Our micro-Tunnel Boring Machine (m-TBM) called Domenica has today (16 November) broken through to Miranda Reserve, Avondale after travelling 1212m from Dundale Ave, Blockhouse Bay as she builds the first of two branch sewers for our Central Interceptor.
This is the third breakthrough for the m-TBM and longest drive of the branch sewer project, second only to our Hūnua 4 pipeline (completed in July) which was constructed using the similar pipejacking methods and held a southern hemisphere record for the longest single drive (1296m).
Central Interceptor executive programme director, Shayne Cunis says the breakthrough was achieved well ahead of schedule: “We are incredibly proud of the efforts of the Ghella Abergeldie JV tunnelling teams who have achieved this milestone more than a month ahead of schedule. They are a tight team with good skills and a bucketload of experience.
"I’d also like to pay tribute to our designers, who modified the original plans so that we did away with the need for a shaft at Whitney St. This has saved residents considerable disruption, reduced the cost and carbon footprint of the overall project."
The m-TBM began tunnelling in July last year and has been travelling up to 25m/day and laying up to eight 2.1m diameter pipe rings per day. The branch sewers will connect to the main 14.7km Central Interceptor tunnel (which is currently being laid underneath the Manukau Harbour en route for Hillsborough) and will significantly clean up Auckland’s waterways by preventing wet-weather overflows.
Domenica will now be removed from the tunnel so the cutterhead can be inspected and refurbished before she completes the final 330m early next year.
Work on the second branch sewer, running from a site next to Mount Albert Memorial to Rawalpindi Reserve is due to begin in August 2023 and will be completed before the end of the year.
To learn more, watch this video.