Huge machine on its way to build key Auckland road connection

By: NZ Transport Agency – Auckland Regional Office

Date: 06.03.2013

The start of tunnelling on the NZ Transport Agency’s (NZTA) landmark Waterview Connection project in Auckland has moved a significant step closer with the NZTA’s Well-Connected Alliance formally accepting the huge machine it will use to construct the twin 2.5km-long tunnels.

Huge machine on its way to build key Auckland road connection

The state-of-the-art Tunnel Boring Machine (TBM) is the 10th largest machine of its kind ever to be built worldwide and has been designed specifically for the unique ground conditions on the $1.4b Waterview Connection - the biggest transport construction project in New Zealand's history and the key to unlocking the full benefits of Auckland's motorway network.

The handover – marked by an official signing at Guangzhou in south east China where the German manufacturer of the TBM, Herrenknecht, has a factory – follows 14 months of design, build and testing of the giant machine.

The TBM's circular cutting head, painted black with a silver fern logo, is more than 14 metres wide – the equivalent of a building three storeys high – and the machine is almost 100 metres long – the length of a rugby field. The machine will now be dismantled for shipment to New Zealand and is due to arrive in Auckland in July before being reassembled at the project's southern tunnel portal to begin tunnelling in October.

The Waterview Connection is part of the Western Ring Route road of national significance and will join SH20 (Southwestern Motorway) and SH16 (Northwestern Motorway) to complete a 47 kilometre-long motorway alternative to SH1 and the Auckland Harbour Bridge.

"The size of this project and the size of the tunnel boring machine are both on a scale the likes of which we have never seen before in New Zealand," says the NZTA's State Highways Manager for Auckland and Northland, Tommy Parker.

"Since mid-2012 we have preparing a trench that will not only form the southern tunnel approach, but provide the TBM's launch pad," Mr Parker adds. "This requires us to excavate to a depth of 30 metres, initially, drilling and blasting through a 15m-thick layer of very hard volcanic rock."

To construct two 2.5km-long tunnels, each wide enough for three lanes of traffic, the TBM will pass beneath the rock and tunnel through softer, clay-like soil known as the East Coast Bay Formation. It is expected to take a year to complete the first tunnel, emerging beyond Great North Road in Waterview, where work is already underway to prepare for its arrival and turnaround for the return journey.

Mr Parker says that when completed in 2017, the project will help unlock Auckland's potential for economic growth and will also have considerable benefits for its Northland and Waikato/Bay of Plenty neighbours.

"Easing pressure on the city's existing motorway network will have flow-on effects that will encourage business growth, tourism and jobs. For the first time there will be a direct motorway link between Auckland International Airport and the CBD. The network will become more resilient – two motorway links through Auckland reduce the risk of any disruption to traffic bringing the city to a standstill."

The Waterview Connection, Mr Parker adds, aims to deliver maximum regional and national benefits with a minimum long-term impact on the communities surrounding the project.

"Tunnelling obviously allows us to do this, and a strong focus on urban design and landscaping – like the rehabilitation work we've already carried out around Oakley Creek – ensures that the effects of all above ground work are carefully mitigated."

TBM quick facts

At 14.5m, the TBM's shield or head diameter is the 10th largest ever built. Its total length is 97m.
The 12 metre-long shield will arrive in NZ in 8 pieces, collectively weighing 2300 tonnes
The TBM will have a top speed of 80mm a minute, or 0.0005km/h
Approximately 800,000 cubic metres of earth will be removed from both tunnels – enough to full 320 Olympic-sized swimming pools

For more information visit: www.nzta.govt.nz/waterviewconnection. Latest news and videos are also available via Well-Connected's Twitter and Youtube channels www.twitter.com/wcnow and www.youtube.com/wcnow.

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