Post 658 -by Gautam Shah



ANTI-LIGATURE –Issues for Design -8








Risk on Brinks










Door of a traditional Indian House

Sheth ni Pol Ahmedabad --a gated community

City Gate Prem Darwaja Ahmedabad



Post 570 by Gautam Shah



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.


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.


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.


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.


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).


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.


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.


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.


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.




Post 535  by Gautam Shah


Mies van der Rohe’s Barcelona Pavilion Wikipedia image by Marb~commonswiki

A built space is a conditioned entity. The conditioning of the space through various types of barriers endows unique spatial character. The spatial characteristics are environmental, sensorial and function or task oriented. The barriers are protective, directive, indicative, transitive and formative. Barriers protect by their configuration, position and occurrence affect all things passing by, touching, or going through them. Barriers by their body and shape redirect energies and energy laden (moving) objects. Barriers are physical presences and so indicate spaces and segments in it. and through the degree of transparency allow transitions. Barriers are formative, doing many intended and unintended effects. The effects are distinguished by the context or the surroundings where they operate.

Walls of Dubrovnik (Croatia) Wikipedia image by Author László Szalai (Beyond silence)

Barriers are obstructing and intervening entities in buildings and outside in nature. Barriers are effective as a surface and so changes distinctly different conditions on its sides. One must perceive ‘the non-change situation’ to recognize the change caused by the barrier. Barriers are often so extensive that the change or modified environment is not recognized. Barriers, as a result, are evident at the ends, edges, joints, thresholds, cut sections, or gaps. And as a result a built-form manifests at its openings. Barriers in built forms are conceived as an intervention to delay or condition the reach to other spaces.

Poulnabrone Dolmen, County Clare, Ireland wikipedia image by Author User Kglavin on en.wikipedia

Barriers condition the reach to the other spaces by their capacity to obstruct, absorb, filter, reflect or deflect not just energies and physical things but cause metaphysical variations. The metaphysical variates are indicative, unreal or make-believe. A society accepts certain words, signs metaphors, and indications as warnings, danger, caution, or permissible signs. Such indicatives in the form of taboos, beliefs, customs etc. derive from the accumulated experiences. Belief in God is one such indicative. The metaphysical variates are reinforced by their association to predictable effects. Certain spatial experiences are associated with specific forms, materials and environmental conditions. When one or few of these manifest, the barrier like effect takes place. Designers exploit such conditions to generate dramatic or melodramatic effects. The Make-believe occurs because we are conditioned by predictable responses of form sequencing, materials, textures, colour, illumination frequency and schedules of occurrence etc. Certain predictable effects, when fail to happen and a delusion occurs.


Notional barriers are indicative ones used for ceremonial purposes. Other indicative barriers consist of signs and symbols, which are effective if the users acknowledge and confirm it as a social behavioural requirement. Notional barriers are not recognized in a crowded area or in a chaotic situation. Similarly, where barriers are required as protection against unknown elements, notional barriers are not effective. Physical barriers demarcate territories, ownership and right of ways, but notional indicatives like presence of a person, smoke coming out of chimney, foot-ways or foot-prints, ashes of fire, etc. are accepted as indications of human occupation and possession or sign of trespassing.

Nepal – Sagamartha Trek Stone house Wikipedia image by Author McKay Savage

Barriers need not be very extensive, persistent and with substantial change capacity to be effective. Some subtle conditions are good enough to effect the change. A small sensory variation such as shift in colour, texture, gradient, illumination, view, temperature, audio perception, can have profound behaviour changes, and are effective as barriers. The sensory variations are caused by spatial context, background-foreground contrasts, extent of field, exposure to the sensorial limbs, time delay or interlude, sequencing, etc.

Barriers consume energy to bar or control the exchange between its two faces. The barricading systems use energy to cause specific changes during the exchange process, and also to revert to the nominal status. These barriers are machines, or a live beings, if additionally can reproduce or self-sustain. Barriers absorb the forces like impacts and generate energy, ultimately dissipated to environment, or consumed for productive purpose.





