As part of the future O’bahn extension we were engaged to lay approx. 360m of sewer trunk main along North Terrace and Botanic Road. Due to the traffic management requirements in the busy metropolitan area the works were done at night under a strict timeline. Contraflow traffic was required to be maintained throughout the whole project.

This existing main to be replaced was required to be kept live throughout the project until a bypass system was implemented to divert flows into the new main. Works also involved crossing Hackney Road with the sewer encased in a 16m mild steel cement lined (MSCL) pipe. The trunk main had an average depth of around 5m and was comprised of both 450 and 525dia rib lock pipe. It involved the installation of 7 new man holes that were made up of pre-cast bases to minimise the time spent constructing them in situ.

Once laid, the downstream end of the new system was livened up to allow the 6 existing connections to be sequentially transferred over to the new main. After the new main became fully operational the existing man holes were broken down 1m below surface level and grout filled with the old main.


Hackney Road, Adelaide, SA




December 2015 – January 2016


Fulton Hogan