TYPES of BARRIERS

Post 570 by Gautam Shah

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Barriers are obstructing and intervening entities. Barriers through their configuration, position and occurrence affect things passing by, touching, or going through them. Barriers rarely operate on their own, so are distinguished by the context or the surroundings where they operate. Barriers operate as multi functional entity doing many intended and unintended things.

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Wikipedia image by Elelco72

Physical barriers are omnipresent in structure and effect. But non-physical barriers could occur through sensory variations. A subtle shift in texture, gradient, colour, illumination level, view, temperature, audio perception changes the behaviour of the user and can become an effective barrier.

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Visual barricades use colours in terms of their brightness and other optical qualities such as fluorescence, reflection and background-foreground contrasting. Visual barricades also include use of illumination or brightness, blinking (dynamic) lights, iridescence. Some of the most important virtual barricades are communication jammers and devices that open channels within jammed zones.

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Tactile paving in Subway at Nagoya Japan, Wikipedia image > Attribution LERK

Barricades Consuming Energy bar or control the exchange between the two faces. Barricades, themselves are variously affected by the exchange occurring through them. Some barricading systems use energy, to cause specific changes during the exchange process and also to revert to the nominal status. Barricading systems capable of using energy are machines, or some live beings, if additionally can reproduce or self sustain.

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Electrified barbed wire fencing at Nazi death camp Auschwitz, Poland > Wikipedia image by Pimke

Protective barricades are designed to resist the most unfavourable combination of imposed loads (impact, wind, etc.). Such barricades allow planned deflection and distortion, with or without a collapse. A noncollapsible barricade is resilient enough to revert to the original position, whereas the collapsible barricade at a predetermined stage becomes ineffective. These conditions are included through a structural configuration, material technologies and through machine devices (operating on feed forward and feed back).

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Soft Barricades recover after an impact, but do not bounce-back the striking object. Rubber flaps or plastic stripes on warehouses doors are flexible barriers.

Hard Barricades are used to divert (bounce back) the force of the impact. On express highways the shape and height of the railings and curbs are so designed that a vehicle on striking slides along it rather than thrown-back into the fast-moving traffic.

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Concrete barriers > Wikipedia image by Pushcreativity

Transparent, Translucent Or Opaque Barriers: A glass barricade could be transparent for light but not for other objects. A large aperture grill could be ‘transparent’ for light, air and view, ‘translucent’ for an infant, pet etc., but ‘opaque’ for a fat man. A vertical or horizontal Venetian blind could be ‘transparent’ or ‘translucent’ from a particular position and could be ‘opaque’ from another position. A smoke glass is ‘opaque’ for view from outside but ‘transparent’ for view from inside. Fast-moving air in an ‘air curtain system’ is a transparent barricade.

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Notional Barricades are used for ceremonial purposes or as a representative form of a barricade. A wrought iron chain, a rope around a monument, podium, dais or rostrum, a red ribbons for inauguration, yellow tape of police investigation teams, are all notional barricades. Similarly signs and symbols (danger, do not enter, slow, stop) can also be used for barricading. If the users are knowledgeable, and are ready to accept a set social behavioural norm, than indicative barricades (non physical) are as effective as physical barricades. However, it should be possible for the user to recognize, feel and experience the presence of such barricades. Where such opportunities for recognition are not available, non physical barricades fail to be effective. Notional barricades are not recognized in a crowded area or in a chaotic situation. Similarly where barricades are required as protection against unknown elements, notional barriers are not effective.

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Barricades are required at all places of hazards such as: construction sites (for the safety of workers, visitors, and trespassers), works in public areas (such as trenches, excavations), place near electrical equipments (with exposed parts that could be live, and installations with voltage of over 440 volts), any area where explosives are used or stored, to define the radius of any cranes or such equipments, etc. Barricades serve as warning (through visual and other sensorial recognition) and also as a protective element. Barricades also denote territories, ownership and right of ways.

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OPENINGS and BARRIER SYSTEMS

 

An architectural opening occurs within a barrier or at the junction of two distinctive barriers. A very strong barrier provides for equally important opening. Doors, windows, gates, gateways, etc. are openings within barrier systems such as: walls, fencing, fort walls, enclosures, partitions, dividers, etc. Barriers are continuous entities, and can only be experienced through the openings. Barrier systems define a domain, so an opening becomes the representation of the domain. Opening systems can never supersede a mother barrier system. Openings are subordinated or minor systems as these must occur within a barrier system.

SCALE OF OPENINGS: An opening is a finite entity with definite size, however, the barrier system within which it manifests could be infinite in size. An opening can never be larger or equal to the barrier system within which it resides. An opening, occurring in a finite barrier system could be relatively small or large, but openings occurring in very large or infinite barriers can be judged to be large or small in terms of the user.

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A small opening makes a barrier system very evident, whereas a large opening or multiple openings make barriers less effective. The exchange occurring across a small opening is very intense, compared to a large gateway. Small openings due to their smaller scale allow a controlled scale of exchange. However, a large opening often requires re-scaling through various appendages such as: segregation channels for up – down, and fast -slow traffic, compaction through funneling, filtration for selective processing acceleration and de-acceleration mechanisms.

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A large window is divided into smaller units –lites, each of which can have a varied configuration. Entrance foyers of skyscrapers, lounges of Airports and Railway stations, have ganged or multiple doors to serve the demand for a wider but controlled opening. However, air hangers, garages, barns and warehouses require very wide doors to meet the functional carriage width. Very large or wide doors often have an insert small opening (‘a door within a door’) for passage. Openings are spaced out to take advantage of the location and orientation, and diffuse the exchange over a larger zone. Openings are concentrated or grouped together, to few locations to reduce the wastage of distributed operations.

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Openings are scaled in terms of the image projection. A large opening means: capacity to build better, greater control over security, desire for extravagance or grandeur, need to be perceptible from distance. Smaller and fewer openings mean: conservative building technology, problems of safety and security, prudence and need to be less visible.

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A Large window illuminates the interiors brightly, creating a fearless but public (non-private) space. Bright spaces are warm, a desirable quality in some climates. A Small window mean a sturdy and stable structure, an intimate (private) space, safety, security and cool interior or a ‘cold’ space. Walls, traditionally have been massive entities, so fewer openings disrupt a wall less.

LEVELS OF OPENINGS: Openings are essentially of two types: negotiable for egress or transit-able in an emergency. In both cases, the degree of conveyance may have been intentionally made difficult or easier. A French window is a door for conveyance, and a trapdoor or a hatch door is a window for all purposes. A door could occur at a negotiable level but a barn door for fodder, is placed at first floor level. A warehouse gantry girder could extend out of an upper level door like opening to lift up goods and bring it in. Windows have many grades, of ‘high to low’ sill levels, as referenced from interiors or exteriors. A high sill from interior space cuts off the view to the outside as in medieval cathedrals. A low sill or zero sill window ‘opens’ a space as in case of traditional Japanese houses. The upper floor windows of a glass curtain high rise building, clerestory windows and skylights offer a static view, lacking in dynamism.

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