Rudder Area - Archer Rule
Rudder-area rule-of-thumb using Archer's formula - a function of underwater lateral area, used in early design feasibility.
Archer area
31.50m²
Det Norske (DnV) area
20.51m²
Formula, assumptions, and limits
$$A_R^{Archer} = \frac{L \cdot T}{60}$$
Modern flapped or high-lift rudders can be up to 30 % smaller. DNV rule-based area includes correction for draft-length ratio. Always verify against full manoeuvring analysis.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $L$ | LBP | m | ship particulars |
| $T$ | Mean draft | m | hydrostatics |
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