Fiber optic cables should be pulled using the internal strength members, proper tools, and controlled tension to prevent damage and ensure reliable installation.

Key Best Practices

Use the Strength Member: Fiber optic cables contain internal kevlar or aramid yarns, known as the strength member, which should bear the pulling force rather than the outer jacket. Pulling by the jacket can cause stretching, tearing, or breakage, compromising the cable's performance and connector terminations. Expose the strength member by stripping a small portion of the jacket, then loop it into a pull-eye and secure it with tape or a knot for safe pulling . Maintain Proper Bend Radius: Exceeding the minimum bend radius can damage fibers internally, even if the cable appears intact. Modern bend-insensitive fibers may allow radii as small as 4.4mm, while older fibers require larger radii, often 30mm or more. Use cable guides and avoid twisting to maintain the recommended bend radius throughout the pull . Use Appropriate Pulling Tools: Tools such as fiber optic cable pullers, capstans, or automated pullers with tension control help manage the pull safely. Capstans allow controlled pulling speed and can handle rope, tape, or the cable itself. Advanced pullers, like the Condux Fiber Optic Cable Puller, provide load cell tension measurement and variable speed control to prevent exceeding maximum tensile loads . Lubrication and Long Pulls: For runs over 40 meters, use compatible cable lubricants to reduce friction. For runs over 100 meters, pull from the middle out to both ends if possible. Always monitor tension and avoid sudden jerks or twists . Safety Measures: Never place hands on a moving pulling line. Ensure all crew members maintain visual or voice communication during the pull. Avoid loose clothing near moving parts, and follow federal, state, and local safety regulations . Connector Protection: Keep dust caps on connectors until final termination to prevent contamination, which can cause signal loss. Avoid pulling on connectors directly; use a proper pulling grip with a swivel to prevent twisting .

Summary

Pulling fiber optic cables through shafts requires careful attention to tension, bend radius, and cable handling. Using the internal strength member, proper pulling tools, and safety protocols ensures the cable remains intact, maintains signal integrity, and extends the lifespan of the installation .