Twenty-two year old Craig Logan and an experienced crane operator were working on an unloader crane at the terminal jetty when Logan was trapped between drive motors fitted on the crane's cab and cross beams on the boom.
Clydeport failed to properly assess the risks associated with releasing the cab when it became stuck, according to an investigation carried out by the Health and Safety Executive (HSE).
The company pleaded guilty to breaching Section 2(1) of the Health and Safety at Work Act and was fined £300,000.
After the hearing, which took place at Kilmarnock Sheriff Court, HSE inspector Russell Berry said: "The company repeatedly put their maintenance engineers at risk when they had to retrieve the crane cab when it stuck out on the bottom of the crane. The lack of risk assessment for retrieving the cab led to an ad hoc unsafe system of work being developed which continued for approximately eight months up until the time of Mr Logan's death."