An out of service water level sensor led an Aurizon freight train to plough through flood waters that had inundated a rail bridge near Tully, Queensland, in 2018.
The Australian Transport Safety Bureau (ATSB) found that the driver had attempted to stop the train before the flooded bridge, but as the bridge was soon after a curve, applying the emergency brake was not enough to stop the Brisbane-bound train.
Following investigations unearthed that the water level sensor at the bridge had been out of service for several weeks, and the crew was not informed that the bridge was flooded. A CCTV camera also installed had an out-of-service illuminator, so was ineffective at night.
Further inquiries by ATSB established that Queensland Rail (QR), the infrastructure operator, could not effectively ensure that network control staff knew that monitoring systems were working or not, especially during conditions such as wet weather. The ATSB also noted that control staff were not required to actively search for information about track conditions ahead of a train when there was a realistic potential that conditions had deteriorated.
“This investigation highlights the importance of having serviceable weather monitoring stations at known flooding locations on a rail network, and ensuring that if these systems are not functioning all relevant parties need to be aware of the defect,” said ATSB director transport safety Mike Walker.
The incident occurred on March 7, 2018, after a significant period of wet weather, the Tully area is also one of the wettest towns in Australia, with an average March rainfall of 756mm. A flood watch had been issued on the afternoon of March 6 for that area.
Due to these conditions QR had placed a speed restriction on the area, limiting the speed of trains so that they could stop short of an obstruction within half the distance of a clear line that was visible ahead.
“Operating under a condition affecting network (CAN) requires effective communication between all relevant parties,” said Walker. “Train controllers need to ensure that all relevant information associated with the network conditions are passed to train crews and track maintenance personnel so that they can effectively perform their roles.”
The train driver and crew were not injured, and following the incident moved the train to the Tully yard.
QR has improved its processes to ensure weather systems are reliable, and that control personnel are aware of any faults. Network control staff have also been trained to proactively monitor network conditions.