Stockbridge Dampers

Stockbridge dampers are placed on power lines and light poles to prevent oscillation through resonance. 

Possible Guiding, Compelling and/or Anchoring Questions

• What is their purpose?
• What would happen if they were not on?
• Where should these be placed in order to be the most effective? 
• What does it mean by a tuned mass damper?

Classroom Suggestions

• Start off with showing the picture of the stockbridge damper then the video of it in use. 
• This can be observed in class by oscillating a thick rope by hand. Or a mechanical oscillator with string. Then put a small mass at a node, then move to an antinode to see what place is the most effective.
• Students should see that dampers are not very effective on the node, and rather effective everywhere else. The mass, and how the mass is mounted also makes a difference. That is the tuned aspect of the tuned mass damper.
• The stockbridge damper is also considered a tuned-mass damper. Looking into those next will help fill in the extra information on how these work. You will note that the tuned mass dampers allow the mass to flex up and down, it is not just a weight attached to the powerline.
• After students have a brief understanding of oscillating systems and how tuned dampers prevent the oscillations. You can extend this thinking into the Tacoma Bridge, and how we use bridge dampers today to prevent it from happening again. 
• This concept also applies to breaking a wine glass with your voice.

Related Resources

Stockbridge Damper Demo: This is a short video of a stock bridge damper in action. 
What is a Tuned Mass Damper?: This video has a small scale demonstration on how tuning a mass damper will increase its effectiveness. 
What’s That Thing Hanging From Lampposts and Power Lines?: This is an overview on what stockbridge dampers are and how they work.