A chain-link fence (also referred to as wire netting, wire-mesh fence, chain-wire fence, cyclone fence, hurricane fence, or diamond-mesh fence) is a type of woven fence usually made from galvanized or LLDPE-coated steel wire. The wires run vertically and are bent into a zig-zag 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.
In the United Kingdom, the firm of Barnard, Bishop & Barnards was established in Norwich to produce chain-link fencing by machine. The process was developed by Charles Barnard in 1844 based on cloth weaving machines (up until that time Norwich had a long history of cloth manufacture).
The Anchor Post Fence Co. bought the rights to the wire-weaving machine and was the first company to manufacture chain-link fencing in the United States. Anchor Fence also holds the first United States patent for chain-link. The machine was purchased from a man in 1891 from Belgium who originally invented the wire bending machine.
In the United States, fencing usually comes in 20 ft and 50 ft rolls, which can be joined by "unscrewing" one of the end wires and then "screwing" it back in so that it hooks both pieces. Common heights include 3 ft, 3 ft 6 in, 4 ft, 5 ft, 6 ft, 7 ft, 8 ft, 10 ft, and 12 ft, though almost any height is possible. Common mesh gauges are 9, 11, and 11.5. Mesh length can also vary based on need, with the standard diamond size being 2". For tennis courts and ball parks, the most popular height is 10 or 12 feet, and tennis courts use a diamond size of 1.75" measured flat side to flat side. Tennis courts often use this smaller diamond size so that power hitters won't be able to lodge the ball into a larger diamond size.
The popularity of chain-link fence is from its relatively low cost and that the open weave does not obscure sunlight from either side of the fence. One can make a chain-link fence semi-opaque by inserting slats into the mesh. Allowing ivy to grow and interweave itself is also popular.
The installation of chain-link fence involves setting posts into the ground and attaching the fence to them. The posts may be steel tubing, timber or concrete and may be driven into the ground or set in concrete. End, corner or gate posts, commonly referred to as "terminal posts", must be set in concrete footing or otherwise anchored to prevent leaning under the tension of a stretched fence. Posts set between the terminal posts are called "line posts" and are set at intervals not to exceed 10 feet. The installer attaches the fence at one end, stretches it, and attaches at the other, easily removing the excess by "unscrewing" a wire. Finally, the installer ties the fence to the line posts with aluminum wire. In many cases, the installer stretches a bottom tension wire, sometimes referred to as "coil wire", between terminal posts to help minimize the in and out movement that occurs at the bottom of the chain-link mesh between posts. Top horizontal rails are used on most chain-link fences, although not necessary. Bottom rails may be added in lieu of bottom tension wires, and for taller fences, 10 feet or more, intermediate horizontal rails are often added.
Once stretched, a bottom wire should be secured to the line posts and the chain-link mesh "hog ringed" to the tension wire 2' on center. One generally installs this wire before installing the chain-link mesh.
The manufacturing of chain-link fencing is called weaving. A metal wire, often galvanized to reduce corrosion, is pulled along a rotating long and flat blade, thus creating a somewhat flattened spiral. The spiral continues to rotate past the blade and winds its way through the previous spiral that is already part of the fence. When the spiral reaches the far end of the fence, the spiral is cut near the blade. Next, the spiral is pressed flat and the entire fence is moved up, ready for the next cycle. The end of every second spiral overlaps the end of every first spiral. The machine clamps both ends and gives them a few twists. This makes the links permanent.
An improved version of the weaving machine winds two wires around the blade at once to create a double helix. One of the spirals is woven through the last spiral that is already part of the fence. This improvement allows the process to advance twice as fast.
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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, occasionally corrupted as bobbed wire or bob wire, is a type of steel fencing wire constructed with sharp edges or points arranged at intervals along the strands. It is used to construct inexpensive fences and is used atop walls surrounding secured property. It is also a major feature of the fortifications in trench warfare.
Barbed tape or razor wire is a mesh of metal strips with sharp edges whose purpose is to prevent passage by humans. The term "razor wire", through long usage, has generally been used to describe barbed tape products. Razor wire is much sharper than the standard barbed wire; it is named after its appearance but is not razor sharp. The points are very sharp and made to rip and snag clothing and flesh.
A saw is a tool consisting of a tough blade, wire, or chain with a hard toothed edge. It is used to cut through material, very often wood though sometimes metal or stone. The cut is made by placing the toothed edge against the material and moving it forcefully forth and less forcefully back or continuously forward. This force may be applied by hand, or powered by steam, water, electricity or other power source. An abrasive saw has a powered circular blade designed to cut through metal or ceramic.
