How to build a Smart Farm Fence

How to build a Smart Farm Fence main image How to build a Smart Farm Fence image

There are many Books and fact sheets available on how to build a good farm fence and they all say much the same thing … what they don’t tell you is how to separate fact from fallacy.

FACT No 1:

Proper Planning is the most the most important part of any construction including fencing. A fence is nothing more than a management tool which should be planned as part of an overall system for a farm. There are several factors to consider:

  1. What is the Purpose of your fence?
    • Is it a Boundary, internal or stock holding fence?
    • Is it keeping in livestock or protecting crops?
    • The purpose will affect the design & materials used
  2. What type of animal is it keeping in, keeping out or allowing passage through?
    • Is it keeping in sheep, cattle, goats or other types of animals?
    • Is it keeping out feral animals or just the neighbour’s cattle from eating your crops?
    • Do you want native animals to pass through?
    • How many types of animals will the fence be affecting?
    • Will your fence determine grazing patterns or animal movement?
  3. What are the site conditions?
    • Topography? – is it flat or mountainous terrain?
    • Soil? – Acidic levels will affect the type of post you use. Hard soil will affect the post spacing’s.
    • Is the area subject to floods or fire? – Do you need to install floodgate sections?
  4. Is going to be permanent or temporary?
    • How long do you expect the fence to last?
  5. Electric or Non electric?
    • Consider the initial cost and yearly upkeep of electric fencing verses the benefits?
  6. Access
    • How many gates do you need to accommodate people access. Vehicle access and animal movement?
  7. Legislation
    • Is there any government legislation affecting the location or construction requirement s of your fence.
    • If it is a boundary fence – is your neighbour obliged to pay half or contribute to its construction?
Lightning Dropper on a Farm Fence

FACT No 2:

The strength of a fence is determined by its end or straining assemblies.

This ranks as the top mistake made in fencing. The main issues are the use of undersized posts and not setting the strainer posts deep enough, particularly in sandy or soft soils.

The diameter of the posts and the method of construction and bracing of the end assemblies affect the strength and limitations of the rest of that section of fence.

The design and construction of your end assembly should be established in your planning stage and is affected by the purpose and the animals being managed.

Here are some examples:
Fence Diagram 1
Fence Diagram 2


Posts placed closer make a stronger fence.

When is it a Fact? – When it comes to security fencing used to keep out 2 legged animals or housing animals like cattle or sheep in a confined area, fences need to be tough and stable to handle the constant impact of strikes.

When is it a fallacy? – When putting animals out to pasture. Pasture fencing requires a simple barbed wire or Hi Tensile fence.

Another big fencing mistake is placing farm fence posts close together. Allowing for the contour of the land, fence posts can be placed as much as 30mtrs apart using fence droppers in between.

FACT: Elastic Fencing is Smart Farm Fencing

Elastic fencing is the best way to fence rural grazing areas – strongly and affordably. Like the ropes around boxing rings, tests have proven that flexible material is best for “bounce back” strength and durability.

Here’s Why

For example, a typical elastic (or suspension) fence will have 6 strands of 2.5mm high tensile wire, with strainers spaced every 500m. If you add it all up, there’s over 100 kg of wire in that 500m.

Absorbs more energy

Elastic fencing permits ALL 100 kg’s weight of that wire to act as a multi strand spring to absorb stock impact. This 100kg spring elastically absorbs a LOT more energy than two lengths of steel post.

Less Bending Force

It’s an engineering fact that the two posts either side of the impact point must resist the full bending force caused by a beast impacting a fence. The further apart the posts are spaced, the smaller the bending force on the posts will be – because the angle of deflection for the fence strands at these two posts is less for the same amount of stretch and energy absorbed in the wire strands.

Fence Strain Diagram

A good example is a bull striking a fence with post spacings of 4m. With approximately 450kg of force, it can impose a load of over 200kg of lateral force on the posts.

If that same bull hits a fence with its posts spaced 30m apart, the impact felt at the post will be around 80kg. Roughly 80 percent less.

A wire subjected to a tension less than its yield point will return to its original length when tension is removed. However, if the tension exceeds the yield point, the wire will stretch permanently.

Better for your livestock

Good fencing is about keeping your livestock in – not bashing them up. A smaller force on the posts means a smaller force on your beast – because it hits a spring instead of a brick wall.

Building the Fence

You know there’s a lot of work involved in putting in posts and attaching the wires. And more posts = more work. That’s why we know you’ll appreciate how easy it is to put on Lightning® Fence Droppers instead.

Why are Lightning® Fence Droppers so good?

Constructed from high-tensile galvanised spring steel, the Lightning® Fence Dropper will recover more effectively from stock impact than timber or rigid metal droppers. As well as the right material, The Lightning® dropper is also implemented in such a way that provides the maximum flexibility exactly where it’s needed.

Used between posts, lightweight, resilient Lightning® droppers increase and maintain correct spacing of the fence strands.

Cutting the Real Cost of Fencing Use Lightning® Fence Droppers –

  • You’ll use less posts, while at the same time improve your fences with the energy absorbing ability of elastic fencing.
  • You’ll make your fencing more cost effective AND …..

stronger for longer.

Ferdinand the Bull