STM did not follow its change management process for adopting the new hardwood chock type. Subsequently, the hardwood chock could not be applied reliably under the ‘J’ class wheel and could not restrict its movement.
Since the incident, STM has communicated to all staff that any proposed changes are required to be communicated to the Rail Safety Management Team (RSMT). The changes will subsequently be implemented in accordance with STM’s change management procedure.
The Australian Transport Safety Bureau notes the response provided and is satisfied that the action taken by STM addresses the safety issue.
