City Rail Link Ltd CEO Sean Sweeney (left), Auckland Mayor Phil Goff, and Transport Minister Phil Twyford. Photo / Supplied
COMMENT:
The City Rail Link (CRL) is taking its next big, exciting construction step — one that I, as the project's chief executive, describe as the start of a massive voyage into uncertainty and engineering complexity.
A piling rig has started the hefty job of drilling holes deep into Mt Eden soil for the first of 66 concrete piles that will support a curving wall for the southern portal or entranceway to the two tunnels that will run all the way to Britomart Station in lower Queen St.
Mt Eden will be our "base camp" for the biggest contract of CRL work to complete the tunnels and stations, and I'm not exaggerating when I say it marks the launching pad for the voyage into engineering uncertainty.
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Nothing on this scale has been undertaken before, certainly not in Auckland and probably not in New Zealand, since the massive hydro-electric projects last century.
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I doubt any of those projects would have been undertaken with the central city engineering complexity, disruption and scrutiny or the legislative legacies — safety regulations for working underground in the wake of Pike River is one example — that oversee our work.
The $4.4 billion CRL project is a transformational driver for Auckland's future growth. It includes construction of twin 3.45km-long tunnels below the central city and two underground stations connecting dead-end Britomart with the Western Line.
Train travel will be easier and quicker and the number of people within 30 minutes travel of the CBD — New Zealand's biggest employment hub — will double.
Building the portal retaining wall is one visible sign of the complexities challenging my team. Before we could start piling, some 30 buildings had to first be demolished — one 19th century colonial cottage was saved — to clear the Mt Eden site.
It will take us 10 months to drill piles between 8m and 38m long to support a retaining wall 127m long and 25m high.
Importantly, a completed site will then become our launching pad — not aimed vertically at the heavens but at a more modest horizontal destination: central Auckland.
From Mt Eden, CRL's tunnel-boring machine will set off on its two journeys up to 42m below central Auckland to complete its sections of the tunnels.
The machine will be our project star — mechanical muscle with a combined weight of 1600 tonnes that will help get our job done quicker.
The tunnel-boring machine is arriving from China in sections next spring to be reassembled in front of the portal.
Early next year, it will start worming its way 1.km under Auckland to the Aotea station and connect with the cut-and-cover tunnels we already have under construction from Britomart and along Albert St.
It will be an unknown journey of many different parts. We've planned it as best we can, but I know from experience you can't nail everything down.
Thousands of bore holes have been punched into the ground along the project's route to map soil conditions, but there still may be gaps that affect our tunnelling. Last year we unexpectedly came across buried fragments of a tree that could be as old as 40,000 years.
Building underground stations 400m long is an unknown engineering challenge, as is navigating our tunnel-boring machine through Auckland's volcanic foundations and dragging it across the huge holes dug for the stations — not once, but twice.
And at the end of all that, perhaps the most complex of all — safely integrating 3.45km of new railway with the rest of the network.
One of CRL's legacies will be the upskilling of a workforce that will benefit New Zealand long after we've finished.
I'm committed to opening the employment door for rangatahi — young people — and giving them job opportunities and support they may struggle to get elsewhere.
Mt Eden is one part of CRL's largest programme of work being delivered by the Link Alliance, a group of New Zealand and international companies with a proven record of delivering large and complex infrastructure.
I have a CRL team that includes the best expertise from New Zealand and overseas, taking the next big step of an outstanding project for Aucklanders.
While CRL will deliver a world-class rail system necessary for Auckland's future growth, I acknowledge its central city location makes the project impossible for Aucklanders to ignore or avoid.
Disruption is the word that comes to mind — disruption and more disruption!
Busy intersections are being closed in central Auckland to traffic, public transport schedules are being revamped, and bus services diverted. The Mt Eden station will close later this year for redevelopment and we will not reopen it until the project's end in 2024.
Communication has become just as important a tool to our planners and builders as a complicated tunnel-boring machine or a simple spade.
We get fantastic support from Aucklanders and I don't intend to lose that.
Our close partnership with Auckland Council, Auckland Transport and KiwiRail has some very direct goals to keep the city working and moving — "business as usual" train services while the Western Line remains open during the Mt Eden station closure is one successful outcome of that co-operation.
I know that one key to building a successful CRL is making sure Aucklanders know what is going on, and to give them time to plan ahead.
CRL is a project being constructed on several fronts: Mt Eden, Karangahape Rd, Aotea in the central city, and Britomart and the lower end of Albert St. Beyond the project's boundaries, we are working with KiwiRail on changes to the wider Auckland rail network to accommodate a new generation of train services.
I encourage people to look beyond the temporary inconvenience of disruption and diversion.
Auckland's future, I believe, will benefit greatly from CRL — much better transport choices, outstanding stations with uniquely New Zealand designs, nicer and more friendly streets, a smarter workforce, and an economic windfall from jobs and a housing and commercial building boom to come with my project's development.
• $4.4 billion rail project.
• Twin 3.45km tunnels under central city.
• Two underground stations.
• Who's involved in the next CRL stage: The Link Alliance, a group of New Zealand and international companies with a proven record of delivering large and complex infrastructure. The Link Alliance companies are Vinci Construction Grands Projets S.A.S., Downer NZ, Soletanche Bachy International NZ, WSP Opus (NZ), AECOM New Zealand and Tonkin + Taylor Limited.
New Zealanders are getting the chance to become involved in the CRL by choosing a name for the project's tunnel-boring machine.
The machine the Link Alliance will operate to complete the tunnels is being designed and built by German company, Herrenknecht. By tradition, machines like tunnel borers carry a woman's name to honour St Barbara, the patron saint and guardian of those who work underground.
"All New Zealanders are getting the chance to name the tunnel-boring machine after an amazing New Zealand woman," says CRL chief executive Sean Sweeney.
"The machine will help create huge changes for Auckland and it deserves the name of a New Zealand woman who, equally, has had an enormous impact on our country."
CRL's machine will be built at Herrenknecht's Guangzhou factory. It will be delivered to the Link Alliance in sections next September. The $13.5m machine will be 130m long, weigh 1600 tonnes and has a rotating cutter head 7.15m in diameter. It will start the first of its two 1.6km drives from Mt Eden to Aotea underground station in central Auckland next February.
The underground journey will take nine months. The machine will then be returned to Mt Eden in sections, reassembled, and its second drive is planned to start in January 2022.
At Aotea, the TBM-excavated tunnels will connect with the cut-and-cover tunnels under construction from Britomart Station and along the lower end of Albert St. Apart from excavating the tunnels, the machine will remove tunnel spoil by conveyor belt and install almost 15,000 concrete segments to line the tunnels.
It will have an underground crew of about 12 and at peak operation can travel 32m a day.
Herrenknecht also designed and built Alice, the machine used to construct Auckland's Waterview tunnel.
• Dr Sean Sweeney is chief executive of City Rail Link.
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