Failed chain link – catastrophic failures in mooring system

  • Safety Flash
  • Published on 14 July 2011
  • Generated on 13 November 2025
  • IMCA SF 06/11
  • 1 minute read

The Bureau of Ocean Energy Management Regulations & Enforcement (BOEMRE) has published Safety Alert No. 296 regarding the catastrophic failure of a chain link in a mooring system, which could have put a floating structure at risk.

In the incident, a single point mooring system failed at the tether chain for a free-standing hybrid riser, allowing the buoyancy air can and the free-standing flow line riser to separate. The 440-ton buoyancy air can rose suddenly to the surface while the free standing riser collapsed.

Further information may be found here.

Latest Safety Flashes:

Bunker hose obstructing emergency exit

A bunker hose was discovered routed in a way that partially obstructed the stern emergency exit hatch.

Read more
Watertight door and emergency hatch found open at sea

Watertight doors and an emergency hatch were observed open in the ER (Engine Room) during an offshore audit.

Read more
ATSB: Undocumented modification contributed to steam burns

An unplanned pressure release resulted in burn injuries to three crew members.

Read more
Smoke in the battery room

Smoke was observed in the battery room of a vessel alongside.

Read more
Hull crack arising from vibration

A small vessel built of aluminium experienced vibration coming from the propeller.

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.