Electric Fence History

Electric fences have been used for enforcing borders, preventing intrusion in high-security areas, and for containing livestock and wildlife. Electric fences are designed to discharge electric current through anything that touches them, causing a painful shock and a psychological deterrent to a subsequent approach to the fence. Electric fences consist of a voltage source, conductive fence wire, fence posts and insulators. Standard voltage is converted into a high-voltage pulse that is sent periodically through the fence wire. Installing an electric fence is simple, but for safe operation, many mistakes have to be avoided.

  1. History

    • Electric fences were first used by the military in World War I to enforce borders and are still used in high-security areas such as prisons and military facilities, but their most common use is for the containment of livestock. They have been used agriculturally in the U.S. since the 1930s and were also developed in New Zealand at about the same time. The first agricultural electric fences used alternating current powered by an electrical main. With advances in the charger or power source, many electric fences, particularly temporary ones, are now powered by batteries with solar chargers. An early developer of the electric fence, William Gallagher of New Zealand first electrified his car to keep the horse away from it and then developed battery-powered fences as well as fences linked to the main power supply.

    Significance

    • Electric fences are generally much cheaper and easier to deploy than other types of fencing. They are frequently used as temporary fencing, allowing pastures to be rotated for grazing, or providing fences for temporary situations such as horse shows. Electric fences are also used for wildlife management (even of elephants) in Africa and other areas.

    Types

    • Over 200 U.S. patents have been issued for electric fence components in the past 25 years. Posts have gone from steel to fiberglass to plastic composites. Insulators have evolved from glass to ceramic to plastic, and now incorporate height adjustment, insulation and wire stabilization. Horses and cattle are contained with one or two strands; more strands are used for sheep and other livestock. A variation on the electric fence uses a radio-wave emitting border that activates a shock collar worn by a pet (don't forget to take the collar off if you take your pet out in the car).

    Expert Insight

    • Early inventions caused a lot of brush fires and both human and animal casualties. The fence charger should be placed in a dry area. The ground wire should be placed at least 50 feet away from utility grounds or water pipes. The lead (hot) wire should be insulated and attached to a single wire on the fence. Additional wires can be electrified using jumper wires. All wires must be insulated from the posts, the ground, any obstructing vegetation or any other possible electrical contacts. Check the voltage per manufacturer's specifications after hooking up the charger.

    Features

    • Modern fences are a combination of physical as well as psychological barriers, constructed with smooth wire that withstands 1000 lbs. or more before breaking. Conductive strands woven into plastic rope or tape are common for temporary paddocks, providing a strong visual deterrent as well to the contained livestock.