Microtunnelling, Pipe jacking, Tunnelling

Launching gantry assists with Waterview tunnel project

Dennis, a yellow launching gantry, is being used to construct the massive interchange to join the Northwestern and Southwestern motorways at the northern end of the project.

Dennis – 98 m long and weighing about 140 tonnes – will be the most publicly visible feature of the Waterview Connection project over the next three years.

The gantry was designed and built in Italy specifically for the Waterview project. It was chosen over conventional bridge construction methods to minimise impacts on adjacent archaeological areas and traffic flows.

Meanwhile, drilling at the Waterview Connection project is stopping for three weeks while workers get ready for the next stage of the massive motorway project.

During the break, a giant white gantry will be pushed into the tunnel behind Alice. This gantry will be used to lift into place large concrete culverts, each about 2 m tall and weighing 5 tonnes, that will create a passageway on the tunnel floor to carry services like water, electricity and telecommunications links below the new motorway.

The gantry is the first of its kind in the world and was designed by Herrenknecht, the German company that constructed Alice.

It arrived in New Zealand in parts and was re-assembled outside the entrance to the southern portal. The 95 m, 400 tonne gantry will be moved into the tunnel in the next few days.

“Waterview is the country’s largest roading project, and the gantry is another example of the size and complexity of the work that’s underway there,” said NZ Transport Agency Regional Highway Manager Tommy Parker.

Twin 2.4 km-long tunnels, both 13.1 m in diameter, are being constructed to connect Auckland’s Southwestern and Northwestern motorways as part of the city’s Western Ring Route, one of the Government’s flagship Roads of National Significance. Each tunnel will carry three lanes of motorway traffic.

Alice has now reached the 500 m mark on her journey north to construct the first of the two tunnels. She is 30 m below ground, and will eventually reach a depth of 45 m.

Mr Parker says the lifting gantry has been designed so that Alice can continue her work uninterrupted when tunnelling resumes. Supplies, like the concrete segments of tunnel linings that Alice installs, will be transported along a special tunnel trail running over the new culvert and the gantry, down a ramp to the tunnel floor and then on to the tunnel boring machine.

The Waterview project is being delivered by the Well-Connected Alliance, which includes the Transport Agency, Fletcher Construction, McConnell Dowell, Parsons Brinckerhoff, Beca Infrastructure, Tonkin & Taylor and Japanese construction company Obayashi Corporation. Sub-alliance partners are Auckland-based Wilson Tunnelling and Spanish tunnel controls specialists SICE.

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