Post 392 ⇒   by Gautam Shah 


An opening is any space or gap within a barrier. An opening is meaningful so far it is in a barrier. The opening could be a ‘puncture’, surrounded by the barrier on all its sides, or a cleavage between two barriers. Openings are also called ports, as across the opening one can ‘board’ a new system. An opening is called a passageway, as this is the only way, one can, transit a territory.

Chaco Canyon Pueblo Bonito doorways

An opening can never be larger or equal to a barrier within which it resides. All physical openings have a finite size. A smaller opening makes a barrier system very evident, whereas a large opening or multiple openings make barriers less effective. Opening systems are also ineffective in transparent, translucent or frequently interrupted (broken or discontinuous) barriers. A room with a lattice wall all around has no need for a window, or a glass cabin has no need for an opaque (solid) door.

Manhattan Bridge Arch and Colonnade

Openings are defined by superlative structures to denote the presence and control the activities occurring through it. The superlative structures over passageways such as Gates, Gateways or Doorways are large in size and very distinctively formed. Formal structures have shutter devices whereas symbolic structures are simple openings. Nominally a passage is a linear entity, and so do the gates have singular passage. Cross junctions of passages require four or more sided gates.

Multiple Openings

The superlative structures function as control Gateways over openings. Such openings’ control the transactions, by way of the size, volume, temporal rate of passage and the qualitative nature of things. The transactions across the openings are of two ways, exit and entry types, and so the controls are also dualistic.

Gates with sensors

Gates with minimal structure

All communication channels have Gateways, from where the traffic gets diverted to appropriate channels and portals where divergent traffic gets ‘routed. These gateways register size of individual transactions, time of arrival-departure and source-destination of traffic. But most importantly there are ‘protocols’ that check whether the destined item has reached or not.

Surveillance gates or ports

In buildings openings like Gates, Doors, Windows, Ventilators, Gaps, Cracks, Crevices and Punctures all denote physical entities, but there are innumerable imperceptible points where observance and control occur. The sensors, cameras, readers, etc., are concealed, made minute in size and programmed so that ‘Gates’ structures are not imminent.

Openings in buildings have facilities for allowing sunlight, air, sounds and for framing view of the outside. The openings also create architectural patterns, compositions through scaling and proportioning, endow specific style character, affinities and identities. The openings occur in a barrier system as a connecting threshold or edge between two distinct worlds, but their own presence assumes many different guises. An opening is designed to be a distinct medium investing a nature of relationship between spatial domains.



STAGE CURTAINS – Part 2 -forming the performance spaces

Post 308 – by Gautam Shah



Stage curtains are barriers, used for spatial definitions. Settings are more permanent barriers lasting an act or entire play or performance, whereas curtains as barriers mark temporal divisions that distinguish the physical depth, width, heights, and also pretentious presence of spaces ‘beyond’ the stage. Here a performer projecting different environments on a stage or arena has limited time, space and means. As a result the performance space or the stage is extended beyond its physical limits by exploiting both, the real barriers and indicative barriers. The curtains are also used as gestural break or end of an act. Curtains are soft partitions that occlude the backstage, side-stage and top section of the stage from eye sight. Curtains are also used for projecting an image of slides, movies and in shadow-plays.

3 Roman Theatre Backdrop


Commedia dell’Arte has been depicted as actors in masks performing on temporary stages in market squares in woodcuts, paintings, engravings, and drawings by artists such as Callot, Scarron, and Dujardin. The stages in these depictions often appear to be elevated by six foot tall scaffolding with audience members standing on three sides of the stage. Simple curtains often are depicted hanging behind the actors sometimes painted with an urban background, similar to a backdrop. Sometimes actors were depicted peeking through behind them, and sometimes there would be slits in the curtain indicating doors and windows – Wikipedia (Hildy, Franklin J.; Wilson, Matthew R. (2015). The Rutledge Companion to Commedia dell’Arte)


A performance area could be a boundless space. Its extent needs to be defined for several purposes. Audiences need to focus on an act, and so want a performance area within their visual perspective and audio perceptibility. Even with means of electronic sound amplification, the need to synchronize the sound and action, need for focus remains valid.

