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.
Barbed tape or razor wire is a mesh of metal strips with sharp edges whose purpose is to prevent trespassing 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.
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 Bangalore torpedo is an explosive charge placed within one or several connected tubes. It is used by combat engineers to clear obstacles that would otherwise require them to approach directly, possibly under fire. It is sometimes colloquially referred to as a "Bangalore mine", "banger" or simply "Bangalore" as well as a pole charge.
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.
The cheval de frise was a defensive obstacle, existing in a number of forms, principally as a static anti-cavalry obstacle but also quickly movable to close breaches. The term was also applied to underwater constructions used to prevent the passage of ships or other vessels on rivers. In the anti-cavalry role the cheval de frise typically comprised a portable frame with many projecting spikes. Wire obstacles ultimately made this type of device obsolete.
The Gaza–Israel barrier is a border barrier located on the Israeli side of the Gaza–Israel border. The Erez Crossing, in the north of the Gaza Strip, is the only crossing point for people and goods coming from Israel into Gaza; there exists a second crossing point in the barrier, called the Kerem Shalom border crossing, which is exclusive for the crossing of goods coming from Egypt, as Israel does not allow goods to go directly from Egypt into Gaza through the Egypt–Gaza border.
Tatura is a town in the Goulburn Valley region of Victoria, Australia, and is situated within the City of Greater Shepparton local government area, 167 kilometres (104 mi) north of the state capital (Melbourne) and 18 kilometres (11 mi) west of the regional centre of Shepparton. At the 2021 census, Tatura had a population of 4,955.
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.
Dragon's teeth are square-pyramidal anti-tank obstacles of reinforced concrete first used during the Second World War to impede the movement of tanks and mechanised infantry. The idea was to slow down and channel tanks into killing zones where they could easily be disposed of by anti-tank weapons.
The McNamara Line, an operational strategy employed by the United States in 1966–1968 during the Vietnam War, aimed to prevent infiltration of South Vietnam by NVA forces from North Vietnam and Laos. Physically, the McNamara Line ran across South Vietnam from Cửa Việt port to Route 9 and to the Laotian border along the Vietnamese Demilitarized Zone (DMZ) till Mường Phìn, Laos. The eastern part included fortified field segments, with Khe Sanh as linchpin, along with stretches where roads and trails were guarded by high-tech acoustic and heat-detecting sensors on the ground and interdicted from the air. Assorted types of mines, including so-called gravel mines, and troops at choke points backed sophisticated electronic surveillance. Named the barrier system by Robert McNamara, it was one of the key elements, along with gradual aerial bombing, of his war strategy in Vietnam.
A screw picket is a metal device which is used to secure objects to the ground. Today, screw pickets are used widely to temporarily "picket" dogs. They are also used to graze animals such as sheep, goats, and horses. Screw pickets are also used to stabilize small trees, tent poles, and other objects that are intended to remain upright.
Wiring parties,, were used during World War I on the Western Front as an offensive countermeasure against the enemy’s barbed wire obstacles. Though hazardous and stressful duty, work was done at night to repair, improve, and rebuild their own wire defences, while also sabotaging and cutting the enemy's. In battles all across the Western Front, cutting parties were successful in creating breaches in the wire lines, offering their comrades a better chance to cross no man's land.
Barbed wire was one of the attacker's great problems. There were cutters, but not enough, and men were often killed before they could cut a way.
The inner German border was 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.
In 2015, Hungary built a border barrier on its border with Serbia and Croatia. The fence was constructed during the European migrant crisis, with the aim to ensure border security by preventing illegal immigrants from entering, and enabling the option to enter through official checkpoints and claim asylum in Hungary in accordance with international and European law. The number of illegal entries to Hungary declined greatly after the barrier was finished as it effectively abolished the entry to Hungary.
The Slovenian border barrier was a border barrier constructed by Slovenia in 2015–2016 on its border with Croatia as a response to the European migrant crisis. Both Slovenia and Croatia are European Union members, therefore the barrier was located on an internal EU border; but previously only Slovenia was a member of the free travel Schengen Area, with Croatia joining the area in 2023. In March 2016, Slovenia announced that only migrants who apply for asylum in Slovenia and those with clear humanitarian needs will be allowed to enter Slovenian territory.
Perimeter security refers to natural barriers or built fortifications to either keep intruders out or to keep captives contained within the area the boundary surrounds.
The Bulgaria–Turkey border is a 513 km (319 mi) long international border between the Republic of Bulgaria and the Republic of Turkey. It was established by the Treaty of San Stefano in 1878 as an inner border within the Ottoman Empire between Adrianople Vilayet and the autonomous province of Eastern Rumelia. The current borders are defined by the Treaty of Constantinople (1913) and the Bulgarian–Ottoman convention (1915). The border was reaffirmed by the Treaty of Lausanne ten years later, though Bulgaria was not a party to the latter treaty as it had earlier ceded to Greece that part of its border with Turkey which was modified by the Bulgarian-Ottoman convention.
The flexible defense is a military theory about the design of modern fortifications. The examples of "flexible" defense-lines are not based on dense lines of heavily armed, large and expensive concrete fortifications as the systems such as the Maginot Line were. Their protective capacity hinges on multiple lines of obstacles and small shelters fitting into the environment. They are "flexible" because soldiers are not locked in pillboxes, but fight instead in easily replaceable open earth-wood made positions, while bunkers serve only as shelters during bombardments. As a result, they are able to adapt to the opponent's movements, and there are no easily targeted large buildings in these lines.
