Comment
Make sure that what you sign for is what you get. Be certain that the bunker receipt reflects the facts as witnessed. Do not sign anything unless you have witnessed it.
Always take a representative sample.
Info Centre >> Fuel and Lube Oil Technical Manual >> 3. Fuel Oil - Delivery & Sampling >> 3.4 Dubious Practices
Fuel Oil Delivery: Dubious Practices
The vast majority of companies involved in the fuel oil supply and bunkering industry carry out their business in an honest and professional manner. The behaviour of a few individuals can cast a shadow over the whole industry but genuine mistakes can be made. It is, however, worthwhile to be aware of some of the malpractice which is known to have been used in the past. The figure shows a hypothetical cross section of a bunker barge.
Fuel Oil Delivery: Quantity
One method of adjusting the delivered quantity of fuel oil is by measurement of the same fuel oil twice. This is done by transferring from one tank to another by gravity during taking of the opening readings. One of the first tanks measured is then dropped under gravity to a convenient slack tank which will be measured last. Usually this is achieved by transferring from a fuel tank aft to a slack tank forward, the gauging having been started in the aft tanks.
Counter measures - re-check the first tanks that you measured before delivery begins.
Ullage
The delivery barge contends that seals on sounding pipes cannot be broken. The statement is usually backed by excuses such as customs seals or a seized sounding cock. As an alternative to gauging the tanks, fuel oil is delivered by meter and air is pumped through the meter to increase the measured delivery displayed.
Counter measures - don’t agree to meter only fuel oil deliveries. If customs seals are used then issue a letter of protest.
Meter Readings
If fuel oil delivery is determined by a meter reading, air may be pumped which will reduce the amount actually delivered. Meter readings record a volume which has to be converted to weight by knowledge of the density.
Counter measures - use a Kittiwake Density meter to check the density.
List & Trim
Sometimes the barge may have a list or trim and no correction tables are available. It is possible that in these circumstances the trim/list is to the advantage of the supplier and the measured fuel on board is more than that which actually exists. The difference between the apparent and actual fuel oil on board can be considerable, especially if the tanks have a large surface area.
Counter measures - insist on an even keel before taking fuel oil delivery or gauging tanks - if “not possible” issue a letter of protest.
Temperature
The temperature of the fuel oil is important as it affects the volume delivered. If the declared temperature is lower than the actual temperature this means that less fuel oil is actually delivered. For the supplier, lose a few degrees - gain a few tonnes.
Counter measures - check and record the temperature during the initial ullaging.
Calibration Tables
It is not unknown for duplicate barge tables to be used. At first sight they appear in order but have, in fact, been modified to the advantage of the supplier. Inserted pages, photocopies, corrections, different print and paper types are all indications of tampering.
Counter measures - check if original or a copy - issue a letter of protest if unsure.
Water
Water may be mixed with the fuel oil just before the actual bunkering takes place. “Sealed” samples are taken from the barge before the water is introduced and used as “official” supplier samples. Another trick is not to use water-detecting paste on the sounding tape (Water-detecting paste can be used for distillate fuel deliveries but does not work with black residual fuels). Instead an alternative paste is used, like chrome cleaner, which looks and smells the same, but does not change colour on contact with water.
Counter measures - check using a Kittiwake Water in Oil test.
Others
There are other less sophisticated methods of reducing the real quantity of fuel oil delivered. These include “unofficial” piping between the storage tanks and other un-nominated tanks, such as coffer dams or void spaces.
Counter measures - care, diligence and education for staff responsible for fuel oil deliveries.
The purchaser should obtain specification acceptance by the fuel supplier.
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