Estimate engine NOx tier from the vessel's keel-laid year for C3 vessels.

calcTier(engineType, keelLaidYear, shipCategory)

Arguments

engineType

Engine type (vector of strings) (see calcEngineType). Valid values are:

  • "SSD"

  • "MSD"

  • "MSD-ED"

  • "GT"

  • "GT-ED"

  • "ST"

  • "LNG"

keelLaidYear

Keel-laid year (vector of ints). If not available, interpolate from build date

shipCategory

Ship category (vector of ints) (see calcShipCategory). Valid values are:

  • 1

  • 2

  • 3

Value

tier, a factorized vector with possible levels of:

  • "None" (used for C1/C2 vessels)

  • "Tier 0"

  • "Tier 1"

  • "Tier 2"

  • "Tier 3"

Details

This function is designed to determine the engine NOx tier for C3 vessels. Therefore, it will return "None" for C1 or C2 vessels.

"Tier 0" is returned for steam turbine, gas turbine, and LNG engines, as well as for diesel engines that were keel-laid prior to Tier 1 taking effect (2000).

"Tier 1", "Tier 2", and "Tier 3" refer to Tier I, Tier II, and Tier III, respectively.

References

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. Pg 3-118:119

See also

Examples

calcTier(c("MSD","GT","LNG","SSD"),c(1985, 2011, 2001,2004),c(3,3,3,2))
#> [1] Tier 0 Tier 0 Tier 0 None #> Levels: None Tier 0