Martin Greenwood was working as a driver for YCT at Thurrock Parkway in Tilbury. He was coupling a HGV tractor unit to a trailer on 20 October 2015 when the vehicle started to roll forward out of control.
Greenwood attempted to climb into the lorry's cab to apply the brakes but was crushed between his vehicle and another, Southend Magistrates' Court was told.
He sustained serious injuries and died that day.
The Health and Safety Executive (HSE) found during its investigation that a culture had developed whereby the company's HGV drivers were not using the brakes on the trailers and instead relied on the tractor brakes to prevent the whole vehicle from moving.
It said YCT had not implemented safe systems of work or monitoring arrangements to ensure workers were safely carrying out coupling and uncoupling procedures in line with industry guidance.
One week after Greenwood's death, the company retrained all drivers and introduced three-month refresher training, according to local newspaper Thurrock Gazette.
YCT pleaded guilty to breaching s 2(1) of the Health and Safety at Work Act. It has been fined £170,000 and must pay £6,268 costs.
It has since ceased trading.