Thirty freight train wagons rolled away unattended for 1,425 metres from a crossing loop before slowing and coming to a stop just before the end of a siding, road and level crossing at Bordertown, South Australia on 23 November 2019, a new ATSB report details.
The Bowmans Rail-operated freight train was being moved out from the siding onto the crossing loop, where locomotive drivers involved in preparing the train for its journey to Adelaide detached the train’s two locomotives for a run-around movement to reattach the locomotives to the other end of the train’s consist.
As the runaround movement started, the unattended wagons started to roll back towards the siding. The wagons rolled over a level crossing, bounced over a derailer and continued back into the siding. A driver in the siding saw the rolling wagons and ran alongside and commenced applying the handbrake to one of the wagons before they slowed and came to a stop.
In total, the wagons rolled unattended for about 1,425 metres, before stopping about 47 metres from the end of the siding, immediately before a level crossing.
“The ATSB found that while detaching the locomotives a misunderstanding between the driver in the lead locomotive and the driver uncoupling the wagons led to the brake pipe air taps being closed out of sequence and before a full application of the trains air brakes had propagated to the wagons,” said ATSB Director Transport Safety Dr Stuart Godley.
In addition, handbrakes were not applied to any wagons, the report notes. Not applying handbrakes during the run-around at Bordertown had become a common practice, as it saved time and had not caused any issues in the past.
“Once the locomotives were detached, the lack of air brakes and handbrakes allowed the wagons to roll away on the descending grade.”
Dr Godley said the occurrrence highlights how omitting a procedural step may result in over-reliance on remaining protective measures.
“The non-application of handbrakes increased the train’s reliance on the full application of wagon air brakes to prevent a runaway,” he said.
“However, a slight out of sequence implementation of the air brake process resulted in only partial application of the wagon air brakes and the subsequent runaway of unattended wagons.
“It is essential that all procedural steps are undertaken when uncoupling wagons for run-around movements.”
In response to the incident, operator Bowmans Rail has issued a safety alert requiring uncoupled wagons to have all air exhausted and handbrakes applied when left unattended.
“Additionally, the operator has communicated the findings of their investigation and their expectations to train crew, as well as consulted on improvements planned for its Bordertown shunting processes,” Dr Godley said.
The ATSB also found that the baulk installed on the Bordertown siding before the road and level crossing was only suitable for restraining runaways at speeds of up to 1.5 km/h and was unlikely to restrain the speed and momentum of a faster runaway.
The Australian Rail Track Corporation has since installed an arrestor bed on the track at the Bordertown dead end.
Read the investigation report RO-2019-020: Runaway of freight train wagons Bordertown, South Australia, on 23 November 2019Last update 23 September 2020