While both overhead conductor pulling and underground cable pulling involve moving conductors, the environments and methodologies are fundamentally distinct, requiring specialized equipment and techniques:

Overhead Conductor Pulling (OHTL):

• Environment: Conductors are pulled in the open air, supported by towers or poles, often over long spans and challenging terrain.

• Primary Goal: To string conductors to precise sag and tension specifications, ensuring proper clearances and preventing ground contact.

• Key Equipment:

  • Hydraulic Pullers: Generate the pulling force, typically connected to a pulling rope that is then attached to the conductor.

  • Hydraulic Tensioners: Apply back-tension to the conductor reel, keeping the conductor elevated and under controlled tension throughout the pull.

  • Stringing Blocks (Sheaves): Suspended from towers, these rollers guide the conductor smoothly along the path, minimizing friction and preventing damage.

  • Pulling Grips & Running Boards: Specialized devices to connect the pulling rope to the conductor(s) without damaging them.

• Challenges: Managing sag, avoiding obstacles like trees and existing power lines, navigating difficult terrain, and dealing with weather conditions.

Underground Cable Pulling:

• Environment: Cables are pulled through pre-installed conduits, ducts, or directly into trenches, often in confined spaces like manholes, vaults, or narrow urban trenches.

• Primary Goal: To safely install cables without exceeding their maximum pulling tension or bending radius, protecting the cable jacket and insulation from abrasion or damage.

• Key Equipment:

  • Cable Pullers (Winches): Often compact, designed for high pulling force over shorter distances, adapted for conduit pulling. They may be hydraulic, electric, or even manual.

  • Cable Lubricants: Applied generously to the cable and/or inside the conduit to drastically reduce friction during the pull.

  • Duct Rodders/Fish Tapes: Used to pre-string a pilot line through the conduit or duct.

  • Cable Rollers/Guides: Used in open trenches or manholes to support the cable and guide it into the conduit/trench without dragging on abrasive surfaces.

  • Specialized Pulling Eyes/Grips: Designed to attach securely to the cable, often to its central conductor or strength member, and capable of withstanding significant tension without damaging the outer sheath.

• Challenges: High friction within conduits, navigating tight bends, potential conduit blockages, limited working space in vaults, precise route planning to avoid existing underground utilities, and managing heat generated during long pulls.

Our company provides comprehensive, one-stop solutions for both these critical areas, offering state-of-the-art equipment and tools specifically designed for the unique demands of overhead tension stringing and efficient underground cable laying.