Direct-buried optical cables contain optical cable steel wires

Direct-buried optical cables typically include steel wires or steel tape in their outer layer to provide mechanical protection and durability.

Direct-buried optical cables are designed to be installed directly into the ground without the need for ducts or tunnels, often in trenches or using vibratory plows . To withstand harsh underground conditions, these cables are armored with steel tape or steel wires on the outside, which protects against mechanical damage, soil corrosion, and rodent attacks . This armoring ensures the cable maintains structural integrity and reliable performance over long periods.

Cable Construction

• Armored Layer: Steel wires or steel tape form the outer protective layer, providing crush resistance and preventing damage from external forces .
• Optical Fiber Core: Inside, multiple optical fibers are organized in loose tubes or ribbon formats, often with water-blocking gels or tapes to prevent moisture ingress .
• Central Strength Member: Many designs include a fiber-reinforced plastic (FRP) or steel central member to maintain tensile strength during installation and handling .
• Outer Jacket: A durable thermoplastic or polyethylene jacket surrounds the armor, offering UV protection and additional environmental resistance .

Advantages of Steel Armoring

1. Mechanical Protection: Prevents crushing or bending damage during installation and from soil pressure.
2. Rodent Resistance: Steel layers deter gnawing by animals.
3. Durability: Enhances long-term reliability in direct-buried applications.
4. Electrical Continuity: In some designs, metallic elements allow for electrical testing and grounding .

Installation Considerations

Direct-buried cables with steel armoring require careful handling to avoid exceeding bending radii or applying excessive tension during manual or mechanical installation . Pulleys, guide devices, and proper trenching techniques are used to ensure the cable is laid flat and evenly stressed. In summary, direct-buried optical cables commonly contain steel wires or steel tape as part of their armoring, which is essential for protecting the optical fibers from mechanical, environmental, and biological hazards while maintaining long-term performance in underground installations .