IMCA provides lessons learned from an incident in which, during backloading of an empty refrigerated container to a Pipe Supply Vessel (PSV), adverse weather conditions, combined with technical issues and the effect of high thrust wash, resulted in a loss of position of the PSV and an uncontrolled swinging load.
There was no damage to equipment and no-one was harmed.
What went wrong
- Sudden gusts of wind of around 40 knots created high external forces, which resulted in an increased thruster wash towards the PSV, which caused the PSV to lose position;
- The PSV’s azimuth thruster lost its running DP signal, contributing to the loss of position;
- The PSV was operating outside its Activity Specific Operation Guidelines (ASOG);
- The operational limits of PSVs operating alongside were not considered in the Activity Specific Operation Guidelines (ASOG);
- No-one stopped the job: the operation wasn’t stopped despite alarms indicating the PSV was outside defined operational limits.
Lessons learned
- Review any (project specific) ASOG to include vessel to vessel operations and the effect that thruster wash can have on vessels alongside;
- Review and update procedures for the lifting of cargo to/from PSVs to reflect the potential for loss of position;
- Ensure personnel responsible for DP operations review and consider the requirements of the ASOGs and document their review process;
- Planning, risk assessing and adhering to operational guidelines and limits is crucial to ensuring safe cargo transfer operations.
