Three TBMs Now Tunnelling on Melbourne’s Suburban Rail Loop

Three tunnel boring machines are now operating simultaneously on Melbourne’s Suburban Rail Loop project, according to an update dated October 27, 2026. TBM Hacia, TBM Alice and TBM Aayushi have excavated a combined 138 metres of tunnel.

TBM Aayushi has launched from the Clarinda site and is tunnelling towards Glen Waverley. Its launch brings another machine into active excavation, with three TBMs now contributing to the project’s underground works.

The operational significance lies in managing concurrent excavation. Running several TBMs at once can create opportunities to advance work in parallel, while increasing the need to coordinate machine support, material deliveries and the removal of excavated material. Whether simultaneous operation translates into faster overall delivery will depend on how consistently those activities support tunnelling.

The combined 138-metre total records progress to date, but does not establish an excavation rate or demonstrate performance across different ground conditions. For TBM practitioners assessing the project’s relevance to complex urban tunnelling, subsequent progress reports would be more informative if they show sustained advance rates, machine availability and the conditions encountered.

The immediate milestone is the operation of three machines at the same time. Continued excavation will provide a clearer basis for assessing how effectively the project converts that capacity into sustained tunnel production.