Before launch of an Air Diving Launch and Recovery System (LARS) from a third-party DSV, the winch wire for the clump weight/guide weight became lodged between the winch body and the winch drum wall. As the winch operator paid out on the clump weight, the winch wire tightened on the winch hub and parted. This resulted in the 300kg clump weight falling to the seabed and narrowly missing a saturation diving bell and divers already deployed near the seabed. There were no injuries or damage to equipment.
What went wrong? What were the causes?
- It was not standard operating procedure to inspect the clump weight wire or winch, before launch of the Air Diving LARS;
- There was no pre-use check program in place for operating the LARS;
- The winch operator’s position did not allow a clear line of sight to the winch drum;
- The LARS design enabled a loose wire when the A-frame is in stored position, i.e. a loose wrap became lodged between the winch housing and the winch drum wall.
What actions were taken? What lessons were learned?
- Consider additional engineering controls, where there is a possibility for winch wire loose wrap movement off the winch drum;
- Ensure adequate equipment pre-use checks are conducted;
- Maintain line of sight to the winch drum during spooling;
- In operations that involve equipment being deployed overboard, consider dropped objects and ensure that adequate ‘drop-zones’ are identified.
Members may wish to refer to:
IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of all. The effectiveness of the IMCA Safety Flash system depends on Members sharing information and so avoiding repeat incidents. Please consider adding [email protected] to your internal distribution list for safety alerts or manually submitting information on incidents you consider may be relevant. All information is anonymised or sanitised, as appropriate.
IMCA’s store terms and conditions (https://www.imca-int.com/legal-notices/terms/) apply to all downloads from IMCA’s website, including this document.
IMCA makes every effort to ensure the accuracy and reliability of the data contained in the documents it publishes, but IMCA shall 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.