Keywords: Parts / Components / System / a unique personality / a coherent character / a man-made system / natural system / a physical system / conceptual or non physical system / universe / user / independent or mutually less related systems / intense coherence / biological system / built-in capacities or reserves / strategical planning / synergetic devices / consume energy / byproducts.

A building is a very complex entity made up of many parts, components and systems. Some Parts of the building come together to form a Component. Parts and Components function in unison to form a System. A system has twofold identity: a unique personality of what it does, and a coherent character of how it carries out its functions. The ‘first identity makes a system substantially self-sufficient’, but the ‘second identity makes it a participant of a larger system’.

A building is a man-made system compared to many natural systems (such as weather, ecological, solar etc.). It is a physical system unlike many ‘conceptual’ or nonphysical systems (such as information, taxation etc.). Buildings are physical entities composed of many elemental units. Buildings have systems of form and size, which render subsystems like scaling, modulation, proportion, hierarchy, patterns, etc. These subsystems in reference to the Universe provide orientation, siting, location, etc., and in association of the User offer left-right positioning, sense of vertical and equilibrium, anthropometric functions and sensorial values.

A building can be perceived as a very large and complex system consisting of many different types of systems and subsystems. The systems are customarily categorised in terms of what they do: such as Structural, Architectural, Interior, Electrical, Mechanical, Air-conditioning etc. Some of these are fairly independent or mutually less related systems, and so can be installed, replaced or removed without many of the consequential effects. However, other systems have very intense coherence, and so once installed cannot be easily removed or replaced without affecting other systems.

Buildings have emulated the biological system of live beings. Buildings are designed with not only built-in capacities or reserves, but designed to be responsive, through strategical planning and synergetic devices. Buildings consume energy to be a functional system, and as consequence of it, generate byproducts.

1.0.1 BUILDING : A SYSTEM FOR INHABITATION

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Keywords: system for inhabitation / structural and nonstructural system swap their roles.

A building can be defined as a system for inhabitation. The building or the shell can be built exclusively out of structural systems, but for inhabitation many other subsystems must be incorporated into it. These incorporated subsystems have no or a very little structural role, though may depend on the structure to be operative. All subsystems of the buildings cannot be typecasted neatly as structural versus nonstructural entities. There are several reasons for this. Structural and Nonstructural systems swap their roles under specific conditions. For example a door or a window frame of opening systems may carry some loads in an earthquake like a situation. Inversely, a structural system may become latent or redundant, as for example a retaining wall of a swimming pool filled in on both sides may not be required to act as a retaining structure. In both types of swapping of roles, the changeover may be temporary, permanent, reversible or nonreversible.

1.0.2 CATEGORIES OF BUILDING SYSTEMS

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Keywords: STRUCTURAL SYSTEMS / constancy / subsystems repositioned or removed / NONSTRUCTURAL SYSTEMS / TYPES OF NONSTRUCTURAL SYSTEMS / Protective systems / Filler systems / Independent systems / building as a composite system / CONSIDERATIONS FOR A BUILDING AS A COMPOSITE SYSTEM / Identity elemental units / Location, position, and orientation / Schedules and conditions of occurrence / Nature of interrelationships / Design compulsions / Technological relevance / User considerations / User relevance / Environmental concerns / Operational aspects / Social values / Economics / Occupation and Inhabitation factors.

STRUCTURAL SYSTEMS: A structural system by its intrinsic nature, composition, position, or arrangement, provides a whole that stays stable, in equilibrium, or constant (yet may be mobile like a ship, spacecraft etc.). The structural subsystems of a building system must exist in the required location or be available at the required moment and duration to achieve the distinctive constancy. The stability of a building is disturbed, when the structural subsystems are repositioned or removed. Structural systems of the building seem to be well integrated, because by being together they achieve constancy, which is fundamental to a structure’s being.

NON STRUCTURAL SYSTEMS: Non structural systems of a building apparently have no role to play in the constancy of the building. Subsystems within a building that do not affect the constancy of a building may be called nonstructural systems (e.g. partition walls, doors, windows, finishes, etc.). Non structural systems though useless in structural sense, are not totally dispensable. Many nonstructural systems protect the structural elements, like plaster, walls, claddings etc. Some nonstructural systems achieve their own stability by depending on the structural systems, e.g. a stretched net or a sail. Nonstructural systems need not be integrated with the structure so are replaceable or relocatable.

TYPES OF NON STRUCTURAL SYSTEMS used in a building:

1 Protective systems: that cover the structural systems and non structural systems, e.g. plasters, waterproofing, roofing.

2 Filler systems: fill up the gaps or spaces between structural subsystems, e.g. non load-bearing walls, joints.

3 Independent systems are complete systems by themselves that independently provide peculiar functionality, e.g. air conditioning, illumination, communication.

CONSIDERATIONS FOR A BUILDING AS A COMPOSITE SYSTEM:

○ Identity elemental units such as parts, components and subsystems.

○ Location, position, and orientation of the elemental units within the system (the building).

○ Schedules and conditions of occurrence or being relevant for the elemental units within the system (the building).

○ Nature of interrelationships between the elemental units, such as: synergy, coordinated behaviour, dependency, autonomy, and also: order, patterns, sequence, proportion, modulation system etc. involved.

○ Design compulsions such as minimum standards, codes, laws, regulations.

○ Technological relevance: Materials, specifications, experience, skills that are required.

○ User considerations: anthropometric and ergonomics, safety aspects such as hazards, risk management, sensual qualities, aesthetics.

○ User relevance in terms of novelty, tradition, vogue.

○ Environmental concerns: ecological value, disposal mode.

○ Operational aspects: repair, maintenance, replacement, accidental and malicious damage.

○ Social values such as acceptability, relevance, validity.

○ Economics such as value, cost, price.

○ Occupation and Inhabitation factors: life span, adaptability.

1.0.3 HOW BUILDING SYSTEMS EMERGE

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Keywords: Invent a novel entity / Improvise important subsystems / Upgrade the working of the system / Adopt subsystems / Universalize systems Provide distinct intra connectivity / Facilitate networking capabilities / Provide for greater integration.

Building as system emerges at many levels and modes, some of these are:

○ Invent a novel entity using none or few of the existing subsystems, to replace several existing subsystems.

A window like opening system consists of many sub systems like grills, glass, railing, filters (jalis, nets), awnings, weather sheds, ventilation, safety and security hardware etc., but a comprehensive device can replace all such sub systems.

○ Improvise important subsystems to substantially transform the physical nature of the main system.

Installing an elevator or air-conditioning system into an old building completely transforms its nature.

○ Upgrade the working of the system by rationally relocating and time scheduling the various subsystems.

○ Adopt subsystems as offered by others such as: designers, innovators, inventors, vendors, through facilitation and customization.

○ Universalize systems by following standards, codes and protocols. Follow international practices such for Quality -QMS, Environment -EMS, etc.

○ Provide distinct intra connectivity between subsystems through a distinctive network or an ancillary subsystem.

○ Facilitate networking capabilities between systems with a view to achieve a larger system, through provision of nodes, interfaces.

○ Provide for greater integration between physical and nonphysical subsystems.

1.0.4 BUILDING, USER AND THE ENVIRONMENT

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Keywords: technological up-gradation of building as a system / efficient system / comprehensive system / spatial rearrangement / rescheduling / use and environmental relevance / greater productivity / use of nonphysical systems / Changes in buildings / Intentional changes / Circumstantial changes / Environmental changes / User on occupation customises the building / Building begins to affect the user / Environment moulds the building / Building impacts the environment.

A building as a complex system is designed to function in an environment and inhabited by a user. A building affects and gets affected by the user and environment. (For detailed discussion, refer: notes on Alterations and Renovations) The building’s innumerable systems are permanent, replaceable or up-gradable. The technological up-gradation of building as a system occurs through:

○ Replacement by an efficient system.

○ Elimination of several sub systems by adoption of a comprehensive system.

○ Integration of several systems by spatial rearrangement or rescheduling.

○ Regrouping the systems by their user and environmental relevance or affinities so that systems operate with greater productivity.

○ Greater use of nonphysical systems instead of action elements, sensing mechanisms, control elements, decision elements, connecting elements, distancing elements, converters etc. (for more see: 2.0.2).

Changes in buildings are:

○ Intentional changes such as: functional, technological upgrading, styling.

○ Circumstantial changes such as: due to ageing, wear and tear of use, over-use, under-use, non use, and mis-use).

○ Environmental changes: some major categories are listed here:

1User on occupation customises the building by self-help, but changing only the familiar and easily removable subsystems. The user has to hire semiskilled crafts-persons, or retain specialists or professionals like architects, interior designers, engineers, etc. for altering partially integrated or coordinated subsystems.

2Building begins to affect the user, through its awe, form, discipline, flexibility, unyielding rigidity, historical values, location conditions or setting, economics considerations, perceived stability, and expected life, etc.

3Environment moulds the building, nominally at a very consistent pace and in a predictable manner. Some changes are of imperceptible measures and often ignored till the cumulative effect is beyond remedial correction. The environment also changes the building at an inconsistent rate and unpredictably, so all precautions prove useless.

