Construction of the Great North Road interchange was greatly assisted by the use of the distinctive yellow lifting gantry named Dennis
Waterview Connection leaves a legacy of innovation
New Zealand’s most ambitious roading project to date, the Waterview Connection, has finally opened to traffic, but the much-awaited project is so much more than just a new tunnel under Auckland’s western suburbs.
The Waterview Connection – the twin 2.4 km long tunnels, connections to existing motorways, and the Great North Road Interchange – is the final link in Auckland’s Western Ring Route, a 48 km alternative route to State Highway 1 and one of the NZ government’s roads of national significance to support growth and development. It links Manukau and the airport to the south with Auckland city, Waitakere to the west and the North Shore, improving network resilience and travel time reliability.
“The Waterview Connection is changing the way people and freight move around Auckland and the rest of the country, offering a true alternative route that bypasses the city centre,” says the NZ Transport Agency’s (NZTA) system design manager, Brett Gliddon.
Following several open days for the public to walk and cycle through the tunnels, the tunnels were opened to traffic without any fanfare shortly after midnight on Sunday 2 July, five years after construction first began on the $1.4 billion project. In the days since being opened, Auckland motorists have reported reduced travel times on their usual routes, with freight businesses reporting that they’re saving on average 40 minutes on a round trip from the wharf to the airport.
“These travel time savings are great news, not only for commuters but also for business productivity, because these improved travel times mean cost savings for hundreds of businesses,” says Mr Gliddon. “One of the Waterview Connection’s key aims was to provide a more efficient link between the port and airport to support growth and reduce the cost of doing business, and this has proved to be the case so far.”
Planning for deliveryPlanning for the route for the Waterview Connection first got underway in the early 2000s, and in 2009 the project was listed by the government as a road of national significance, meaning consenting would be managed by a board of inquiry and fast-tracked so as to take months, rather than years.
With the board of inquiry process underway, early works started in 2010, and in June 2011, the board’s final decision was released, confirming the project as a combination of twin tunnels and surface roads, and – importantly for the local communities – including the provision of improved walkways and cycleways.
Following a comprehensive tendering process, it was announced in mid-2011 that the contract for the project had been awarded to the Well-Connected Alliance made up of the NZTA (as the client on behalf of the NZ government), Fletcher Construction, McConnell Dowell, WSP, Beca Infrastructure, Tonkin+Taylor and Obayashi Corporation.
Sub-alliance partners included Auckland-based Wilson Tunnelling and Spanish tunnel controls specialists SICE, Downer EDI Works, Boffa Miskell, and Warren and Mahoney.
With the project affecting five different suburbs, there was understandably a fair bit of community concern about the impact something the size of Waterview would have. From day one, a project goal was to ‘build communities’ – a commitment endorsed by the NZTA board, its senior managers, John Burden and Iain Simmons the two project managers, and everyone across all work sites. Community and stakeholder engagement was a large part of the project, and this work was recognised with a number of awards.
Enabling works for the southern approaches to the tunnels commenced in January 2012, with work on the southern portal starting six months later (July 2012) and on the northern portal 10 months after that (May 2013).
AliceThe date of 11 November 2013 marked a significant milestone for the project, when Alice the tunnel boring machine (TBM) commenced excavating the twin tunnels. At 90 m long – almost as long as a rugby field – and weighing 3100 tonnes, with a cutter head measuring four storeys high, Alice was the tenth largest TBM in the world at the time, and was specifically designed for the Waterview geology by the German company Herrenkencht, and manufactured in China.
Alice the tunnel boring machine breaks through into daylight on 19 October after completing the second tunnel
The first tunnel was completed in September 2014, and in a rare manoeuvre for any TBM worldwide, Alice was then turned 180 degrees to commence boring the second tunnel, which was completed in October 2015. “We certainly grabbed some pretty amazing headlines in New Zealand and overseas at the time,” Mr Gliddon says.
During her time underground, Alice excavated down to a depth of 45 m, travelling at a top speed of 8 cm a minute – about as fast as a snail over the same distance – and removed more than 800,000 cu m of dirt – enough to fill 320 Olympic-size swimming pools. While excavating, Alice also installed more than 24,000 precast concrete segments to line the tunnels. The segments were made at a purpose-built factory in East Tamaki and delivered to Waterview in the precise order needed for installation.
