Lifting chains parted – hydrogen embrittlement
- Safety Flash
- Published on 21 June 2023
- Generated on 5 December 2024
- 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.
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.
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