Innovative Mechanized Stringing Method for Manual Sections in Transmission Lines Reducing Manpower, Enhancing Safety, and Improving Efficiency

This paper presents an innovative ground-based mechanized stringing methodology developed specifically for manual sections of 765 kV D/C transmission lines. The proposed approach eliminates aerial pulley systems by relocating all critical activities—sag calculation and marking, dead-end preparation, tension control, and bundle assembly—to ground level. Preassembled conductor bundles are lifted to tower crossarms using synchronized mini-pullers or winches with real-time load monitoring, limiting tower-top work to final clamping only[1] [3][6].

A detailed technical feasibility assessment is carried out for AL-59 Zebra conductors in a hexabundle configuration over a representative 300 m span. The analysis confirms that the maximum vertical lifting load (~4.2 tonnes including dynamic safety margins) and axial tensions (≤25% of rated tensile strength) remain well within the capacity of commercially available mechanized equipment and standard 765 kV tower crossarm designs. Comparative evaluation demonstrates a manpower reduction of approximately 60%, execution time reduction from 5-7 days to 1.5–2 days per section, and a substantial enhancement in safety by minimizing work at height. [2] [1] [3]

The methodology is scalable to quad and hexa bundles, compatible with existing tower geometries, and adaptable for future deployment with high-temperature low-sag (HTLS) conductors. The proposed approach offers a practical, safe, and future-ready alternative for manual section stringing in extra-high-voltage transmission projects [1] [3] [6] .