When a non-magnetic armour is present, $d$ is replaced by $d_e$ in the following formulas.

Symbol
$\lambda_{\mathrm{0}}$
Unit
-
Formulae
$\frac{3 d_{\mathrm{s}}^{2} m_{\mathrm{0}}^{2}}{4 s_{\mathrm{c}}^{2} \left(m_{\mathrm{0}}^{2} + 1\right)}$trefoil arrangement and non-flat formations
$\frac{0.375 d_{\mathrm{s}}^{2} m_{\mathrm{0}}^{2}}{s_{\mathrm{c}}^{2} \left(m_{\mathrm{0}}^{2} + 1\right)}$flat formation, outer cable leading phase)
$\frac{3 d_{\mathrm{s}}^{2} m_{\mathrm{0}}^{2}}{2 s_{\mathrm{c}}^{2} \left(m_{\mathrm{0}}^{2} + 1\right)}$flat formation, center cable phase
$\frac{0.375 d_{\mathrm{s}}^{2} m_{\mathrm{0}}^{2}}{s_{\mathrm{c}}^{2} \left(m_{\mathrm{0}}^{2} + 1\right)}$flat formation, outer cable lagging phase
Related
$d_{\mathrm{e}}$
$d_{\mathrm{s}}$
Used in
$\lambda_{\mathrm{1es}}$