A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or netting. A fence differs from a wall in not having a solid foundation along its whole length.
Barbed wire, also known as barb wire, is a type of steel fencing wire constructed with sharp edges or points arranged at intervals along the strands. Its primary use is the construction of inexpensive fences, and it is also used as a security measure atop walls surrounding property. As a wire obstacle, it is a major feature of the fortifications in trench warfare.
In agriculture, fences are used to keep animals in or out of an area. They can be made from a wide variety of materials, depending on terrain, location and animals to be confined. Most agricultural fencing averages about 4 feet (1.2 m) high, and in some places, the height and construction of fences designed to hold livestock is mandated by law.
Concertina wire or Dannert wire is a type of barbed wire or razor wire that is formed in large coils which can be expanded like a concertina. In conjunction with plain barbed wire and steel pickets, it is most often used to form military-style wire obstacles. It is also used in non-military settings, such as when used in prison barriers, detention camps, riot control, or at international borders. During World War I, soldiers manufactured concertina wire themselves, using ordinary barbed wire. Today, it is factory made.
In the military science of fortification, wire obstacles are defensive obstacles made from barbed wire, barbed tape or concertina wire. They are designed to disrupt, delay and generally slow down an attacking enemy. During the time that the attackers are slowed by the wire obstacle they are easy to target with machine gun and artillery fire. Depending on the requirements and available resources, wire obstacles may range from a simple barbed wire fence in front of a defensive position, to elaborate patterns of fences, concertinas, "dragon's teeth" and minefields hundreds of metres thick.
A guy-wire, guy-line, guy-rope, down guy, or stay, also called simply a guy, is a tensioned cable designed to add stability to a freestanding structure. They are used commonly for ship masts, radio masts, wind turbines, utility poles, and tents. A thin vertical mast supported by guy wires is called a guyed mast. Structures that support antennas are frequently of a lattice construction and are called "towers". One end of the guy is attached to the structure, and the other is anchored to the ground at some distance from the mast or tower base. The tension in the diagonal guy-wire, combined with the compression and buckling strength of the structure, allows the structure to withstand lateral loads such as wind or the weight of cantilevered structures. They are installed radially, usually at equal angles about the structure, in trios and quads. As the tower leans a bit due to the wind force, the increased guy tension is resolved into a compression force in the tower or mast and a lateral force that resists the wind load. For example, antenna masts are often held up by three guy-wires at 120° angles. Structures with predictable lateral loads, such as electrical utility poles, may require only a single guy-wire to offset the lateral pull of the electrical wires, at a spot where the wires change direction.
A cattle grid – also known as a stock grid in Australia; cattle guard, or cattle grate in American English; vehicle pass, or stock gap in the Southeastern United States; Texas gate in western Canada and the northwestern United States; and a cattle stop in New Zealand English – is a type of obstacle used to prevent livestock, such as sheep, cattle, pigs, horses, or mules from passing along a road or railway which penetrates the fencing surrounding an enclosed piece of land or border. It consists of a depression in the road covered by a transverse grid of bars or tubes, normally made of metal and firmly fixed to the ground on either side of the depression, so that the gaps between them are wide enough for an animal's feet to enter, but sufficiently narrow not to impede a wheeled vehicle or human foot. This provides an effective barrier to animals without impeding wheeled vehicles, as the animals are reluctant to walk on the grates.
An electric fence is a barrier that uses electric shocks to deter people and/or other animals from crossing a boundary. The voltage of the shock may have effects ranging from discomfort to death. Most electric fences are used for agricultural fencing and other forms of non-human animal control, although they are also used to protect high-security areas such as military installations or prisons, where potentially-lethal voltages may be used. Virtual electric fences for livestock using GPS technology have also been developed.
Picket fences are a type of fence often used decoratively for domestic boundaries, distinguished by their evenly spaced vertical boards, the pickets, attached to horizontal rails. Picket fences are particularly popular in the United States, with the white picket fence coming to symbolize the ideal middle-class suburban life.