2 Orange_roman_theatrescaffold stage

A stage as a raised platform, even though not a pointed entity, needs focus, and that focus shifts with the action or the performer. The performer moves around the stage designating transient zones, and orienting own self to various sides except the back. In a Roman Amphi theatre the actors on the front section are active, and by retreating to the backside become inactive. Going back is like going off the stage and act. These enacted clues were often supported by acting and sounds, but not substantiated with physical barriers or stage settings. The Greek theatre was open on three sides but had an architectural backdrop. Street plays, rudimentary story telling performances and public religious and political ceremonies worked with the presence of a backdrop. The backdrop was a strong architectural entity like wall, building facade, or a non-interfering (static) natural entity like mountain, valley, sea shore, river or lake.

3 Ramlila_DasrathaThe strong backdrop was non-disturbing reference but focussing element. Audiences from side edges distracted the actors, or the actors were in a puzzle which section to concentrate. Gradually informal stages (like street plays) began to be covered on sides. The stage became a box. The boxed stage, however did not allow designated entries or exits, such as hell, heaven, another room, street, etc. Side wings are fixed curtains to obscure side sections of a stage. Curtain-covers or head-wings are used to hide the upper section of stage properties such as the hanging gears, ropes and rolled or folded section of the curtains. A second layer was required to arrange a concealed passage on three sides. The second layer over the wings was of both hard settings and soft curtain materials. The second layer was fashioned temporary for the act or scene, whereas the wings were permanent arrangements of the stage

5 Theater_Bielefeld_InspizientenpultThe sets, stage property, curtains, side wings, lighting, audio-video effects, etc. are used for creating a variety of spaces and signify connections. A cleavage in side wings or a gap between two stage properties could signify a door, window, opening, corridor or a passage. The stage thus becomes a place where a multiplicity of spaces ‘Here’ and a series of connected spaces supposed to exist ‘Beyond’ occur. Whatever is lacking in such definitions is further reinforced by the actors. The acting makes the audience feel as if the actor is actually dealing with or reacting to a real barrier. Mime acts are such explorations with unreal barriers. Since it is not possible to accommodate the entire set of physical barriers, only the acute or important sections are highlighted through frames, outlines, edges, cleavages, thresholds

street performance

A fly is a rig system in the upper section of a stage with ropes, pulley, counterweights, battens (for hard and soft flats or barriers). These are automatically or manually operated by crew walking on the hanging cat-walks. These enable crews to hoist (drop and raise) stage components like curtains, lights, scenery, people, equipments, effects, without noise, quickly, and safely. The upper section of the stage, fly-loft is tall enough to stock these properties or there are folding arrangements.

In informal performances, like street drama, where stage and related provisions are not available, the performers have to devise specific means and strategies to convey the effects.


Stage curtains, side wings, scenery flys, all form the soft furnishings of the performance. These are further exploited through colour, texture (of material surfaces, and folds or creases), degree of transparency, horizontal angle of position, vertical inclination and nature of illumination (frontal, backside, top-down or upward, spot or diffused), dynamics of movements and projections.

6 Glenn_Davis_COH_2011_Event_Scenic_Design

adble scenery

A stage sets and curtain barriers are perceived by the audience from a limited and fixed angle view. Curtains as result are made from black, dark, opaque and translucent materials, and with folds, pleats and gathers, but it is the lighting that casts its sensorial effect.

