Replacing an OPGW cable requires careful planning, proper tensioning, precise splicing, and thorough testing to maintain both grounding and fiber communication functions.

Preparation and Planning

Before replacement, conduct a line survey to determine tower positions, drum lengths, and splice locations based on accessibility and obstacles such as roads or other lines ( ). Prepare the site by ensuring flat, solid, and well-drained areas for cable drums and equipment ( ). Verify the mechanical properties, transmission performance, and splice loss of the new OPGW cable, and ensure all accessories and tools are available, including tension machines, pay-off machines, pulleys, anti-torsion devices, and intercoms ( ).

Safety Measures

Establish an equal potential zone using temporary grounding cables and protective equipment such as hot-sticks, conductive mats, gloves, and face shields ( ). This is critical to prevent electrical hazards while working on high-voltage transmission towers.

Cable Removal and Installation

1. Remove the old OPGW cable carefully, avoiding damage to the tower hardware and adjacent lines.
2. Install the new cable using the tension pay-off method, maintaining appropriate tension to prevent sagging or abrasion ( ). Use pullers, tensioners, swivels, and pulley-blocks to guide the cable along the towers ( ).
3. Ensure the cable is properly aligned and supported on each tower, observing the minimum bending radius to protect the optical fibers ( ).

Splicing Procedure

1. Prepare the cable by straightening at least 2–2.5 meters and marking the section for splicing ( ).
2. Remove the armor layers carefully using a metal saw or mini grinder, exposing the inner fibers without damaging them ( ).
3. Insert fibers into protective transport tubes if the cable has metal loose tubes, separating fibers into groups as needed ( ).
4. Fusion splice the fibers and seal with heat-shrink sleeves, then place the splices into closures mounted on the tower ( ).
5. Perform OTDR testing to verify optical continuity and splice quality ( ).

Final Checks

After installation, verify the mechanical tension, sag, and optical performance of the cable. Document all test results, including OTDR traces and splice losses, and ensure proper handover procedures are completed ( ). Replacing OPGW fiber optic cables is a complex task requiring coordination, specialized equipment, and strict adherence to safety and technical standards to ensure reliable electrical grounding and fiber communication.