The incident happened in December 2014 during the ground preparation for laying a concrete slab at incinerator ash processor Ballast Phoenix in Sheffield.
A 21-tonne tracked excavator was digging out an old steel cable duct from a trench where the concrete was due to be poured, and a dump truck was parked behind it.
As the excavator tracked back while digging out the duct, Darren Richardson was crushed between the two machines.
RMB Contractors, whose website states that it has "developed an expertise [in providing civil engineering solutions for business and industry] that is hard to surpass", says all its workers are Safety Pass Alliance qualified. The contractor adds that it uses in-house and external professionals to "ensure continuous updating of training".
Health and Safety Executive inspector Medani Close said back-to-back plant activities should be avoided because pedestrians and vehicles could be put at a greater risk of contact.
The two tasks could have been carried out safely had RMB Contractors put up barriers to exclude workers from the excavator's operating area. "Bunting or plastic fencing can be used to create and maintain a pedestrian exclusion area," said Close.
The company should have ensured at the planning stage that the two operations were separated by a safe distance.
The inspector added: "If this is not reasonably practicable, [the company] should ensure the excavator driver does not rely solely on his reversing aids but slews the excavator through
90 degrees to have direct vision of the danger area he is reversing into, or [should] consider the use of a banksman to direct the excavator while reversing in the danger area."
On 8 January RMB Contractors, which is based in Derbyshire, pleaded guilty at Sheffield Crown Court to breaching s 2(1) of the Health and Safety at Work Act.
Judge Watson determined that culpability was medium. The seriousness of harm risked was level A and the likelihood of harm was medium (harm category 2).
The starting point for the fine was £54,000 because the company fell in the "small organisation" turnover range. RMB Contractors' average turnover of £3m was at the lower end of the range, so the judge adjusted the fine to £130,000 to reflect this but also because the risks were a factor in the worker's death.
There were no aggravating factors. Judge Watson recognised the company had no previous convictions, an exemplary safety record and had fully co-operated with the investigation. He reduced the starting point to £110,000.
Taking into account RMB Contractors' early guilty plea, the judge fined the firm £75,000 and ordered it to pay £24,483 costs.
The HSE said that, since the incident, RMB Contractors had improved its workplace transport risk assessments and provided extra training.