7 New_York_State_Theater_by_David_Shankbone


10 Theatre_Stage_Albert_Hall_looking_stage_left_showing_theatre_curtains_(2016)Curtains are either dropped downward or moved sideways. In smaller theatres curtains have two leaves which part away horizontally. In larger theatres the curtains are suspended from a batten or staff and dropped down. The dropping is quickest way of adjusting a curtain. The curtains are dropped or raised flown in theatre terminology, up to a required height to mask the upper section of the stage. The masking also substantially hides the back stage settings. The main or the first curtain on the audience side is called a grand drape, act curtain, house curtain, house drape or main drape. These are made of heavier fabric. A curtain call is a curtsy or thanks call offered beyond the closed position of the main curtain, in front part of the stage.


8 Tableau_curtain_central_opening_system_-_Grand_théâtre_d'Angers

Main curtains were first drop curtains but these required a heavy bottom staff. As this was hazardous, roll curtains was soon adopted. ‘The curtain was raised after the prologue and remained up throughout the performance, all scene shifting was in view of the audience. It was not until 1750 that an ‘act drop’ was used; previously, even intermezzi were performed in front of a full stage setting’.

9 Mariinsky_Curtain

A single curtain which moves horizontally is called a wipe. A tab or tableau curtain has two overlapping leaves which are lifted from the corners in a diagonal direction, by the stage assistant or conductor (Sutradhar) of the performance. A scrim is a curtain made of a gauze like fabric that seems to be opaque when lit from the front and transparent when backlit. A backdrop curtain is a painted or scenery curtain forming the back surface of the performance area. A cyclorama is a large white curtain that encircles the stage and provides a background.

11 Interview_with_Francis_Ford_Coppola_&_Alden_Ehrenreich_at_SIFF

STAGE CURTAINS Part 1 (Blog published earlier here)



Post 167  – by Gautam Shah

swaziland_-_traditional_homes Fences are barriers to confine or exclude people or animals, to define boundaries, or to decorate. Fort walls and compound or estate walls, are solid and heavy structures, but are not considered fences. Fences are lighter and of limited height. Fences are transparent to translucent to allow unrestricted flow of vision, water and air.


557px-Gaudi_iron_door_LaPedrera_BarcelonaFences are nominally erected over the ground but any physical obstruction, natural or man-made can function as fencing. So a ditch or dry or water filled moats can work as a fence. Fences of vegetation such as plants, hedges, climbers, cactus and dry thorny shrubs are used in farms and fields. Timber, earth, stones, and lattices, wires and nets of metals are widely used for fencing.


 In 19 C North America, many varieties of timber fencing were developed, such as the split rail laid zigzag, the post rail, and the picket. Other common fences are chain-link fence, hurricane fences, and white picket fences. In comparatively low rainfall areas like East Europe and in W. USA, turf was dumped to form a fence.

Reconstruction of Camp Dubois along the Mississippi River, Lewis and Clark State Historic Site, Illinois18163278404_1b31a6e018_z

Split_rail_fencing The first patents on barbed wire fencing were taken out in the United States in 1867. However, it was in 1874, when its production by machines, made its use widespread. Woven wire fences and expanded metal lattices, affixed to wood, steel, or concrete posts, proved economical and durable.

434px-CeutaBorderFenceElectrified fences, frequently a single strand of barbed wire, are sometimes used for temporary confinement of animals. A mild shock is given to the animal at intervals of a few seconds if it is in contact with the fence. Fence wire usually consists of two longitudinal wires twisted together to form an entwined cable and having wire barbs wound around either or both of the cable wires at regular intervals. The varieties of barbed wires are numerous, with cables being single or double, round, half-round, or flat and having a range of gauges. The twisted double wire provides extra strength and permits contraction and expansion without breakage. Barbs are diagonally cut in order to provide sharper points and they may be formed of one or two pieces (two or four points) and are generally spaced at intervals of 100 to 130 mm. 

