Link maker

Auckland City Rail Link project tunneling complete

The tunnel boring phase of the City Rail Link (CRL) project in Auckland, New Zealand has been completed after tunnel boring machine (TBM) Dame Whina Cooper broke through at Te Waihorotiu Station (Aotea).

This phase involved the drilling of twin 1.6km tunnels up to 42m under the country’s largest city.

The City Rail Link tunnels were constructed with over 64,200 m³ of concrete.

Traveling over 3.2 km, the TBM placed 2,118 segment rings and removed 260,000 t of cuttings while drilling the twin tunnels from Maungawhau/Mount Eden Station to Te Waihorotiu Station.

With a length of 130m and a diameter of 7.15m, the Dame Whina Cooper TBM weighs 910t.

This tunnel boring machine will be dismantled and lifted above ground, as the boring of the tunnel is now complete. It will be sent to port to be returned to its manufacturer, Herrenknecht.

In a statement, Auckland Mayor Phil Goff said: “The final tunnel breakthrough is the culmination of 13 months of hard work by tunnel boring crews.

“When completed, City Rail Link will provide faster and easier access to central Auckland and surrounding areas, immediately doubling heavy rail capacity and ultimately carrying up to 54,000 passengers per hour at peak times.”

Link Alliance is a group of companies responsible for contracting major tunnels, stations and rail systems for CRL.

Link Alliance project manager Francois Dudouit said “the faster completion of the second tunnel reflected operational improvements and efficiencies”.

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