Pedestal Drill Chuck Assembly Detached Causing Head Injury

What happened?

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.



What went wrong?

Our member’s investigation noted the following:

  • The bench top drill was not fit to use, as the spindle sleeve was not available;
  • There had been an unauthorized 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.

What were the causes?

  • 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 unauthorized use;
    • there had been no appropriate toolbox talk or risk assessment beforehand;

What lessons were learned?  What actions were taken?

  • Handmade or modified tools should not be used;
  • Tools and equipment to be inspected for their fitness, and unfit equipment to be isolated – all equipment was subject to further inspection and unfit equipment was removed from the vessel.