Armored Fiber Optic Cable Guide: Types, Construction, and Selection
Armored fiber optic cables provide enhanced protection for fiber strands in demanding environments. The metal armor layer protects against crushing, rodent damage, and moisture ingress.
Types of Armored Cable
Steel Tape Armored (STA): Corrugated steel tape wrapped around the cable core. Provides excellent crush resistance and rodent protection. Suitable for direct burial and duct installations.
Steel Wire Armored (SWA): Galvanized steel wire braid surrounding the cable. Offers superior tensile strength for long-span aerial installations. Common in outdoor trunk cabling.
Aluminum Armored: Lighter than steel, used where weight is a concern. Provides good mechanical protection while being more flexible.
Construction Layers
A typical armored cable includes: central strength member, fiber buffer tubes, water-blocking materials, inner sheath, armor layer, and outer sheath. Each layer serves a specific purpose in protecting the optical fibers.
When to Use Armored Cable
Armored cable is recommended for direct burial installations, areas with rodent activity, industrial environments with heavy machinery, aerial spans between buildings, and underground conduit systems. For indoor use, non-armored cables are usually sufficient.
Selection Tips
Choose STA for underground ducts where crush resistance is critical. Choose SWA for aerial installations. Consider aluminum armor when weight is a factor. Always verify minimum bend radius and maximum tensile load specifications before installation.
