Auckland’s 1.6km long City Rail Link (CRL) is celebrating a mighty milestone with its 7.15m diameter Herrenknecht EPBM, Dame Whina Cooper, breaking through into the Karangahape Station construction site at the end of its 860m journey from Mt Eden.
CRL workers 32m below ground at Karangahape welcomed Dame Whina Cooper as the TBM breached a 100mm thick protective wall of concrete into the station cavern.
“Despite all the curve balls, complications and challenges covid keeps throwing our way, we’ve arrived – it’s a positive, exciting and significant arrival,” says City Rail Link Ltd’s Chief Executive, Dr Sean Sweeney. “Aucklanders can’t see it, but far below their streets a railway that is going to change their lives for the good is rapidly starting to take shape.”
Dr Sweeney says breakthrough success is tempered by covid’s continuing consequences for New Zealand’s largest transport infrastructure project. “It is very clear, and it shouldn’t surprise anyone, that the pandemic has had serious impacts on our project costs and construction timings” he says. “Assessments are underway now so that we have a much clearer picture of the extent and depth of covid’s effects on us.”
New Zealand’s recent five-week-long covid lockdown delayed the TBM’s planned September breakthrough. CRL’s main contractor, the Link Alliance, continued to operate the TBM during the lockdown, well below full capacity, to stop earth settling around it. Tunnelling accelerated when lockdown restrictions eased.
“Great collaboration, planning and old-fashioned hard labour from all our teams below and above ground helped us regain some of that momentum lost to the lockdown – we’re at Karangahape in great shape well ahead of our rescheduled time in November – a real bonus,” says Link Alliance Project Director, Francois Dudouit. “The TBM was running sweetly at a rate higher than planned during its drive under Spaghetti Junction on the motorway.”
Covid-related health and safety protocols curtailed larger breakthrough celebrations. The TBM operators did mark their arrival with a symbolic gift for Karangahape Station workers – a hard hat representing the Link Alliance’s commitment to achieve industry-leading standards in health, safety, and wellbeing. The hard hat bears Dame Whina Cooper’s portrait.
The TBM began mining from the Mt Eden Station construction site five months ago, in May. The TBM multi-tasked – cutting into the earth, removing spoil to the surface, and installing the concrete panels that line the tunnels.
At Karangahape the 130m long TBM will now be pushed 223m to the northern end of the station cavern and readied for the next stage of its journey, to Aotea Station in Auckland’s midtown. Its planned arrival is early in the new year where it will connect with the tunnels already built from Britomart and under the lower end of Albert Street.
A single Alliance is delivering the main CRL works – the stations and tunnels. The Link Alliance consists of Vinci Construction Grands Projets S.A.S., Downer NZ Ltd, Soletanche Bachy International NZ Limited, WSP Opus (NZ) Limited, AECOM New Zealand Limited and Tonkin + Taylor Limited.
The second CRL tunnel from Mt Eden to Aotea will be bored in 2022.