calcSubType.Rd
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 )
shipType | Ship type (vector of strings) (see |
---|---|
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):
Note: this argument is not used if |
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. |
subType
(vector of strings)
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.
International Maritime Organization. 2014. "Third IMO GHG study 2014 - Final report." London: International Maritime Organization.
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