• Drone-assisted pilot line pulling has revolutionized overhead transmission line (OHTL) construction across mountainous terrain, dense forests, and wide river crossings. The drone acts as the initial payload delivery vehicle, eliminating the need for ground clearing, heavy tree felling, or risk-heavy manual line hauling.

The multi-stage stringing sequence operates as follows:

• Stage 1 (Drone Payload): Heavy-payload industrial drones fly over the towers to drop a ultra-lightweight, high-strength synthetic leader rope (typically 2mm–3mm UHMWPE line) over high-lead stringing blocks suspended from pylon cross-arms.

• Stage 2 (Step-Up Rope Transition): The lightweight synthetic leader rope is attached to a medium anti-twist steel rope or larger braided synthetic pilot wire.

• Stage 3 (Hydraulic Pulling): A Ningbo Changshi Hydraulic Conductor Puller on the ground reels in the intermediate pilot rope, which in turn pulls the heavy steel anti-twist wire rope and main power conductor through the suspended sheaves under precise tension control.

To support drone-assisted operations, Ningbo Changshi produces specialized ultra-lightweight synthetic pilot ropes, smooth-entry drone stringing blocks, and micro-tension hydraulic winches designed for frictionless step-up pulling.