Builders liability insurance holders have been warned about carrying out checks of their equipment after a Workington company was fined.
ACP (Concrete) pleaded guilty to breaching Section 2(1) of the Health and Safety at Work Act 1974 and was fined £15,000 with costs of £6,638.
Workington Magistrates Court heard that worker Jamie Graham, 25, was left with a hole through his shin bone after a steel cable shot through it.
It happened when the cables were being threaded through concrete moulds and stretched to 2,000lbs tension.
A grip holding one of the tensioned cables failed, and when Mr Graham went to re-thread it another failed, which led to it passing straight through his lower right leg, leaving him impaled.
Health and Safety Executive (HSE) inspector, Mike Griffiths, said: "This terrifying incident should have been prevented. The lack of any inspection or maintenance of the grips meant that problems with them were only detected when a grip failed."
Earlier this month, the HSE warned that construction sites should not be used as playgrounds, and told builders liability insurance holders to make sure that they were left secure.