Calculates ship power (kW) using the admiralty formula.

calcShipPwrAdm(
  shipSpeed,
  actualDraft,
  refSpeed,
  maxDraft,
  totalInstalledPwr,
  n = 3,
  foulingMargin = 0,
  serviceMargin = 0,
  refSpeedType = "serviceSpeed"
)

Arguments

shipSpeed

Ship actual speed (m/s) (see calcSpeedUnitConversion)

actualDraft

Actual draft (m)

refSpeed

Reference speed of the ship (service speed or maximum speed) (m/s)

maxDraft

Maximum summer load line draft (m)

totalInstalledPwr

Total installed main engine power (kW) (maximum continuous rated power)

n

Exponential relationship applied to the ship speed ratio (dimensionless). Default = 3

foulingMargin

A fouling margin to account for hull surface deterioration. Default = 0

serviceMargin

A service margin to account for weather and sea effects:

  • At-sea operations = 15

refSpeedType

Indicates if the reference speed is service speed or maximum speed:

  • "serviceSpeed (Default)"

  • "maxSpeed"

Value

power

Details

Ship speed and actual draft are typically obtained from sources such as AIS messages or ship records.

This implementation assumes the following default values:

n = 3 (IMO greenhouse gas study)

serviceMargin = 10 or 15, based on IMO (Prpic Orsic and Faltinsen, 2012). 15 indicates 15% increased resistance in at-sea water conditions, and 10 indicates 10% increased resistance in coastal water conditions.

A possible value for fouling margin is 9, based on IMO (Doulgeris, Korakianitis et al. 2012). (9 indicates 9% increased resistance due to hull fouling). However, the default value for this is assumed to be 0.

Note that service and fouling margins are treated as added resistances here (instead of reduced efficiencies) to maintain consistency with the other power models used in this library. (See MAN, 2011).

References

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

MAN Energy Solutions. 2011. "Basic Principles of Propulsion."

See also

Examples

calcShipPwrAdm(seq(0,13,1),12.48, 15, 13.57,9363, n=3, foulingMargin = 9, serviceMargin = 0)
#> [1] 0.0000 187.2600 187.2600 187.2600 187.2600 296.9052 513.0522 #> [8] 814.7079 1216.1237 1731.5511 2375.2416 3161.4466 4104.4175 5218.4059