4Building impacts the environment in many ways. It causes changes in the surroundings by its presence, operations, and ultimately on its demise, demolition and disposal. A benign presence is one that disturbs the environment for small time scale and over minor extent, compared to very long lasting and extensive disturbances to the balanced state. A building has nine lives like a cat. A building reincarnates itself in spite of disintegration of many of its sub systems. A building may lose its original form and functional identity, yet continue to be relevant as a shell for a different nature of occupation.

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2.0 PARTS COMPONENTS AND SYSTEMS

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CHAPTER 2.0 INDEX

2.0.1 Objects

2.0.2 Parts, Components, Tools and Devices

2.0.3 Systems

2.0.4 Elements of Systems

2.0.5 Systems Approach

2.0.6 Designing Systems

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2.0.1 OBJECTS

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Keywords: PHYSICAL OBJECTS / simple objects / complex objects / Intrinsic qualities of physical objects / extrinsic marks of physical objects / NON PHYSICAL ENTITIES / Intrinsic qualities of non physical entities / Extrinsic marks of nonphysical entities.

PHYSICAL OBJECTS have a peculiar size and shape. Simpler ones consist of one or few materials. Simple objects are useful on their own, or be useful when placed with others. When a simple object is useful by being in company of other objects, it by itself becomes dysfunctional or inoperative but the assemblage does not get affected significantly. However, there are complex objects, that are so well integrated in the assemblage that their absence can make the entity completely useless.

Intrinsic qualities of physical objects: size shape and constituent materials. Intrinsic qualities allow standardised manufacturing, use, disposal and recycling processes.

Extrinsic marks of physical objects: position, orientation, nature of relationships, duration etc. Extrinsic qualities become apparent only when a physical object is connected to another one.

NONPHYSICAL ENTITIES are like: process, programme, reports (feedback, feed-forward), expression, etc. A nonphysical entity may contain very essential and less essential section within it. For example in a computer programme, there could be sections that are not very essential, compared to sub processes like ‘routines’ which are not only key features but are accessed frequently.

Intrinsic qualities of nonphysical entities: extent, duration, form and constituent elements.

Extrinsic marks of nonphysical entities are the frequency of reference, protocol of access etc.

2.0.2 PARTS, COMPONENTS, TOOLS AND DEVICES

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Keywords: PARTS / placement, location and function / elemental unit / active to passive interactions / determined by the design / indeterminable behaviour / COMPONENTS / unique composition / role within the system / static / dynamic / a part is also a component / Categories of Components / Action elements / Sensing mechanisms / Control elements / Decision elements / Connecting elements / Distancing elements / Converters / TOOLS AND DEVICES / use of their own / end use / machine / automatises a process / using multiple tools and devices and by combining several strategies / replaceable component.

PARTS: In our day to day life, we use many different types of objects. At a very simple level an object is made up of only one or few materials. Such objects though have variety of sizes and shapes, serve similar purposes. For this reason parts are always replaceable, and similar parts are affected similarly. When we recognize an object as a part, we know that a whole range of nearly similar objects, worthy of being a ‘part', are available. A part has universal character, but when assembled into a component, it acquires a different personality, due to the placement, location and function. A part is that elemental unit to which the whole can be reduced or resolved.

A screw, nail, handle, razor blade, button, are examples of parts. These are destined to become members of a larger entity -the component. Cement, sand, water and bricks, as parts, form a masonry wall, which in turn is component of a building. Parts like a tube, tyres, air, rims, together create a component -the wheel. The wheel with many other components makes up a system of movement.

Within a composition, parts exhibit an active to passive interactions with other parts, as determined by the design. But parts dealing with the environment (including the user) often show indeterminable behaviour.

COMPONENTS: A component is unique composition of many parts, to serve a specific purpose, and must remain steadfast to the specific function to be relevant. Components have a specific identity, compared to Parts, which have a universal character. A component is more intimately linked to the larger composition-the system, than a part is. Components are conceived to be within a larger composition or system, and derive their identity on the nature of their role within the system. Some components remain static and so are useful, but many others are dynamic and only for that reason, become members of the functional system. Components manifest at very specific location and occasion, so can be easily identified and separated. A part is also a component where it becomes exclusive due to the placement, location or function. Components show reactivity to presence or elimination of energy by becoming dormant, active to hyperactive.

Some Categories of Components are:

Action elements: These trigger an action (like tools, devices), such as commands in computer or machine codes: start, stop, redo, wait, seek, words, phrases or expressions that excite, incite, inspire, tranquillize, annoy or hurt.

Sensing mechanisms: These require a feed-forward or generate feedback, so have state device or switch, and a communication node.

Control elements: Control elements operate within a designed range of effectivity, which whenever is breached it activates a sensing mechanism.

Decision elements: A decision element is mix of sensing mechanism and a control element, the logic for decision making is preset, but could involve a linear, looped, fuzzy or random process.

Connecting elements: These elements connect several components for synchronous movement or action, transfer of energy, electrical charge, messaging and communication. Examples include wires, levers, cranks, shafts, axles, ties, circuits, etc.

Distancing elements: These distance two components in space or delay a process in time. Compaction, diffusion, acceleration, deceleration, are the characteristic of such elements. A washer, spacer, gasket, sprocket wheels, timer belts, are examples of such components.

Converters: These elements convert movements from linear to planner, circular, or read a pattern, create a pattern, scale, focus, de-focus, enlarge and compress it. Examples include measuring devices, pantographs, digital printers, plotters, monitors, keyboards, projectors, etc.

A PA system has several physical components like power supply, microphones, cables, amplifiers, speakers, etc. A computer system has physical components like processors, memory modules etc., as well as nonphysical components like software. A publication or report includes components in the form of indices, links, references, conditions of use, intellectual rights -copyright, patent. A DNA has genetic modules (code) as the components. A programming language consists of code components that trigger certain activity or keep a check on it.

TOOLS AND DEVICES: A knife, screwdrivers, pliers, scissor, axe, etc. consist of several parts, so are components, but have use of their own, and may not be destined to become members of a larger entity. Such components with a definite end use are tools and devices. Tools and devices, as a component, become part of the larger system such as a machine.

A machine automatises a process, and so allows heavier, lighter, measured and intricate use of force then a human possibly could do. The same process or the style of working can be employed using different types of tools. Thus a press can bend, puncture, or cut a piece of metal by change of tools. A machine is rational unaffected by moods or emotions. Tools and devices by becoming parts of machines help a number of processes. The efficiency is enhanced by using multiple tools and devices and by combining several strategies to output a complex object, such as done by an automated lathe, turning, drilling machine or a forging press. Tools and devices are expected to wear, and so are replaceable components.

2.0.3 SYSTEMS

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Keywords: SYSTEMS / purposive entities / a complex whole / scheduled in time / appropriately located in space / TYPES OF SYSTEMS / SMALL SYSTEMS / finite entity / LARGE SYSTEMS / infinite entity / groups of subsystems / SIMPLE SYSTEMS / man-made systems / natural systems / COMPLEX SYSTEMS / interdependent / independent / sea current system / active systems / biological entities / dynamic systems / synergetic systems / PHYSICAL SYSTEMS / exploit material based qualities / use configuration related characteristics / NONPHYSICAL SYSTEMS / ethereal / metaphysical / arrangement / sustain larger physical or nonphysical systems / core / periphery / Simple nonphysical systems / complex nonphysical systems.

SYSTEMS: Systems are purposive entities qualifying the togetherness of parts, components and subsystems. A system is a set of contributing elements and a culture (manner) that allows it function as a unified whole. A system is also a group of interacting, interrelated, interdependent, as well as distanced and independent elements forming a complex whole. A system also consists of components which are connected together in order to facilitate the flow of information, matter or energy, or by togetherness project cohesion, holistic unity, commonality, universalism.

Systems have their elemental units scheduled in time and appropriately located in space. For every change in the constitution, composition (form and size) and position of an elemental unit there is a corresponding change in the system. Though, some changes are insignificant, and are ignored. Elemental units of a system due to their scheduling, positional value, or designed inactiveness, are often not relevant to others. A system, however, composed of such apparently irrelevant elements is relevant as a whole.

TYPES OF SYSTEMS: Systems can be primarily classified by their size, complexity and nature.

SMALL SYSTEMS: A small system has linear (sequential) architecture of arrangement or relationships. A Small system persists for a limited time, and dominates small extent of space, so is a finite entity.

LARGE SYSTEMS are in the form of 2D or 3D matrix, or looped with entwined structures. Its spread in time and space is infinite and so such systems could be an infinite entity, such as for example the atomospheric or economic system. A large system consists of several groups of sub systems, some of which outlast others.

SIMPLE SYSTEMS: A simple system is composed of few elemental parts and components, which are essentially interrelated. All man-made systems are simpler, for the basic reason that these are always finite and logical, in comparison to natural systems. Simple systems are static or dormant in particular time segments. A simple system consists of the physical or non physical entities, but rarely both.

