Permissible pull force on cable

The maximum tension which may be used is limited by the tensile strength of the conductors or armour wires, or by the gripping capability of the cable stocking, depending on the method used.

When pulling using a stocking/grip, a stocking with the correct diameter and length should be selected, such that all the tension is transferred to the conductor(s). Following installation it is recommended to cut off two metres beyond the point where the cable stocking/grip is attached and check for no signs of stretching on the sheath.

Where the pull is on the armour it shall be confirmed that the sidewall pressure does not exceed that which would occur when using the maximum pull on the conductor in conjunction with the minimum installation bend radius. For example, if the armour pull for a particular cable exceeds the conductor pull by 50% then the minimum bend radius shall also be increased by 50%.

$\frac{A_{c} f_{ppc} n_{c}}{10}$pull on conductor
$\frac{A_{a} f_{ppc}}{10}$pull on armour
$\frac{9 D_{e}}{10}$pull with stocking, armoured cable
$\frac{3 D_{e}}{10}$pull with stocking, sheathed but unarmoured cable
$\frac{D_{e}}{10}$pull with stocking, three-core lead sheath cable