A.C.P (Concrete) Ltd, which produces pre-stressed concrete panels, was prosecuted following the incident in its factory on the Derwent Howe Industrial Estate in March 2009.

The accident left worker Jamie Graham, 25, from Cockermouth, in a hip to toe full leg cast for six weeks and on crutches for another four months.

Workington Magistrates Court heard that steel cables were threaded through the concrete moulds by workers and then stretched to 2,000 lbs tension.

A grip holding one of the tensioned cables in place failed, releasing a 200-feet long cable.

When Graham went to re-thread the cable, another grip failed, releasing a second 200-feet-long steel cable, the end of which passed straight through his lower right leg, leaving him impaled on the 9mm steel cable.

The fire and rescue service had to cut the cable to release him and he was taken to hospital with the end of the cable still imbedded though his shin.

A subsequent HSE investigation found the company did not have any system in place for inspecting and maintaining the grips and that an average of eight grips were failing each week at the premises.

HSE Inspector Mike Griffiths, said: “The lack of any inspection or maintenance of the grips meant that problems with them were only detected when a grip failed.

“That could sometimes result in a cable being released with 2000 lbs tension.

“The fact that the grips had to fail before they were replaced meant that there were significantly more failures under tension, and the chances of a potentially serious injury were increased.”

The court heard that Graham, who is a keen weight trainer, was significantly immobilized for 6 weeks after the accident and he still suffers pain and weakness in his right leg.