Tunnelling

Excavation of Legacy Way’s twin parallel tunnels started in August 2012. Transcity used two specially imported Double Shield tunnel boring machines (TBMs) to excavate the 4.6 kilometre tunnels from the Western Freeway at Toowong to the Inner City Bypass at Kelvin Grove.

It took the TBM’s 10 months to complete their journey beneath the suburbs of Toowong, Auchenflower, Milton, Paddington, Red Hill and Kelvin Grove, with the first TBM launched in August and the second TBM in October.

Once excavation of the parallel tunnels was completed, Transcity excavated 37 cross passages and two substations between the two main tunnels.

Backfilling & construction of the road surface commenced in September 2013 with the installation of mechanical and electrical systems to be completed throughout 2014.

Tunnel Boring Machines