The 40-year-old man was working on the cross travel beam of the crane to clean built up dirt when he fell, suffering multiple fractures to his skull, a broken collarbone and several broken ribs.
He has not yet returned to work.
The fine was handed down at Wolverhampton Magistrates’ Court after the firm pleaded guilty to health and safety breaches.
HSE investigating inspector David Evans said: “Falls from height remain the single biggest cause of workplace deaths and one of the main causes of major injury, but the vast majority of these accidents are preventable if companies assess the risks properly.
“The most common causes of falls from height involve failure to recognise a problem, provide safe systems of work, ensure that these systems are followed and provide adequate information, instruction, training or supervision. There really is no excuse for this.”
MES Environmental was also ordered to pay £3,532 in costs