from Sydney Metro;

TBM Peggy achieved the project’s penultimate tunnelling breakthrough last Friday after making a smashing entrance at the newly named Bradfield Railway Station site, which was previously known as Aerotropolis Station.  

TBM Peggy’s breakthrough follows TBM Eileen’s breakthrough at Bradfield on 29 May and completes major tunnelling work to construct the 5.5-kilometre tunnels from Airport Business Park, underneath the new Western Sydney International Airport, to Bradfield. 

At the opposite end of the alignment, TBM Catherine was first to wrap up its tunnelling journey on 20 May. The TBM has built a 4.3-kilometre tunnel from Orchard Hills, under the M4 Motorway and the Great Western Highway to St Marys.  

TBM Marlene is working hard to complete the final 230 metres of tunnel for the project and is expected to break through at St Marys in the coming weeks. 
 
The TBMs have worked around the clock up to seven days a week to build the tunnels and have excavated 1.8 million tonnes of material, enough to fill 293 Olympic pools, and the installation of 68,360 concrete segments to line the new tunnel walls.   

The focus of the mega project will now turn to the delivery of six new metro stations at St Marys, Orchard Hills, Luddenham, Airport Business Park, Airport Terminal and Bradfield.   
 
Major station construction is already underway at St Marys, with the first large concrete pour taking place on 22 May to build a 13-metre by 22-metre slab that will form part of the base to support the multi-level station above.  

Orchard Hills, Luddenham and Bradfield station sites are also being prepared for major station construction to commence in the coming months.  

Work inside the tunnels will continue and involve completing the construction of 39 cross passages and preparing for track laying. 
 
Sydney Metro

source:

https://www.sydneymetro.info/article/three-tunnels-done-and-dusted-sydney-metro-western-sydney-airport-one-go