Featherston St rising main renewal



Wellington Water




December 2022


Mobile Plant Fleet,Underground Services,Traffic Management,Dynamic Pipe Bursting,Static Pipe Bursting,PE Welding

Customer Type:

Government & Local Government


Renew approximately 240m of existing cast iron rising main with 315OD PE100-RC SDR17 pipe by slip lining. Replacement of complex pipework in the intersection of Waring Taylor & Featherston Streets where rising mains from PS8, PS9 & PS42 join a shared rising main. Commissioning of the new network including testing, shutdowns and cut ins to the existing system.

We rose to the challenge, working with our friends at Stantec, to deliver this project in a complex traffic management environment, congested services and working in a live existing rising main network – all requiring some innovative solutions.

We planned and delivered all traffic management that supported the work and kept disruption to a minimum. We worked closely with the RCA throughout to ensure that the Traffic Management solution was the best possible for all stakeholders.

This was also a project where our knack for solutions came to life. We designed a phasing solution to address working in an existing live rising main network, running trials to prove that the work could be carried out without putting the existing operations and the environment at risk.

We also designed and fabricated a specialist scraper to clean an existing cast iron pipe to accept a slip line. The scraper was supported by high pressure water flushing and resulted in an ideal host pipe for slip lining.

We slip lined approximately 180m of pipe using PE welding to produce a high-quality string of PE pipe with a resin additive that made it resistant to crack propagation. The string was pulled into place using a constant tension winch that effectively managed the forces applied to the pipe.

We were surprised by the level of service congestion and the team on site did an outstanding job of managing to install high quality infrastructure under very challenging conditions.

Last but not least, by renewing this main trenchlessly, the project has reduced waste, minimised carbon emissions and kept the City moving.