John Wyatt, 61, from Northumberland, was employed by Tynedale Roadstone Limited and had been carrying out an inspection of the conveyor area at its premises in Newcastle when the incident happened on 18 June 2009.

Newcastle Magistrates’ Court heard that Wyatt had gained access to the conveyor area to carry out the inspection, but slipped and fell forward and was caught up in the snub pulley roller and the conveyor belt.

His right arm was so badly injured that it had to be amputated at the shoulder.

He suffered spinal injuries for which he had to undergo surgery to fuse his spine back together.

He also fractured all his ribs on the right side, broke his left wrist and suffered friction burns to his stomach and severe cuts to his face.

Wyatt was in intensive care for more than three weeks and was in hospital for more than three months. He can no longer work and still has mobility issues.

An HSE investigation found that although safety gates to the plant had been fitted with locks to restrict access these had been disabled.

The investigation also concluded there were no suitable risk assessments, inadequate safe systems of work and a lack of information and instruction for employees.

Tynedale Roadstone Limited, of Durham, was fined £8,000 and ordered to pay £18,994.17 costs after pleading guilty to safety breaches.

After the hearing HSE inspector Sal Brecken, said: “Mr Wyatt’s horrific injuries should not and need not have happened.

“This incident was easily preventable had Tynedale Roadstone carried out an adequate risk assessment of their equipment and properly supervised their employees.

“Plant of this type is recognised in the industry as being high risk, which is why they are so heavily guarded with trapped key systems.

“Safety devices are installed on machinery with dangerous moving parts to protect those who work with them. Companies have a legal duty of care to ensure they are properly fitted and working effectively at all times.

“Disabling or switching off safety devices puts workers at unnecessary risk and is simply not acceptable. HSE will not hesitate to take enforcement action in cases such as this.”