• Excessive pulling tension and high Sidewall Pressure (SWP) at bends are the leading causes of outer sheath tears and insulation damage in high-voltage XLPE power cables. Selecting the right auxiliary layout keeps pulling forces within manufacturer-specified limits ($SWP < 300 \text{ to } 500\text{ kg/m}$).

To optimize underground duct and trench pulls:

• Straight Trenches (Every 2 to 3 meters): Install heavy-duty straight line cable rollers with aluminum or synthetic nylon sheaves to suspend the cable above the trench bed and reduce ground friction factor from $0.8$ down to $<0.2$.

• Bends and Manholes: Position curved multi-sheave corner roller arrays or large-radius corner sheaves. The radius of the corner assembly must exceed the cable’s minimum bending radius (typically $15\times$ to $20\times$ cable outer diameter).

• Long-Distance or Multi-Bend Ducts: Integrate Hydraulic Cable Pushers along the route in tandem with the main pulling winch. Cable pushers apply positive thrust along the cable length, breaking tension buildup and pushing the cable away from the inner radius of conduit bends.

Ningbo Changshi manufactures complete underground cable installation toolsets, including heavy-duty trench rollers, triple-corner sheaves, duct entry bellmouths, and synchronized hydraulic cable pushers with real-time tension sensors.