The TBMs have covered a combined length of 2.5 kilometres and are expected to arrive at Airport Central Station in the coming months.
TBM Grace began tunnelling last August, and is travelling an average of 26 metres per day.
The second TBM, Sandy, began tunnelling in October 2017 and is one kilometre into the second tunnel.
As the TBMs progress, 54,000 locally made concrete segments will be installed to line the seven-metre diameter tunnels, creating the tunnel walls.
More than 16,000 of the concrete segments have already been locally manufactured at a purpose-built facility near the project site in Forrestfield.
About 2,000 jobs will be created over the life of the project, including in the manufacturing and construction industries.
Completing the Forrestfield-Airport Link is a key part of the McGowan Government's METRONET plan, creating a 20-minute direct link between the eastern foothills and the central business district - as well as the wider public transport network - via the airport.
The project is jointly funded by the State and Federal governments.
Comments attributed to Premier Mark McGowan:
"Completing the Forrestfield-Airport Link is a key part of my Government's METRONET plan to connect Perth's suburbs and ease congestion.
"METRONET will provide an innovative public transport system that will invigorate communities and create thousands of local WA jobs.
"We are committed to delivering on our election commitment to create more WA jobs and a rolling stock strategy to grow our State's capacity to build METRONET railcars locally."
Comments attributed to Transport Minister Rita Saffioti:
"The Forrestfield-Airport Link will open up the Perth foothills, providing a new option for the community to access the CBD, Perth Airport and wider public transport network.
"The METRONET team has been planning land use opportunities around Forrestfield and Redcliffe Station to create well-connected communities within the station precincts.
"The next major milestone will be when the first TBM reaches Airport Central Station in the next month or so."
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