Steel strand optical cable splicing

Splicing steel strand optical cables requires combining steel cable splicing techniques with careful optical fiber splicing to maintain both mechanical strength and signal integrity.

Overview

Steel strand optical cables, often used in aerial or high-tension applications, consist of optical fibers protected by a steel messenger or stranded reinforcement. Splicing these cables involves two main objectives: mechanical continuity of the steel strands and optical continuity of the fibers. Proper splicing ensures load-bearing capacity, prevents signal loss, and maintains long-term reliability .

Mechanical Splicing of Steel Strands

1. Eye Splice: Creates a loop at the cable end for attachment to hardware. Steps include measuring and marking the cable, unraveling strands, forming a loop, and weaving strands back into the main body using a fid. This method preserves flexibility and strength .
2. Lap Splice: Joins two cable ends side by side using wire rope clips or clamps. Ensures a smooth profile and distributes load evenly. Typically, a minimum of three clips is used, tightened to manufacturer specifications .
3. Mechanical Sleeve Splice: Involves inserting cable ends into a pre-sized sleeve and compressing it with a hydraulic or manual swaging tool. Provides quick, reliable splices suitable for emergency repairs .
4. Long Splice: Maintains nearly 100% of the original cable strength by unwinding several feet of both cable ends and interweaving strands without fully unraveling . Tools and Safety: Essential tools include fids, wire cutters, swaging tools, cable clamps, thimbles, gloves, and safety goggles. Proper handling prevents strand damage and ensures a secure splice .

Optical Fiber Splicing

1. Fusion Splicing: The preferred method for steel strand optical cables. Fiber ends are precisely aligned and fused using an electric arc, producing a permanent, low-loss connection (typical loss ~0.1 dB). Fusion splicing is ideal for long-haul or high-bandwidth applications .
2. Mechanical Splicing: Uses a splice unit to align and hold fibers without fusion. Suitable for temporary repairs or field conditions where fusion splicers are unavailable. Loss is slightly higher than fusion splicing but provides quick restoration . Best Practices: Fiber ends must be carefully stripped, cleaned, and cleaved. Splice protection sleeves or enclosures are used to shield the splice from environmental stress and mechanical strain, especially when integrated with steel strands .

Integrated Approach

For steel strand optical cables:

• Step 1: Mechanically splice the steel strands first to restore load-bearing capacity.
• Step 2: Splice the optical fibers using fusion or mechanical splicing techniques.
• Step 3: Protect the splice with a reinforced sleeve or enclosure that accommodates both the steel strands and fiber, ensuring tension relief and environmental protection .

Considerations

• Avoid excessive bending or tension on fibers during steel strand splicing.
• Ensure alignment of fibers to minimize insertion loss.
• Periodically inspect splices for mechanical integrity and optical performance.
• Follow manufacturer guidelines for both steel and fiber components to maintain warranty and safety standards . By combining these mechanical and optical splicing methods, steel strand optical cables can be safely and effectively joined, maintaining both structural strength and high-quality signal transmission.