Platforms at dozens of train stations across Perth will need to be extended to support upgraded and longer rail cars.
About 40 platforms will be lengthened on the Armadale, Midland and Fremantle lines in a program expected to be rolled out over more than a decade.
Longer platforms will help move more patrons onto trains during peak commuter hours.
The proposal is also necessary because the Public Transport Authority is set to retire old trains which run on the three “heritage” rail lines following a broader $1.4 billion deal to build rail cars locally.
The new C-series cars assembled by Alstom will operate on the Joondalup and Mandurah routes, with the existing B-series trains running on those lines to be shifted to the three older lines.
But those trains run in three and six-car sets, and stations along the Armadale, Fremantle and Midland routes are mostly designed for four-car trains.
The State and Federal governments chipped in $22.5 million in 2019 to develop business cases for the platform upgrades, with a targeted due date of 2022. That later slipped to mid-2024.
Stages one and two of the plan will see $290m spent to extend the Claisebrook, Maylands, Meltham and Victoria Park stations.
InfrastructureWA released its assessment of that business case on Thursday.
The independent umpire said there were platforms on the old rail lines without sufficient length to support six-car trains.
![Stations needing extensions.](https://timesofsydney.com/wp-content/uploads/2024/07/f0f0eb203d771a84f61aac7dc127946a2cd35925.jpg)
“Without upgrades to platform lengths or operational changes, only three-car B-series trains will be able to operate, limiting service capacity,” IWA said.
Services on the new Ellenbrook and Thornlie-Cockburn lines would also be impacted because they link in to the existing network.
“Without upgrades to existing four-car platforms or operational changes, these new lines will be restricted to three-car operations, which over time will impact on forecast passenger demands,” IWA said.
The report shows that alternatives were assessed, including retaining the older trains and opening only selective doors at platforms, adding that the financial evaluations between them had been “reasonably applied”.
The program will also update signalling on the rail network to move trains more frequently, with as many as 15 services an hour in the early 2030s.
The State Government has been contacted for comment.