Swansea Crown Court heard that trainee crane driver Kelvin Watts and two colleagues escaped from the top of a crane and over the boom when a huge ladle dislodged spilling the molten metal, which then caught fire, at Tata Strip Products in Port Talbot on 2 April 2013.
Mr Watts, 50, from Port Talbot, was operating an electric overhead crane and being supervised by an experienced trainer and had another trainer present when the incident happened.
He had picked up a full ladle, some 300 tonnes, of molten metal using the crane and had asked for confirmation that one of the hooks was properly on the ladle as the crane's camera system was not working.
When he was alerted by the plant control room that the hook was not fully attached, he stopped the crane and put it into reverse. But the ladle dislodged, spilling the load onto the floor. Moments later, fire broke out and reached the cab of the crane, resulting in burns to the three men as they desperately tried to escape to safety.
Mr Watts suffered severe burns on his head and forearms and spent several days in hospital. He has suffered repeated infections in the burns since and has been unable to return to work.
His two colleagues, also from Port Talbot, were less severely burnt and although they are back at Tata, neither can face driving the cranes or entering the area where the incident occurred.
The Health and Safety Executive (HSE) investigated and prosecuted TataSteel UK for failing to take reasonable steps to ensure the safety of the workforce.
The court was told the crane's camera system had not been operating properly for some time. Although it had been reported on near-miss forms and pre-use checks, it had still not been fixed. The lighting, which employees stated was poor, cut out completely during the incident as did the control systems.
In addition, training documents were ambiguous and instructions were not communicated to all drivers.
Tata has since installed a new camera system, improved lighting, and managers now scrutinise all pre-use checks. If the camera system fails, spotters are put in place to ensure crane hooks are properly latched onto ladle handles.
Tata Steel, of Millbank, London, pleaded guilty to a breach of Section 2(1) of the Health and Safety at Work etc Act 1974.
HSE inspector Joanne Carter said: "There was clear evidence at Tata Steel of poor maintenance, inconsistent training and managers misunderstanding the problems faced by operators.
"Given the potential consequences of a ladle holding 300 tonnes of molten metal spilling its load onto the floor, control measures should be watertight. The incident could have been avoided had the safety measures introduced afterwards been in place at the time.
"Companies must maintain plant and machinery properly and instruct, train, inform and supervise staff consistently if they are going to prevent injury. Reacting after the event is not acceptable and can be too late for some workers."