CommScope ConQuest Conduit Construction - Manual (Page 40)

5.2 Pulling Cable into Conduit
Route Geometry
Route Geometry
Route geometry is an important contributor to pulling tension. The lowest pulling tensions are found in straight
sections of conduit. Low sidewall pressure (LSWP) occurs in horizontal straight sections of conduit. SWP is caused
by the weight and friction of the cable against the conduit, with a minimal amount of force being applied to the
cable’s jacket. For calculating LSWP see Section 8.14.
In bends, the amount of force applied to the cable jacket increases exponentially. This is known as high sidewall
pressure. The more severe the bend radius of the conduit the higher the sidewall pressure will be. The effects of
high sidewall pressure (HSWP) can include rope burn through in the bend and cable damage. WHUPP!
® Cable
Pulling Lubricant will help in reducing pulling tensions and rope burn-through by greatly reducing friction. For
calculating HSWP see page 8.15.
It is much easier to pull through the greatest number or most severe bends first and then through the longest
straight sections.
Conduit should be placed as flat and level as possible to maintain low pulling tensions. When the conduit is
installed on an incline, typically due to terrain features, pulling tensions may be reduced by pulling the cable down
hill, working with gravity rather than against it.