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City West Water

Boring Machine On Interesting Journey

One of City West Water’s sewer upgrades has reached a major milestone, with a Tunnel Boring Machine (TMB) currently working its way under Spencer Street in Melbourne’s CBD.

Kate Houlden, Project Delivery Manager City West Water, says the installation of the tunnel borer is an exciting ‘next step’ for the Spencer Street Sewer Upgrade project.

“With population growth set to increase by 14,000 apartments within the Spencer St Sewer catchment, tunnelling works to increase its capacity are vital.

“Our TBM - owned by Bothar Boring - has made its journey from its last project in Lismore, NSW, and is now beginning its next journey under Spencer Street.

“Weighing in at an impressive 25 tonnes, our TBM is about four times as heavy as a Tyrannosaurus Rex!

“The borer is 9 metres and is made up of three sections – cutter head, power pack and telescopic sections - which have been lowered into the 12-metre-deep launch shaft in stages.


“The sections were delivered one day at a time, with our crews working hard to ensure that each was installed safely, on time and with precision.”


The Tunnel Boring Machine is now making its way from Lonsdale Street towards the 7.5 metre-deep retrieval shaft that will be constructed at Flinders Lane.


The borer works its magic quite quickly, with 6-8 metres of pipe being installed every 12 hours for the next several months, says Kate Houlden.


“The total length of the bore will be just over 590 metres with a bore diameter of 1.5 metres.


“On completion our TBM will be pulled out of the retrieval shaft at Flinders Lane and transported to another project location for reuse.”