COMPLEX SYSTEMS: Complex systems are composed of several sub systems, only some of which are directly interrelated, yet all function towards a unified whole. In a complex system some of the subsystems are intentionally designed to be interdependent and other are isolated in time or space, to make them independent. Complex systems include, both physical and non physical entities, but a nonphysical system due to its nature seems very complex one. Systems seem to be complex when the change causing intrinsic or extrinsic elements cannot be easily or adequately identified. A sea currents’ system, is one such complexity, where the al Nino causing elements have not been yet identified. Active systems exchange energy and efficiently deliver a product or an advantage. Some complex or High-end systems emulate biological entities. But man-made systems are not capable of procreation, like the biological systems. Dynamic systems have an intensity ranging from dormancy to a high vibrancy. Synergetic systems have inbuilt capacities to adjust to the environment so are self-regulating, but dynamic systems.

Systems are physical, nonphysical or both. Examples of Physical systems are: equipments, utilities, buildings, etc.; Nonphysical systems are: banking, software, defence, healthcare, marketing systems, environment, solar, etc.

PHYSICAL SYSTEMS: Physical systems are of various sizes, shapes, materials and configurations, and each combination serves a peculiar need. Physical systems exploit materials-based qualities like: constitution, mass, weight, capacities, performance, etc. and use configurations related characteristics such as: geometry or the structural arrangement. Some physical systems generate information which in turn support non physical subsystems like software or programme. Physical systems are finite. Their elements are ‘domains’ bound (territorial). As a result a physical system can be considered to be static and dealt accordingly. A physical system, like the human body, is continuously affected by the environment, and is a complex entity. Such systems display multiple functionality.

NONPHYSICAL SYSTEMS: Nonphysical systems are both ethereal and metaphysical. Ethereal systems can be experienced, but have no material body or affirm to a conceptual structure, so are difficult to define. Metaphysical systems are abstract systems with ideas or concepts organized in some manner or arrangement (algorithms) to serve specific ends. The arrangement is based on relevance of occurrence, action sequence, affinity, etc. of the elements. Such systems may show a strategy (a long term plan), a tactic (a short term or immediate), or an action-reaction response programme. Output of such conceptual systems sustains either larger nonphysical or physical system. Non physical system like the environment, has no physical territory or a finite edge, but can be sensed in terms of core (or themes) effect, and overlapping zones with other systems representing the periphery and the weaker or diffused effect.

Simple Nonphysical Systems have distinctive elemental units (e.g. taxation system) structured to provide a facility, strategy, solution, explanation, conclusion, etc.

Complex Nonphysical Systems are extremely persistent (omnipresent and pervasive), or not fully comprehensible in the nominal time and space scale of the perceiver (e.g. solar system). The simplest element of a nonphysical system is -the core or nucleus, an area where effects of other systems are least effective.

2.0.4 ELEMENTS OF SYSTEMS

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Keywords: ORDER / recognition of order / primary orders / selection / processes of assembly and manufacture / degree of coordination / formation of concept / CORE or NUCLEUS / PERIPHERY / exchange information / transfer energy / INTERVENING ZONES / convergent areas / gaps and interludes / DOMAINS / internal and external / nodes for dependency or connectivity.

ORDER: Order is an inherent characteristic of all systems. Order begins to emerge as soon as parts and components are selected for inclusion in system. Initially systems have order that is alogical and loosely definable, and it may or may not be apparent. But it is noticeable when the system begins to perform. At this stage, in simple system the order is obvious, logical and definable. But in nonphysical system the order can be elusive due to the scale and complexity. Yet recognition of order in a system helps in many ways:

○ It helps the definition of a system.

○ It endows self sufficiency, so that the system can become an ever replaceable component.

○ It provides nodes for dependency so that the system becomes integrated whole.

In all systems the primary orders are: selection (inclusion and exclusion) of parts, components, etc. and the process of assembly or manufacture. However, in complex systems there are many levels and categories of orders.

‘Every human effort follows some intrinsic logic’. Parts of an entity, even before being manufactured and even before physically placed together, have some degree of coordination. The coordination begins within the thought processes of the designer along with the formation of concept for the object.

Another important characteristic of systems is their domain or territory. This is very apparent in physical system, but nonphysical systems seem infinite with no edges. However, metaphysical systems have a zone where they are adequately active in comparison to sections where such systems are diffused, i.e., partially effective.

Recognition of order in system, is both subjective and objective. Subjective involvement allows the system author to see through the nascent logic, or blinds in recognising the order. Objective evaluation of the system by an uninvolved person rides over personal biases. Objective evaluation can occur for an operational system.

CORE OR NUCLEUS: Nonphysical systems have a strong focus from which other subsystems emanate or converge to. In very pervasive nonphysical systems a core or nucleus like a focus is the zone where one establishes conceptual mooring or base to start the encounter with the system. For a human being encounter with the atmosphere as a system begins at the surface of the earth, i.e. technically at the optimum sea level. The core is considered a multi faceted entity because most of the subsystems have a bearing here. The core distinguishes two directions: inward and outward.

PERIPHERY: Periphery zones are well defined in systems that are holistic or as sub system has a semblance of independence. The periphery zones or edges are recognised when a subsystem touches other subsystems at few locations spatially or on certain occasions temporally. During rest of the conditions the periphery is not perceptible. The periphery is well delineated in systems that exchange information or transfer energy at specific nodes and through protocol.

INTERVENING ZONES: Intervening zones are the convergent areas formed by overlapping subsystems and also by gaps or interludes between subsystems. The convergence and gaps-interludes occur, both in time and space. A holistic entity, has no intervening zones, and the subsystem have little or separate identity. A loosely conglomerated system like transit, courier, etc. consist of several modulated units, occurring across different regions, or across technologies. Here planned or recognised gaps and interludes give all subsystems a component like ‘replaceable’ identity. The gaps and interludes are not completely devoid, but are full of metaphysical things, as in case of solar system. Systems flourishing at different historic times or across geographical regions can have concepts, ideas, etc. that are common, making them universal.

DOMAINS: Physical systems have a finite edge and so reflect a domain. A domain marks what is internal and external to the system. It indicates how a system is part of the larger system. It identifies nodes for dependency or connectivity of the system.

2.0.5 SYSTEMS APPROACH

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Keywords: COMPONENT APPROACH / working whole / two major external variables / environment / user interfaces / man made systems / natural systems / parts to whole / SYSTEMS APPROACH / manufacturing activity / physical systems / conceptual systems / operations / test run / model or prototype / surveys / whole systems / fuzzy systems / SYSTEMS’ THINKING / systems theory / organization and interdependence of relationships / SE: SYSTEMS ENGINEERING design, execution and operations / OR: OPERATIONS RESEARCH.

COMPONENT APPROACH: During the Industrial revolution period (1850 onwards), component approach was recognised as a way of combining and organizing a working whole out of parts and components. It helped evaluation of parts in terms of the whole. The component approach helped understanding of systems of small size and limited utility (like industrial plants).

Later (after the world war I) it was recognised that systems are much more versatile and complex. Systems could be any organized effort like roads, buildings, health care, taxation, etc. Postwar planning and development taught that systems were affected by two major external variables. Systems were required to accommodate the environment and offer user interfaces. There was also realization that man made systems were ‘put together’ and non changing entities, compared to natural systems that were much more persistent, though very changing. Parts to whole, the simplistic component approach, was now a very inadequate definition for systems.

SYSTEMS APPROACH: Systems approach, which began with manufacturing activity, was soon applied to all types of human activities. It was realized that there are physical systems consisting of materials-objects, distinct from conceptual systems formed of nonmaterial entities.

Physical systems were tested on actual operations or test run in parts, or as a model or prototype. Conceptual systems require surveys to check the presumptions or derivations. Physical systems are objective, and variables like environment and the user interfaces are external to it. The conceptual systems are very much governed by the external factors, and often have no distinct boundaries.

Systems were recognised to be whole systems, when endowed with very distinctive environments, and to be fuzzy systems, where the outer boundaries are indistinct.

SYSTEM’S THINKING: When large production plants, military efforts, structural entities etc. were being developed in early 20^th C, these were each considered as set of problems. The approach to the problem and the possible solutions were perceived as a system. Systems theory was the word early investigators used to describe the field which focussed on organization and interdependence of relationships. A system was perceived as a family of relationships among the members acting as a whole. ‘The joining and integrating of the web of relationships create emergent properties of the whole’.

System’s thinking is a style of thinking / reasoning and problem solving. It starts from the recognition of system properties in a given problem. The problems have physical as well as abstract bearings. It was realized that a system is as strong as its subsystems are, and subsystems can gain strength from conceptual clarity of what the whole should be. A system was perceived as composed of regularly interacting or interrelating groups of activities/parts which, when taken together, form a new whole. In most cases this whole has properties which cannot be found in the constituent elements.

SE: SYSTEMS ENGINEERING: The systems approach was now scientific pursuit: for planning and validation of systems as a matter of relationships. It was now recognised that systems need attention at three distinct levels: Design, Execution and Operations.

OR: OPERATIONS RESEARCH: Another parallel discipline Operations Research emerged with exclusive concern for the planning, assessment and control of operating systems. Both, SE and OR overlap, but together provide a comprehensive method of systems approach.

