The first tracks have been laid on the METRONET Morley-Ellenbrook Line, marking a major milestone for the game-changing project in Perth's northeast - the biggest expansion of the city's rail network since the Mandurah line.

The first section of rail will see approximately 1.5 kilometres of ballast and sleepers installed north of Whiteman Park Station through to the Gnangara Underpass and along Drumpellier Drive.

Specialised equipment has been used to undertake the feat, including a ballast box spreader which positions the ballast and an excavator with an 'octopus' attachment to position the sleepers.

The $1.1 billion project is jointly funded by the Federal and State Governments and is the longest METRONET project.

The 21-kilometre Morley-Ellenbrook Train Line also represents the most significant expansion of the Perth rail system since the Mandurah Line opened in 2007.

It includes new stations at Morley, Noranda, Malaga, Whiteman Park and Ellenbrook, with patronage expected to reach 18,000 people boarding per day by 2031.

The project will support the area's growth as a major activity centre, while making the most of development opportunities nearby, including for new housing.

The journey from Ellenbrook to Perth City will only take 30 minutes once complete, giving those living in the north-eastern suburbs greater transport choice, reduced travel times and new modern stations.