Project proponent City West Water decided to employ Trenchless Technology for the construction of the water mains across tram tracks and major intersections like Flinders Street, Collins Street and Latrobe Street. This allowed for faster construction and less disruption to traffic and local residents. It also meant shutting down tram services could be avoided. Further benefits included minimisation of excavation and reinstatement of pavements; and enabling the removal of their old wrought iron main for recycling.
City West Water contracted Scarriff Pipelines to undertake the work, with trenchless works sub-contracted to Harris Civil. The Trenchless Technologies considered included: pipe cracking, which was deemed not suitable for installing the MSCL pipes required; sliplining, which would have reduced the size and capacity of the pipe; and laser boring and directional drilling, both of which would require a new alignment and posed a higher risk of damaging other utilities during boring and drilling.
Pipe ramming was chosen as the preferred method because it enabled construction along the existing pipe alignment and fit the other necessary requirements.