By lyndamyer
As an advancement and remarkable landmark within the Watercare Services Limited’s Central Interceptor project, the TBM Hiwa-i-te-Rangi, that is almost 200 meters in length, has successfully breached into a shaft at a depth of 47 meters beneath ground at the Lyon Avenue site in Mt Albert. Running from the shaft at Haverstock Road in Sandringham to Pt Erin in Herne Bay, where the 16.2-kilometer-long tunnel is being constructed, this journey was just over 1 kilometer. Excavating a distance of 2450 meters, the TBM heading towards Western Springs later this year in its next phase, whereas Hiwa-i-te-Rangi is one of three TBMs actively involved in the Central Interceptor project in Auckland.
Breaking through the concrete shaft wall at the Norgrove Ave site in Mt Albert on April 27th, 2024, was up to the micro-TBM Domenica with a diameter of 2.8 meters, while it was an indication of completing the second of two link sewers. Domenica, initially commissioned in June 2021 by the construction Ghella Abergeldie JV, has accomplished over 4 kilometers of tunneling.
With over than 1 kilometer in length, Link Sewer B intersects the main Central Interceptor tunnel at the Mt Albert War Memorial site and in collaboration with Link Sewer C, which links to the main tunnel at May Rd, these link sewers are going to gather combined wastewater and stormwater flows from West Auckland, diverting them to the Māngere Wastewater Treatment Plant for processing, thereby preventing discharge into streams and beaches during heavy rainfall.
In order to safeguard against the corrosive impact of wastewater, and ensuring a lifespan of up to 100 years, the teams of welders are engaged in thermal welding on joints in the tunnel’s plastic liner, while Domenica is currently being extracted from the shaft, using pipe-jacking equipment and other necessary services.
As the third TBM involved in the Central Interceptor project, Victoria is a micro-tunnelling TBM measuring 12 meters in length, and now is linking the main tunnel to the local wastewater network in Keith Hay Park, Mt Roskill.
Although the determined date for completion of a portion of the Central Interceptor tunnel, along with the link sewers, is before the year’s end. The project is scheduled for completion in 2026.
