The driver of an iron ore train that collided at low speed with the rear of a stationary second train had been experiencing stress, sleeping with the lights on, and waking up often throughout rest periods, an ATSB investigation report details.
The collision occurred in the yard at BHP’s Finucane Island site at Port Hedland, Western Australia, where both trains were waiting to be unloaded, shortly after 4:30am on 2 March 2024.
After detecting the train ahead of them had moved, the driver applied power to move their train forward, with the intention of stopping behind the second train, which had come to a stop 325 m ahead at a handover point, to be prepared for unloading.
“The driver set their train in motion, and without the awareness of or memory of having done so, acknowledged four subsequent audible vigilance alerts which, by design, prevented a penalty brake activation prior to collision,” ATSB Chief Commissioner Angus Mitchell said.
With no brake application or reduction in throttle during that time, the train collided with the rear of the second train.
“The driver reported that they were awoken by the collision, and thought they must have had a microsleep.”
The impact sequence lasted 38 seconds and, although the locomotive brakes were fully applied on the stationary train, it was pushed forwards about 40 m.
Fortunately, there were no injuries or damage.
"It was dark at the time of the collision, the driver had been experiencing a low workload while waiting to move their train in the yard, and it was their fourth consecutive night shift,” Mr Mitchell said.
“Poor quality sleep meant the driver was operating the train with a degraded level of alertness.”
An unusual set of circumstances contributed to the driver’s poor-quality sleep, with the report detailing that about three months before the accident, the driver (who was working under fly-in fly-out arrangements) was bitten by a white-tailed spider while sleeping in accommodation barracks at Port Hedland.
After having the spider bite assessed at a Port Hedland medical centre the driver returned home to Sydney, where they underwent surgery for the bite, and were subsequently cleared by their GP to resume duties about six weeks later.
A week after returning to work, in January 2024, the driver again awoke in the same barracks room and noticed similar signs of a white-tailed spider bite.
After returning to Sydney, the driver again underwent surgery, and another period of rehabilitation.
“Upon returning to Port Hedland after the second spider bite, the driver began to experience panic attacks and stress,” Mr Mitchell explained.
“Fearing another bite, the driver frequently sprayed insecticide in their locomotive cabs and, including waking from sleep to do so, their bedroom.”
While the driver had adequate opportunity for sleep, this stress and subsequent action disrupted their ability to obtain restorative sleep.
“While sleep duration is important, so too is sleep quality,” Mr Mitchell reiterated.
“Stress and interrupted sleep should prompt workers to assess and report an elevated risk of fatigue.”
As a result of the accident, BHP undertook a series of actions to manage fatigue, and to address the limitations of its relevant locomotive’s vigilance systems.
Read the report: Low-speed collision between trains MO5519A and MO5519B at Finucane Island Balloon Loop, Port Hedland, Western Australia on 2 March 2024