wildlife friendly fencing High Tension Wire
Plain Wire and Suspension Fencing

 

"They contain less material and are faster to erect than traditional fences yet they provide an equally good, if not superior, barrier."

" Fences require sufficient material to deter animals seeking to satisfy either nutritional or sexual needs. These fences also need to be sufficiently strong to absorb the impact of running, frightened and panicked animals. The longer the strain the greater the impact required to break the wire and the less the load exerted on the end assemblies. Another important reason for making these strains as long as possible is that if for any reason the end assemblies move, or a knot slips, long strains can absorb this movement with very little loss of tension. The strength of a fence is increased by minimising the number of in-line posts. Insert sufficient in-line posts to maintain the desired space between the ground and the bottom wire and no more. Droppers rather than in-line posts should be used to strengthen the fence. Droppers are used to help keep the wires at the correct spacing, and transfer the load from an impacaton one wire to the rest of the wires in the fence. Light gauge wire (2.5mm) made from high tensile steel has the same strength yet greater elasticity than the softer, heavier gauge wire (4mm).
Barbed wire is not recommended for suspension fencing as it does not move freely past in-line posts and its full elastic potential is never reached. It also has a tendency to unravel on impact, continually losing its tension. Barbed wire should never be used in electric fencing as it may prevent a person or animal from moving away after receiving a shock and it can become tangled with other wires creating a short circuit."
Plain Wire Works in Pastoral Areas W.A. Agricultural Dept, from "Wires and Pliers", a publication by the Kondinin Group .

"High tensile (HT) wire will stretch, then return to its original length. It is more difficult to handle, but the wire absorbs the load as it resists the urge to stretch. When wire is subjected to stock pressure, the pressure must be allowed to dissipate down the fence. When this is allowed to happen there is less damage at the point of impact and less damage to the animal and the fence. All fences today with the exception of electric fencing should be constructed with this in mind. Pressure applied to a fence must be absorbed by the wire and not the fence posts."( from Wires and Pliers)

" High-tensile wire is made with thinner but higher-strength steel. Its greater strength make fences longer-lasting because cattle cannot stretch and loosen it. It copes with the expansions and contractions caused by heat and animal pressure by stretching and relaxing within wider elastic limits. It also supports longer spans, but because of its "springy" nature it is hard to handle and somewhat dangerous for inexperienced fencers. Soft wire is much easier to work but is less durable and only suitable for short spans such as repairs and gates where it is less likely to tangle. (from Wikipedia)

This project is interested in promoting the use of plain wire in fences wherever possible, and minimising the use of barbed wire.

 

We live on 500 undulating (to steep) acres abutting the National Park at Eungella in the Mackay hinterland. We farm cattle, goats, horses and a pig and grow mixed hardwood trees for timber. We have been here since 2000 and have worked hard to protect the soil water and wildlife in this beautiful area. Within two weeks of arriving in 2000 we had our first Little Red flying fox caught on a barbed wire fence. Having contacted all local agencies with no assistance we undertook to free the wee critter. We were aware of the inherent risks involved so we approached the task fully protected. We have a large enclosure, previously used for pigeons, which proved to be an ideal environment for rehabilitation of our first and subsequent victims.

It seemed we had to find a solution to this ongoing problem. On advice from our daughter (EPA, Atherton) we replaced the top wire of the worst fence with plain wire and the difference was amazing. From a maximum of seventeen entrapments in one day down to one (which was snared on the second top wire but was holding onto the plain wire and was easily freed). We are sold on wildlife friendly fencing.

 


Photo: The top strand of barbed wire has been replaced with plain wire. We have had no problems with cattle or horses getting through the fences, rather they seem to push the lower strand to get to the inevitably greener grass on the other side.
(In one short section, there is a single strand of electric wire behind this fence to protect a bush regeneration site).


Over the years we have noticed the following:

  • Entrapments only seemed to occur on windy nights and only ever in places where gullies/valleys meet ridges (wind turbulence areas)

  • Fences along ridge tops should be avoided (even though it is the easiest place to put fences)

  • Not all fences need to have the top wire replaced. Most people will know where their problem areas are.

