The West Gate Tunnel Project is gigantic not only in scale, but also in the tools and machinery that were used to construct it.
Using various construction techniques and some of the biggest pieces of machinery in the Southern Hemisphere, we built twin tunnels under Yarraville and the elevated road above Footscray Road.
Tunnel boring machines
The twin tunnels were built using 2 tunnel boring machines (TBMs), so that the community and businesses could continue above ground while work happened below ground.
A 24/7 operation, the TBMs excavated 1.5 million cubic metres of rock and soil from the tunnel – enough to fill the MCG.
TBMs operate like moving underground factories, using their giant cutting heads to dig through the soil and rock. The TBMs on the West Gate Tunnel Project, named Bella and Vida, dug up to 27m under Melbourne’s west while progressively installing a watertight concrete lining behind them to create the new tunnels.
Bella and Vida – our TBMs
Tunnelling tradition dictates that a TBM cannot start work until it has been given a female name, a sign of good luck for the project ahead. This tradition dates back to the 1500s when miners and military engineers working with explosives for underground excavation prayed to Saint Barbara for protection.
Our TBMs are named after notable Victorian women:
- Bella Guerin – Born in Williamstown, Bella Guerin was the first woman to graduate from a university in Australia in 1883 and went on to teach at Loreto Convent in Ballarat.
- Vida Goldstein – Vida Goldstein was a groundbreaking campaigner for women's rights, establishing the right for women to vote and stand for elections.
Each machine weighs around 4000 tonnes, is 90m long and spans 15.6m in diameter – as tall as a 5-storey building. Behind the TBMs, crews worked to build the road surface and install electrics, ventilation and safety systems.
The tunnel boring machines started their journey from the portals in Yarraville and travelled south west underground towards the West Gate Freeway. TBM Vida took 295 days to complete her 2.8km journey building the inbound tunnel, breaking into the West Gate Freeway on 16 February 2023. TBM Bella, working on the outbound tunnel, broke through on 3 May 2023, taking 415 days to travel 4km.
Launching gantry
An elevated road above Footscray Road connects the tunnels to the city. The 1.5km-long road is up to 13m in height and is built atop pillars on Footscray Road, separating traffic coming from the tunnel and the inner west.
The elevated road was built using a launching gantry. It weighed in at 1200 tonnes, and was 40m tall and 116m long.
It sat on top of concrete pillars and lifted massive concrete segments into place to build the road deck. The launching gantry started building the road on the westbound side of Footscray Road. It made its way for 1.2km toward the Maribyrnong River and then changed direction, moving to the citybound side of Footscray Road, to construct the inbound road toward CityLink.
In total, it took 2 years to travel 3.7km.