The TBM broke through a Khyber Pass Road, setting a record of 1216 m for the longest single drive in the southern hemisphere by a TBM larger than 3 m in diameter.
Watercare Project Manager David Moore said the beauty of the project is a huge piece of infrastructure has been built with minimal disturbance, as the 60 t Herrenknecht machine bored at depths up to 30 m below ground level.
“We tunnelled from right next to the new Westfield Newmarket mall under New Zealand’s busiest road – the southern motorway – to Khyber Pass Rd without disturbing the public,” said Mr Moore.
Watercare’s project contractor, McConnell Dowell, broke its own previous record – achieved for the Christchurch Ocean Outfall project in 2007 – by 345 m.
McConnell Dowell Project Manager Richard Atkin said the new record demonstrates the skills and experience of its tunnelling teams, as well as the contractor’s commitment to working through challenges.
“In this tunnelling drive she bored through more than a kilometre of basalt rock, and curves with a radius of 750 m, which placed pressure on the interjacking stations,” said Mr Atkin.
There is one more drive to go in the final section of the watermain project, which will see a new record set once again at 1296 m long.
The watermain project will cater for Auckland’s growing population and add resilience to its water network, with construction aiming to be finished next year.
For more information visit the Watercare website.
This article was originally published on 7 August 2020.
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