Anchor + chain sizing starts from the Equipment Number. IACS UR A1 combines displacement, side projected area and tier-level superstructure areas.
Formula
$$ EN = \Delta^{2/3} + 2 (h \cdot B + \sum A_i) + \tfrac{A_\text{profile}}{10} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $Δ$ | Ship displacement at SLWL | t | hydrostatic table |
| $h·B$ | Effective height × beam (hull+superstructure) | m² | GA plan |
| $\sum A_i$ | Sum of tier-level superstructure areas | m² | GA plan |
| $A_\text{profile}$ | Side-projected area above SLWL | m² | GA plan |
| $EN$ | Equipment number | - | result |
Sources
- IACS UR A1 - Anchor Equipment.