TBM starts second drive on Auckland underground

26 April 2022

The TBM digging New Zealand’s first underground railway has started its second journey.

The TBM, named in honour of Maori champion Dame Whina Cooper, this week started its second drive to build the link from City Rail Link’s (CRL) Mt Eden site to central Auckland. Its first destination will be the underground station below Karangahape Road before a planned arrival next spring at the project’s Aotea site.

The first of the two CRL tunnels was completed on Christmas eve last year.

“Fantastic teamwork by the TBM crew to get cracking today despite all that Omicron could throw at us is a great achievement and something Aucklanders should rightly celebrate as we take a huge step towards completing CRL,” said Dr Sean Sweeney, CRL chief executive.

Dame Whina Cooper is operated by main contractor the Link Alliance, a consortium comprising Vinci Construction Grands Projets, Downer NZ Ltd, Soletanche Bachy International NZ Ltd, WSP Opus (NZ), AECOM New Zealand Ltd and Tonkin + Taylor Ltd delivering CRL’s main tunnels, stations and rail systems contract. The Herrenknecht EPB TBM is 130m long and has a 7.15m diameter.

Link Alliance project director Francois Dudouit said the TBM’s second drive would be just as challenging as the first.

“We learnt a lot from last year but constructing a bored tunnel is a unique and complex task bound to bring challenges, particularly when you’re working below a city. Importantly, our TBM crews are experts at successfully confronting obstacles – restricted working conditions because of Covid or Auckland’s ground conditions – and getting the job done safely,” he said.

CRL is the largest transport infrastructure project ever to be undertaken in New Zealand. It comprises a 3.45km twin-tunnel underground rail link up to 42m below Auckland city centre. It will transform the existing downtown Britomart Station into a two-way through-station that better connects the city’s rail network.

The project is due to be completed in late 2024, but CRL is currently assessing the impact the Covid-19 pandemic is having on the construction timetable and costs.