How Vibration Damper Works in Transmission Line?

How a Small Size Damper Reduces Vibration in Transmission Lines?


Vibrations dampers are usually used in high voltage and extra high voltage electrical energy overhead transmission  line to handle aeolian and galloping or dancing vibrations in the transmission lines conductors. The dampers are designed such a way that they attenuate the line vibrations by reaching the same frequency as the cable that has wind induced vibrations.

The overhead Transmission Line mainly experiences two types of vibrations in vertical plane which can be categorized into two groups.

  • Aeoline Vibration;
  • Galloping or Dancing vibration.



Aeoline Vibration is having a high frequency and low amplitude at very low velocity (4 to 15 km/hr) of wind, like- vibration frequency 5 to 40 cycle/second and the amplitude being 2 cm to 5 cm with a loop length of 1 m to 10 m. 

Galloping or Dancing Vibration is having self exited type a low frequency but higher amplitude, like- 1/4 – 3/2 cycle/second and amplitude of vibration around 10 m.

The Vibration Phenomena in Transmission Line is solved by using specially designed dampers called Stockbridge Damper that is basically a device to absorbed vibration energy and prevent vibration in Transmission Line.

Stockbridge Damper

Stockbridge Damper

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The Stockbridge damper was invented in the 1920s by an engineer George H. Stockbridge, as per his name it is called Stokbridge. In early stockbridge damper used concrete as damper mass material, now a days it use some heavy metal.

As in figure right end, Stockbridge Damper has two masses at the ends of a connecting rod or stiff cable which gives it a dumbbell shape. It is connected to the line conductor immediately above it through a clamp. They can effectively damp out Aeolian wind vibrations.


See video what actually happen during conductor vibration

Stockbridge Dampers absorb vibrational energy and thus prevent formation of standing waves which can cause serious stress fatigue to the energy transmission line and damage it. 

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Spiral Vibration Damper

Smaller diameter  (less than 0.75") conductors like shield wire or optical ground wire (OPGW), a stockbridge damper is not suitable rather a different type and more effective damper is available named Spiral Vibration Damper

The Spiral Vibration Damper has been used successfully for over last few decades to control Aeolian Vibration on these smaller sizes of overhead transmission line conductors and wires.



Spiral Vibration Damper
Spiral Vibration Damper

Spiral vibration dampers have a helically-formed damping section sized for interplay of damper and cable to provide the action/reaction motion such that they impact during Aeolian vibration activity that absorve the natural vibration wave.

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