VESSEL VERIFICATION

GHG Rating source data, assumptions & documentation

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GHG RATING SOURCE DATA

The data used to calculate a vessel’s GHG Emissions Rating can be viewed:

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  • In RightShip Qi – for RightShip customers
  • By sending an e-mail to the environment team who will assist you with GHG Ratings and the vessel verification process.
  • Via the Shipping Efficiency website which provides access to the GHG Rating free of charge. A username and password can be set up to gain access.

RightShip recognises that the reliability of its calculations directly correlates to the accuracy of source data. RightShip continues to work closely with ship owners, managers, yards and classification societies to validate the data used for the calculations.

The data utilised for the GHG Rating calculation is, as far as practicable, in line with the IMO guidelines (MEPC.245(66)) for EEDI calculation. RightShip obtains data for the GHG Rating from various industry sources as outlined below.

The source data for the GHG Rating is based on the hierarchy found in the table below.

As outlined in the DNV GL review, due to the pre-defined set of data assumptions applied to ‘non-verified’ vessels, there is an incentive for shipowners to update relevant data within Qi as it is likely to result in an improved GHG Rating.

PREFERENCE / VERIFICATION LEVELDATA TYPEDATA SOURCE / EXAMPLE
Most preferred / highest level of verification
Energy Efficiency Design IndexClassification Societies e.g. EEDI Technical Files

EEDI certificate (including supplement)
Ship specific specificationsShip-sourced data, e.g. sea trial and shop test supplied by the vessel owner / manager
Industry / third party data sourcesEngine manufacturer's specifications

Data sourced from ship yards
Least preferred / benefit from verification
IHS Maritime database

Industry publications
IMO publications

IHS Maritime Database

RELEVANT DOCUMENTATION

The following documentation is requested to ensure the ship particulars are up to date:

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  • EEDI Technical File – as defined in the IMO Guidelines (MEPC.245(66)) for EEDI calculation.

If the EEDI Technical File is not available, please provide the documentation outlined in the table below.

Upon receipt of the documentation, RightShip’s sustainability team will review and update the vessel particulars and provide the updated GHG Rating.

DOCUMENTATION TYPERELATING FACTORRELEVANT DETAILS
Sea TrialVref Speed (Knots)Trial Speed at Summer/ Scantling Load Draught at 75% Maximum Continuous Rating (MCR). In the form of a sea trial curve (calculated and/or model curves are acceptable)
Shop Test - Main and Auxiliary EnginesNumber of Engines

Power of engines (MCR)

Specific Fuel Consumption (SFC)

Fuel Type (test conditions)
SFC for the Main Engine is read at 75% MCR

SFC for the Auxiliary Engines is read at 50% MCR
Class Certificate and/or Ship Capacity PlanCapacityDeadweight (DWT)

Gross Tonnage

TEU (if applicable)

CBM (if applicable)
Ship classification notationsCommon Structural Rules (include LBP and LWT)

Ice-class

Shuttle tankers

Cubic-capacity correction factor

General cargo equipped with cranes
Other documentation as appropriateInnovative energy efficient technologies Examples include waste heat recovery and shaft motor generator

ENGINE SPECIFIC FUEL CONSUMPTION (SFC) ASSUMPTIONS

As stated above, SFC figures are sourced from vessel-specific shop tests or EEDI technical files.

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If the data is not provided by the ship owner, the values used in the calculation are based on the same assumptions used in the IMO GHG Study and / or detailed in IMO Circulars on the calculation of the energy efficiency measure as listed below.

Main Engine Assumptions (SFCME)
ENGINE AGEMCRME (kW)SFCME (g/kWh)
Pre 1983> 15,000205
5,000 to 15,000215
< 5,000225
1984–2000>15,000185
5,000 to 15,000195
< 5,000205
2001–2007>15,000175
5,000 to 15,000185
< 5,000195
Post 2008>15,000175
5,000 to 15,000185
< 5,000195
Auxiliary Engine Assumptions (SFCAE)
MCRAE (kW)SFCAE (g/kWh)
> 800 kW220
< 800 kW230