2.0.6 DESIGNING SYSTEMS

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Keywords: Innovators or designers / lay person / the process of creation / documentation / NATURE OF DESIGN EFFORT / personal and impulsively formed systems / holistic / planned systems / CLOSED ENDED SYSTEMS holistic systems / prime or unique effort / compact and rigid / HOLISTIC APPROACH / a complete and self contained system / work of art / OPEN ENDED SYSTEMS / multilateral effort or multi trial endeavours / large number of people / different time and locations / common measurements and standards for materials and procedures / wasteful / built-in reserves / DESIGN OF A SYSTEM / governing aspects / DESIGN APPROACH / holistic / components / Redesign or re-engineering / Reverse engineering / Simultaneous or Concurrent design / NATURE OF OUTPUT / PRESENTATION TOOLS AND METHODS / approval, test, execution and operations / intellectual property rights / public domain system / SCALE AND NATURE OF DETAILS / Conceptual systems / explicit idea level details / Executable systems / NASCENT -FIRST EVER EFFORT or ROUTINE APPLICATION / fail-safe / exact definition / HUMAN AND OTHER RESOURCES AVAILABLE / TECHNOLOGY INVOLVED / conceptual systems / material systems / tactical corrections / strategic forethought / CODES AND UNIVERSAL CONFIRMATION / Dimensional coordination / Size and shape modulated parts / universal codes and regulations / greater acceptance / common platforms / HUMAN CENTRED DESIGN / ENVIRONMENTAL CONCERNS / Environmental Management Systems EMS ISO 1400x.

Innovators or designers may perceive an entity, or select its constituents by instinct, but must discover the logic behind it and justify their actions intellectually. A lay person devising entities solely through creative impulses lacks such a prowess. Designers continuously refine their capacity to improvise and innovate, by registering the process of creation or design decisions. It allows them to selectively improvise the smallest section of the entity.

The initial impulses of design, the dreams, intuitions or inspirations thin out or get wiped out completely with passage of time. These often need to be recalled in a different time and space context. Documentation of every aspect of design process is very necessary. Such expertise helps a designer to handle extensive or more complex dreams, intuitions or inspirations.

NATURE OF DESIGN EFFORT: A system reflects the nature of effort used in its formation. Personal and impulsively formed systems tend to be holistic, with few or no sub systems. On the other hand, planned systems whether personal or evolved through multilateral effort, and over a longer period of maturation, consist of many sub sets.

● CLOSED ENDED SYSTEMS: These are also called holistic systems. Close-ended systems result from prime or unique effort. Spontaneous and one-man creations tend to be closed systems, unless a conscious effort is made to make it an open system. Closed systems are improvise-able only by its author or inventor. Closed-ended systems have few sub systems, and equally rare are the components. The few components are very specific and not easily replaceable. Closed systems as a result are compact and rigid. Closed ended systems become useless when faced with even minor changes in their environment or working.

● HOLISTIC APPROACH: Design effort that conceives a complete and self-contained system initially is called a Holistic approach, i.e. whole to the part. Holistic approach entails germination of an intuition as a complete system. Such creations are akin to a work of art, often not functional, and not necessarily reproducible. However, such impulsive concepts may be detailed later on to become component systems.

● OPEN-ENDED SYSTEMS: Open-ended systems evolve from multilateral effort or multi trial endeavours, and so have sub systems. Where large number of people are involved in design and execution, and where these processes are likely to take place at different time and locations, the system automatically becomes open ended. The subsystems for a variety of reasons are conceived as substantially independent systems. The subsystems are often designed or manufactured by different vendors. The success of the open-ended systems depends on the adaptation of common measurements and standards for materials and procedures. To accommodate all these, open-ended systems tend to be open or loose, and have a skeleton type frame structure (infrastructure). Open-ended systems many times are wasteful, because every subsystem has built-in reserves or additional safe capacities, though such individual reserves make systems more persistent. Open-ended systems allow replacements, improvisations and up-gradations of their subsystems and components.

DESIGN OF A SYSTEM: Design of a system, governing aspects are:

DESIGN APPROACH: The design approach determines the nature of system being evolved. The design approaches include: Holistic (whole to the part), Components (parts to the whole), Redesign or re-engineering, Reverse engineering, Simultaneous or Concurrent Design. (For more on this topic refer to notes on: Interior Design Practice and Office Management Section III = Chapter 8 at www.gautamshah.in ).

NATURE OF OUTPUT: The nature of system being conceived, physical (‘real’‘material’) or nonphysical (conceptual), governs the design process of a system. The nature of output, are: Construct forming, Strategic, Tactical planning, Assessment exercise, Executable scheme, Operational methodology, Corrective interventions like supportive additions, reformations, Reductive changes like curtailing, partitioning, miniaturization, condensation, Scheduling, Sequencing, Algorithms, etc.

PRESENTATION TOOLS AND METHODS: In what form the system will be presented for approval, test, execution and operations, such as: Report, instructions, drawings, images, digital data files, graphics, metaphoric, etc. determines its constitution. Systems that involve intellectual property rights may not be very revealing, but a public domain system has to be transparent.

SCALE AND NATURE OF DETAILS: The scale and nature of details are determined by the type of system. Conceptual systems have very explicit idea level details such as the domain of the system, definitions of subsystems, subsystem to subsystem relationships, dependencies, external nodes, etc. Whereas Executable systems have information of materials and processes, sequences of execution, siting of the system within the larger whole.

NASCENT -FIRST EVER EFFORT OR ROUTINE APPLICATION: First-ever systems ventures into unknown territories, and so these are conceived with extra efforts to make them fail-safe. This results into over explicit or very exact definition, making it ironclad, with no scope for improvisation. Routine application systems are more open, flexible though with very little wasteful features.

HUMAN AND OTHER RESOURCES AVAILABLE: Design of a system is an effort requiring both human and other resources. The human resources include the human-power and expertise. Other resources include, materials, time, plant, equipment, tools, and finance.

TECHNOLOGY INVOLVED: Involvement of technological features is as important in conceptual systems (nonphysical) as much as it is with material systems (physical systems). First-ever systems (novel) involve use of unproven technologies and unknown circumstances. Where as routine systems (traditional) are based on familiar grounds. Both types of systems could be of open architecture, in the first instance openness allows tactical corrections, in the second case it is as strategic forethought.

CODES AND UNIVERSAL CONFIRMATION: Designers prefer to design parts, components and systems that have dimensional coordination. Dimensional coordination also allows creation of geometric compositions. Size and shape modulated parts allow easy replacement. Affirmation to universal codes and regulations though restricts the design creativity but allows greater acceptance in the society. ‘Common platforms’ achieve greater economy.

HUMAN CENTRED DESIGN: Human centred design approach focuses on serving human needs in all endeavours by redefining and developing concepts and employing technologies. When human needs are genuinely served in all their manifestations it becomes an all-inclusive design system. It becomes a universal system above the racial, geopolitical and other barriers. It becomes a nondiscriminatory system.

ENVIRONMENTAL CONCERNS: Environmental concerns are now being recognised by International Standards Organization, ISO, through their recommendations for ISO 1400x : EMS, Environmental Management Systems. These standards are similar to ISO 900x series of standards dealing with QMS, Quality Management Systems.

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3.0 BARRIER SYSTEMS

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CHAPTER 3.0 INDEX

3.0.0 Barrier Systems

3.0.1 Natural Barriers

3.0.2 Man made Barricades

3.0.3 Make-believe Barriers

3.0.4 Other Barricades

3.0.5 Barricades for Physically Impaired Persons

3.0.6 Barriers for Performing Arts

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3.0.0 BARRIER SYSTEMS

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Keywords: obstructing and intervening entities / configuration, position and occurrence / context or the surroundings / intended and unintended things / extensive / opaque to transparent / lattice / membrane / barricades / separator.

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.

Barriers change the environment on both the sides. Barriers have a capacity to obstruct, absorb, filter and reflect, and so cause distinctly different conditions on the other side. However, barriers are often so extensive that the modified environment is not recognised, as the perceiver has no idea of, what the original (one beyond the barriers or without the barriers in position) experiences were. Barrier systems, as a result, are evident at the joints, thresholds, ends, edges, cut sections, or at the gaps.

Barriers are selectively opaque to transparent for various energies and objects. A lattice may allow a rat or insect to pass through but not a cat or dog. A membrane filter can allow gas but not any particulate matter. A barrier system, by deflecting, reflecting, by absorbing within its own body, does not let certain things to pass through them.

A barrier is a separator that not only divides an entity. It allows a new set of cultures to flourish on both the sides. However man-made barriers are not powerful enough to cause extensive changes in the environmental system within which they occur.

3.0.1 NATURAL BARRIERS

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Keywords: NATURAL BARRIERS / extensive / long lasting / territorial / temporal / start and end of natural barriers / overlapped / ATMOSPHERIC BARRIERS.

