Te Ara o Te Ata Mt Messenger Bypass
DATE: 2019-2026
CLIENT: NZ Transport Agency Waka Kotahi
LOCATION: Mount Messenger, North Taranaki
CONTRACTOR: Mt Messenger Alliance; NZTA, mana whenua iwi partner Ngāti Tama, Downer, HEB Construction, Tonkin + Taylor and WSP
PLANNED CONSTRUCTION TECHNIQUE: Road header
ESTIMATED COST: $
Te Ara o Te Ata: Mt Messenger Bypass is a new 6km route between Uruti and Ahititi that avoids the existing steep, narrow and winding route over Mt Messenger on State Highway 3 in North Taranaki.
Te Ara o Te Ata includes two bridges of approximately 125m and 30m in length and a 235m tunnel. The route will be lower and less steep than the existing road.
The 235-metre tunnel is a significant feature of the new bypass. The design and construction 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.
A 120-tonne road header machine will excavate the upper portion (top heading) and then the lower section (bench) at a rate of up to 3 metres per day in two work shifts. The tunnel will be constructed with temporary rock bolts and steel fibre reinforced shotcrete, sprayed at high velocity, stabilising the tunnel excavation.
The shotcrete also contains synthetic microfibres for protection in the event of a fire. Other safety measures to meet New Zealand and international best practice standards include a safety egress passage and a public warning system.
The tunnel will allow easy movement for wildlife over the new road, ensuring their safety from traffic. The finished tunnel will also incorporate cultural elements, acknowledging Ngāti Tama tūpuna, the traditional guardians of the northern gateway to Taranaki.
