be very robust.”
Co-owners of Taranaki Mix Kezia and Steve Beard had risen to that challenge.
“It’s a really specialised mix which has a lot of products in it. It has fibre, micro-silica, super-plasticisers and it has to turn up on site on time and it has to be the same everyday. It has to be really consistent for the guys to spray it on the wall and it is the integrity of the tunnel wall,” said Kezia.
Meanwhile, tunnel supervisor Steve Wiley was taking the breakthrough celebrations all in his stride.
“For me it’s another day in the office, but for a lot of our workers the fruition of a lot of hard work is that we actually get to the end and we breakthrough and I hear our timing was impeccable. But, yeah nah, it’s a great day for everyone.”
Zane Gray was piloting the one kilometre-long cable car ferrying guests to tunnel head.
“We lift all the heavy machinery into the gully, take people in there, workers and bring them out at night.
“We also bring all the unsuitable products dirt, logs and stuff that’s not needed in the gully, out with the cable crane.
“We take down dump trucks even, we have a safe lifting load of 20 tonnes.”
The gondola – the first ever used on a construction site in New Zealand – would soon no longer be required.
“The cable crane and gondola will be decommissioned demobilised at the end of February because we’ll have access to the rest of the works through the tunnel.”
He wasn’t worried about his future.
“For me it doesn’t change a lot. I also operate machinery diggers and the like and I’ll fit into whatever role they have for me.”
The Crown was still locked in a legal battle to acquire 11ha of private land required for the project on its northern side.
Once secured, Waka Kotahi has said it would take another four years to complete the 6km bypass which it estimated would save motorists between four and six minutes of drive time.
-RNZ