# Thingamawhatsits on high tension lines? **URL:** \ **Category:** Factual Questions\ **Created:** [January 11, 2012, 11:20pm UTC](https://boards.straightdope.com/t/thingamawhatsits-on-high-tension-lines/609228 "2012-01-11T23:20:33Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [January 11, 2012, 11:20pm UTC](https://boards.straightdope.com/t/thingamawhatsits-on-high-tension-lines/609228/1 "2012-01-11T23:20:33Z")
What are these little objects on some high tension lines? They look like pairs of cones horizontally attached point to point like a bowtie, with rounded hemispherical bases. I’ll guess they’re 200 or 300 mm in overall length. They are suspended from the cables themselves on short little pylons to their mutual attachment point. They have no connection to anything other than the actual wire. They appear on every wire, perhaps on one side of each support tower, perhaps on both sides, and are a very short distance from the termination of the wire on its insulator. I see them on the largest lines in our area, the high towers carrying three groups of two or so conductors each. After some browsing around I think these are something like 200 KV to 400 KV and 1 KA or so. Anybody know? I’m just curious. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [January 11, 2012, 11:24pm UTC](https://boards.straightdope.com/t/thingamawhatsits-on-high-tension-lines/609228/2 "2012-01-11T23:24:52Z")
They’re Stockbridge Dampers. Sheesh, that was easy… > **[Stockbridge damper](https://en.wikipedia.org/wiki/Stockbridge_damper)** > > A Stockbridge damper is a tuned mass damper used to suppress wind-induced vibrations on slender structures such as overhead power lines, long cantilevered signs and cable-stayed bridges. The dumbbell-shaped device consists of two masses at the ends of a short length of cable or flexible rod, which is clamped at its middle to the main cable. The damper is designed to dissipate the energy of oscillations in the main cable to an acceptable level. > Wind can generate three major modes of oscillation i... ---
**Author:** ![freckafree](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/freckafree/32/3050_2.png) [@freckafree](https://boards.straightdope.com/u/freckafree)\ **Post date:** [January 12, 2012, 12:43am UTC](https://boards.straightdope.com/t/thingamawhatsits-on-high-tension-lines/609228/3 "2012-01-12T00:43:11Z")
You’re a one-person SDMB! You ask! You answer! You diss yourself for posting an easy question! 🙂