WorkSafe Victoria recently issued a safety alert about the risks associated with operating plant with inadequate guarding following an incident in which two employees received crush injuries and amputations to their hands after working with unguarded power presses.
The guarding was not interlocked with the power press, so the employees were able to continue operating the press without any guarding.
At another workplace, an employee was operating a power press to cut out metal parts for manufacturing. The employee was able to use tools to disable the mechanical interlock and operate the press with guarding in the open position.
The plant also had an electrical interlock switch which was not operational. The employee placed their hand in the press area of the plant during operation where three fingers were amputated and a fourth finger was partially amputated.
The alert said guarding and safety devices on older power presses may not prevent bodily access to the danger area of the plant and therefore will not meet current Australian Standards.
There are also significant risks during tool changes (die change) on power presses if the guards are not replaced while test strokes are being conducted.
Where guarding is used as a control measure, the alert said electrical interlocks form an important part of the guarding to ensure the plant is unable to operate without the guarding correctly in place.
A guard can perform several functions: it can prevent bodily access, and contain ejected parts, tools, offcuts or swath.
Older machinery (eg manufactured in the early to mid-20th century) may not have guards fitted as standard, and will present a risk to the operator if danger points and moving parts can be accessed.
Guarding should be retrofitted to older machinery and equipment to prevent access to:
Where access to the moving part is not required (eg for service and maintenance), the guarding must be permanently fixed, so far as is reasonably practicable. A fixed guard can be permanently applied by bonding agent, welding or secured with one-way screws.
A permanently fixed physical barrier provides the highest level of protection against hazards.
The alert also said to ensure systems are in place to lock out and tag out machinery during cleaning, service and maintenance.
People performing tasks such as maintenance, repair, installation, servicing and cleaning have a higher risk of being killed or injured through inadvertent operation of plant they are working in, on or around.
Accidental start-up or movement of a plant mechanism can occur if control levers or buttons are bumped or knocked, if a short circuit of the control system occurs, when hydraulic or air pressure is released, or when undoing retaining bolts. It is essential that people who work in, on or around plant are not exposed to hazards due to accidental start-up or movement of the mechanism.
The alert also said it is important to provide employees with instructions and training on safe operating procedures, and to also review procedures regularly, including lock out and tag out systems when undertaking service, cleaning and maintenance.