Fencing for Rocky or Compacted Ground – Using a Dropper System

I grew up with the mindset that fences had to be fortresses. Rigid and taut as well as non-penetrable was the desired fence in the old days. Then along came high tensile wire and electric fences, and the idea that a fence could act as a psychological barrier (fear of touching it) rather than a physical barrier (unable to penetrate it).

But the greatest benefit of high tensile wire is in its tensile strength – its ability to stretch then return to its initial tension, especially if it’s built with flexible line posts that allow it to react as intended. This tensile strength, combined with its lighter weight compared to traditional wire, meant that line posts could be spread farther apart. Line posts make up a large percentage of your total fencing cost, therefore spacing them farther apart lowers the total fencing cost. And that’s where droppers come in.

Droppers (different from a stay, which doesn’t touch the ground) maintain wire spacing between boss posts on multi-wire high-tensile electric fencing (3+ wires recommended). Droppers simply rest on top of the ground, and their sole purpose is to maintain vertical wire spacings between the line or boss posts. The biggest benefits of a dropper system are:

  • Less Cost. Droppers are a smaller diameter than line posts and cost less than line posts.
  • Easier Installation. Droppers are ideal for areas with tough terrain and in areas with rocky or compacted soils because only the corner assembly and boss posts are driven into the ground, which provides simple and quick installation. Fewer posts in the ground = less work.

Yes, I realize that this concept may be very hard to swallow, let alone to digest. Firstly, we must recognize the fact that an electric fence is a psychological barrier and that the animals fear of the shock they receive from touching it is the actual barrier. They aren’t actually going to push on it, rub on it or even touch it.  This type of fence primarily needs to stand erect and maintain an unabated flow of electric pulses down the fence wires.

One such system that used this technique was the Gallagher Insultimber System. It was actually the norm for electric fences in certain parts of the country. Many people were using it. Insultimber posts were made of a very dense wood product that did not absorb water and was basically an insulated wood post.  Wire was attached with a cotter pin through a drilled hole. This system was discontinued. From my understanding, this was not due to lack of demand, but rather because the source of this wood was basically logged out and no longer available.

Photo Gallery of fences using PasturePro Droppers (click on photo to enter/exit)

 

Steve built his first post & dropper fence several years ago. He built a perimeter fence on some pretty rocky ground during the hottest time of the year. He installed native wooden hedge (Osage Orange) posts at about a 120 foot spacing, then filled in with droppers at about a 20 foot spacing. This fence has 6 strands of high tensile wire.  I inspect this fence every time I go by and it looks great and appears to be working good too. His thoughts on the dropper system:

For years I’d heard about the Insultimber dropper fencing that Gallagher promoted consisting of in-ground posts with stays in between the posts to maintain wire spacing. Having neither built one nor seen one didn’t keep me from judging them as not being as good as a proper fence with all in-ground posts.

However, we kept being told how well our posts would work as droppers. So, we decided to try out a dropper fence on some very steep rocky ground where we needed a new perimeter fence. Though electric fencing is for the most part, a psychological fence, on the perimeters we like to build a fence with hi-tensile woven wire or multi-wire individual wires that would keep stock inside even if the fence was off for weeks. I was somewhat skeptical that a dropper fence would work for this application, but wanted to test our droppers to see how they would perform.

 We have been observing this fence carefully over the past three years, and have been very pleased with the performance of the fence. It looks as tight and sharp today as it did when we installed it, and we’ve found it to be a very effective perimeter fence.

Since that first dropper fence, I’ve built a few more and learned a few things.  In the first dropper fence we built, we used cotter pins to hold the wire to the droppers and we [actually my wife Judy] had to drill 7 holes in every dropper. In the recently built 4 wire fence shown in the video below, the wires were attached with spring clips that hold the wire tight and make attaching the wire a much quicker job. 

Your corner posts and bracing for this system need to be done in the same fashion as you would build any fence, and getting the tension right is really important. In the video below, you’ll notice that the fence swings much more freely than the one above, which can be accounted for by the difference in tension.

A few final things to keep in mind.

  • Droppers won’t work unless you are building two or more wire fences (we recommend at least 3) as they need at least two points of tension to keep them upright and straight. Using droppers that touch the ground every 15-20 feet keeps the wire tight and the height of the fence consistent.
  • The wire attachment at the posts should provide for free travel of the fence wire. However, the fence wire needs to be attached securely to the droppers. Otherwise they will tend to move up or down the fence line. In addition to our cotter pins (which require drilling), we also now have a stainless steel spring clip for attaching wire to droppers. It is a very quick and easy installation and requires no drilling.
  • There is a widespread set of recommendations for the distance between line posts for high tensile wire. I, personally, contend that this depends primarily on terrain and the number of strands of wire. I have friends and customers in the rangeland of the Western USA that commonly go 100 to 150 feet between line posts. As you travel eastward, the spacing’s generally run from 30 to 60 feet. The droppers would generally be every 10-30 feet in between the line posts. But again, you’ll really want to base your spacings on your terrain and fence configuration.

We’d love to hear your thoughts and experiences with dropper fences in the comments below. As always, we’re happy to answer any questions you may have about the system and tell you more about our experiences using them.

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About Gary Duncan

Gary has been active in the fence business for over 15 years. He also raises Highland cattle in a management intensive grazing system and was the first person to market the PasturePro post back in 2005. He enjoys discussing all things grazing and is the main contributor to the blog.
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