Two tunnel boring machines have reached the Airport Central Station at the Perth International Airport as part of the Forrestfield-Airport Link in Western Australia.

TBM Sandy broke through the arrival box at Airport Central Station last weekend, while TBM Grace arrived on 8 May.

These machines are 2km into their 8km journey to Bayswater, which lies 17m underground. The two were used last year for tunnelling purposes at Forrestfield.

Once works will be completed, passengers will be able to enter the station at ground level and proceed to a concourse and board train at platform level just as in the Perth Underground.

Before the arrival of the two machines, local workforce prepared the Airport Central Station box by assembling 2,200m² of concrete blocks in order to allow the machines to enter the station. These blocks also not only helped to stabilise the walls but also cut down water ingress during the breakthrough.

“These breakthroughs are an exciting milestone for this METRONET project – the station construction workers and machine operators are to be congratulated.”

The machines were taken through the 12.5m block for around 24 hours. A group of 15 workers were present inside each machine for the final breakthrough.

The two machines will be put under a month-long maintenance programme during which they will be cleaned and serviced. TBM Grace will then proceed to Redcliffe Station and TBM Sandy will follow about two weeks later.

Extensive works were completed in the past weeks at the Airport Central site, including the construction of the station’s base slab.

Providing a 20-minute connectivity between the eastern foothills and the CBD, this $1.86bn Forrestfield-Airport Link project is jointly funded by Western Australia ($1.37bn) and Federal ($490m) governments.

Western Australia Premier Mark McGowan said: “These breakthroughs are an exciting milestone for this METRONET project – the station construction workers and machine operators are to be congratulated.

“The scale of these machines are incredible, they are taller than a two-storey house, and the footage of them boring into the box structure is equally impressive.

“This job-creating, city-transforming project is just one element of our record rail investment for METRONET.”

The project is to be completed in 2020.