BHP Billiton's rail operations in the Pilbara are expected to be out of action for a week after a runaway train laden with iron ore travelled 92 kilometres with no-one on board before it was deliberately derailed.

BHP Billiton's rail operations in the Pilbara are expected to be out of action for a week after a runaway train laden with iron ore travelled 92 kilometres with no-one on board before it was deliberately derailed.