Temperature of filler for multi-core cables type SS with sheath

The filler temperature is calculated in the middle between the sheath (which is separate for each core) and the armour bedding (or innermost layer over the filler).

Symbol
$\theta_{f}$
Unit
$^{\circ}$C
Formulae
$- T_{1} \left(W_{c} + \frac{W_{d}}{2}\right) - \frac{T_{2_{f}} n_{c} \left(W_{c} \left(\lambda_{1} + 1\right) + W_{d}\right)}{2} + \theta_{c}$
$\theta_{c}$
$W_{c}$
$W_{d}$