2506993864_8bc2386d8e_zFences are considered as safety barricades against animals, insects, humans and vehicles. These pose Height and Width factored hazards. Barbed wire fences have straight head, inward, outward bend or double head (Y form) at the top to make the crossover difficult. Armed forces place extended coils of barbed wire loops on ground without any posts. During world war-II barbed wire fence posts were spiked to prevent air craft landing.auschwitz-history-concentration-camp-the-museum

Hitler’s concentration camps are grim-reminder of fencing used for forceful confinement. Berlin, Germany was first divided by barbed wire fencing, which however did not prevent people escaping through it, so were replaced with massive RCC walls. Yet nations of the world still put up barbed wire fences to demarcate boundaries, as it provides a cheap and fast way of erection. India and Pakistan boundaries are fenced with double rows fencing, with an inspection path in the middle, and recognized no-man’s land across it. 

640px-thumbnailOwnership of a fence between two properties is matter of dispute. The person who builds the fence first, remains the owner of it, and is also responsible for its upkeep. This, however, does not prevent the neighbour to place a patch at places of break. Ownership of a fence is often marked on title deeds with horizontal ‘T’ symbol, with the leg of T shown towards and in the property of the owner. Nominally fencing wires, lattices, or the cladding is placed on the non-owners side, to enable repairs or straightening of posts as and when required.

Other posts on Similar Topics

1.  Environmental Barricades

2   Barrier Systems in Buildings

3   Barrier Systems

4   Use of Barriers in Performing Arts




Post -by Gautam Shah



Environment is a complex system. Its various aspects affect us differently. Some effects are concurrent and few are directional. Environmental barriers serving many different purposes are required.

Noise barrier Geluidscherm_OverschieWIND BARRICADES

Wind barricades are used for heavy wind sections as well as for the storm prone locations, such as sea fronts, valleys etc. These are designed to deflect the direction and diffuse the velocity of the winds. The barricades primarily depend on the quality of the terrain and man-made formations, such as sand dues, walls, screens, vegetation, walls etc. Projections like galleries, Chhajjas, screens, are also used for diverting the winds to the buildings. The flow is also diverted to specific interior areas of rooms by wind catcher ducts. Tropical houses have terrace parapets with a grill or lattice design to let the air pass through. Louvered doors and windows also control the air movement. WATER BARRICADES

Water barricades are required against sea tides and ebbs, tsunamis, flooding, land washouts, snow and rain storms and eddy currents. These are in the form of vegetation, walls, dumps of modular or irregularly shaped cast units, landscaping and terrain contouring. Holland has devised variety of technological means against ingress of sea waters.


Sea front barricades of Concrete blocks against land erosion



Sun shading barricades are shading devices, usually vertical or horizontal, and often in inclined positions. Locations above 23° N or South of the equator receive no sun rays from respectively North and South faces. All location under (within) 23° N or S of equator, however, receive some sun rays, and to curtail it sun shading devices of horizontal flat or inclined shape are required. For the same locations, on East and West faces, early part of morning and later part of the afternoons receive horizontal rays, but with Southern inclination. These require a dual shading consisting of horizontal and vertical (on the South side of the opening) elements. Sun shading devices such as Brise de soleil are used.

Solar baffles


Radiation barricades are used against radiation sources, such as furnaces, open fires, oil wells and oil storage tank yards. Such barricades could be natural or man made. Natural radiation barricades are in the form of hills, contours, dunes, slopes, trees, hedges, foliage, plants, grass, climbers etc. Man-made radiation barricades are protection walls, embankments, ramparts, retaining walls and dykes.

Jet Blast Barricade


These are created against super highways, railway tracks, airport runways, open mines, stone crushing plants and sites with pile drivers. The noise control barricades are made of dense vegetation, fibre boxes (grass), and hollowed or staggered construction. Stage podiums have parabolic overhangs to direct sound away from the stage and thus avoid the feedback in sound amplification system. Telephone booths in public spaces like malls, road sides, railway stations have specifically designed envelopes to prevent the background noise. Cinema and performance auditoriums are designed with optimum 1/4 to 1/3 audience occupation, as the bodies of audiences and their clothing absorb sound. Noise control barricades are in form of contoured planes to deflect and amplify the sound, low density surfaces treatments, baffles or cavities to absorb select frequencies of sound, or frequency generators to produce sound attenuation.