NATURAL BARRIERS: Natural barriers are like rivers, mountains, ridges, valleys or atmosphere. Natural barriers are very extensive in space, and long lasting in time. Natural barriers are territorial, affect macro or micro regions, and also temporal in terms of occurrence like, eternal, seasonal, diurnal, etc. The start and end of natural barriers are not always within the relevant time and space scale. Natural barriers start or become effective somewhere and imperceptibly end or become ineffective somewhere. Natural barriers as a result are often not experienced because the other side experience (without the barrier) is not possible due to their large spread. Natural barriers are overlapped by other natural barrier systems, so have no distinct definition.

ATMOSPHERIC BARRIERS SYSTEMS: Atomospheric barrier systems are natural barriers formed by the constituents of the atmosphere such as: air, moisture, breeze, winds, radiation, temperature, etc. For example, air or its gases control the level of radiation penetration, the moisture checks the amount of dust in the air, and presence of dust and other particles helps distribution of illumination. The atmospheric barriers are very extensive, consisting of over lapping layers, and so do not have the sharp edge definition. Some of these barriers are very acute and causative, while others are mild and almost irrelevant. Atmospheric barriers are so common and omnipresent that we many times take them for granted. Some effects of the atmospheric barriers are so fast or short lived that it becomes very difficult to notice or learn any thing about them.

3.0.2 MAN-MADE BARRICADES

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Keywords: PHYSICAL BARRICADES / contrived structures / conditions, properties of materials / METAPHYSICAL BARRICADES / indicative and unreal / make-believe / INDICATIVE BARRIERS / signs, signals, symbols / taboos, beliefs, customs / class of beings.

Man-made barriers are finite in size, designed for specific function and alterable. Man-made barriers occur as barricading elements such as: Curbs, embankments, Guard, Railing, Fender, Shield, Buffers, Balustrades, Fence, Parapet, Rampart, Bumper, Cushions.

PHYSICAL BARRICADES: Physical barriers are contrived structures (peculiarly shaped, sized and formed) that exploit conditions, properties of materials (strength, weight, bulk, ductility, etc.), and energy reactivity.

METAPHYSICAL BARRICADES: Metaphysical barricades are indicative and unreal, or Make-believe. A society by a tacit understanding accepts certain words, signs metaphors, and indications as allowable and non allowable actions (warnings, danger, caution, etc.). When such commonly acceptable norms are displayed, they function almost like a real barricade. Signs like Caution, Danger, ‘Do not trespass’, ‘keep off the grass’, etc. operate as barriers.

INDICATIVE BARRICADES: Indicative barricades occur as signs, signals, symbols etc. Unreal barriers arise as a response to our accumulated experiences, in the form of taboos, beliefs, customs etc. Indicative barriers are effective only for that class of beings, who not only know the meaning, but are willing to abide by it.

3.0.3 MAKE-BELIEVE BARRIERS

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Keywords: unreal and metaphysical / MAKE BELIEVE EFFECTS AND BARRIERS / predictable effects / mirrors / echoes and reverberations / predictable space dimensions / mould the visible space / stage like make believe and or indicative effects / dramatic or melodramatic / delusion / Maha Bharat / Lakshagriha.

Make-believe barriers exploit the instinctive associations and conditioning of physiological and mental faculties. Man-made barrier systems are often unreal and metaphysical.

MAKE BELIEVE EFFECTS AND BARRIERS: We are generally conditioned by predictable effects of the traditional or known materials. However, when we discover that any peculiar configuration or additional input creates an experience that is different from the one that is predictable, we get a tool for a make believe effect. Mirrors play a very important role in creation of duplicate spaces. Glasses provide a transparent wall compared with a nominally solid opaque structure. Rooms other than square or rectangular shape provide an unusual experience. Echoes and reverberation of sound provide predictable space dimensions, but different perception gives unusual experience of the space. Lights and shadows mould the visible space. Ionized air endows a garden like freshness in an otherwise stifled space.

In real life we do use the stage like make-believe and indicative effects. We use these to create situations that are called ‘dramatic or melodramatic’. Discotheques, Night Clubs, Amusement Parks, etc., are places where such make-believe effects are extensively exploited. Make-believe effects occur because we are conditioned by certain predictable responses of materials, texture, colour, illumination frequency and schedules of occurrence etc. When these predictable effects fail to arrive in the nominal context, or arrive in spite of a different situation a delusion occurs. Make-believe effects are almost magical or ethereal, and defy logic or reason.

Indian epic Maha Bharat mentions Lakshagriha, a palace where solid looking floors were water surfaces, and water surfaces were real floors. We perceive a dark space to be quiet and cold, but in a ‘maze’ of an amusement area, the reverse experience is provided. We perceive load-bearing walls to be opaque, so a glass wall seems different.

3.0.4 OTHER BARRICADES

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Keywords: SENSUAL VARIATIONS AS BARRICADES / VISUAL BARRICADES / optical qualities / sensory variation / BARRICADES CONSUMING ENERGY / machines / PROTECTIVE BARRICADES / planned deflection and distortion / noncollapsible barricade / collapsible barricade / SOFT BARRICADES / HARD BARRICADES / TRANSPARENT, TRANSLUCENT AND OPAQUE BARRIERS / NOTIONAL BARRICADES / representative form of a barricade / Notional barricades are not recognised / NEED FOR BARRICADES.

SENSUAL VARIATIONS AS BARRICADES: A non physical barrier could also occur through sensory variation. 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: 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.

BARRICADES CONSUMING ENERGY: Barricades bar or control the exchange between its 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 a live beings, if additionally can reproduce or self sustain.

PROTECTIVE BARRICADES: 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: These 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: These 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.

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: These 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 (non physical) barricades 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 recognised in a crowded area or in a chaotic situation. Similarly where barricades are required as protection against unknown elements, notional barriers are not effective.

NEED FOR BARRICADES: 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.

3.0.5 BARRICADES FOR PHYSICALLY IMPAIRED PERSONS

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Keywords: exclusive route / barricades have distinguishing elements / visually impaired persons / visually deficient person / colour blind person.

Persons with physical deficiencies require barricades for: extra support to the body, as a facility to ease the movement and as a guidance for the route. The barricades however must not create an exclusive route for the physically impaired. The barricades have distinguishing elements such as: shape, size (height, width), materials and their surfaces, nature of sensorial qualities available in the defined zones.

Barricades for visually impaired persons are required at two levels. The main barricade is like that required for a normal person. The barricade for the visually impaired persons should be continuous and have same texture, size, shape and feel throughout its spread. For the visually impaired person, a secondary set of barricade system is required at near the floor level to strike the walking stick. Even where, primary barricades are not ordinarily required due to the absence of a height-related hazard, a secondary barricade (at floor level) helps in directing a visually impaired person to a specific destination. Visually deficient persons require colour contrast from their background or neighbouring elements, Ramps or steps on passages must be indicated by colour, illumination and textural difference. A colour blind person may not read a colour but recognises the later two elements.

3.0.6 BARRIERS FOR PERFORMING ARTS

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Keywords: nonphysical or indicative barrier system / performing arts / real barriers / indicative barriers / acute or important sections / stage / here / beyond / mime acts / sage Bharat Muni / Natya Shastra / stage barriers / real life barriers / permanent / longer lasting / experienced dynamically.

The best and perhaps the most imaginative use of non physical or indicative barrier systems occurs in the performing arts. Here a performer wishing to express different experiences 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. 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.

The sets, stage property, curtains, side wings, lighting, audio-video effects, etc. are used for creating a variety of spaces (‘here’ and ‘beyond’). 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.

Stage set barriers are experienced by the audience from a limited and fixed angle view. Sage Bharat Muni in his treatise on Natya Shastra (Canons on Dramatics) says actor turning back to the audience is out of the scene or dead. Even in Roman Amphi theatres the actors on the front section are active and by retreating to the backside become inactive. Stage barriers serve a very limited purpose effective for a short period, and last only for a scene, dialogue or the expression. However, real life barriers are rather permanent or at least are longer lasting, seen or experienced dynamically, that is from all sides.

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3.1 BARRICADES IN BUILDINGS

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CHAPTER 3.1 INDEX

3.1.1 Barrier Systems in Buildings

3.1.2 Varieties of Barriers in Buildings

3.1.3 Environmental Barricades

3.1.4 Railings and Parapets

3.1.5 Fences

3.1.6 Guard Rails

3.1.7 Hand Rails

3.1.8 Components of Railings and Parapets

3.1.9 Materials for Barricades

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3.1.1 BARRIER SYSTEMS IN BUILDINGS

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Keywords: man-made barriers / control of environment / hazards / control of movement / barriers protect / barricades serve purposes / Types of barriers in buildings / operational ability.

A building is formed by a number of man-made barriers. The barriers in a building are designed mainly for the control of environment, followed by barriers against hazards and for control of movement.

The barriers protect a building from environmental effects, shocks, vibrations, other effects of energy, malicious abuse, use and age related wear and tear. In a building, barricades serve purposes like: restrict, control or direct movements of people and vehicles, indicate routes, provide defence against impact and risks from elements like fire, extreme temperatures, radiation, light, noise, wind, lightening, fast-moving objects, etc.

Types of barriers in buildings are: walls, roofs, floors, doors, windows, curtains, awnings, ceilings, panelling, etc. Building related barriers are well integrated into the fabric of the building and rarely function alone. Barriers in the building derive their operational ability by being part of the larger system.

