The Auckland City Rail Link celebrated a major milestone today with the Albert St tunnels connecting to the Commercial Bay site.
The CRL is the most significant infrastructure project in New Zealand. When complete it will carry more than 50,000 passengers during peak hours.
Mayor Phil Goff said with the Albert St trench excavation complete the city was one step closer to delivering Auckland's first underground rail line.
"The CRL will not only change the way we travel through Auckland's central city, it will significantly enhance the efficiency of our entire public transport network, freeing-up our streets from bus congestion and delivering more efficient and frequent train services across the city."
CRL CEO Dr Sean Sweeney said despite some financial issues with one of their contracts, today's breakthrough proved they were on track and making great progress.
"It's fair to say getting to this point has not been without its challenges. This is the largest transport project ever undertaken in New Zealand and building it within the middle of a built-up city is no small task.
"The nature of the excavation, the tight confines and the location all make building this project extremely complex and I'm delighted with the progress we have made to date."
The tunnel breakthrough required a staged approach over the past month to excavation, construction of shotcrete support between piles, and demolition of temporary concrete piles separating the two sites, Dr Sweeney said.
The tunnels between the two sites meet under the Customs St traffic deck, which was built last year to keep traffic moving while the work was carried out underneath.
Sweeney said now the contractor would construct the remaining third of the tunnel box.
Backfilling of the trench would continue until it was completely covered – expected to be mid-2019.
Early next year the tunnels from the former CPO (Britomart) site would also connect to tunnels across the Commercial Bay site, providing a complete tunnel section from Britomart through to Wyndham St.
The City Rail Link
• Albert St trench: completed late 2019.
• The trench has 29 sections of tunnel box, each 12 metres long.
• 60m3 concrete for side walls of tunnel box and 28m3 for central wall.
• 50,000m3 of fill required for the Albert St trench: 20 Olympic pools' worth.
• Britomart: completed 2020.
• Stations and tunnels, systems and Western Line upgrade: completed 2024.
• More than doubles the capacity of the existing rail network.
• Speeds travel times to and from the city: 17 minutes saved between Henderson and Aotea.
• Budget $3.4 billion.
• 1600 jobs during peak construction: tender companies required to upskill the local workforce with a focus on Maori, Pasifika and youth, and to support local businesses in the supply chain.