Pedestal Drill Chuck Assembly Detached Causing Head Injury

A crewman was drilling a hole through a wooden plank using a benchtop heavy drill machine in the vessel’s engine room. The drill chuck assembly detached and hit the right side of his forehead resulting in a laceration above his right eyebrow.

Our member’s investigation noted that:

• The bench top drill was not fit to use, as the spindle sleeve was not available.
• There had been an unauthorised modification of the drill chuck assembly (spindle sleeve) – a hexagon headed bolt was modified for use as a spindle sleeve.
• The injured person and the supervisor were not fully aware of the scope of the assigned activities or job requirements.
• The job should have been stopped but the risk was deemed tolerable. Safety controls were bypassed.
• No personal protective equipment (PPE) was worn.
• The injured person was not familiar with the bench top drill assembly, operation or safety precautions and it was his first time operating the machine.

• The immediate cause of the injury was the ejection of the chuck assembly along with the modified spindle sleeve from the spindle hole.
• The root causes were lack of appropriate supervision and lack of a safe system of work – the injured person should never have been allowed near the machine.
• Causal factors included:
  • risk was seen as tolerable by both the supervisor and the injured person.
  • the bench top drill had not been quarantined to prevent unauthorised use.
  • there had been no appropriate toolbox talk or risk assessment beforehand.