3.1.2 VARIETIES OF BARRIERS IN BUILDINGS

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Keywords: SAFETY BARRICADES / Types of safety barricades /height related hazards / physically handicapped or infirm person / situational conditions / downward end of a ramp or slopping terrain / height for safety barricades / HEIGHT FACTORED BARRICADES / effective height / nature of surroundings / configuration / gaps in the balustrades / WIDTH FACTORED BARRICADES / barricades of greater widths / greater width with greater bulk / wider barricades / PEDESTRIAN CONTROL BARRICADES / tallest user / barbed wire fencing / notional barricades / ANIMAL BARRICADES / capacity to leap / run depth / traps at gates / wicket gates / TRAFFIC SAFETY BARRICADES / CROWD MANAGEMENT BARRICADES / safety / security / temporary / permanent / height safety standards / resist horizontal thrust / SECURITY BARRICADES / prevent access or exit / entry by terrorist / high speed impact / Berlin wall / BARRICADES FOR VEHICLE CONTROL / guard rails / BARRICADES FOR OPENINGS / fall related hazards / controlling the entry or exit / environmental controls / control vision in and out / effective sill level / barricades within the doors.

SAFETY BARRICADES: Types of safety barricades are: Height related hazards, isolation of dangerous zones, exposure to effects of radiations, against high speed movements, security from anti social persons, theft, animals, etc.

Height related hazards require barricades. Nominally a fall of 600 mm is difficult to negotiate (climb up or down), so even for a normal adult it is considered a hazard. A provision of an intermediate step or support is required. For physically disable and infirm people a barricade may be necessary even when the height difference is only 25 mm. For situational conditions such as at the downward end of a ramp or slopping terrain, a fall of less than 300 mm requires a safety barricade. In buildings for human habitation a 900-mm minimum to 1100 mm optimum height for safety barricades like parapets, balustrades, etc., is prescribed on balconies, stair sides, and terrace edges of are prescribed. The height is often compromised to 790 mm or less by, alternatively, providing wider widths, for drama, cinema or assembly hall balcony fronts, to prevent visual obstruction to the view of the front edge of the stage.

HEIGHT FACTORED BARRICADES: These are preventive barricades of specific height to control the crossover movement. Effective height actually available for the barricade is determined by the nature of the surroundings. A very steep gradient in front, and difficult to negotiate terrain (moats, pits, trenches) can also act as a barricade.

Effective height of a barricade system is affected by its configuration. A horizontal mid-bar or any such element can accommodate a toe of a user, to reduce the effective height of the available barricade. To prevent children less than five from falling, gaps in the balustrades (balcony and stairs) must not allow a 100-mm diameter sphere to pass through.

WIDTH FACTORED BARRICADES: As shown earlier in case of safety barriers, width of the barricade compensates the height requirement. Barricades of greater widths are also required, when a structure is required to resist horizontal stresses and thrusts, as in case of retaining walls and dams. Walls and partitions of greater width with greater bulk (low density) are created as insulation system for heat, x ray or other radiations. Wider barricades cut off the view of areas immediately close-below, an ideal provision for stepped floor balconies in sea shore resorts.

PEDESTRIAN CONTROL BARRICADES: Pedestrian barricades should be taller than approximately 2/5 the height of the tallest user, as for example for a mid-road verge. Security barricades should be taller than tallest persons to be barricaded. Often the effective width of the barricade structure controls the actual height required. Barbed wire fencing of Y and T, ‘shapes are used in jails and defence installations. Pedestrian control can be effected by notional barricades, like a thin rope, a horizontal pipe, a small ledge, a floor marking.

ANIMAL BARRICADES: The barricades should take in to consideration, animals’ the capacity to leap and also the ‘run depth’ available in the surroundings. Animals are confined by a variety of methods including water-filled moats, dry moats, and wire-mesh fences. Animal traps at gates have gaps to trap the animal’s feet, and width to prevent a ‘non run’ leap. Wicket gates are intentionally made of narrow width and have a nonlinear passageway to prevent vehicles like cycles and animals.

TRAFFIC SAFETY BARRICADES: Traffic safety barricades are meant to be safe, stable (wide based, secured or resilient enough to revert to the original position) and visible. Traffic barricades direct the flow of traffic, prevent unauthorized entry or exit from the designated areas or lanes.

CROWD MANAGEMENT BARRICADES: Crowd management barricades are designed for the safety and security of people, control the direction of their travel and to control their numbers. Such barricades are temporary (occasional) and permanent. The barricades are designed with the height safety standards (the nominal balustrade height and leap over prevention), but in addition have a capacity to resist horizontal thrust. Such barricades are in place at the famous temple of Tirupati Balaji, South India, and at Ambaji Temple, Gujarat.

SECURITY BARRICADES: A security barricade is meant to prevent access or exit to a specific area, such as a hazardous zone, protection from theft, and forceful entry by terrorist. Security barricades may be designed to withstand assaults such as high speed impacts like a high speed or armoured vehicle. Some of the most important security barriers include: fort walls, the Great Wall of China, Dykes in Holland, Wall dividing East and West Berlin in Germany and quadruped sections on Bombay sea shores.

BERLIN WALL: During the period from 1961 to 1989, East Germany built a barrier to close off the migration after about 2.5 million skilled workers, professionals, and intellectuals to west Germany. This barrier, the Berlin Wall, was first erected on the night of Aug. 12–13, 1961. The original wall, built of barbed wire and cinder blocks, was subsequently replaced by a series of concrete walls up to 5 mts high, that were topped with barbed wire and guarded with watchtowers, gun emplacements, and mines. By the 1980s this system of walls, electrified fences, and fortifications extended 45 km through Berlin, dividing the two parts of the city, and extended a further 120 km around West Berlin, separating it from the rest of East Germany.

The Berlin Wall came to symbolize the Cold War's division of East from West Germany and of eastern from western Europe. Yet, about 5,000 East Germans managed to cross the Berlin Wall (by various means) and reach West Berlin safely, while another 5,000 were captured by East German authorities in the attempt and 191 more were killed during the actual crossing of the wall.

During October 1989 during the wave of democratization swept through eastern Europe and on November 9 the East German government had to open the country's borders with West Germany (including West Berlin). East Germans could travel freely now to the West.

BARRICADES FOR VEHICLE CONTROL: Guard rails are used to prevent vehicles from veering off a road into oncoming traffic, crashing against solid objects (like a bridge pillar) or falling into a ravine. Guard rails are designed with an objective to keep the vehicle upright while it is deflected along the guard rail. Vehicle barriers are generally taller than ½ the diameter of the wheel. A tall guard rail of ideal height for a car, though may not keep a truck from toppling over it, whereas a thin vehicle like a motorbike may slip under a high rail. Vehicle barriers on bridge sides, auto-ways, should be capable of resisting (strength) and deflecting (shape) the impact of cars, lorries, etc.

One-way streets and gates have small stepped fall at entry points to prevent exit of the vehicles. Wharfs, boats and ships use rubber buffers or tyres as preventive barriers against impact and rubbing.

BARRICADES FOR OPENINGS: Barricades are required in openings like Doors, Windows, Gaps, etc. These are required for fall related hazards and for controlling the entry or exit of human beings, animals, pets, flies and insects, and mosquitoes. Barriers are also required for environmental controls, such as heat, solar radiation, breezes, odours, audio. Barriers such as the louvres are required in openings to control vision in and out.

Barricades for a fall-related hazard are required if the sill level is lower than height required for a balustrade in a similar position. Barricades are also required if a piece of furniture against an opening like a window is likely to reduce the effective sill level. Barricades within the doors are required in nursery areas, stair ways, etc. where infants are likely to crawl.

TAPE OR ROPE BARRICADES: Cloth, plastic or fibre tapes and ropes are used as a visual boundary or indicative barrier by police and military to isolate sensitive zones.

3.1.3 ENVIRONMENTAL BARRICADES

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Keywords: aspects of environment affect simultaneously / composite systems / WIND BARRICADES / deflect the direction / diffuse the velocity / natural terrain / man-made formations / Projections / wind catcher ducts / terrace parapets / SUN SHADING BARRICADES / vertical or horizontal / inclined positions / dual shading / Brise de soleil / RADIATION BARRICADES / Natural radiation barricades / Man made radiation barricades / NOISE CONTROL BARRICADES / stage podiums / parabolic overhangs / background noise / contoured planes to deflect / low density surfaces treatments, baffles or cavities / frequency generators / sound attenuation / BARRICADES IN TOILETS AND OTHER UTILITY AREAS / shower over-sprays.

Different aspects of environment affect simultaneously, and so a variety of barrier systems are required. Environmental barriers are often composite systems serving many different purposes.

WIND BARRICADES: Wind barricades are used on regular heavy wind as well as storm prone locations, such as sea fronts, valleys etc. to deflect the direction and diffuse the velocity of the breeze. These barricades primarily depend on the quality of natural 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 flow of winds in the buildings. The breeze is also diverted to 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. Louvred doors and windows control the breeze.

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

RADIATION BARRICADES: 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.

