BHP reveals multiple braking failures on ore train
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BHP Billiton has disclosed that the driver of last week’s runaway iron ore train failed to engage the emergency air brake after getting out to check on a problem with another part of the braking system.
It has also disclosed the driver was out of the train for at least one hour. As a result, the electric braking system that initially stopped the train was automatically released.
In addition, its backup braking system was not able to deploy successfully due to an unspecified integration failure.
These are the key findings of its preliminary internal investigation into the derailment of the iron ore train in the Pilbara nearly two weeks ago.
The train, with four locomotives and 268 wagons laden with iron ore, was deliberately derailed after travelling 92 kilometres with no-one on board.
The derailment damaged 1.5km of track and forced BHP to temporarily halt all train haulage in the Pilbara.
WA Iron Ore president Edgar Basto said the initial findings of the investigation showed the train came to a stop after a braking system control cable became disconnected.
“The train began to move after the driver had disembarked to carry out an inspection, becoming what is termed a 'rollaway' train,” Mr Bastos said in a statement.
“The train was then derailed intentionally, because it could not be brought to a stop with the braking system.”
Mr Basto said the preliminary internal investigation sought to understand why the rollaway occurred, and why the train could only be brought to a stop by derailment.
“Our initial findings show that the emergency air brake for the entire train was not engaged as required by the relevant operating procedure,” he said.
“In addition, the electric braking system that initially stopped the train, automatically released after one hour while the driver was still outside.
“Due to integration failure of the backup braking system, it was not able to deploy successfully.”
Regulatory investigations are ongoing.