Lessons Learnt: Oil spill during bunkering

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Vessel Type: Bulk Carrier

Incident description

The vessel was stemmed to receive 250 MT of IFO 380 from a supply barge. The bunkers were to be received in a pair of empty top side tanks, each with a full capacity of 200 cubic metres. As per company management procedures, the bunker tanks were not to be filled in excess of 85% capacity, which corresponded to a minimum ullage of 55 cm. The Chief Engineer delegated the task of performing the bunkering operation to the Third Engineer. After the bunker transfer hose was connected, the operation was started at 15:20 hours, filling only the starboard side tank. At 16:30, the Third Engineer recorded the ullage of the tank as being 51 cm and yet bunkering operations continued. At 16:35, he saw that the ullage had reduced to 35 cm and rushed to the engine room to divert the bunkers into the empty port side tank. However, by the time he reached the valve station, the starboard side tank was already overflowing on deck, with oil being spilt overboard.


This was a poorly planned bunkering operation, demonstrating a serious neglect of the company SMS procedures. The bunkering checklist was completed by the Chief Engineer on his office PC, instead of being done with the participation of the Third Engineer at the site of the job, resulting in some checks not being performed.. The failure of the Third Engineer to closely monitor the filling of the tank and his lack of awareness of the minimum ullage figure led to a critical loss of control. He was not properly supported during the operation and was not in ready radio communication with other crew members or the bunker barge personnel.

The tank overflowed from both the forward and aft air ventilators. At the aft ventilator, the saveall quickly filled up with oil which then spilled onto the main deck. At the forward ventilator, the saveall did not fill up but oil was still able to escape because the drain plug was not fitted. Although the main deck scuppers were plugged, oil was able flow over the deck edge guttering and into the sea.

Lessons Learnt

  • Bunkering operations should be performed in strict compliance with SMS procedures
  • Bunkering plans are to be carefully considered by the chief engineer and discussed with the bunkering team.
  • Checklists need to be diligently completed at the site of the task, not treated as a “tick box exercise”
  • Bunkering is not a one person job. It requires teamwork and good communication with ship and barge personnel
  • A saveall is not a saveall if the drain plugs are not fitted!

The UK Club’s Loss Prevention team combines practical solutions that address Members’ needs and claims experience with research into the wider issues that impact directly on P&I insurance and the Club’s exposure to claims. Every year, the UK P&I Club deals with thousands of claims using the expertise and experience of its professional claims handlers, ex-seafarers and lawyers. With five decades of research into loss prevention issues the Club has developed a formidable body of technical material on maritime risks. Each month the Loss Prevention team aim to share some of the Club’s claims experience, by looking at real case examples and identifying lessons learnt to help Members avoid similar incidents – you can find past lessons learnt here: https://www.ukpandi.com/loss-prevention/training-advice/lessons-learnt/

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