Third IMO Greenhouse Gas Study 2014

38 Third IMO GHG Study 2014
In some countries with cabotage, such as the United States, Japan and China, some ships may be employed
in domestic navigation only and this could be consistent with explanation 2. As the bottom-up method will
include both international and domestic fuel consumption and emissions (in order to assist in separating out
international fuel consumption and emissions alone), this category of ships will have to be included in the
method, but with high uncertainty because they cannot be given technical characteristics.
Type 3: ship appears in IHSF but cannot be identified in the activity data set
After the matching process, a number of ships may be identified in the IHSF database with no corresponding
activity data. Explanations for this could be:
a
b
the ships were not active or had their transponders turned off; e.g. FPSOs, barges, platforms and older
ships awaiting scrapping;
the ships may be less than 300 gt without any AIS installation.
If the ship was >300 gt, it was assumed to be inactive and omitted from the model. If the ship was