A collision involving two trams operated by a tram museum highlights the importance of strong risk controls and ensuring that any changes to procedures do not reduce a risk-control’s effectiveness, a new ATSB investigation has found.
The accident occurred in Loftus in Sydney’s south when a ‘J’ class tram, operated by the Sydney Tramway Museum, was parked on a downhill gradient using its air brakes with a hardwood chock applied under its wheel. With no one on board, the tram suddenly rolled away, heading towards another of the museum’s trams – a ‘Nagasaki’ class that was travelling in the opposite direction on the same line.
Sighting the approaching ‘J’ class tram, the driver of the Nagasaki applied the emergency brake and instructed all 16 passengers to evacuate immediately. All passengers and crew had exited the Nagasaki safely before the trams collided, with both trams sustaining minor damage.
In line with the museum’s procedures, the runaway tram’s handbrake had not been applied when it was parked and when air released from its brake system, a single hardwood chock was left to restrain the tram’s movement. Previously a softwood chock, which would deform and create a tight wedge, would have been placed under the tram’s front wheel, but the tram was able to roll over the hardwood chock.
The investigation highlights the importance of ensuring that any changes to a risk-control process do not reduce that risk control’s effectiveness.
The investigation, conducted by the Office of Transport Safety Investigation on behalf of the ATSB, found that the hardwood chock was newly adopted, and its use had not gone through a change management process.
As a result of the investigation, the museum has taken a number of proactive safety measures, including making the application of handbrakes mandatory, and taking steps to ensure that trams are parked securely on level track.
The investigation also highlights the importance of ensuring that any changes to a risk-control process do not reduce that risk-control’s effectiveness.
Read the report: Runaway and collision between 'J' class and 'Nagasaki’ class trams, Sydney Tramway Museum, Loftus, New South Wales, on 15 May 2016