MELBOURNE – BHP said on Friday that driver error caused an iron-ore train to run away without its driver and a brake problem caused the company to intentionally derail the train in order to stop it, according to a preliminary investigation.
BHP said its initial findings of the November 5 incident showed the nearly 3-km long train came to a halt after a braking system control cable became disconnected. After the driver got off the train to carry out an inspection, it began to move "becoming what is termed a 'rollaway' train".
The train, which was on BHP's private Mount Newman railway line in the Pilbara in the northwest of the state of Western Australia, rode on without a driver for 92 km at around 100 km per hour before being derailed by the company's remote operations centre in Perth.
"Our initial findings show that the emergency air brake for the entire train was not engaged as required by the relevant operating procedure," BHP's Western Australia Iron Ore president Edgar Basto said in a statement.
"In addition, the electric braking system that initially stopped the train, automatically released after one hour while the driver was still outside," he said.
Integration of the back-up braking system had also failed, BHP said, therefore, for safety reasons, the company chose to derail the train intentionally because it could not be stopped with the braking system.
"As a result of these initial findings, we put in place a range of safety controls. Following this, we safely restarted our rail operations," Basto said.
Investigations by regulators are continuing.