A panel on the sectional vertical door at ESP's premises in Malvern, Worcestershire, was broken and the company's manager asked the worker and his colleague to check it. There was a spare panel in the factory and they decided to replace the faulty one on 5 May 2015.
The panel sections of the door were connected by hinges. On the side of each section was a bracket with a roller that ran inside the vertical track in the door frame. The 150 kg door was held in position by two cables that connected the bottom panel to a pair of springs near the ceiling.
The workers planned to first remove the hinges holding the bottom panel. They would then attach the new panel.
According to Health and Safety Executive (HSE) inspector Wai-Kin Liu, however, they did not fully plan the task and failed to consider the destabilising effect of taking out the side bracket and roller.
Part-way through the job, when the damaged section's top brackets with the rollers had been removed but the bottom brackets holding the cables still under tension had not, the injured worker knelt to unfasten a hinge.
The tension in the cables pulled the bottom panel up and the panels above dropped und er their weight. Thee result was that the door folded suddenly so the bottom two panels formed a horizontal V shaped projection. The tip of the V hit the worker in the chest and pinned him to a baling machine behind the door.
He sustained a broken sternum, three cracked ribs and had a respiratory arrest that caused him to lose consciousness for eight hours due to oxygen deprivation. A forklift truck was used to lift the door off the worker.
The HSE said that ESP failed to assess the risks of fixing the sectional door. It did not give the workers suitable instructions to and there was no system to check staff members' competence for non-routine maintenance tasks.
The managers were unaware that mechanical energy was stored in the tensioned springs and the two workers did not have the correct equipment for the job, such as a scaffold tower for height access or a special key to unwind the springs.
During the investigation, the director of a specialist door company said he would have fixed the panel by first lowering the door to the ground and unwinding the springs to remove the tension. He said dismantling the door section by section, starting from the top and working downwards, was the safest way to complete the job.
ESP pleaded guilty to breaching s 2(1) of the Health and Safety at Work Act. The judge said that, under the sentencing guidelines for health and safety offences, ESP's culpability for the offence was medium because it was an isolated incident and there was a system, though it was not followed.
The seriousness of harm risked was Level B with a medium likelihood (harm category 3), the judge determined, because of the stored energy in the spring and the tight space between the door and the baler.
He accepted the company's mitigation that it had a good safety and health record, and cooperated fully with the HSE. He issued a starting fine of £35,000 that was brought down to £30,000 due to the company's financial situation and its small cash flow. This was reduced further to £20,000 once the judge applied a one-third discount for an early guilty plea. ESP must also pay £2,714 costs.