Colin Jones, 44, was operating a front-end loader which tipped and crushed his right arm, trapping him. Rather than wait for rescuers who were minutes away, Jones amputated the arm which was virtually severed in the accident.
The Australian newspaper said workmates arrived almost immediately and had called for help when the amputation occurred. Jones reportedly asked for help to remove the arm but fellow workers were unable to do so.
No-one is sure why Jones took the drastic action but police said a state of delirium may have influenced his decision. Jones may also have been concerned about the loader catching fire.
His work mates recovered the arm and staunched the bleeding before taking him to pit top where he was flown by helicopter to Newcastle's John Hunter Hospital.
Surgeons were unable to reattach his arm.