Why Should We Use Pulling Grip?

On many occasions, if the pulling distance is short (less than 3000 ft) and the pathway is straight enough, one can pull a fiber optic cable by hand without the help of any tools. Only when additional mechanical force or distance of long term is needed for a pull, the external pulling lines and pulling grips are needed.

Various types of pulling lines/ropes/tapes have been used successfully with optical cables. When pulling fiber optic cables, they are often referred to. And these pulling ropes are normally pulled through ducts to ensure a straight pulling path as shown below.

Since a pulling rope with a small diameter may cut the inner duct when being pulled, it is necessary to lubricate the pulling rope.

In addition, wire mesh pulling grip and breakaway swivel are recommended as well during cable pulls. External pulling grips (figure 2) are designed to lock into and tighten a fiber optic cable as a tensile load. The pulling end of the grip is a loop for attachment of the pulling tape or rope.

The pulling grips can provide effective coupling of pulling loads to the jacket, aramid yarn, and central member of fiber optic cables. The swivel installed between the pulling rope and the pulling grip makes sure a twist in the pulling rope is not translated to the fiber optic cable. And the swivel can be used to ensure that the maximum tension of the cable is not exceeded. During manual pulling, applied pulling tension higher than the cable tensile rating can damage the cable and negatively impact its lifetime. Featured with different tensile ratings, breakaway swivels will break if excess tension appears during cable pulling. For example, if cable rated tensile is 2700N and the breakaway swivel adopted has a fixed tensile strength of 2500N, when the cable pulling tension goes above 2500N , the swivel will break, making no impact on the fiber optic cable.