Marine Safety Forum released a Safety Alert noting a case where deck crew could not use the approved securing device because the wing nut was defective.
The incident
A company vessel was preparing to load dry bulk cargo in port. The dry bulk tank had been inspected via the access hatch in the upper cement room and the hatch secured on completion.
A toolbox talk had been carried out, all operational checkswere carried out in accordance with the company checklist and loading operations commenced.
A few moments later, a pre-warning alert was raised on the fire control panel on the bridge indicating smoke detection in the upper cement room.
The Chief Engineer immediately investigated and found the atmosphere flooded with product from the dry bulk tank in use. The emergency stop signal was given and the operations ceased.
Further investigation revealed that part of the securing arrangement was damaged. The defective wing nut prevented use of the approved securing method which was required to ensure a good seal on the pressurised tank.
Findings
The investigation was carried out onboard with the following conclusion:
- The deck crew could not use the approved securing device because the wing nut was defective. – It is unclear when the defect occurred.
- The risk assessment and operational checklist identified the need for an appropriate securing device but failed to confirm if the device was free from defect.
- The inspection regime in the planned maintenance system did not include this specific check.
- Several opportunities to detect and rectify the defect were missed.
Lessons learned
- The generic risk assessment on the vessel was updated to include a check that the securing device is inspected and confirmed without defect.
- The vessels IMS Checklist was revised to include the same.
- The planned maintenance inspection regime is to be updated in due course.
- The defective wing nut was replaced, and operations continued without further incident.
