Fatal crushing from CNC turret punch press

Background

A CNC turret punch press is designed to punch shapes into sheet metal by following programmed instructions.

When the machine is in operation, powered components can move suddenly at high speed and without warning, such as the carriage holding the sheet metal and the table sections supporting it.

The operator of a CNC turret punch press was recently crushed when he entered the plant's operational space between the carriage and a ball transfer table that abutted the edge of the press's primary table.

Safety issues

Employees are at high risk of death or serious injury when systems of work do not prevent access to danger areas of powered plant, such as moving parts and trapping spaces.

For example, depending on the various components of a turret punch press and its proximity to other environmental and physical features, a crush space can sometimes be created. This can be a temporary opening where a person can enter and become trapped.

Administrative controls, such as training and line marking on the floor to deter employees from entering into a plant's danger areas, cannot be relied upon to adequately control the risks associated with plant.

Other safety issues include:

• In a turret punch press, the carriage may take the sheet metal beyond the perimeter of the machine's table, leading to a person being struck by the sheet metal.
• An operator is also at risk of being struck by moving powered components when they enter the operating space of plant.
• The removal of guards from plant can allow access to a previously controlled danger area.
• Making modifications to plant can create new danger areas or points.

Recommended ways to control risks

The risk of being injured by a turret punch press should be controlled by:

• Installing a system to control access into the operating area of the plant. For example, physical perimeter fencing with interlocked access gates or a presence sensing system (light curtain) around the perimeter of the plant. A combination of physical fencing and presence sensing system may also be appropriate. Consider and account for factors such as the rundown time of the plant.
• Using captive or trapped key systems to manage isolation and access during activities such as maintenance, repair, inspection, servicing and cleaning. This may be used in conjunction in the access control system discussed above.
• Ensuring interlocked guards are fitted to prevent access to any moving parts and nip points (points where rotating or reciprocating parts move toward each other) while the plant is in use.

In addition to the above, the following should also be considered:

• Consult the manufacturer before making any modifications to the plant.
• Provide emergency stop systems to shut down operation of the plant.
• Follow the manufacturer's installation and operating instructions.
• Provide employees with adequate information, instruction, training and supervision prior to and when using the plant.
• Provide and maintain adequate warning signs as a constant reminder to employees of the potential hazards associated with the plant.
• Keep the work area clear of unnecessary equipment, rubbish and other clutter.

Legal duties

Under the Occupational Health and Safety Act 2004, employers must:

• so far as is reasonably practicable, provide and maintain a working environment that is safe and without risks to the health of employees and independent contractors
• provide or maintain plant or systems of work that are safe and without risks to health, so far as is reasonably practicable
• make arrangements for ensuring, so far as is reasonably practicable, safety and the absence of risks to health in connection with the use, handling, storage or transport of plant
• provide employees with the necessary information, instruction, training or supervision to enable them to do their work in a way that is safe and without risks to health
• ensure, so far as is reasonably practicable, that people other than employees are not exposed to risks to their health or safety arising from the employer's conduct

Employers and self-employed persons have additional duties under the Occupational Health and Safety Regulations 2017 (OHS Regulations) associated with the use of Plant, including:

• identifying all hazards associated with the use of plant at the workplace, so far as is reasonably practicable
• controlling risks in accordance with the plant hierarchy of control

If guarding is used to control the risk associated with plant, the guarding must comply with the requirements of regulation 99 of the OHS Regulations.

Resources

• AS4024 Safety of machinery, Part 3001: Materials forming and shearing - Mechanical power presses.