Cableizer ®

Effective length per unit lay length armour

For concentric wires or straps, touching, or tapes with overlap, or two or more layers of tapes in contact with each other, the effective length is limited to 2.

Symbol
$F_{lay,ar}$
Formulas
$\sqrt{1+\left(\frac{\pi d_{ar}}{L_{lay,ar}}\right)^2}$single-core/multi-core cable
$\operatorname{Min}\left(2, \sqrt{1+\left(\frac{\pi d_{ar}}{L_{lay,ar}}\right)^2}\right)$for touching wires or tapes with overlap, single-core cable, IEC 60287-1-1 clause 5.4.2 (2.4.1)
$\sqrt{1+\left(\frac{S_{ar}}{L_{lay,ar}}\right)^2}$multi-core duplex/triplex cable, CIGRE TB 880 Guidance Point 23
$1$TECK cable
Related
$d_{ar}$
Mean diameter armour [mm]
$L_{lay,ar}$
Length of lay armour [mm]
$\pi$
Archimedes' constant $\pi$
$S_{ar}$
Circumference armour [mm]
Used in
$R_{ar}$
Electrical resistance armour [$\Omega$/m]