Paragraph 22 Method A: BDN and periodic stocktakes of fuel tanksF1
In this Schedule, a reference to method A is to be construed in accordance with this paragraph.
This method is based on the quantity and type of fuel as indicated on the BDN combined with periodic stocktakes of fuel tanks based on tank readings. The fuel at the beginning of the period, plus deliveries, minus fuel available at the end of the period and de-bunkered fuel between the beginning of the period and the end of the period together constitute the fuel consumed over the period.
The period means the time between two port calls or time within a port. For the fuel used during a period, the fuel type and the sulphur content need to be specified.
This method must not be used when BDN are not available on board ships, especially when cargo is used as a fuel, for example, liquefied natural gas (LNG) boil-off.
The periodic stocktake of fuel tanks on board is based on fuel tank readings. It uses tank tables relevant to each fuel tank to determine the volume at the time of the fuel tank reading. The uncertainty associated with the BDN must be specified in the emissions monitoring plan. Fuel tank readings must be carried out by appropriate methods such as automated systems, soundings and dip tapes. The method for tank sounding and uncertainty associated must be specified in the emissions monitoring plan.
Where the amount of fuel uplift or the amount of fuel remaining in the tanks is determined in units of volume, expressed in cubic meters, the maritime operator must convert that amount from volume to mass by using actual density values.
For the purpose of sub-paragraph (6), the maritime operator must determine the actual density by using one of the following—
on-board measurement systems;
the density measured by the fuel supplier at fuel uplift and recorded on the fuel invoice or BDN;
the density measured in a test analysis conducted in a fuel test laboratory, accredited in accordance with EN ISO/IEC 17025 as updated from time to time, where available.
The actual density must be expressed in kg/cubic meter and determined for the applicable temperature for a specific measurement. In cases for which actual density values are not available, a standard density factor for the relevant fuel type must be applied.