Fuel Oil Contamination Suspected Before Departure
A coastal vessel has taken on 40 tonnes of marine gas oil at a berth. Before departure, the engineer notices the fuel in the settling tank looks cloudy and there is a slight increase in the main engine fuel filter differential pressure during a brief engine trial. The bunker receipt is signed but the sample was taken from the barge's line, not from the receiving line. The vessel is due to sail in 4 hours on a short coastal run with several manoeuvring periods. There is no spare fuel on board and no time to take on more.
1. Assess the likely problem and the significance of the sampling error.
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Cloudiness in the settling tank plus a rising filter differential pressure suggests water or particulate contamination, or fuel that is off-specification. It could also be waxing if the fuel is cold, but marine gas oil in a coastal trade makes gross contamination a strong possibility.
The sampling error matters: a sample taken from the barge's line does not prove the quality of what was actually received. A receiving-line sample, taken continuously through the transfer, is the evidence normally relied on in a dispute. Without it, the vessel's position in any claim is weaker.
Before departure, the engineer should:
- Drain water from the settling tank and check for water or sediment.
- Examine the filter elements for what has been caught.
- Test the fuel with on-board means if available.
- Report the findings to the master and consider whether the fuel is fit for the intended voyage.
2. What operational measures would you take for the short coastal run given that the fuel must be used?
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Given no alternative fuel and a short run with manoeuvring:
- Settle and drain the tanks thoroughly, and use the purifier if fitted, running it at a suitable throughput to remove water and solids.
- Change or clean filters before departure and keep spares ready at the engine room.
- Consider using the second filter housing so a changeover can be made quickly.
- Monitor filter differential pressure frequently and record it.
- Watch fuel pump and injector performance, exhaust temperatures, and any smoke or knocking.
- Keep manoeuvring periods short where possible and ensure the bridge knows the fuel situation.
- Have a plan to stop and change filters safely if differential pressure rises sharply.
If the engine cannot be run reliably, the master must be told before departure so the sailing decision is made with full information.
3. Describe the notifications and records you would make, and what you would do differently next time.
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Records and notifications:
- Log the appearance of the fuel, filter differential pressures, water drained, and any engine symptoms with times.
- Retain the filter contents and any samples taken on board, labelled and sealed.
- Inform the master and the company technical department, and note that the retained sample was taken from the barge's line.
- Raise a note of protest or written reservation about the sampling if the fuel proves unsatisfactory, following company procedure.
Next time:
- Take samples continuously at the receiving line, with the barge representative and ship's representative present, and seal and label them.
- Test or sight the fuel before signing the receipt where practicable.
- Record tank soundings and temperatures before and after transfer.
The broader lesson is that the evidence trail at the bunkering stage is as important as the engineering response afterwards.