The IMO commissioned report then provides a brief description of each measure including summary information about the measure, followed by discussion on how these considerations relate directly to the port area. The report then, in systematic way, summaries the findings using the following symbols as shown in brackets below:
- Applicable emission sources – describes which emission sources can be affected by the “measure” and include:
- Propulsion engines (P)
- Auxiliary engines (A)
- Auxiliary boilers (B)
- Applicable to propulsion engines, auxiliary engines, and auxiliary boilers (all)
- Working VOC cargo tanks (Tank).
- Retrofit-able: This provides information if the measure can be retrofitted on existing ships with three options; (Yes – Y) or limited to only new builds (No – N), and not applicable (N/A).
- Terminal/vessel: The port/terminal operational efficiencies measures are sub-categorized as below:
- Terminal (T)
- Vessel (V)
- Applicable operational modes: This specifies the ship operational mode category in which the measure is effective. These operational modes are sub-categorized as:
- Open water or sea conditions (S)
- Transition (T) or Manoeuvring (M)
- At-berth (B) or At-anchorage (A)
- All modes (all)
- Emissions and energy efficiency: This lists the pollutant specific emission changes anticipated by the measure and provides a relative potential reduction. The IMO commissioned report highlights that emission reduction impacts are based on public data and published values, which do not necessarily represent verification by appropriate authority. For case where information have been available, the following symbols on impact of measure on emissions are used:
- ↑ for increases in emissions
- ↓ for decreases in emissions
- | for either increase or decrease depending on various factors
If a percentage value is provided it represents the potential maximum value. If published levels or limited data are such that the reductions cannot be quantified at this time, then the symbol “to be determined” (TBD) denotes this case.
It should be noted that emission reduction levels are dependent on applicable modes, engine loads, ship power configuration, fuels, operational parameters, equipment parameters, and other factors. Typically, each application of a measure needs to be evaluated on a case-by-case (CBC) basis such that specific parameters and conditions are considered to determine the most appropriate reduction level. Energy consumption is included as an indicator for energy efficiency (MariEMS 2017).