A downrigger is a device used while fishing using the trolling method, which places a lure at the desired depth. A downrigger consists of a three to six-foot horizontal pole which supports a cannonball, generally 10 to 15 pounds, by a steel cable. A clip, also known as a "release," attaches a fishing line to the cannonball weight. The bait or lure is attached to the release.
A chain-link fence is a type of woven fence usually made from galvanized or linear low-density polyethylene-coated steel wire. The wires run vertically and are bent into a zigzag pattern so that each "zig" hooks with the wire immediately on one side and each "zag" with the wire immediately on the other. This forms the characteristic diamond pattern seen in this type of fence.
A post pounder, post driver, post rammer, post knocker or fence driver is a tool used for driving fence posts and similar items into land surfaces. It consists of a heavy steel pipe which is closed at one end and has handles welded onto the sides. It is normally used by one person, but larger versions may require two.
Marston Mat, more properly called pierced (or perforated) steel planking (PSP), is standardized, perforated steel matting material developed by the United States at the Waterways Experiment Station shortly before World War II, primarily for the rapid construction of temporary runways and landing strips (also misspelled as Marsden matting). The nickname came from Marston, North Carolina, adjacent to Camp Mackall airfield where the material was first used.
Temporary fencing is a free standing, self-supporting fence panel. The panels are held together with couplers that interlock panels together making it portable and flexible for a wide range of applications. A common type of temporary fencing is Heras fencing.
A swimming pool fence is a type of fence placed around swimming pools, to create a passive barrier to restrict the access of small children to the swimming pool. Swimming pool fences must have a self-closing and self-latching gate/s to be compliant to most countries' laws and codes.
A pest-exclusion fence is a barrier that is built to exclude certain types of animal pests from an enclosure. This may be to protect plants in horticulture, preserve grassland for grazing animals, separate species carrying diseases from livestock, prevent troublesome species entering roadways, or to protect endemic species in nature reserves. These fences are not necessarily traditional wire barriers, but may also include barriers of sound, or smell.
Number 8 wire is a 0.16-inch-diameter (4.064 mm) gauge of wire on the British Standard Wire Gauge that has entered into the cultural lexicon of New Zealand.
A synthetic fence, plastic fence or (when made of vinyl) vinyl or PVC fence is a fence made using synthetic plastics, such as vinyl (PVC), polypropylene, nylon, polythene (polyethylene) ASA, or from various recycled plastics. Composites of two or more plastics can also be used to increase strength and UV stability of a fence. Synthetic fencing was first introduced to the agricultural industry in the 1980s as low-cost, durable horse fencing. Now, synthetic fencing is used for agricultural fencing, horse race track running rail, and residential use. Synthetic fencing is generally available preformed, in a wide variety of styles. It tends to be easy to clean, resists weathering and has low maintenance requirements. However, it also can be more expensive than comparable materials, and cheaper products can be less sturdy than more traditional fence materials. Some types may become brittle, faded or degrade in quality after long exposure to extreme hot or cold conditions. Recently, titanium dioxide (TiO2) and other UV stabilisers have proven to be a beneficial additives in the manufacturing process of vinyl. This has greatly improved the durability of vinyl by providing essential UV protection from the sun's harmful rays, preventing premature ageing and cracking of the product, making it more durable than other materials such as wood.
An aluminum fence is a fence constructed primarily out of the element aluminium. Due to the metal’s low density and ability to resist corrosion, it has become a popular choice as lightweight, durable fence and railing structure.
Old Laura Homestead is a heritage-listed homestead in Rinyirru National Park, Lakefield, Shire of Cook, Queensland, Australia. It was built from 1902 onwards. It was added to the Queensland Heritage Register on 28 July 2000.
A steel post on a standard seven wire fence in New Zealand.
End-on view of a T-post, showing the T-shape that gives the post its name.
Two T-posts and red post pounder (or driver) used to drive them into the ground. The flat plate helps stabilize the post, which is driven into the ground until the plate is buried.
