Damage to chain hoist subsea

  • Safety Flash
  • Published on 24 October 2022
  • Generated on 11 April 2026
  • 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.

Latest Safety Flashes:

MAIB: Sinking of tug Biter with loss of two lives

MAIB has published Accident Investigation 17/2024 relating to the girting and capsize of tug Biter with the loss of two lives.

Read more
Dropped object – strop parted over sharp edge

A cylinder was lifted to a height of approximately 6 metres over deck of the vessel, the sharp steel edges of the cylinder cut through the firehose protection and caused the strop to part.

Read more
Person injured when pry bar slipped

A crew member who was applying downward pressure to their pry bar to lift a track, fell towards the deck when the pry bar slipped.

Read more
MSF: High potential near miss during FRC maintenance

The Marine Safety Forum has published Safety Alert 26-01 relating to an incident where there was an unplanned lowering of an FRC to the sea

Read more
BSEE: Crane incident leads to serious facial injuries

BSEE has published Safety Alert 512 relating to a crane incident during well abandonment which led to a worker being struck and suffering serious facial injuries.

Read more

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.

The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.

All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.

IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.

The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.

Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.