Gorge replacement road takes shape
Huge earthworks are changing the face of the Ruahine Range’s southern peaks, home to a muchanticipated four-lane road connecting the eastern and western sides of the lower North Island.
Construction of Te Ahu a Turanga Manawatu¯ Tararua Highway began in January and it is scheduled to open in December 2024.
Until then the road will take shape, ready to be covered in tarmac for the 6000 vehicles a day now using the windy Saddle Rd when travelling between Manawatu¯ and Hawke’s Bay.
It’s estimated the new road will take about 13 minutes to drive.
Among the work sites is a gully near the Ashhurst end of the $620 million project.
Stuff was this week granted access to the area, where huge machines were scraping massive piles of soil down a steep gradient to fill the gully – ‘‘fill 9’’ as it’s known.
It will transform into a sweeping upward curve heading towards the wind turbines and will be the steepest part of the new 111⁄2 kilometre road.
‘‘This bit of earthworks will be ongoing for the next three years,’’ said Waka Kotahi NZ Transport Agency project spokesman Lonnie Dalzell.
The construction alliance’s project engineer for this section of work, zone 2, Dane Gray, said that of the four scrapers smoothing the area into a highway this week, two were working nonstop, while two were operating when needed.
‘‘One of these machines can do roughly 1500 [cubic metres] a day.’’
It’s a lot of material, but a drop in the bucket overall. Dalzell said about 300,000 cubic metres of material would be moved this year, rising to 21⁄2m a year in 2022 and 2023.
‘‘The work we’re doing here is ramping us up for those big years.’’ Work is happening six days a
week, with plans to move to seven and the possibility of introducing two shifts a day. Earthworks are possible on 109 days a year but scraping on a steep slope is not feasible in muddy conditions.
Motorists from the Ashhurst end will arrive at the up-hill section after crossing two bridges, one over the Manawatu¯ River and one over sensitive wetland. Each bridge will be more than 300 metres long.
Bridge work is expected to start within weeks and the progress will be easy to follow from a viewing platform at the car park created for gorge walk users.
A slip in April 2017 closed the old State Highway 3. Concerns about the stability of the hillside shut the route indefinitely.
The replacement highway includes a shared cycling and pedestrian path.
Nearly 50 hectares of native forest will be planted and pest control measures introduced. About 100 people from the alliance are working on the site. That is expected to rise to about 350 a day at
the project’s peak.