Factor of permissible pull

Where a cable is to be pulled using a winch and steel wire rope, the rope may be secured to the cable by either:

To apply a pulling eye on the conductors of the cable is typically recommended. Do not use metallic shielding wires, tapes, braids or armor not designed for the purpose in pulling tension calculations.

Note that both copper and aluminium are extremely ductile metals which, in their annealed state, have no clearly defined yield point so that elongation can commence at stresses substantially less than the yield stress for the material. Galvanised mild steel, as used for cable armouring, has a more clearly defined yield stress below which negligible elongation will occur.

The following values apply when using pulling eyes on the conductors or where a pulling eye is constructed from the armour or designed to pull on the armour only.

Used in
Copper conductor50.
Aluminium conductor30.026.330.030.0
Steel wire armour150.0130.0130.0130.0
Aluminium wire armour30.052.750.030.0