Perth's Forrestfield-Airport Link project has reached a major milestone, as the first tunnel-boring machine arrives at Redcliff Station. 

It has now tunnelled 62 per cent of the 7.4 km tunnel component of the train line to Bayswater.

On Saturday, West Australian Premier Mark McGowan and Transport Minister Rita Saffioti announced the machine had reached the station construction site on Thursday.

It was the first time the machine surfaced since leaving the Airport Central Station box in June 2018.

Mr McGowan said both machines completed tunnels under Perth Airport’s runways.

“The last time I saw this incredible machine it had just broken through the wall at Airport Central Station,” Mr McGowan said.

The project’s second machine is about 500 metres behind the first.

It is expected to break into Redcliffe in June.

Ms Saffioti said once works and maintenance are complete, the two tunnel-boring machines will begin the final leg of their journey.

“They will tunnel to a depth of 22m under the Swan River before surfacing at the Bayswater dive structure.”

The Forrestfield-Airport Link project involves building a new rail service to Perth’s eastern suburbs, adding three new stations at Redcliffe, Airport Central and Forrestfield.

The $1.86 billion project is jointly funded by the federal and state governments.

The first trains are expected to operate in late 2021.