• Function:
  • A winch-like machine that pulls pilot ropes or conductors through pulleys.
  • Provides controlled pulling force.
• Key Features:
  • Hydraulic drive system (smooth and controllable).
  • Load measuring system (monitors pulling force).
  • Multiple drums for twin/quad bundle conductors.
  • Rope capacity (usually steel or synthetic pulling rope).
• Capacity Rating: Given in kN of pulling force (e.g., 30 kN, 60 kN, 100 kN).

• Function:
  • Maintains the conductor under controlled tension during stringing.
  • Prevents conductor from sagging or galloping.
  • Avoids conductor damage by ensuring the conductor never rubs against the ground or structures.
• Key Features:
  • Bull-wheel design with rubber/lining to protect conductors.
  • Hydraulic braking system (applies precise back-tension).
  • Reel stand for conductor drums.
  • Double or four-wheel units for bundle conductors.
• Capacity Rating: Given in tension force (kN) and conductor diameter range it can handle.

• The puller pulls a pilot rope (or conductor).
• The tensioner pays out conductor under controlled back-tension.
• Together, they ensure safe stringing, keeping conductors elevated and under constant controlled force.

1. Rated Pulling Capacity:
   • Must exceed the maximum stringing tension required for your longest span.
   • Typical:
     • 30–50 kN → Distribution lines (33–66 kV).
     • 60–100 kN → Sub-transmission (110–220 kV).
     • 120–200+ kN → EHV/UHV lines (400–765 kV).
2. Rope Diameter & Drum Capacity:
   • Should fit the pulling rope size (steel/kevlar).
   • Must hold enough length for the span/section.
3. Speed Control:
   • Adjustable (e.g., 0–5 km/h) for safe stringing.
4. Safety Systems:
   • Load limiter, emergency stop, rope anti-slipping system.

1. Rated Tension Capacity:
   • Must match/exceed the maximum conductor tension during stringing.
   • Rule of thumb:
     • 15–30 kN → Small distribution conductors.
     • 40–60 kN → Single conductors (110–220 kV).
     • 80–150 kN → Bundle conductors (EHV/UHV).
2. Conductor Diameter Range:
   • Bull-wheel groove must suit conductor size (e.g., 9–50 mm).
3. Bundle Capability:
   • Single, twin, triple, or quad bundle handling.
4. Braking Control:
   • Hydraulic system with fine adjustment to prevent over-tension.

1. Get line design data: max span length, conductor type/size, stringing tension.
2. Calculate max pulling tension (span + friction + sag requirements).
3. Choose hydraulic puller with ≥25–30% margin above required pulling force.
4. Choose hydraulic tensioner rated for the max conductor tension, bundle type, and diameter.
5. Check rope/drum capacity, hydraulic system reliability, and safety certifications.

In short:

• Puller = provides pulling force.
• Tensioner = controls back tension & protects conductor.
• Choose based on conductor size, span length, voltage level, and number of bundles.