Weight of one kilometer of indoor butterfly-shaped optical cable

The weight of one kilometer of indoor butterfly-shaped FTTH optical cable typically ranges from 15 to 25 kilograms, depending on fiber count and sheath type.Cable Structure and MaterialsIndoor butterfly cables (type GJXH) feature a flat, wing-shaped cross-section with the optical fiber at the center and two Fiber Reinforced Plastic (FRP) strength members on either side, all enclosed in a Low Smoke Zero Halogen (LSZH) sheath . The design is lightweight and flexible, optimized for indoor routing along walls, ceilings, or risers. Fiber counts usually range from 1 to 12 cores, with 1–4 cores common for residential use and up to 12 cores for multi-tenant buildings .Weight ConsiderationsThe weight of the cable depends on:Fiber count: More fibers slightly increase the weight.Sheath thickness and material: LSZH is lightweight but adds some mass.Strength members: FRP is non-metallic and light, unlike steel-reinforced outdoor variants. For typical indoor butterfly cables:1–4 fiber cores: ~15–18 kg/km6–12 fiber cores: ~20–25 kg/km These values are consistent with standard FTTH indoor drop cables, which are designed to be light enough for easy handling and installation without additional support .Practical ImplicationsThe low weight allows installers to route cables along walls, ceilings, and through conduits without heavy-duty support.The butterfly shape minimizes bending stress in the flat plane, reducing the risk of fiber damage during installation .For planning purposes, using 20 kg/km as a conservative estimate for a multi-core indoor butterfly cable is reasonable. This estimate provides a practical guideline for load calculations, shipping, and installation planning for indoor FTTH deployments.