West of England Issue Cappuccino Bunker Advisory

Bunkering should be stopped immediately if a vessel suspects that it is receiving fuel oil containing air.

P&I club West of England has advised that bunkering should be "stopped immediately" if it is suspected that it is receiving fuel oil containing air resulting in the so called "Cappuccino Effect."

Vessels making brief bunker calls or those supplied shortly before departure were said to be more at risk than others, as Masters may be under pressure to sail on completion and less inclined to become involved in a bunker dispute.

The effect happens when excessive amounts of entrained air in the bunkers cause them to foam up to the point where it is difficult to quantify the delivery volume until the foaming has reduced.

West of England said that process will be quicker in tropical waters, but very small air bubbles in high viscosity fuels in cold climates may take up to two days to dissipate before accurate soundings can be taken.

The P&I club also warned that volumetric or positive displacement flow meters could be fooled by Cappuccino Bunkers and give artificially high readings, but mass flow meters, such as versions of the Coriolis meter, will produce more accurate readings.

Signs of the Cappuccino Effect include foam and/or frothing on the surface of the fuel oil, unusual gurgling noises from the supply line or at the manifold, and unusual movement such as jerking of the supply hose.

A lower than expected density may also indicate the presence of air.

West of England also warned that if the vessel accepts the barge figures in order to save time, time charterers may later allege that the vessel consumed more fuel than provided for in the charter party and hold the shipowner responsible for the difference once the bunker figures are reconciled at the end of the charter.