As the Nautical Institute reports, a tanker was berthed and discharging cargo when carbon shoot particles were observed on the sea side of the vessel. It was quickly identified that the shoot particles were coming from the overboard discharge of the Inert Gas Generator (IGG) scrubber.
The incident
The discharging operation was interrupted to further investigate the cause and rectify the issue. There were no overdue maintenance, inspection or defect jobs related to IGG and associated equipment. The vessel’s engineers found that the inert gas sampling lines to the IGG oxygen analyzer were partially clogged due to carbon deposits.
The planned maintenance system (PMS) did not include any requirement for periodic inspection of the sampling pipes of the oxygen analyser. Although the likelihood of the lines becoming clogged is considered low, the company’s PMS was updated to provide for periodic checks and cleaning of inert gas sampling pipes for the oxygen analyser.
Also, the frequency of scrubber tower inspection/cleaning was changed from 12 to six months in vessels with inert gas generators as this could provide an early indication of systems component clogging.
Lessons learned
- Often, complex systems depend on a variety of small but important components that must all function correctly in their own right for the system to operate properly. Make sure these components are included in your PMS.
- Every incident gives lessons learned, and in this case the company took positive action gleaned from their investigation.