Scaled Management Systems

Production machine guarded by infra-red rays


A production plant manufacturing tin cans had problems with a machine guard. Fixed guarding had been installed to prevent access to the machine. However, the machine jammed regularly and removal and replacement of this guard was extremely time consuming. Also, operators were not inclined to replace the guarding when it had been removed.

The length and complexity of the machine made guarding it unusually difficult. Workers suffered hand injuries when trying to clear the machine of the jammed product. Before workers attempted to clear a jammed machine an automatic way of stopping the machine was needed.


Consultation was used between health and safety representatives, maintenance and management to find a solution to the problem. It was decided to install a vertical light curtain spanning the hazardous area of the machine. Interrupting the light curtain stops the machine and process instantly, should any object, no matter how small, cross its path (see illustration).

To prevent operators getting underneath the beam to clear parts, a fixed guard was installed between the floor and the light curtain.

Hierarchy of Controls:



  • These control measures reduced the possibility of an employee becoming trapped or receiving an amputation.