Jason Burden, 19, died after a 970kg tunnel thruster from a ship overturned and landed on top of him.
He was reassembling the machine on a work bench when it toppled onto his torso and left leg, causing fatal chest and abdominal crush injuries.
A subsequent investigation by the Health and Safety Executive (HSE) found that although Tyne Slipway and Engineering was aware that the tunnel thruster – a gearbox and propeller used to manoeuvre a ship – was only notionally stable, it did not take sufficient steps to ensure it was safe to work on or near.
Judge James Goss, QC, said: “The fine I impose on the defendant is not and cannot be any reflection of the value of the young life of Jason Burden, which was so tragically lost as a result of health and safety shortcomings.
“He was a much-loved son and brother and a friend to so many.
“He was intelligent, gifted in many ways, hard-working and a valued employee who always gave his best.”
The judge said there had been no risk assessment carried out for the heavy task Jason was carrying out, and he was unsupervised and uninstructed.
Dominic Adamson, defending the family-run company, entered a guilty plea to a charge of failing to discharge a duty under Health and Safety legislation on its behalf.
In a statement read out by Mr Adamson, Harry Wilson, managing director of Tyne Slipway and Engineering, said: “I would like to express the shock and distress of all at the company.
“Jason was a well-liked and highly-regarded member of the company who remains sorely missed by all who worked with him.
“The loss of Jason had a traumatic on his work colleagues and continues to affect the company.”