Safe railways for Australia

ATSB report: Signal control system irregularity, Ballarat, Victoria, on 11 August 2016

30 April 2018

The ATSB has released its investigation report into a signal control system irregularity, at Ballarat Railway Station, Victoria, on 11 August 2016

Report summary:

The ATSB’s investigation into a signal control system irregularity at Ballarat in Victoria highlights the need for train control system designers to include the functionality and performance requirements for all potential operational scenarios.

On 11 August 2016, three sets of points were Blocked to prevent them being operated from the train control system (TCS) in preparation for track maintenance. The points then unexpectedly moved when the TCS established a route for a train about to travel through the area. While the Blocked points were not on the route, there were located within its overlap area. There were no injuries or equipment damage.

The investigation found the TCS did not provide Blocking for points that lay outside the selected route but within its overlap area. As a result of the incident, TCS designers have improved their design procedures and check and test processes to ensure that Blocking is provided for overlap points during route establishment.

The Victorian Office of the Chief Investigator, Transport Safety, carried out the investigation on behalf of the ATSB under the Transport Safety Investigation Act 2003.

Investigation report: Signalling control system irregularity, Ballarat, Victoria on 11 August 2016