  • The planting of trees for windbreaks and shelter belts along fence lines is proving to be a win-win. Shelter for cattle, trees for timber, aesthetically pleasing and no entrapped wild life.

 

"We have pulled out miles of old barbed wire fences here, I would estimate about 10 miles with 4 strands each. In addition we have replaced all the barbed wire in remaining fences with plain wire so we know a lot about the difficulties of tackling this job. .... The price difference when building a new fence is marginal and is balanced by the increased time involved in running out barb when compared to plain wire. The main problem is convincing old-timers that they don't actually need barbed wire to contain cattle. We have a friend with 100,000 acres of cattle property out past Charleville who runs high tensile plain wire with wooden posts every 0.5km and star pickets in between. This contains his scrub cattle very well. Around here though everyone is convinced that you need 5 strands of barb and a wooden post every 10m to contain cattle. This thinking comes from the old days when soft wire was not as strong and labour was cheap. (also everyone hates working with high tensile wire)."


Peter Richards writes regarding his use of of low tensile plain wire:
"Low tensile wire will stretch and not return to its original length when it has pressure applied to it. This means that when cattle lean on the fence, as they always do, the fence gradually become slack and they can get through it. When the wire is strained it also gradually gets loose as the daily change of temperature tightens it and stretches it over and over. The old solution to this was to put wooden posts every half a chain (10m) or even closer together, and then to put star pickets or droppers in between the wooden posts. This meant that even when the wire wasn't tight cattle couldn't get the strands apart enough to get through. The other reason for this form of fencing was that wooden posts were effectively free, just requiring the labour to cut them, split them dig the holes, ram them firm etc. Labour was cheap and star pickets were expensive. Also I guess HT wire wasn't available.
High tensile wire doesn't stretch once it has been strained tight. If cattle lean on the fence, it springs back and stays tight. This means that wooden posts are not required between the strainer posts. The tight wire and the star pickets are enough to stop cattle getting through. Now, if you have some scrub cattle who do run into the fence, with low tensile wire, they will get through (even if it is barbed wire) but the wire will usually stretch and need to be restrained. With a HT fence, the cattle may get therough but the fence stays intact. In a real
suspension fence (where the wooden strainer posts are in the ground andin between are just droppers that are above the ground, the fence will either flip over (and then back again) or work like a big elastic band and bounce the cattle back. With valuable animals this means that they may escape but they don't get injured in the process. Running through barbed wire the cattle get cut up and when they get to market they fetch a lower price because the scarring affects the appearance of the meat. Most people in Australia don't build true suspension fences (using droppers), they build semi-suspension fences using star pickets.
As we have no stock other than horses, the bottom strand of wire was not required. The difficulty of using high tensile wire was avoided as horses do not tend to push on fences when there is adequate feed available. "

Photo and story: Peter Richards, near Gatton, southern Queensland.

This inspiring project outside Rockhampton in central Queensland, has come up with some ingenious WFF solutions to a number of problems. The fencing at Duckpond E. Reserve is to keep cattle out but still allow access for wildlife. Sections of it can be inundated for months at a time and the potential for damage to the fences in these areas is high. Jeff Simmons is coordinating the project for the local branch of the Wildlife Preservation Society of Queensland.

 

An obvious gap between two posts which will serve as a kangaroo access while excluding fully grown stock.  This is located at junction of two fence runs on different alignments.

  

The left panel in this corner Post & Rail  arrangement, has the bottom wire deliberately left off and the next one up is plain wire.  This is intended provision for Macropod access.

 

 

This section of fence is constructed through The Dip, an area subject to complete inundation for long periods of time. It therefore has a minimum of barbed wire and a minimum of wire.  There are three wires, Plain, Barbed, and Plain.  The two plain run through the posts and the barbed runs on the posts, displacing the barbed toward the stock about 100mm to 150mm.  This section of fence is entirely of wooden posts for both longevity and  minimal hazard to a turtles, birds, flying-foxes, water rats, gliders etc.

 

The configuration in this fence is Plain, Barbed, Plain, and Barbed.  However the bottom wire between the wooden post and star-picket is Plain wire, intended as a Macropod access. It will provide WFF access for kangaroos resting in the shade of the tree whose trunk can be seen in the background of the photo.