Opening an 8-shaped optical cable

To open and lay a figure-8 optical cable safely, use the “figure-8” looping method to prevent twisting, maintain bend radius, and protect the fibers during installation.

Understanding Figure-8 Optical Cable

A figure-8 optical cable combines the optical fiber core with an integrated messenger wire in a distinctive “8” cross-section, making it self-supporting for aerial installations . This design allows the cable to span long distances without additional support hardware, commonly used in rural broadband, 5G backhaul, and utility co-deployment projects . The cable consists of two components: the messenger component (support strand) and the cable component (fiber core), both enclosed in a single jacket .

Preparing the Cable for Installation

• Storage: Keep the cable on its reel with protective material intact until installation. Store reels on flat, firm surfaces, away from sharp objects or flooding risk . Seal cable ends with heat-shrink caps to prevent moisture intrusion .
• Inspection: Before de-reeling, visually inspect the cable for damage. Avoid rolling or kicking the cable to prevent internal fiber stress .
• Cleanliness: Use a plastic sheet or tarp when laying the cable on the ground to keep it clean .

Laying the Cable Using the Figure-8 Method

1. Figure-8 Loops: Lay the cable on the ground in large figure-8 loops (commonly 2–4 meters or 6–12 feet depending on cable stiffness) to prevent twisting. The half twist on one side of the 8 is undone on the other side, minimizing mechanical stress .
2. Offset Loops: Slightly offset each loop from the previous one to reduce pressure points and kinking .
3. Flipping the Cable: After laying the loops, pick up the cable and flip it over so the end to be pulled next is on top .
4. Pulling: Attach the cable end to a pull rope using a swivel-pulling eye to prevent additional twisting during the pull . Pull slowly and steadily, ensuring the cable is not bent beyond its minimum bend radius .

Midspan Pulls for Long Runs

For very long runs (over ~4 km), a midspan pull may be necessary: place the reel at an intermediate point, pull one end to one side, figure-8 the remaining cable, then pull the second end to the other side . This method reduces the need to flip the cable on the ground and maintains fiber integrity.

Additional Handling Tips

• Avoid exceeding the cable's minimum bend radius to prevent attenuation or permanent fiber damage .
• Do not pinch, squeeze, or twist the cable during installation .
• Use plastic clamps with large surface areas for securing the cable, applying gentle pressure .
• Protect connectors and ends from contamination to maintain signal quality .

By following these procedures, you can safely open, handle, and install figure-8 optical cables while minimizing the risk of fiber damage and ensuring reliable network performance.