Case History Catch-Up: Central Interceptor NZ – Dundale shaft

Dundale cascade shaft segments and installation (composite image)

Case history Catch-up – July 2023:

Another great milestone for the RPC Infrastructure team managing the Cascade Shaft engineering, manufacture and installation for Central Interceptor project in Auckland, NZ. Congratulations!

RPC have manufactured, delivered and installed the 6th Glass Reinforced Polymer (GRP) cascade shaft consisting of a 4.5m diameter x 24m deep, at Dundale, NZ, for our customer GAJV, for the WaterCare Central Interceptor project in Auckland. This comprised two x 4.5m diameter cascade GRP segments, 11.33m and 12.2m long, weighing 34 and 26 tonnes, respectively.

A third unit, a 3m diameter control chamber, 7.7m long, weighing 7.7 tonnes, connects to the adjacent main GRP cascade shaft. In the top image you will see the massive units alongside the excavated shaft ready to be installed. In the second image you can see the first segment in-situ with Daniel from RPC Seven Hills and Michael Hannan from our contractor Pollock Cranes securing the segment. Off to the sides are the two 2.1m diameter sewer link connections.

The cascade shaft structures were manufactured using GRP materials by RPC showcasing advanced engineering in underground infrastructure.

GRP structures boast outstanding resistance to harsh environmental conditions, making them ideal for sewage and wastewater applications such as this.

GRP structures also deliver exceptional strength and asset life, ensuring the structural integrity of the shaft over time. Their lightweight nature, compared to traditional materials such as steel and concrete, facilitates efficient installation, reducing construction time and costs.

Following the December 2023 completion of the May Road GRP Cascade Shaft, the 8th and final cascade shaft structure, for Rawalpindi, is currently being manufactured and is due for installation in June 2024.

Case studyCentral InterceptorDesign, manufacture, delivery and installation of nine GRP shafts, 3m–7.5m in diameter, joined to the 16.2km wastewater tunnel, the largest wastewater project in NZ history.

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Point Erin GRP cascade shaft segment on a transport trailer

Infrastructure

Significant Milestone – Point Erin

Last week we celebrated a significant milestone at RPC with the final two (section 1 and 4) segments of the Point Erin 3.2 diameter shaft departing from our manufacturing facility in Batam, Indonesia.

Looking down the Tawariki shaft during installation

Infrastructure

Tawariki GRP cascade shaft Installation

RPC Technologies has recently installed the first 4 segments of the Tawariki GRP cascade shaft as part of Watercare’s Central Interceptor project in Auckland, New Zealand.

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