Wellington's Transmission Gully motorway project hits halfway mark

Sunday, 10 June 2018

The 27km Transmission Gully motorway north of Wellington has been designed specifically to withstand an earthquake.

The countdown is on: Transmission Gully is halfway finished and set to open in two years' time.

Work on the $850 million, four-lane motorway between northern Wellington and the Kāpiti Coast had surged ahead in recent months, project director Boyd Knights said.

A peak workforce of up to 950 people moved more than 3.5 million cubic metres of soil over the summer and four of the project's 27 structures were now completed, he said.

Looking south over bulk earthworks under way towards Belmont Regional Park.

'We're in a great position moving into the next phases of works for the new motorway.'

**READ MORE:

A group of Labour MPs visited the site recently to check out progress.From left, Paul Eagle, WGP chief executive Sergio Mejia, Greg O'Connor, Kris Faafoi and Adrian Rurawhe.

* Transmission Gully slowly takes shape

* Gully earthworks estimates out by 50 per cent

Heavy machinery taking a break on a section of the alignment near Whitby.

* Transmission Gully 'opens' two years before it opens)

* Aerial photos show progress on Gully**

Progress on the Transmission Gully motorway, north of Wellington, is going well with the project now 50 per cent complete.

Described as one of the most technically challenging roading projects ever seen in New Zealand, work on the 27-kilometre motorway started in 2014.

Knights credited fine weather and a keen workforce for breaking the back of the project and Wellington Gateway Partnership (WGP) chief executive Sergio Mejia said it boded well for future work.

A construction team working on a reinforced earth wall for Bridge 15 over Pauatahanui Stream.

'We are on schedule to complete what will be one of New Zealand's safest, most resilient - not to mention most keenly anticipated motorways - in 2020.'

Since its start, more than four million work-hours had been completed.

Porirua City councillor Anita Baker said the project had been nothing but positive for the city.

'It's absolutely exciting for Porirua, it gives us great potential for future development.'

While future plans could see subdivisions and business parks spring up around the motorway, its effects were already being noticed, she said.

View of the Cannons Creek bridge’s huge steel girders being tied together onsite.

'Businesses are already doing a lot out of it and workers have been renting in the city. Government departments are already moving here because of it.'

Baker said the motorway would link the city to Wellington and Kāpiti, making it easier for commuters.

'It will almost create a super city, dare I say it.'

It hasn't all been smooth sailing, with the project having had its fair share of challenges along the way including the Kaikōura earthquake and its aftermath as well as multiple torrential rain showers and subsequent slips.

With winter having already taken hold of the region and daylight hours fading fast, the project team will turn their attention away from earthworks to focus on planting, installing environmental controls and continuing work on the project's remaining structures.

The next bulk earthworks season will start in October.

Four interchanges and two new link roads will connect the route to Mackays, SH58 (Haywards Hill), eastern Porirua and Kenepuru.

WGP, a private group of financiers and contractors, hold the contract to maintain the motorway for 25 years after construction.

Together with the $630m Kāpiti Expressway further north, and a project under way to address congestion in Wellington central, it is hoped the motorway will make the journey in and out of the capital safer and faster.

BY THE NUMBERS:

6,000,000 - cubic metres of earth moved.

Five - kilometres of gas pipeline relocations completed.

Four - of the project's 27 structures finished.

Eight - kilometres of motorway at pre-pavement level.

1.5 - kilometres of permanent stream diversions completed.