An 112-year-old bridge supporting trains between Perth and City West stations requires urgent replacement at a cost in the hundreds of millions, according to an advisory body report.
An 112-year-old bridge supporting trains between Perth and City West stations requires urgent replacement at a cost in the hundreds of millions, according to an advisory body report.
The Sutherland Street Bridge carries a trainline between the Perth and City West stations, running 3.7 metres above a road intersection near Watertown shopping centre.
The bridge has been struck by 11 vehicles over the past decade, including one last year, while concerns have been flagged over its capacity to serve its purpose given its age and height.
A 2023 structural assessment recommended immediate risk mitigation measures and a full replacement within two to five years, owing to the bridge’s age and condition.
Planning for that work is now underway, and a proposal submitted by the Public Transport Authority of WA to the independent advisory body Infrastructure WA earlier this year has shed new light on the urgency and cost of the requisite work.
“The deteriorating platform condition, including sagging and retaining wall movement, have been identified as requiring continuous monitoring and potential reconstruction,” IWA’s assessment of the PTA’s submission noted.
But the cost and disruption caused by replacing the bridge and carrying out station upgrade works required to support six-car trains at City West station – estimated at $723 million – was deemed unviable by the PTA, despite being the Authority’s preferred option.
It instead settled on a $267.9 million scope of work at Sutherland Street Bridge, which would prioritise the urgency of the bridge’s replacement and level crossing removals.
A 4.9-metre clearance would be introduced in place of the current 3.7m opening.
Platform upgrades and replacement works would be deferred under the smaller work program, deemed less urgent despite the government’s hopes of running six-car trains on the Fremantle, Midland and Airport lines by 2036.
IWA endorsed the latter of the two options – noting that pricing was likely to change with updates expected by the end of the year and recommending more detail be put forward before a funding approval is made.
The body also suggested clarifying the federal government’s willingness to chip in for half of the bill.
“IWA recommends that further design progression with associated cost estimates providing a higher degree of certainty, be provided to the WA Government to ensure confidence in the funding request,” it said.
“Additionally, the PTA indicates it will seek a 50/50 funding split between the State and Australian Government, and IWA recommends clearly outlining the funding sources, approval processes and associated timeframes.”
Both business cases assume closure of the Sutherland Street Bridge from as soon as 2028, with replacement bus services operating around the disrupted trainline.
The replacement Fremantle Traffic Bridge, being built to support road traffic between North Fremantle and central Fremantle, is forecast to cost $430 million – split 50/50 between state and federal government.
Infrastructure WA carries out independent assessment and analysis for major government projects with capital costs above $100 million.
