Assign ship subtype according to the vessel's ship type and size, based on the requested methodology.

calcSubType(
  shipType,
  DWT,
  GT,
  TEU,
  nPassengers = NULL,
  method = "imo",
  inputTableLocation = NULL
)

Arguments

shipType

Ship type (vector of strings) (see calcShipType)

DWT

Deadweight tonnage (metric tons) (vector of numericals)

GT

Gross tonnage (metric tons) (vector of numericals)

TEU

Twenty-foot equivalent units (TEUs) (vector of numericals)

nPassengers

Maximum number of passengers (vector of numericals. Note: only applicable when using the Starcrest method)

method

Select the methodology that should be used (i.e., which set of subtypes to return):

  • "imo"

  • "starcrest"

Note: this argument is not used if inputTableLocation is used.

inputTableLocation

File path (optional). Used to specify a user-supplied set of subtypes. If used, this is typically the same as the auxiliary and boiler load table so that correct loads are assigned. See details for formatting requirements.

Value

subType (vector of strings)

Details

When passing ship size data in the DWT, GT, TEU, and nPassengers parameters, use NA if the parameter is unknown or not applicable (e.g., TEU doesn't apply for passenger vessels).

This function has two sets of ship subtypes available for use: IMO's subtypes or Starcrest's subtypes. Since ship subtypes are important for assigning default auxiliary and boiler engine assumptions, the methodology selected here should match with the methodology used for assigning auxiliary and boiler loads. The IMO subtypes are based on the Third GHG Study, and the Starcrest subtypes are based on the 2017 Port of Los Angeles Air Emissions Inventory.

If custom subtypes are desired, user-supplied subtypes could be specified using the inputTableLocation parameter. This file should be in .csv format with five columns and a header row (additional columns are acceptable). The headers should be:

  • "shipType"

  • "sizeMin"

  • "sizeMax"

  • "sizeUnits"

  • "subType"

Valid values for "sizeUnits" are:

  • "Deadweight"

  • "TEU"

  • "Gross_Tonnage"

  • "Number_of_Passengers"

sizeMin is inclusive and sizeMax is exclusive (i.e., subType is matched where sizeMin <= vessel size < sizeMax).

See data(IMOGHG3_AuxLoadFactor) or data(Starcres2016_AuxLoadFactor) for an example of how this table can be structured.

For more information about ship subtypes, see Section 3.3.3 of the Port Emissions Inventory Guidance.

Note: IMO GHG 3 uses vehicle carrier subtypes which are based on number of vehicles. This information is frequently unavailable in vessel characteristics datasets. However, the auxiliary loads are assumed to be the same for all vehicle carriers regardless of size, so these number of vehicle subtypes are replaced by those used in the C3RIA.

Note: IMO GHG 3 uses cubic meters (m^3) for liquified gas tankers. This information is unavailable in vessel characteristics datasets, and it is unclear which ship parameter value was used to determine these values. Therefore, these vessel subtypes are defined by the same DWT bins as those used for chemical tankers.

References

International Maritime Organization. 2014. "Third IMO GHG study 2014 - Final report." London: International Maritime Organization.

Starcrest Consulting Group. 2018. "Port of Los Angeles Air Emissions Inventory - 2017." APP 171019-517 A.

EPA. 2020. "Port Emissions Inventory Guidance: Methodologies for Estimating Port-Related and Goods Movement Mobile Source Emissions." Ann Arbor, MI: Office of Transportation and Air Quality. US Environmental Protection Agency.

EPA. 2009. "Regulatory impact analysis: Control of emissions air pollution from category 3 marine diesel engines." Ann Arbor, MI: Office of Transportation and Air Quality. US Environmental Protection Agency.

See also

Examples

calcSubType(shipType = c("reefer","bulk.carrier"), DWT = c(NA,56188.016), GT = c(NA,33511), TEU = c(NA,NA), nPassengers = NULL)
#> subType #> 1: reefer #> 2: bulk.carrier.handymax