With excavation and construction complete, the twin tunnels were fitted out with lighting, ventilation and safety equipment. Alice was dismantled in large sections in what was a technically difficult operation. Each part was lifted out of the trench and cleaned before being shipped back to Herrenknecht in Germany.
“Lots of people have asked whether we couldn’t use Alice for other tunnelling projects in New Zealand, but each TBM is built specifically for one job. It’s designed to take into account the size of the tunnel and the type of material it’s boring through, which are individual for each project,” explains Mr Gliddon.
InnovationOne of the project’s most outstanding achievements has been the innovation developed by the alliance members and its subcontractors. The distinctive yellow lifting gantry used to build the Great North Road Interchange – named Dennis to commemorate one of the project’s workers who died from cancer – meant the heavy concrete beams for the interchange’s flyovers could be lifted and placed without the need for conventional cranes. The motorway below remained open and there was very little disruption for motorists; there was also less impact on the surrounding sensitive environment and it also speeded up work.
The most striking example of Waterview’s innovation was turning Alice the TBM 180 degrees after completing the first tunnel. The turn took six months and was enabled with the use of hundreds of litres of lanolin from New Zealand sheep to complete the turn – sometimes with just a few centimetres to spare in a very confined space.
“The detailed planning and great cooperation between our designers, engineers and our teams on the ground ensured this amazing and critical engineering exercise was completed successfully,” says Mr Gliddon. “Worldwide, tunnel boring machines are rarely turned – we felt as if the eyes of the world were watching us and we won a lot of international accolades when we’d completed the turn.”
Better livesMore than 11,000 men and women worked on the Waterview Connection project spread across many construction sites and offices. An aspirational goal introduced from day one was ‘better lives’, a health and safety message that everyone should be able to go home safe at the end of the working day.
No one was allowed on a construction site without first attending a safety induction briefing and making sure they were dressed appropriately – this applied not just to workers and subcontractors, but to all visitors – including Prime Ministers John Key and Bill English and Ministers of Transport Steven Joyce, Gerry Brownlee and Simon Bridges.
The project used TRIFR (total recordable injury frequency rate), an international measure for worksite injuries, to measure its safety record. Over the length of the project, the alliance achieved a rate of 3.1 against the nationwide average of just under 10.
Workers were encouraged to take a leading role in safety – to develop ideas to keep themselves and the rest of their teams safe. Some of these ideas have since been adopted by other companies and construction sites, both in New Zealand and overseas, and the project’s performance on health and safety has been recognised with a number of national and international awards.
Ongoing improvementsNow that traffic is flowing through the tunnels and over the Great North Road Interchange, work goes on for the Well-Connected Alliance with the development of several community facilities around the project. Valonia Reserve in New Windsor has been vastly upgraded, with two full-size sports fields, complete with irrigation, drainage, lights and sand-turf pitches, a half-size basketball court and skate park near Richardson Road, and new modern changing rooms.
The revamped Howlett-Waterview Esplanade in the suburb of Waterview replaces a muddy track that was almost impassable in wet weather. The all-weather walking route along the coast connects two parks, and the environmental restoration benefits the adjacent Te Auaunga-Oakley Creek, the Motu Manawa Marine Reserve and the region’s biodiversity.
A brand-new playground – designed by Boffa Miskell with help from children of the local Waterview Primary School – plus a skate park and BMX track have been installed at the Waterview Reserve.
The striking arch-shaped Te Whitinga Hendon Footbridge provides a link across the Southwestern MotorwaySeveral important cycling and walking connections have also been constructed and opened for public use, including the striking arch-shaped Te Whitinga Hendon Footbridge, which provides a link across the Southwestern Motorway between the suburbs of New Windsor and Owairaka.
“It’s a stunning addition to the landscape and is another striking example of engineering and design excellence coming together as they have all the way through the Waterview project,” says Mr Gliddon. “It’s been a real pleasure to be able to incorporate community facilities into large infrastructure projects like the Waterview Connection.”