Damage to chain hoist subsea

  • Safety Flash
  • Published on 24 October 2022
  • Generated on 18 August 2025
  • IMCA SF 23/22
  • 1 minute read

Whilst divers were lowering a large clamp for installation, the chain block used to centralise the clamp on the horizontal member became trapped in the hinge point on the clamp.

What happened?

The clamp was opened when it was noticed and damage to the chain link was observed. There was no damage to the clamp itself.

Chain caught in the hinge side of clamp

Chain caught in the hinge side of clamp

Layout of clamp from procedure

Layout of clamp from procedure

What were the causes?

  • Although initial checks of the worksite were performed, checks were not frequent enough during the task of  lowering and closing the clamp.
  • Whilst the procedure did include a safety note on awareness around pinch points, however, it did not specify any checks the hoist chain or loose items of rigging.
  • There was no prompt for entanglement or snagging hazards included in the dive team procedures.

The root cause was found to be that the procedures did not identify and highlight entanglement or snagging hazards.

What our member did

  • Caused heightened awareness around snagging hazards when operating chain lever hoists.

  • Reviewed procedures to include a prompt for the use of chain / lever hoists identifying the risk of entrapment of chains.

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