Requirements for overhead optical cable splicing coiling

Proper splicing and coiling of overhead optical cables require careful cable preparation, adherence to safety standards, precise fusion or mechanical splicing, correct coiling in splice trays, and thorough testing to ensure minimal signal loss and long-term reliability.

Cable Preparation

For overhead cables such as OPGW, ADSS, or SkyWrap, preparation is critical. The outer metallic or dielectric layers must be carefully stripped to expose the fiber tubes without damaging the fibers.

For OPG

W cables, this involves: Measuring and marking 2–2. 5 meters of cable to be strippedSecuring the cable with tape at the marking pointCutting and removing outer aluminum or steel strands using a metal saw or mini grinderExposing inner tubes slightly longer than outer tubes to facilitate splicingUsing gloves and face shields for safety during metal removal For ADSS or all-dielectric cables, preparation is similar but without metallic layers, focusing on careful stripping of protective jackets and loose tubes.

Splicing Techniques

Two main splicing methods are used: Fusion Splicing: Aligns fiber cores precisely and fuses them with heat, producing low-loss, permanent connections (typical loss ~0. 1 dB). Modern fusion splicers use core or cladding alignment for accuracy.

Mechanical Splicing: Uses a gel or mechanical fixture to join fibers, suitable for temporary or field repairs, with slightly higher loss than fusion splicing. Splice trays or closures must accommodate the fiber count, allow for future expansion, and protect splices from environmental stress. Proper routing and coiling of fibers in trays prevent microbends and maintain minimum bend radius.

Coiling and Routing

Fibers should be coiled in organized loops within splice trays or closures, following the manufacturer's minimum bend radius to avoid signal loss. Coils should be color-coded and positioned according to the network plan to facilitate maintenance and testing. For overhead installations, fibers are routed from the splice point to the distribution manifold or cabinet, ensuring no tension or sharp bends.

Testing and Verification

Use OTD

R (Optical Time-Domain Reflectometer) to measure splice loss and verify continuity along the span. Optical Power Meter and Laser Light Source are used to measure power loss at 1310 nm and 1550 nm wavelengths, ensuring proper calibration before testing. Bidirectional testing is recommended to eliminate measurement artifacts and confirm splice quality.

Maximum allowable losses: ~0. 85 dB at connectors and ~0. 31 dB at field splices, with reflectance below -40 dB.

Safety and Environmental Considerations

Always follow personal protective equipment (PPE) requirements, including gloves, eye protection, and insulated tools for overhead work. Ensure proper authorization and environmental measures are in place before performing splicing or coiling tasks. Maintain cable integrity during handling, transport, and installation to prevent damage before and after splicing.

By following these preparation, splicing, coiling, and testing requirements, overhead optical cable installations can achieve high reliability, minimal signal loss, and long-term operational stability.