Inside the individual tanks, parts of the fuel can be found to be varying completely in characteristics due to inhomogenity and as such can cause severe problems. At this point, questions arise that may require more serious action:
Can the tank be heated to a temperature above Pour Point to allow the fuel part to be pumpable?
Does the vessel possess pumps and heated transfer lines to allow sufficient circulation of the fuel part?
If the answer to either of these is ‘no’, then a call at the next port is essential to have the batch pumped out ASAP and the tanks cleared. Homogenizing onboard is possible, however, one should have both the pump capacity and a segregated empty tank. There is also a risk with vessels without tank heating when the inhomegenous product contains material with a Pour Point above that of the ambient temperature that when it re-cools to ambient temperature the fuel will solidify.
When homogenizing onboard mix into an empty tank and in the absence of a fuel blend calculator the supplier should be consulted to reach the correct viscosity.
Consume tank nearest to spec first, allowing more time for circulation of a mixture with other tanks long enough for homogenization. Ideally the entire batch should be circulated at least 4-5 times to acheive maximum possible consistency.