What are the types of OPGW optical cables

OPGW optical cables are classified based on their structural design, fiber arrangement, and mechanical properties, with common types including central loose tube and stranded tube constructions.

Overview of OPGW

An Optical Ground Wire (OPGW) is a dual-function cable used in overhead power lines, combining grounding and telecommunications functions. It contains optical fibers for high-speed data transmission, surrounded by layers of steel and aluminum wires that provide mechanical strength and lightning protection . OPGW cables are installed at the top of high-voltage transmission towers and must withstand environmental stresses such as wind, ice, and electrical faults .

Structural Classification

OPGW cables are primarily classified by their fiber placement and protective structure:

1. Central Loose Tube Type
   • Optical fibers are placed loosely inside a stainless steel tube filled with water-blocking gel.
   • The tube is located at the center of the cable and may be surrounded by aluminum or aluminum-clad steel layers for mechanical protection.
   • This design minimizes fiber strain during installation and operation under harsh environmental conditions .
2. Stranded Tube Type (or Multi-Tube Type)
   • Fibers are distributed in multiple small tubes, often made of stainless steel, which are stranded around a central core.
   • This design allows higher fiber counts and better flexibility for long spans or complex tower arrangements .
3. Hybrid Designs
   • Some manufacturers combine stainless steel tubes with aluminum pipes or other materials to balance mechanical strength, corrosion resistance, and fiber protection .

Code Naming and Classification

OPGW cables are also classified using structured code naming conventions, which indicate the cable type, fiber count, and structural features:

• Format Example: OPGW-XX-YY(ZZ;AA)
  • XX: Cable type or structure code (e.g., B1, B2, D)
  • S: Optional suffix for special features
  • YY: Fiber count
  • ZZ;AA: Additional parameters such as mechanical or environmental specifications
• Common Structure Codes:
  • B1, B2: Variants of central tube or stranded tube designs
  • D: Special designs for high mechanical performance or specific environmental conditions
  • These codes help engineers select the appropriate OPGW type based on span length, environmental exposure, and mechanical requirements .

Summary

OPGW optical cables are classified based on:

• Fiber arrangement: central loose tube vs stranded/multi-tube
• Protective materials: stainless steel, aluminum, or hybrid layers
• Mechanical and environmental performance: tensile strength, corrosion resistance, and ice/wind tolerance
• Code naming conventions: structure codes (B1, B2, D), fiber count, and optional features Understanding these classifications ensures proper selection of OPGW cables for high-voltage transmission lines while maintaining both grounding and communication functions .