At Croydon Crown Court, Bedfordshire-based Dawson-Wam pleaded guilty to breaching the Health and Safety at Work Act.
Company employee John Walsh was killed when the auger drive unit of a piling rig he was attempting to dismantle flew off its stand and struck him on 13 September 2002.
Dawson-Wam Limited accepted that it failed to suitably assess the risk from dismantling the piling rig in a different method from the operator’s manual.
Mr Walsh had fastened chains to the auger drive unit and connected them to the arm of an excavator. When the excavator pulled the chains, the drive unit flew off its stand and struck Mr Walsh, who suffered fatal injuries.
He used the improvised method after the recommended hydraulic release system failed to function.
The Health and Safety Executive warned construction companies of the dangers of using improvised procedures when dismantling heavy machinery.
Their inspector Alec Ferguson said: “Where a pulling force is exerted by using an excavator, the load can increase rapidly to very high levels, leading to a sudden release when the point of resistance is overcome.
“Attempting to dismantle heavy equipment in a way not recommended by its manufacturer is likely to be a very risky enterprise which should only be embarked on when absolutely necessary and, even then, only following very careful planning of a truly safe system of work.”