Pulling at the fiber optic cable joint

Always pull fiber optic cables by the internal strength member, not the outer jacket, to prevent damage and maintain signal integrity.

Key Considerations for Pulling Fiber at Joints

Use the Strength Member: Fiber optic cables contain internal kevlar or aramid yarns, known as the strength member, which are designed to bear pulling forces. Pulling the cable by the outer jacket can stretch, tear, or break the cable, compromising the joint and overall performance. Expose a small portion of the strength member using a cable stripper, loop it through a pulling eye, and secure it with tape or a knot before pulling . Proper Tools: Use specialized pulling tools such as the Cleerline SSF-PULLEYED or SSF-PULLEYEM, which are designed to reduce twisting and distribute tension evenly across the cable or cable bundle. These tools help protect the joint and prevent microbends or kinks . Tension and Bend Radius: Always adhere to the manufacturer's recommended maximum pulling tension and minimum bend radius. Exceeding these limits at a joint can damage the fiber core or the connector, leading to signal loss. For example, standard indoor micro-distribution cables typically support pull ratings up to 225 lbs, while ruggedized outdoor cables can handle up to 600 lbs . Pathway Preparation: Before pulling, inspect the conduit or pathway for obstructions, sharp edges, or tight bends. Use lubricants if necessary to reduce friction and avoid excessive force at the joint . Stop immediately if the cable binds and never force it forward. Handling and Securing: Avoid stepping on, pinching, or compressing the cable at the joint. Use proper cable ties and enclosures to prevent crushing. Service loops should be installed correctly to allow future maintenance without stressing the joint . Testing After Installation: Once the cable is pulled and secured, test the fiber at the joint to ensure optical performance meets specifications. This confirms that the pulling process did not damage the fiber or connectors . By following these best practices—leveraging the strength member, using proper tools, respecting tension and bend limits, preparing the pathway, and testing after installation—you can safely pull fiber optic cables at joints while maintaining long-term performance and signal integrity .