OPWG Optical Cable Construction Process

The fabrication of OPGW cables involves fiber preparation, stranding with metal layers, and rigorous quality control to produce a dual-purpose cable for power line grounding and communication.Overview of OPGW Cable Structure

An OPGW cable combines the functions of a conventional overhead ground wire and an optical communication cable. It typically consists of one or more optical fibers housed in a tubular structure, surrounded by layers of aluminum and steel wires for mechanical strength and electrical grounding . The optical fibers are made of high-purity silica with germanium doping, coated with UV-curable acrylate for protection . The fibers are often placed in loose tubes filled with jelly to prevent strain during installation .

Fabrication Steps

1. Fiber Preparation

• Optical fibers are drawn from preforms using processes such as MCVD, OVD, VAD, or PCVD to achieve high purity and low attenuation .
• Fibers are coated with a primary protective layer and wound onto spools for cabling. 2. Stranding and Armoring
• The fibers are inserted into a metallic tube, which is then surrounded by layers of steel and aluminum wires.
• Stranding requires precise control of tension, pre-forming, mold, stranding speed, and pitch to ensure uniformity and mechanical strength .
• High-speed stranding machines with automatic tension control are used for multi-layer, high-strength OPGW cables. 3. Cable Assembly
• The tubular fiber unit is combined with the metal layers to form the final cable.
• Loose tube construction allows fibers to move freely, reducing strain during bending or thermal expansion .
• The cable is wound onto drums with secure fastening and protective caps for transport . 4. Quality Assurance and Testing
• OPGW cables undergo type tests, factory acceptance tests, and periodic quality checks according to standards like IEC 60794-4-10 .
• Tests include optical attenuation measurement, mechanical strength, and environmental durability.
• ISO 9001 quality management systems are often implemented to ensure consistent performance. 5. Preparation for Installation
• For splicing, the cable's metal layers are carefully stripped, and fibers are inserted into transportation tubes if necessary .
• Fusion splicing is performed in closures mounted on towers, ensuring both mechanical and optical integrity.

Key Advantages

• Combines grounding and communication in a single cable.
• High reliability and mechanical performance under various weather conditions.
• Reduces the need for separate construction of power and communication lines . This process ensures that OPGW cables are durable, reliable, and capable of supporting high-voltage transmission lines while providing optical communication capabilities.