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.
A bandsaw is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and lumbering, but may cut a variety of materials. Advantages include uniform cutting action as a result of an evenly distributed tooth load, and the ability to cut irregular or curved shapes like a jigsaw. The minimum radius of a curve is determined by the width of the band and its kerf. Most bandsaws have two wheels rotating in the same plane, one of which is powered, although some may have three or four to distribute the load. The blade itself can come in a variety of sizes and tooth pitches, which enables the machine to be highly versatile and able to cut a wide variety of materials including wood, metal and plastic.
A guy-wire, guy-line, or guy-rope, also known as simply a guy, is a tensioned cable designed to add stability to a free-standing 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.
Chicken wire, or poultry netting, is a mesh of wire commonly used to fence in fowl, such as chickens, in a run or coop. It is made of thin, flexible, galvanized steel wire with hexagonal gaps. Available in 1 inch diameter, 2 inch and 1/2 inch, chicken wire is available in various gauges--usually 19 gauge to 22 gauge. Chicken wire is occasionally used to build inexpensive pens for small animals though the thinness and zinc content of galvanized wire may be inappropriate for animals prone to gnawing and will not keep out predators.
An electric fence is a barrier that uses electric shocks to deter animals and people from crossing a boundary. The voltage of the shock may have effects ranging from discomfort to death. Most electric fences are used today for agricultural fencing and other forms of 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.
A batting cage is an enclosed area for baseball or softball players to practice the skill of batting.
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use:
A fence insert is an object designed to fit or clip into standard chain link fencing. There are three main objectives typically fulfilled by fence inserts. One is to provide privacy by converting chain link fencing into an opaque surface. Another is to exploit the fence as a site for signage, often providing low-resolution displays of corporate logos, sports mascots or verbal messages. A third objective of fence inserts is to decorate otherwise plain fencing.
A steel fence post, also called a T-post, a Y-post, or variants on star post, is a type of fence post or picket. They are made of steel and are sometimes manufactured using durable rail steel. They can be used to support various types of wire or wire mesh. The end view of the post creates an obvious T, Y, or other shape. The posts are driven into the ground with a manual or pneumatic post pounder. All along the post, along the spine, there are studs or nubs that prevent the barbed wire or mesh from sliding up or down the post. They are generally designated as 1.01, 1.25 or 1.33, referring to the weight in pounds per lineal foot. They are commonly painted with a white tip on top; white improves the visibility of the fence line.
A tensioner is a device that applies a force to create or maintain tension. The force may be applied parallel to, as in the case of a hydraulic bolt tensioner, or perpendicular to, as in the case of a spring-loaded bicycle chain tensioner, the tension it creates. The force may be generated by a fixed displacement, as in the case of an eccentric bicycle bottom bracket, which must be adjusted as parts wear, or by stretching or compressing a spring, as in the case of a spring-loaded bicycle chain tensioner; by changing the volume of a gas, as in the case of a marine riser tensioner; by hydraulic pressure, as in the case of a hydraulic bolt tensioner; or by gravity acting on a suspended mass, as in the case of a chair lift cable tensioner. In the power sector, the tensioner is a machine for maintaining constant tension of the conductors during work of hanging the transmission network..
Mechanical screening, often just called screening, is the practice of taking granulated ore material and separating it into multiple grades by particle size.
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.
Cable railings, or wire rope railings, are safety rails that use horizontal or vertical cables in place of spindles, glass and mesh for infill.
Putcher fishing is a type of fishing which employs multiple putcher baskets, set in a fixed wooden frame, against the tide in a river estuary, notably on the River Severn, in England and South East Wales. Putchers are placed in rows, standing four or five high, in a wooden "rank" set out against the incoming and/or outgoing tides.
A synthetic fence, plastic fence or 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 a low cost/durable solution for long lasting 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.
The fortifications of the inner German border comprised a complex system of interlocking fortifications and security zones 1,381 kilometres (858 mi) long and several kilometres deep, running from the Baltic Sea to Czechoslovakia. The outer fences and walls were the most familiar and visible aspect of the system for Western visitors to the border zone, but they were merely the final obstacle for a would-be escapee from East Germany. The complexity of the border system increased steadily until it reached its full extent in the early 1980s. The following description and the accompanying diagram describe the border as it was around 1980.