NOISE CONTROL BARRICADES: These are created against super highways, railway tracks, airport runways, open mines, stone crushing plants and sites with pile drivers. These 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 auditoria 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.

BARRICADES IN TOILETS AND OTHER UTILITY AREAS: Barricades in toilets are required to curtail the shower over-sprays. Barriers are also placed besides WCs, bathing areas and toilets for isolation.

3.1.4 RAILINGS AND PARAPETS

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Keywords: rail / opaque structure of masonry / height related hazards / architectonic element / resting the hands / RAILINGS / top rail / hand rail / foot rail / mid rails / PARAPETS / coping / corbel / embattled parapets / perforated parapets / panelled parapets / curbs / vehicle parapets / projections and depressions / vehicular impacts / parapets for railway bridges.

Railings and parapets serve many common functions. It is their nature of construction that places them in separate categories. Railings are lattice type barricades built from rails. A rail can be defined as any long member, usually of round section, fixed to posts. A parapet is usually an opaque structure of masonry but could have members like balustrades. Railings and parapets have been used as architectonic element, and placed against height related hazards. Railings and parapets are invariably smaller than the human height, because most such elements are used for resting the hands on it.

RAILINGS: Railings are placed: on sides of stairs, ramps, escalators, at the edges of terraces, balconies, to demarcate zones, to segregate movement channels, to regulate queuing people, as barricade for animals, and to prevent crawling infants and children from moving into unprotected areas. Railings are placed on inclined or slippery floors to prevent slip-fall. Railings are placed in vast grounds for people or groups to anchor themselves. Railings have posts, a top rail for holding -the hand rail, a rail for foot -the foot rail, and mid rails.

PARAPETS: Parapets are upward extensions of the wall, sometimes with a coping at the top and corbel below. Parapets have other sub elements such as: hand rail, Baluster or balustrade, banisters, volute, turn out, gooseneck, rosettes, easing, starting easing, over easing, core rail, newels, fillets, tandem caps, colonnettes. Parapets may be plain, embattled, perforated or panelled. Embattled parapets are placed on fort walls, are sometimes panelled, but have but pierce for styling, view beyond and for throwing defensive projectiles. Perforated parapets are pierced in various shapes such as circles, trefoils, quarter-foils. Panelled parapets are ornamented by a series of oblong or square panels. Parapets are placed at floor and terrace edges, sides of stairs, ladders, ramps, escalators, near wells, tanks and other water bodies.

Parapets are also used for deflecting winds, provide privacy to floor level activities, add weight to the edge to prevent liftoff forces. Parapets serve many other purposes, besides protection, such as: to shield a view, as a noise barrier, barriers against splashes of stormwater, missiles or flying objects. Parapets are often inevitable structural component (functioning as a beam) along the edge of a bridge or similar structures. Parapets that are small in size are called curbs. Curbs are also used as dividers.

The word Parapet comes from the Italian parapetto (parare = to cover/defend and petto =breast). The German term Brustwehr has the same significance. Building Act of 1707 in London banned projected wooden eaves on buildings to reduce fire risks, and instead 450 mm thick brick parapets with the roof set behind were made mandatory. This was continued in many Georgian houses, as it gave the appearance of a flat roof which accorded the classical proportions.

Vehicle parapets on traffic face must be free of projections and depressions. Longitudinal rails must be placed on the traffic side over the supporting posts and present a smooth face to traffic free from sharp edges, except at joints in longitudinal direction. Even here all projections or depressions must not exceed 20 mm. The range of possible vehicular impacts onto a parapet is extremely large in terms of vehicle type, approach angle, speed and other road conditions. The performance of a parapet is defined in terms of containment level based on a standardised impact configuration. Parapets for Railway overbridge must have a minimum height of 1800 mm.

The building act of 1707 in London and other towns of England banned the projected wooden eaves to prevent spread of fire along the wall, to the roof structure. A 18" thick parapet was required and the roof edge was set back. The roof was set back little more to provide drainage of rain water. The parapet which was completely absent in earlier houses began to be treated by crenellation. (During medieval ages, provision of crenelles required permission.) The parapet style was continued in Georgian houses giving an appearance of a flat edge roof. The parapets over the roofs were made taller, shaped, decorated and pierced.

3.1.5 FENCES

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Keywords: fences of vegetation / timber fencings / chainlink fence / hurricane fences / white picket fence / turf / barbed wire fencing / woven wire fences / expanded metal lattices / electrified fences / fence wire / barbs / straight head, inward or outward bend / extended coil of barbed wire / concentration camps.

Fences are barriers to confine or exclude people or animals, to define boundaries, or to decorate. Fences of vegetation such as plants, hedges, climbers, cactus and dry thorny shrubs are used in farms and fields. Timber, earth, stone, and metals are widely used for fencing. In 19^thC North America, many varieties of timber fencings were developed, such as the split rail laid zigzag, the post rail, and the picket. Other common fences are chainlink fence, hurricane fences, and white picket fences. In comparatively low rainfall areas like East Europe and in W. USA, turf was dumped to create fences.

The first patents on barbed wire fencings 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. Electrified 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 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 cable provides extra strength and permits contraction and expansion without breakage. Barbs are diagonally cut in order to provide sharper points; they may consist of one or two pieces (two or four points) and are generally spaced at intervals of 100 to 130 mm.

Barbed wire fences have straight head, inward or outward bend at the top to make the crossover difficult. Armed forces place extended coils of barbed wire on ground without any posts. During world war II barbed wire fence posts were spiked to prevent air craft landing. Hitler’s concentration camps are grim-reminder of fencing used for forceful confinement. 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 put up barbed wire fences to demarcate boundaries, as it provides a cheap and fast way of erection.

3.1.6 GUARD RAILS

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Keywords: strong band / guard rails in buildings / walkway or footpath along a wall / environmental guard rails.

A guardrail is effectively one strong band (long metal strips tied together to a support post) that transfers the side force of a veering car to multiple posts beyond the impact area or directly into a ground anchor at the end of the guardrail emplacement. A guard rail is a system designed to keep people or vehicles from (in most cases unintentionally) straying into dangerous or off-limits areas. A secondary objective is to keep the vehicle upright while it is deflected along the guardrail. This is rather difficult to achieve as a guardrail of the ideal height for a car might not keep a truck from toppling over it, while a motorbike might slip under a higher-placed rail. Guard rails are likely to cause many motor able, as this has to face many different conditions. So transportation engineers are increasingly discourage the use of a guardrail, for the guardrail should only be placed when the roadside conditions pose a greater threat than the guardrail itself.

A guard rail is more restrictive than a hand rail as the former provides both support and the protective limitation of a boundary.

Guard rails in buildings are of numerous types, and are required by building codes in many circumstances. A walkway or footpath along a wall works as a guard against vehicles striking or rubbing a building. Guard rails serve both architectural and environmental functions.

On roads with sumps and causeways which get flooded over in seasonal storms require guide rails or posts to indicate the width of the motor able or safe passage width. This rails or vertical posts are height marked so that depth of the flooding water can be seen.

Environmental guard rails are placed along hiking trails, where adjacent terrain is often steep and un-travelable, along trails at scenic overlooks, and also at many elevated destinations of trails.

Guardrails are also included beneath the high sides of heavy vehicles such as lorries. This is in order to prevent smaller vehicles (e.g. cars) from passing between the lorry's front and rear wheels during a collision, and being crushed subsequently by the lorry's rear wheels.

3.1.7 HAND RAILS

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Keywords: topmost component / guide rail / psychological support / decorative function / wall hand rail gripping element / inclined or slippery floor / high winds and storms / top hand rail / guiding / extra widths and higher height for supporting the elbow / sectional shape / Standards for hand rail design / lateral stability / joins pieces / noncontinuous / continuous / over-the-post and besides the post / post-to-post and newel-to-newel / discourage the usage / wider surfaces / bar stools’ foot rests.

A hand rail is the topmost component of barricade systems like parapet or railing. Hand rails, without the barricade system, are provided in hotel lobbies, corridors, passages. Since no height related or other hazards are operative in such areas, the hand rail functions as guide rail. A hand rail on its own is less protective as a barricade but provides psychological support (assurance) for the hand and body. In this sense it has only a decorative function.

A wall hand rail is used as gripping element, for travel along inclined or a slippery floor. Wall hand rails are required in toilets to change the posture. Hand rails are also provided on ships, sail boats and railway engines for holding in high winds and storms. Hand rails are heated or cooled by water circulation depending on the external conditions. Top hand rails are used in buses and metro trains for commuters to stand. Top hand rails also have hangers for grabbing. Hand rails are also used for guiding visually impaired persons in horizontal movement. A hand rail is the uppermost section of a barricade and so it is used for standing against it, for resting hands or spreading elbows or for gripping. Hand rails are provided with extra widths and higher height for supporting the elbow. For hand support and gripping appropriate sectional shape is required for the hand rail.

