Industry Infrastructure, NSW, Rail industry news (Australia, New Zealand), Tunnelling

Western Sydney Airport tunnels on homestretch

Mega tunnel boring machines (TBMs) constructing the Sydney MetroWestern Sydney Airport southern tunnels are edging closer to their final destinations.

TBMs Eileen and Peggy have built 4.7 and 4.5 kilometres of tunnel respectively so far. Together 852,288 tonnes of spoil have been excavated, enough to fill 136 Olympic-sized swimming pools, while 32,472 concrete segments have been installed to line the new twin tunnel walls.

The mega machines have had a couple of pit stops along the way after starting their journey at Airport Business Park and breaking 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 5.5-kilometre southern metro tunnels.

The TBMs spent nine days traversing the 10-metre-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 per cent respectively through building the 4.3-kilometre tunnels between Orchard Hills and St Marys, as they get ready to cross the finish line.

Once open, Sydney Metro – Western Sydney Airport will become the transport spine for Greater Western Sydney and will drive major development and economic growth in the region.