Sydney Metro has provided an update on its tunnel boring machines (TBM) constructing the new 23-kilometre Western Sydney Airport (WSI) metro alignment in Greater Western Sydney.
The TBMs, affectionately christened Eileen and Peggy, have been building two 5.5-kilometre southern tunnels from the airport’s Business area to its Aerotropolis. They are currently 1.8 and 1.5 kilometres into their construction, respectively.

Boring began in April of 2023, and is expected to conclude in mid-2024.
Since leaving their starting point, the two machines have been travelling at an average speed of 120 metres per week and have excavated a combined 305,000 tonnes of material in their journey, installing 11,800 concrete segments along the walls of the new tunnel.
In addition, two more TBMs have been launched from Orchard Hills, and are now roughly one kilometre into their journey to carve out a 4.3-kilometre tunnel at the northern end of the alignment at St Marys.
The works are expected to create journey times of around 20 minutes between St Marys metro station and Aerotropolis Station end-to-end.