Stripping of underground optical cables

Stripping underground optical cables requires careful layer-by-layer removal using precision tools to avoid fiber damage and ensure reliable splicing or connectorization.

Key Considerations for Underground Fiber Stripping

Layered Cable Structure: Underground fiber optic cables often have multiple protective layers, including an outer jacket, aramid yarn (Kevlar), buffer tubes, and the optical fibers themselves. Each layer must be stripped progressively, not all at once, to prevent damage to the fibers beneath the outer sheath. Precision Tools: Use specialized fiber strippers designed for the specific fiber type and coating.

Mechanical, thermal, or semi-automatic strippers can remove coatings cleanly without nicking the glass fiber. For example, semi-automatic machines can handle coated fibers from 125/250 µm up to 125/900 µm and strip lengths from 3 to 60 mm. Handheld strippers are suitable for smaller-scale work, while automated systems improve efficiency for large projects.

Proper Technique: Strip the outer jacket first, then the aramid yarn, and finally the buffer coating. Avoid exceeding recommended strip lengths (typically 30–50 mm) to prevent fiber weakening. Clean the bare fiber with lint-free wipes and high-purity alcohol to remove residues before splicing or connectorization.

Mechanical Limits: Confirm the minimum bend radius and maximum pulling tension for the cable type before stripping, especially in underground installations where tight bends or conduit constraints may exist. Safety and Maintenance: Keep cutting edges sharp and maintain tools regularly. Damaged or dull tools can nick fibers, leading to cracks or signal loss over time.

Environmental Considerations: Conduct a site survey to assess soil conditions, existing utilities, and conduit layout. Proper planning reduces the risk of fiber damage during installation and future maintenance.

Summary

Stripping underground optical cables is a delicate process that requires layer-by-layer removal, precision tools, and strict adherence to manufacturer specifications. Following best practices ensures the integrity of the fiber, prevents signal loss, and supports long-term network reliability in underground installations.