CommScope ConQuest Conduit Construction - Manual (Page 68)

Maximum Pulling Length
The maximum pulling length is the longest distance that a cable can be safely pulled through a straight and level
conduit. This formula is used as an independent measure for route engineering purposes.
Lm = Tm / ( W * f )
where:
Lm = maximum pulling length in feet
Tm = maximum pulling tension in pounds
W = weight of cable in pounds per foot
f = coefficient of friction (if unknown use 0.500)
Calculated Pulling Tension – Straight Section of Conduit (LSWP)
This formula is used to determine the amount of tension placed on a cable at the end of pull in a straight section
of conduit. The formula is used in conjunction with the calculated pulling tension for a bend section of conduit to
calculate an estimated pulling tension for an entire conduit run.
Example: QR 715
Tm = 340
W = 0.144
f = 0.500
Lm = 340 / ( 0.144 * 0.500 )
Lm = 340 / 0.072
Lm = 4722
Ts = L * W * f
where:
Ts = pulling tension at end of straight section in pounds
L = Length of straight section in feet
W = weight of cable in pounds per foot
f = coefficient of friction (if unknown use 0.500)
Example: QR 715
in a 500’ straight section of conduit
L = 500
W = 0.144
f = 0.500
Ts = 500 * 0.144 * 0.500
Ts = 500 * 0.072
Lm = 36
8.11 Appendix
Calculated Pulling Tension