3.1 Indicator definition
In its most simple form the Energy Efficiency Operational Indicator is defined as the ratio of mass of CO2 (M) emitted per unit of transport work:
Indicator = M CO2/(transport work)
For more details of indicator calculation, see 3.2 to 3.4 and Appendix 1.
3.2 Fuel consumption
Fuel consumption, FC, is defined as all fuel consumed at sea and in port or for a voyage or period in question, e.g., a day, by main and auxiliary engines including boilers and incinerators.
3.3 Distance sailed
Distance sailed means the actual distance sailed in nautical miles (deck log-book data) for the voyage or period in question.
3.4 Ship and cargo types
The Guidelines are applicable for all ships performing transport work.
- dry cargo carriers
- gas tankers
- ro-ro cargo ships
- general cargo ships
- passenger ships including ro-ro passenger ships
Cargo includes but not limited to:
all gas, liquid and solid bulk cargo, general cargo, containerized cargo (including the return of empty units), break bulk, heavy lifts, frozen and chilled goods, timber and forest products, cargo carried on freight vehicles, cars and freight vehicles on ro-ro ferries and passengers (for passenger and ro-ro passenger ships)
3.5 Cargo Mass Carried or Work Done
In general, cargo mass carries or work done is expressed as follows:
- for dry cargo carriers, liquid tankers, gas tankers, ro-ro cargo ships and general cargo ships, metric tonnes (t) of the cargo carried should be used;
- for containerships carrying solely containers, number of containers (TEU) or metric tons (t) of the total mass of cargo and containers should be used;
- for ships carrying a combination of containers and other cargoes, a TEU mass of 10 t could be applied for loaded TEUs and 2 t for empty TEUs; and
- for passenger ships, including ro-ro passenger ships, number of passengers or gross tonnes of the ship should be used;
In some particular cases, work done can be expressed as follows:
- for car ferries and car carriers, number of car units or occupied lane metres;
- for containerships, number of TEUs (empty or full); and
- for railway and ro-ro vessels, number of railway cars and freight vehicles, or occupied lane metres.
For vessels such as, for example, certain ro-ro vessels, which carry a mixture of passengers in cars, foot passengers and freight, operators may wish to consider some form of weighted average based on the relative significance of these trades for their particular service or the use of other parameters or indicators as appropriate.
Voyage generally means the period between a departure from a port to the departure from
the next port. Alternative definitions of a voyage could also be acceptable.