Electric fencing

Abstract

Since 1958, when details of electrified permanent fencing tried by Massey College became known, hundreds of miles of electric subdivision fence have been erected. The key to its popularity has been the great saving in costs of materials, transport and labour. It is also easier to erect, so can be built by farm labour instead of waiting for contract fencers. This reduces the cost still further.

The success of electric fencing depends on (a) Careful insulation of electrified wires. (b) A continuous earth wire running the length of the fence and connected to the earth terminal of the electric fence unit. (c) Removal of stray wires and excessive green vegetation from the fence lines.

In practice, thistles, grass, clover, secondary growth and tussocks gradually reach the live wires and reduce the efficiency of the fence, particularly in wet or misty weather. Sometimes insulators slip, break or become coated with dirt, so that again electric leakage becomes serious.

Furthermore the "wind-charger" units available for inaccessible places sometimes fail to keep the battery fully charged. Consequently a number of electric fences have become ineffective. On the other hand where a "mains" operated unit has been used, and the fence checked regularly, electric subdivision fences have been very effective. In fact, once the stock learn to respect an electric fence over a period of months, there is no need to worry if it happens to be off for some days.

Nevertheless, there are some ineffective electric fences, so many people hesitate to regard them as permanent, and suggest that they should be reinforced or replaced by standard fences when finance becomes available.

This makes it clear that there are definite requirements to be met, and limits to its use as permanent fencing.