Te Ara o Te Ata - Mt Messenger Bypass project construction in February 2025. Photo: NZTA / Waka Kotahi
Tunnelling has begun at the $280 million Te Ara o Te Ata - Mt Messenger Bypass project in North Taranaki.
A 110-tonne road-header machine that would excavate the project's 235m tunnel made the first cut following blessing from mana whenua and iwi partner Ngāti Tama.
NZ Transport Agency/Waka Kotahi project manager Caleb Perry said having the road header onsite was an exciting milestone for the project.
"We'll start to see some progress with the road header excavating up to three metres every day."
Perry said road headers had boom-mounted telescopic cutting heads, making them ideal for diverse geological conditions. A shovel plate at the front of the road header collected the excavated rock and soil, which was then conveyed via a belt to dump trucks at the back of the machine.
"The tunnel will be cut in two stages, with the upper portion (top heading) first, followed by the bottom section (bench). At regular intervals, excavation will be paused and 'shotcrete' - a sprayed-on concrete - will be applied to the crown and walls to line and support the structure.
"The design and construction of the tunnel are similar to the Northern Gateway Tunnel in Auckland and the tunnel will be large enough to accommodate loads up to and including house removals - this isn't something that can currently be accommodated on the steep, narrow winding stretch of State Highway 3."
Te Ara o Te Ata - Mt Messenger Bypass project construction in February 2025. Photo: NZTA / Waka Kotahi
The Mt Messenger project had named the road header 'Hinetūparimaunga' - the atua of mountains and cliffs.
A design on the side of the roadheader depicted Hinetūparimaunga with outstretched limbs supporting the roof, walls and floor of the underground space. A yellow background represented the light that would flood into the tunnel upon its completion.
Perry said the 235-metre tunnel was an important part of the bypass project, and at this stage its excavation was expected to be completed later this year.
Te Ara o Te Ata - Mt Messenger Bypass project construction in February 2025. Photo: NZTA / Waka Kotahi
"The Mt Messenger Bypass will make this stretch of SH3 much more resilient, and safer for all motorists, providing a secure connection through North Taranaki, especially for freight.
"The finished tunnel will incorporate cultural elements acknowledging Ngāti Tama tūpuna, the traditional guardians of the northern gateway to Taranaki."
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