Steel wire for outdoor optical cables

Steel wire armored (SWA) fiber optic cables provide robust mechanical protection, environmental durability, and long-term reliability for outdoor fiber networks.

Structure and Design

Steel wire armored cables are designed with one or more layers of steel wires between the inner fiber sheath and the outer jacket, providing tensile strength, crush resistance, and rodent protection . Common structural elements include:

• Central strength member (often GRP or steel) for core support
• Loose or tight buffer tubes housing optical fibers to isolate them from mechanical stress
• Steel wire armoring helically wound or in a corrugated tape form
• Water-blocking materials such as gel or aramid yarn to prevent moisture ingress
• Outer jacket made of PE or LSZH for UV resistance and weather durability This design ensures fibers remain protected from pulling forces, compression, and environmental hazards during installation and operation.

Fiber Types and Configurations

SWA cables are available in singlemode (SMF) and multimode (OM1–OM5) fibers, with fiber counts ranging from 2 to 96 or more, depending on network requirements . They can be configured as:

• Single jacket or double jacket for added protection
• Gel-filled or dry water-blocked for moisture resistance
• Loose tube or tight buffer depending on termination and deployment needs

Applications

Steel wire armored cables are ideal for outdoor and industrial environments, including:

• Aerial installations over long spans
• Direct burial in soil or ducts
• Interbuilding links and campus networks
• Feeder and distribution segments requiring high tensile strength They are particularly effective in areas prone to rodent attacks, mechanical impact, or extreme weather, supporting stable operation across -40°C to +70°C .

Advantages

• Mechanical robustness: Protects fibers from crushing, pulling, and impact
• Environmental durability: Resistant to UV, moisture, and temperature extremes
• Rodent protection: Steel armor deters gnawing and damage
• Versatility: Suitable for aerial, duct, and direct burial installations
• Long-term reliability: Maintains optical performance under harsh outdoor conditions

Summary

For outdoor fiber optic networks, steel wire armored cables offer a combination of mechanical strength, environmental protection, and flexible deployment options. Choosing the right configuration—fiber type, jacket material, and armoring style—ensures durable, high-performance connectivity for long-term outdoor applications.