Equipment Number (IACS UR A1)

Anchor + chain sizing starts from the Equipment Number. IACS UR A1 combines displacement, side projected area and tier-level superstructure areas.

StructuralIACS A1Anchor

Displacementth × B (effective height × beam)m²Σ tier-level superstructure areasm²Side-profile aream²

Equipment Number (EN): 3,327–

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

EN = \Delta^{2/3} + 2 (h \cdot B + \sum A_i) + \tfrac{A_\text{profile}}{10}

Symbol	Meaning	Unit
$Δ$	Ship displacement at SLWL	t
$h·B$	Effective height × beam (hull+superstructure)	m²
$\sum A_i$	Sum of tier-level superstructure areas	m²
$A_\text{profile}$	Side-projected area above SLWL	m²
$EN$	Equipment number

Source: IACS UR A1 - Anchor Equipment

In short

Anchor + chain sizing starts from the Equipment Number.

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