Common underground optical cable models include GYTA53, GYFTYA53, GYTY53, GYFTY53, GYXTW53, GYTA33, GYFTS, and GYTS, designed for durability, mechanical protection, and environmental resilience.

Armored Underground Cables

Armored cables are widely used in high-risk environments where mechanical protection is critical. Typical models include:

• GYTA53: Double-layer armored cable with aluminum tape and polyethylene sheath, providing strong protection against moisture and soil pressure.
• GYFTYA53: Flexible armored cable reinforced with aramid yarn, suitable for areas requiring bending flexibility.
• GYTY53: Steel tape armored cable for extra durability in harsh conditions.
• GYFTY53: Combines steel armor with water-blocking features to prevent moisture ingress.
• GYXTW53: Lightweight armored cable with corrugated steel tape, ideal for urban areas with construction vibrations .

Non-Armored Underground Cables

Non-armored cables are suitable for less demanding environments but still offer tensile strength and moisture resistance:

• GYTA33: Aluminum-polyethylene sheath for basic moisture protection.
• GYFTS & GYTS: Fiber-reinforced designs providing tensile strength for conduit installations or areas with minimal mechanical stress .

Fiber Types

Underground optical cables can use either single-mode or multi-mode fibers:

• Single-mode fibers: Thin core (8–10 microns), suitable for long-distance transmission (>100 km), commonly used for internet, cable TV, and telephone networks.
• Multi-mode fibers: Larger core (~50–62.5 microns), suitable for shorter distances (up to 2 km), often used in local area networks .

Installation Considerations

• Direct Burial: Cables are buried directly in soil, requiring robust armoring and water-blocking mechanisms to withstand soil pressure, rodent activity, and accidental excavation.
• Conduit Installation: Cables are placed inside protective conduits, which can reduce mechanical stress and simplify maintenance or replacement .
• Environmental Protection: Armored layers (steel or aluminum), water-blocking tapes, and PE jackets rated for temperature extremes (-40°C to +85°C) ensure durability in diverse terrains, including urban, rural, and marshy areas .

Summary

Ordinary underground optical cables are selected based on mechanical protection needs, environmental conditions, and transmission distance. Armored models like GYTA53 and GYFTYA53 are preferred for high-risk areas, while non-armored models like GYTA33 and GYTS are suitable for less demanding installations. Both single-mode and multi-mode fibers are used depending on the required bandwidth and distance, and installation can be direct burial or conduit-based for added protection .