Wheelarra/Jimblebar and Orebody 18 (OB18) are two mine complexes 40 kilometres east of BHP Billiton's Mt Whaleback mine. The Wheelarra/Jimblebar mine complex first commenced in March 1989. We estimate the complex will produce a total of 95Mpta making it one of the world's largest iron ore operations. Cash costs have decreased substantially since 2013 owing to direct cost cutting undertaken by BHP Billiton and the ramp up of the hyper-efficient Jimblebar mine. Lower oil prices and a weaker Australian dollar have also contributed to lower costs.