Poor track condition including a short twist defect as well as a higher than specified train speed contributed to the derailment of 11 loaded grain wagons south of Narwonah, north-western New South Wales, on 1 October 2017.
The Pacific National grain train service 8838N, comprising two 81-class locomotives and 23 wagons, was travelling from Nevertire to Manildra on the Australian Rail Track Corporation (ARTC) operated rail network, when the 11 grain wagons located at the rear of the consist derailed. An emergency brake application occurred in response to the uncoupling, which brought the front portion of the train to a stop. There were no injuries but there was substantial damage to nine wagons and track infrastructure.
A transport safety investigation into the derailment, conducted on behalf of the ATSB by NSW's Office of Transport Safety Investigation (OTSI), found that maintenance of previously identified track defects near the derailment site was not successful in preventing the defects from re-occurring. The investigation also established that the train crew, comprising a driver and an assistant driver, were operating the train at a speed of approximately 80 km/h, in excess of the 60 km/h limit for that section of track specified by ARTC.
"The incident highlights the importance of ensuring that track is free of defects that effect safety and that trains travel at or below the speed specified in rail network standards," said OTSI Chief Executive Office Mick Quinn.
The defects around a rail joint and the train speed contributed to the vertical unloading of the wheels on the 12th wagon, Mr Quinn noted.
"Train 8838N was travelling at 82 km/h immediately before the derailment, where the specified speed for its axle loading was 60 km/h. It is likely that this increased the risk of derailment," Mr Quinn said. "Also, if other wagons had travelled frequently over this track at increased speeds, this may have led to a more rapid deterioration of the track."
Repairing the damaged section of track required the replacement 300 m of rail, fasteners and sleepers and 150 m of new formation.
Since the derailment ARTC made a number of changes to its track maintenance systems and processes, and is continuing with steel and concrete re-sleepering and rail joint removal programs to its network in central and north-western NSW.
You can find here the investigation report RO-2017-014: Derailment of grain train 8838N, Narwonah, New South Wales, on 1 October 2017
