The Mining and Energy Union has accused Rio Tinto of risking workers' safety and potentially contaminating local drinking water following a train derailment in Western Australia. 

In what the union describes as a “catastrophic failure of safety systems”, an autonomous train crashed into stationary wagons around 80 kilometres from Karratha, in the Pilbara region, shortly after midnight last Monday. 

The collision resulted in significant damage to 22 wagons and three locomotives. 

Rio Tinto says that no one was injured and there were no people in the immediate vicinity, but the union claims that five workers were working on stationary equipment further down the line.

“Rio Tinto have put out an incomplete version of events that underplays the risk to workers' lives… This incident could have easily led to serious harm or death,” a Mining and Energy Union statement says. 

The union also raised environmental concerns. 

Diesel from the derailed locomotives was reportedly spilled into the Harding River catchment, which is the primary source of drinking water for several towns in the region, including Dampier, Karratha, Roebourne, Wickham, and Point Samson. 

“The attending workers are concerned that the environmental impact of this incident has not been adequately reported by Rio Tinto,” the union said. 

Rio Tinto has since reopened one of the two tracks affected by the derailment. 

The company says that the rail line has been cleared and operations would resume following repairs. 

“We are confident that our signalling system, AutoHaul, and operating procedures are safe for our railway's operation,” the company said. 

The Office of the National Rail Safety Regulator has launched an investigation into the incident. 

Rio Tinto has pledged to cooperate fully with the investigation and to implement any recommendations to improve safety.

WA’s Water Corporation has indicated that there is no immediate threat to the drinking water reservoir due to the dry weather conditions and the distance between the derailment and the reservoir. 

This derailment marks the second incident involving a Rio Tinto train in the Pilbara this year and the third within the past twelve months. 

An empty autonomous train derailed near Dampier in February, and a similar incident occurred near Karratha in June 2023.

The union is calling for more accountability and safety. 

“We want the facts to get out there. We want accountability and safety. We are at the forefront of automation, we have accepted and embraced it, we just want to ensure that we get home safely to our families at night,” it said.