Pulling Theory - Greenlee G10 Tugger Manuel D'instructions

Cable Pulling Principles (cont'd)

Pulling Theory

This section introduces the main ideas involved with
pulling cable.
Pulling Resistance
The cable puller must overcome two types of resistance:
gravity and friction.
Gravity constantly exerts its force on the vertical
portions of the run. When the pulling force is relaxed,
gravity attempts to pull the cable downward. Friction
develops where the cable contacts the sheaves,
conduit, and tray. Friction resists any movement,
forward or backward, and tends to hold the cables
in place.
Gravity
Gravity
Greenlee Tools, Inc.
Friction
Friction
Conduit
Conduit
Weight
Weight
of Cable of Cable
Cable Pulling Theory Illustrated
30
G10 Tugger™ Portable Cable Puller
To accomplish a cable pull, the cable pulling system
must develop more force than the combination of
gravity and friction.
Generating Pulling Force
To generate pulling force, the capstan works as a
force multiplier. The operator exerts a small amount
of force on the rope. The cable puller multiplies this
and generates the pulling force.
This pulling force is applied to the rope, connectors,
and cable in order to accomplish the pull. The direction
of force is changed, where necessary, with pulling
sheaves.
Pulling Force
Pulling Force
35.6 kN
35.6 kN
(8000 lb) (8000 lb)
Tailing
Tailing
Force Force
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