Precast for Perth’s first elevated rail
A dedicated precast facility, built for one project, helped lift the Armadale Line off the ground
For years, boom gates on the inner Armadale Line were down for several hours a day, dividing suburbs across Perth’s south-east and holding up traffic at six busy level crossings.
The METRONET Victoria Park-Canning Level Crossing Removal Project changed that. Almost four kilometres of the line now runs on elevated rail, the crossings are gone, and new public space has opened up beneath. We manufactured the rail corridor the trains now run on.
Taking a major project approach, Humes, a Holcim company, built a dedicated factory to supply the project. Our facility at a repurposed industrial site in Midland produced 57,000 tonnes of precast concrete.
Cranes lift a precast beam into place on the elevated Armadale Line during night works. Up to 10 beams travelled from our Midland facility to site each night.
Each L-beam, used to construct the rail corridor walls, is a prestressed concrete beam around 30 metres long that weighs 130 tonnes. Steel strands tensioned in the prestress bed allow the beam to carry rail loads between supports.
Manufacturing offsite allowed our production to run ahead of construction, with our L-beams finished before the line closed for works in November 2023. Casting at ground level in controlled factory conditions also moved much of the work at height away from the rail corridor and gave our team consistent quality control on every unit.
Holding production rates at that scale required continuous refinement on the Humes factory floor: identifying bottlenecks, timing each manufacturing step and adjusting the process as we went. Sensors cast into each beam tracked the concrete’s temperature as it cured.
Moving the beams was a project in itself. Up to 10 L-beams travelled to the site each night under careful coordination.
Every unit is part of the Humes FutureCast lower-carbon precast range, reducing the project’s embodied carbon without compromising the strength and durability that an elevated rail corridor demands. All water used to clean the beams was recycled.
The precast was delivered to program for the Armadale Line Upgrade Alliance of Acciona, BMD, WSP and AECOM.
Night works on the elevated Armadale Line, with precast beams spanning the corridor above a former level crossing. Manufacturing offsite in Midland kept production ahead of construction.
