OPGW Optical Cable Structure Classification

OPGW cables combine optical fiber communication with grounding and lightning protection, featuring a central fiber unit, protective tubing, and outer strength members for mechanical and electrical performance.

Core Structure

Central Fiber Unit: The optical fibers, typically single-mode, are housed in a central tube made of stainless steel or aluminum, which may be a loose tube filled with water-blocking gel or a solid stainless steel tube. This central unit ensures the fibers are protected from tensile stress, lateral pressure, and environmental factors during installation and operation . Protective Tubing: Surrounding the fiber unit is a protective layer, which can be an aluminum tube, aluminum-clad steel tube, or stainless steel tube. This layer provides mechanical protection, shields the fibers from abrasion, and contributes to the cable's overall durability . Outer Strength Members: The outer layers consist of one or more layers of aluminum-clad steel wires, galvanized steel wires, or aluminum alloy wires. These layers provide mechanical strength, tensile support, and electrical conductivity for grounding and lightning protection. The arrangement of these wires can be trapezoidal or concentric, depending on the design requirements .

Types of OPGW Structures

1. Central Stainless Steel Tube Type: Fibers are enclosed in a single stainless steel tube at the center, with aluminum-clad steel wires woven around it. This design offers uniform stress distribution and minimal optical loss, suitable for up to 48 fibers .
2. Loose Tube Type: Fibers are loosely placed in a sealed, water-resistant tube with gel filling, allowing for expansion and contraction without fiber damage. This type supports higher fiber counts, typically 24–96 cores .
3. Aluminum Tube or Frame Type: Combines aluminum or aluminum alloy wires with steel for mechanical strength and conductivity, often used in long-span, high-voltage lines .

Key Features and Advantages

• Dual Functionality: Provides both grounding/lightning protection and high-speed optical communication .
• High Mechanical Strength: Outer metal layers protect fibers from tensile stress, lateral pressure, and environmental hazards .
• Electrical Conductivity: Aluminum-clad steel wires ensure effective grounding and lightning protection .
• Durability and Reliability: Resistant to electromagnetic interference, corrosion, and harsh weather conditions .
• Installation Efficiency: Combines optical and grounding functions in a single cable, reducing construction time and cost .

Applications

OPGW cables are primarily used in high-voltage transmission lines (110 kV and above), long-distance spans, and areas with harsh terrain. They support SCADA systems, smart grid communication, and can be leased for high-speed data transmission between cities .