Textron Company Greenlee UT10 Ultra Tugger Manuel D'instructions page 15

Cable Pulling Principles (cont'd)
Cable Pulling Forces (cont'd)
At the Pulling Rope
The product of a force (f) moving through a distance
(d) is energy (f x d), and may be measured in newton-
meters or ft-lb. Energy is stored in a rope when the rope
is stretched. This is similar to the way energy is stored in
a rubber band when it is stretched. Failure of the rope or
any other component of the pulling system can cause a
sudden uncontrolled release of the energy stored in the
rope.
For example, a 100 meter nylon rope with a
50,000 newton average breaking strength could stretch
40 meters and store 1,000,000 joules of energy. This is
enough energy to throw a 900 kilogram object, such as
a small automobile, 113 meters into the air.
Greenlee / A Textron Company
®
Ultra Tugger 10 Cable Puller and Pulling Packages
Stored Energy
Stored Energy
15
A similar double-braided composite rope could store
approximately 300,000 joules of energy. This could
throw the same object only 34 meters into the air.
The double-braided composite rope stores much less
energy and has much less potential for injury if it were
to break.
Double-braided composite rope is the only type of rope
recommended for use with the UT10 cable puller. Select
a double-braided composite rope with an average rated
breaking strength of at least 143 kN (32,000 lb).
4455 Boeing Dr. • Rockford, IL 61109-2988 USA • 815-397-7070