Lessons Learned: Expectation Bias, Lack of Effective Risk Controls
A Sydney Waratah passenger train was overspeeding four times normal limit near Blacktown Station due to expectation bias and a lack of effective risk controls.
Expectation bias and a lack of effective risk controls contributed to a passenger train overspeeding through a turnout near Blacktown Station at four times faster than the posted speed limit, a transport safety investigation report details.
On April 21, 2024, the driver of a Sydney Trains Waratah passenger train was thrown from his driving position when the train traveled at 101 km/h through a turnout with a posted speed limit of 25 km/h.
Fortunately, the train did not derail, no passenger injuries were reported, and the driver was able to safely stop the train at Blacktown Station.
The serious incident was investigated by the Office of Transport Safety Investigations (OTSI), which investigates rail occurrences in New South Wales (NSW) under a collaboration agreement with the ATSB (Australian Transport Safety Bureau).
The investigation found the driver, who had been based at Blacktown Depot for around seven years, did not react to and slow the train in response to signals ahead of the turnout.
“The driver was familiar with taking a different route and did not expect to go through a turnout,” OTSI Chief Investigator Jim Modrouvanos said.
“This turnout was among several identified four years earlier by Transport for NSW as representing a ‘not tolerable’ risk of overspeed and derailment,” he said.
A project to incorporate Automatic Train Protection (ATP) technology at these locations was downgraded in scope, the investigation found.
Sydney Trains therefore did not have effective controls for overspeed where high-risk turnouts had been identified.
After the incident, Sydney Trains lowered speed limits at high-risk turnout locations, including at this turnout, and developed a plan to implement ATP at these locations.
Sydney Trains also developed a response procedure for this type of overspeed incident, after it was identified that the train was not stopped for inspection after the occurrence.
“Overspeed carries a high risk of train rollover and the potential for multiple fatalities,” Mr. Modrouvanos said.
“So, the overspeed risk controls should be reviewed regularly to make sure they are still effective, and to see if there are any practical ways to further reduce or eliminate risk.
“Near-miss events like this one present an opportunity to revisit safety controls and make safety changes to further protect the traveling public.”
Read the final ATSB report: Train overspeed by run 805K, through BN 318 turnout, Blacktown, New South Wales, on 21 April 2024, publication date: 3/24/2026.
Content/image source/credit: ATSB, Train overspeed by run 805K, through BN 318 turnout, Blacktown, New South Wales, on 21 April 2024, publication date: 3/24/2026.
