The two excavators are part of the mine's accelerated stripping project designed to increase the waste stripping and coal exposure capacity of the mine into the future.
A BHP spokesman told Australia's Mining Monthly that each of the excavators cost about $16 million, and weighed approximately 800 tonnes.
"The machine moves about 80 tonnes of dirt in each pass and fills a 930E truck in four passes," he said.
"In total, each excavator will move about 15 million banked cubic metres of dirt each year - roughly 30Mt."
Goonyella Riverside is also bringing additional 18 Komatsu 930E-4 haul trucks on line as part of the accelerated stripping project.