HomeCalculatorsRudder Normal Force - Class Formula

Rudder Normal Force - Class Formula

Rudder normal-force per typical classification-society rule - F_N = 132·A·v²·κ for full-spade rudders.

RudderForceClass
Rudder normal force
489kN

Formula, assumptions, and limits

$$F_N = 132 \cdot A_R \cdot v^2 \cdot \kappa$$

Uses service speed v in m/s. κ = 1.0 NACA section, 1.10 HO profile, 1.35 fish-tail. Astern condition computed separately with different κ.

Symbol legend

SymbolMeaningUnitSource
$A_R$Rudder arearudder drawing
$v$Service speedm/sship particulars
$\kappa$Profile coefficient - class rule table

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