The progress on Transmission Gully
In the north, it was sandy, windswept, filled with boulders and curious feral goats. Head south and there were the bare bones of a sweeping bridge over the motorway, and curious drivers.
The $850 million Transmission Gully project heads into summer after a long wet spell, with the contractor adamant the project will open by the expected April 2020.
Wellington Gateway Partnership chief executive Sergio Mejia said the project was still on schedule. ‘‘If there is more rain, we will have to adjust, and to do our best to keep on schedule.’’
About 400 workers on the road, running between Linden and Mackays Crossing on the Ka¯piti Coast, have dug out about two Westpac Stadiums worth of earth – amounting to 2.4 million cubic metres. Work is now under way along the entire 27 kilometres of the project.
There are 25 structures along the Gully route, such as interchanges and bridges. The biggest, the Cannons Creek Bridge, will be 237m long and 17m high.
In the north, the work has spilled out from the gully, with earthworks set to pre-load sandy, peaty ground on the northern side of the current State Highway 1.
Visible work vanishes over a crest into the hills above the highway to the south, where boulders, brought from Nelson, are stockpiled to create a new bed for Te Puka Stream. The path of the earthworks heads up a long slope to the Wainui Saddle, the highest point, vanishing into the distance.
In the south, Mejia said work had started on replacing the Collins Ave bridge – in fact two separate bridges on SH1, heading north and south over Linden.
Eventually, in 2018, traffic would be diverted on to new sections of the bridge as old sections were closed, demolished and replaced. The entire bridge would be replaced by 2020.
Work just to the north of the Collins Ave bridge was under way on what would eventually be the link road swooping over the motorway into the hills from Kenepuru Drive to the route’s Kenepuru interchange.
Mejia said traffic would continue to run along SH1 as the bridge was built over top of it. As each section was built, traffic would be switched through single lanes. ‘‘The deal is we will guarantee constant flow. We will not change conditions other than speed reductions.’’