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Fuel Oil Delivery

Letter of protestThe 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 that is known to have been used in the past.

Left: bunker delivery note




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 achieved by transferring from one tank to another after the opening readings have been taken. One of the first tanks measured is 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.


The delivery barge contends that seals on sounding pipes cannot be broken. The statement is usually backed-up by excuses such as customs seals or a seized sounding cock. As an alternative to gauging the tanks, fuel oil is delivered via a volumetric 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 volumetric meter reading, air may be pumped which will reduce the amount actually delivered. Meter readings record a volume that has to be converted to weight by knowledge of the density.
Counter measures - use a Parker 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.


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 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 Parker Kittiwake Water-in-Oil test


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 cofferdams 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.


  • Fuel oil purchasers need to advise the ship’s staff what grade of fuel they will receive and how it will be transferred
  • Fuels from different deliveries should be segregated as far as is practicable
  • All receiving fuel oil tanks need to be gauged and the results recorded prior to taking delivery of fuel
  • Don’t sign any documentation before you have witnessed the actual event
  • Always take up witness offers made by the supplier’s representatives
  • If the origin and method by which the supplier’s sample was obtained is unknown then sign for it adding the words “for receipt only - source unknown”
  • Wherever possible always take fuel samples using a continuous drip method throughout the bunkering at the point of delivery on the receiving ship i.e. as close as practical to the hose connection
  • If the fuel oil delivered is supplied by more than one barge, a sample should be taken of each fuel oil from the supplying barges
  • Sign the bunker delivery receipt only for volume delivered. If the supplier insists on a signature for weight add “for volume only - weight to be determined after density testing of representative sample”


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.


Off-line Bunker Fuel

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