Maintenance worker pinned by moving machine parts

Incident summary

A maintenance worker was lubricating a twin-head blow-moulding machine that moulds plastic bottles. Two die plates were cycling back and forth one at a time from each side of the machine to the middle, where the plastic is extruded. The worker lubricated the slider shafts with a spray lubricant by reaching between the die plates as they cycled back and forth. The worker was caught between the moving die plates of the machine and sustained crush injuries to his upper body.

Investigation conclusions

Cause

• Failure to lock out when required: The worker did not render the machine inoperable or isolate the energy source to the machine before performing maintenance. Therefore, the machine was operating when he was reaching between the moving die plates while attempting to lubricate the slider shaft. He was injured when his upper body was caught between the two die plates.

Underlying factors

• Circumvented interlocks located on safety gates: The four interlock switches on the safety gates located in front of the blow-moulding machine had been bypassed. They did not function as intended to stop the operation of the machine when the safety gates were opened if someone entered the machine area. This bypass allowed the machine to continue to operate after the guarding had been opened.
• Inadequate training: The employer did not ensure the worker was adequately trained in the identification of hazards, the safe operation of machinery, lockout procedures, or when lockout is required. As a result, the worker did not lock out the blow-moulding machine before he attempted to lubricate the slider shafts, and he became pinned between the cycling die plates.