Installation of Figure-8 Fiber Optic Cables

Figure 8 fiber optic cable is installed using self-supporting aerial techniques, with careful handling to prevent twisting, maintain minimum bend radius, and ensure proper tension on messenger spans.

Overview of Figure 8 Cable

Figure 8 fiber optic cable integrates a messenger component (steel or dielectric) with the fiber optic core in a single jacket, forming the characteristic “8” shape . This design eliminates the need for separate messenger wires and lashing, reducing both material and labor costs by up to 40% . It is widely used for aerial deployments, supporting spans between poles while maintaining durability and stability under environmental stress .

Installation Techniques

Aerial Placement

• Dead-End Poles: Terminate the messenger component using spirally formed steel wires or strandvise compression sleeves to maintain tension .
• Intermediate Poles: Use tangent support clamps (typically 3-bolt designs) to support the cable without applying excessive tension .
• Hooks: Temporarily hold the cable on poles until the dead-end pole is reached .

Pulling Methods

• Figure 8 Loops: When laying cable on the ground for long pulls, form large figure 8 loops (6–12 feet per loop) to prevent twisting and kinking . For midspan pulls, place the reel at the midpoint and pull each end through the conduit sequentially, laying the remaining cable in a figure 8 on the ground .
• Reel Methods: Two main approaches are used:
  • Moving Reel Method: The reel moves along the span as the cable is pulled.
  • Stationary Reel Method: The reel remains fixed while the cable is pulled to the endpoints .

Bend Radius and Tension

• Always maintain the minimum bending radius specified by the manufacturer to prevent fiber damage .
• Do not exceed the maximum installation load or span distance .

Safety Considerations

• Wear safety glasses and gloves during handling .
• Avoid direct exposure to laser light from fiber ends, as it can cause serious retinal damage .
• Use solvents in well-ventilated areas and follow all PPE guidelines .

Advantages of Figure 8 Cable

• Single-step installation reduces labor and material costs .
• Durable aerial performance with integrated messenger support .
• Versatile configurations: available in dielectric or steel messenger versions, and fiber counts from 2 to 432 .
• Eco-friendly options: some modern cables use up to 80% recycled materials while maintaining performance .

Best Practices

• Lay cable slowly and carefully in figure 8 patterns to avoid kinks .
• Use swivel pulling eyes when attaching cable to pull ropes to prevent twisting .
• Consult tangent support clamp manufacturers for pull tolerances and angle departures .
• Verify all specifications for bend radius, tension, and maximum span before installation . By following these procedures, figure 8 fiber optic cable can be installed efficiently, safely, and with minimal risk of damage, ensuring reliable aerial network performance.