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
$F_{\mathrm{a_{\mathrm{1}}}}$
Unit
mm
Formulae
$\frac{1}{p_{\mathrm{a_{\mathrm{1}}}}} \sqrt{d_{\mathrm{a_{\mathrm{1}}}}^{2} \pi^{2} + p_{\mathrm{a_{\mathrm{1}}}}^{2}}$default
$\min\left(2, F_{\mathrm{a_{\mathrm{1}}}}\right)$for concentric wires or straps, touching, or tapes with overlap
$1$for TECK
Related
$d_{\mathrm{a_{\mathrm{1}}}}$
$F_{\mathrm{a_{\mathrm{2}}}}$
$p_{\mathrm{a_{\mathrm{1}}}}$
Used in
$R_{\mathrm{A_{\mathrm{1}}}}$