Lifting chains parted – hydrogen embrittlement

  • Safety Flash
  • Published on 21 June 2023
  • Generated on 3 August 2026
  • IMCA SF 15/23
  • 2 minute read

Three of four lifting chains on a load parted while the load was being lifted. 

What happened?

The incident occurred in the last lift of sections of grillage from a vessel involved in project demobilisation. At the time of the incident, the grillage was suspended, above the deck, by approximately 4 m.

Following discussion between the Deck Foreman and the Crane Operator, the grillage was slowly lowered down to the deck. There were no injuries.

Three of four lifting chains on a load parted while the load was being lifted. The incident occurred in the last lift of  sections of grillage from a vessel involved in project demobilisation. At the time of the incident, the grillage was  suspended, above the deck, by approximately 4m. Following a discussion between the Deck Foreman and the Crane  Operator, the grillage was slowly lowered down to the deck. There were no injuries.
three of four lifting chains on a load parted while the load was being lifted

What went right

  • All the work was conducted in line with established risk assessments and with company lifting procedures.

  • All the crew involved had the correct competencies.

  • The rigging was only three months in use from purchase.

  • The load was well below the Safe Working Load (SWL) of the chain.

  • The chain was never deployed subsea and was stored in a rigging locker.

What was the cause?

Analysis by an independent third party, and the chain manufacturer, concluded that hydrogen embrittlement, causing pitting, exacerbated by the tensile load on the internal radius of the links caused surface corrosion cracking, leading to internal branch cracking and failure.

Actions

The rigging was changed from a four-way bridle arrangement to slings and shackles, and the lift was completed safely.

Latest Safety Flashes:

MAIB: Catastrophic engine failure and subsequent fire

MAIB has published Accident Investigation Report 10/2026 into a catastrophic failure of a diesel generator engine on board the vessel Kommandor Susan.

Read more
BSEE: Compressed gas cylinder hazards

BSEE has published Safety Alert 516, relating to potential risks involving compressed gas cylinders.

Read more
MSF: dropped object inside vessel tank

MSF have published Safety Alert 26-05 relating to a tank cleaning machine coming lose and falling within a tank on a vessel.

Read more
Uncontrolled movement of cargo

During offshore cargo operations alongside a rig, a single pipe loaded on deck shifted due to vessel motion and swell conditions.

Read more
Positives – rubber seals on hatches, securing of shackle pins, fuel sample box

A Member reports a few positive findings.

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.