Sydney Metro says TBMs Eileen and Peggy have so far built 4.7km and 4.5km respectively of the 5.5km tunnel. Together they have excavated 852,288 tonnes of spoil and installed 32,472 concrete segments in the twin tunnels.

CPB Contractors and Ghella Joint Venture launched the two TBMs at Airport Business Park and broke through at the Airport Terminal station site and temporary shaft before continuing to tunnel under the future Western Sydney International Airport.

Their most recent breakthrough was at the Bringelly services facility shaft, which is being used as a tunnelling and construction support site during the delivery of the 5.5km southern metro tunnels.  

The TBMs spent nine days traversing the 10m-diameter shaft and undergoing maintenance before being relaunched to continue tunnelling towards the Aerotropolis.

Now that the TBMs have relaunched, work at the Bringelly site involved removing the concrete tunnels the machines left behind across the shaft, with access being maintained to supply materials for construction.

A further two TBMs, Catherine and Marlene, are about 89% and 80% respectively through building the 4.3km tunnels between Orchard Hills and St Marys.

Once open, the 23km Sydney Metro – Western Sydney Airport will become the transport spine for Greater Western Sydney.