Optical cable laying adopts the traction method

Optical cable traction laying involves carefully pulling the cable along a predetermined path using manual or mechanical methods while controlling tension and bending to prevent damage.

Overview of Traction Laying

Traction laying is a common method for installing optical cables, especially in aerial or overhead applications. The process involves pulling the cable along support structures such as poles or trays using a traction rope or mechanical winch. The main goal is to maintain the cable's integrity by controlling tension, bending radius, and twisting during installation .

Methods of Traction Laying

1. Fixed-Pulley Traction Method
   • Setup: Large pulleys are fixed at the start and end poles, while small guide pulleys are installed every 10–20 meters along the route. A traction rope is threaded through these pulleys and connected to the cable .
   • Manual Traction: Workers gradually pull the cable by hand, often with one person assigned per two poles for assistance. Communication between the cable laying end, receiving end, and traction head is maintained via telephones or radios .
   • Mechanical Traction: A winch or motorized device pulls the cable. Traction tension is carefully monitored and should not exceed 80% of the cable's allowable tension, with instantaneous peaks limited to 100% . Swivels are used to prevent twisting.
2. Cable Tray Moving and Releasing Method
   • The cable is laid along a tray that moves or releases the cable gradually. This method is less common but useful for certain aerial or indoor installations .

Key Technical Considerations

• Bending Radius: The cable should not be bent less than 15 times its outer diameter during normal handling and 20 times during construction .
• Tension Control: Traction tension must be adjustable, with automatic stop mechanisms to prevent over-tensioning .
• Cable Handling: The cable must be released from the drum in a loose arc to avoid twists, surges, or small loops .
• Guidance and Lubrication: When pulling, guide devices and lubrication reduce friction and prevent damage, especially at turns or entry points .
• Safety Measures: Personnel must use safety harnesses, gloves, and helmets, and follow OSHA and local safety regulations. Only trained personnel should operate traction equipment .

Additional Tips

• For long cable runs, the cable may be laid in sections, with the first half coiled in an “8” shape on the ground before continuing .
• When passing through walls or floors, protective tubes and flame-retardant fillers should be used to prevent mechanical damage .
• Centralized, intermediate, or decentralized traction can be selected based on terrain, cable length, and equipment availability . By following these methods and precautions, optical cables can be installed efficiently while minimizing the risk of fiber breakage, signal loss, or mechanical damage.