Standards for hand rail design are:

A handrail is defined as either a circular cross section with an outside diameter of 32 mm minimum and 50 mm maximum, or a non-circular cross section with a perimeter dimension of 100 mm minimum and 160 mm maximum, and a cross section dimension of 57 mm maximum. For a handrail with a perimeter dimension greater than 160 mm, a graspable finger recess area is to be provided on both sides of the profile. Handrails are located at a height between 860 mm and 960 mm. In areas where children use the facility, a second set of handrails at a maximum height of 710 mm (as measured from the ramp surface or stair nosing to the top of the gripping surface) is necessary. Sufficient vertical clearance between primary and secondary handrails should be minimum 230 mm to prevent entrapment of children. The distance between the wall and handrail is very important. Common requirements are between 38 and 57 mm.

A handrail on one side of a stairway is always necessary, (even where both sides are walls) and on both sides, if the stairway is more than 1000 mm wide. All stairways, balconies and certain other areas above ground level which are likely to be used for other than just maintenance, must also have a balustrade or guard. With a wide balustrade the actual or the effective width of a stair, balcony or passage is reduced. The clear unobstructed width between a wall face and the internal face of a balustrade or between two internal faces of handrails is considered as an allowable passage.

A handrail serves many other functions, it often provides a lateral stability to the barricade and joins pieces of barricade into a functional whole. Hand rails used for supporting the body may be designed to be noncontinuous, but hand rails used for horizontal movement such as in stairs, ramps, escalators, walkways etc. must be continuous. Continuous handrails are called: over-the-post and besides the post, and noncontinuous handrails are called post-to-post and newel-to-newel.

Positions or building elements that are likely to be used as a hand rail are treated to prevent such a purpose. Spikes, sharp knife edge section, sloped top face, coating with non drying (green or ever-wet) paints etc. are some of the means used to discourage the usage. However wider surfaces are provided to support planters and cut off the view of areas immediately close-below. Some handrails also have foot rails that are similar to Bar stools‘ foot rests.

3.1.8 COMPONENTS OF RAILINGS AND PARAPETS

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Keywords: PANELLED PARAPETS / PERFORATED PARAPETS / EMBATTLED PARAPETS / POST AND RAIL PARAPETS / Stupa at Sanchi / American colonists / Indian Railways / MACHICOLATION / floor openings / CRENELS / merlons / EMBRASURE / BATTLEMENT / NEWEL / hollow newel construction / picket / structural supports / half newel / decorative newel drop / tandem caps / quarter-turn caps / BANISTER / VOLUTE / turnout / GOOSENECK / ROSETTE / half newel / EASING / starting easing / over easing / CORE RAIL / BALUSTER / balustrade / guards or spindles / second baluster / window balustrade / quattrocento balustrades / BASE-RAIL OR SHOE-RAIL / FILLET / fillet.

PANELLED PARAPETS: Panelled parapets are made of panels fixed at the top and bottom or as in-fill element between newels and banisters. The panels are ornamented by a carving, relief engraving or are pierced.

PERFORATED PARAPETS: Perforated parapets are latticed structures to restrict view and allow the breeze to pass through. It is also a technique of reducing the dead weight if the parapet over cantilevered structures.

EMBATTLED PARAPETS: Embattled parapets were part of battlements on fort walls with provision of apertures for viewing and throwing objects over the invaders. The same pattern was adopted as a roof parapet decoration of large villas.

POST AND RAIL PARAPETS: These are created with wood or bamboos. In India Stupa at Sanchi has circumscribing stone parapets emulating the wood work. American colonists used local wood to demarcate their lands and for creating cattle yards. Indian Railways use their old wooden sleepers and steel rails for creating such barricades.

MACHICOLATION: A parapet over a projection like brackets, with floor openings through which molten lead, pitch, oil or stones could be poured over the enemy.

CRENELS: Crenels or crenelles are alternating low portions in a parapet of a wall or battlement. The high portions are called merlons. Battlements have crenels to look out and merlons to throw arrows.

EMBRASURE: An opening between two merlons in a parapet (battlement).

BATTLEMENT: The battlement was an early development in military architecture. It was used in Chaldea, Egypt, prehistoric Greece, and Roman fortifications. During the European middle ages the battlements saw greatest development. The crenels became narrower and were splayed on outer sides for wider view. The merlons were rounded or flat at the top. The medieval battlement was often bracketed out from the face of the wall, machicolations, with holes in the floor drop objects over invaders.

NEWEL: A newel was the central post of a spiral or circular stairway, and if such a stairway has no central post, it is said to be of hollow-newel construction. A newel is a large picket or post that supports a handrail of a stair at the starting point or its landing. Newels are also used to support handrails in balconies, etc. Newels are structural supports, and so are anchored very well to the floors. A half-newel is used where a railing ends at the wall. For open landings, a newel may extend below the landing for a decorative newel drop. Newels projecting above the handrails are covered with tandem caps. At corners, there are quarter-turn caps. For post-to-post systems, the newels generally project above the handrails.

BANISTER: The term banister means the vertical mid supports and the handrail, or just either of it.

VOLUTE: A volute is the end of a handrail that is shaped like a spiral in a horizontal plane. A turnout is a quarter-turn rounded spiral at the end of a handrail.

GOOSENECK: The section between sloped handrail of the lower flight, and another sloped handrail of the upper flight of a stair.

ROSETTE: Where the handrail ends in the wall, and if a half-newel is not used, the hand rail is trimmed by a rosette.

EASING: Hand rails that are mounted directly onto a wall with brackets. At the bottom of a stair if such a railing flares to a horizontal railing, the horizontal portion is called the starting easing. At the top of a stair, the horizontal portion of the railing is called over easing.

CORE RAIL: Wood handrails often have a metal core to provide extra strength and stiffness, especially when the rail has to curve against the grain of the wood. The term for such reinforcing metal core is the core rail.

BALUSTER: A baluster is a moulded shaft, square or circular, traditionally in stone or wood, sometimes in metal, and now in plastics, supporting the coping of a parapet or the handrail of a staircase, an assemblage of them being known as a balustrade. Balusters are vertical mid pickets or members that hold the handrail. Sometimes these are made on turning lathes so-called guards or spindles. A nominal tread width, often require two balusters. The second baluster in such cases is closer to the riser and is taller than the first. The extra height of the second baluster is achieved by spacing at the middle, the decorative elements in the baluster. This allows the bottom decorative elements to be aligned with the tread, and the top elements are aligned with the railing angle. However, this means the first and second balusters are not interchangeable and must be manufactured separately. However balusters without decorative elements or with flutes or spirals’ pattern can be interchanged.

Building codes also require that opening within balusters be of a size such that a 4" (100 mm) sphere cannot pass. There are three exceptions according to the 2003 International Building Code Section 1012.3, which allow openings to not exceed 8" or 21" depending on occupancy groups or special areas.

The word Baluster = balaustra = pomegranate flower, from its resemblance to the post. French = balustre, Italian =balaustro, Latin =balaustium, Greek= balaustion.

The earliest examples of balusters are from bas reliefs on Assyrian palaces, where these are shown as window balustrades and had Ionic capitals. Though Greeks0 or the Romans have not used balusters. Balusters have been extensively used in 15^thC balconies of palaces at Venice and Verona. These quattrocento balustrades were descendants of unknown Gothic precedents. Giuliano da Sangallo is credited with using it consistently on the terrace at the Medici villa at Poggio a Caiano (1480 AD).Two types of balusters were used: one favoured by Michelangelo -symmetrical in the profile: inverted one bulbous vase shape over another, separating them with a cushion like torus or a concave ring. The other was a simple vase shape. The style of a baluster is often a method of dating the antique furniture or architectural details. For example, the distinctive twist designs of balusters in oak furniture are a characteristic mark of early 17^th C period of the Charles I in England. The modern term baluster shaft is also applied to the shaft dividing a window in Saxon architecture. In the south transept of the abbey at St Albans, England have some of these shafts, and are presumed to have been taken from the old Saxon church. Norman bases and capitals have been added, together with plain, cylindrical Norman shafts.

BASE-RAIL OR SHOE-RAIL: For systems where the baluster does not start at the tread, they go to a base rail. This allows for identical balusters, avoiding the second baluster problem.

FILLET: A fillet is a decorative filler piece on the floor between balusters on a balcony railing. Fillets also become panels or inserts between balusters. Often panels are edge to edge joined to form a larger surface. Modern stairs have such in-fill panel members of wood, veneer, plywood, metal, plastic sheets and glass panes. A glazed or glass fillet must be of glass blocks, toughened glass or laminated safety glass, but annealed wire glass must not be used.

3.1.9 MATERIALS FOR BARRICADES

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Keywords: stone and brick masonry / wooden casks of wine / concrete / Metal / plastics and composites / ropes wires, woven tapes and plastic tapes / barricades for public gatherings / cycle stand barricades / non rupturing plastic bags / nets.

Barricades are constructed out of a variety of materials depending upon their projected use, the degree of stability and permanence required:

Stone and brick masonry structures were once very common, wood barricades were first created by placing wooden casks of wine. Concrete is preferred choice for barriers in out door public spaces due to their capacity to withstand high impact, climatic conditions and stability. Metal barricades of coated mild steel and stainless steel in cast forms and geometric fabrications of drawn sections (including pipes and structural) and sheet metal formations, are widely used because of their light weight, ease of installation and ease of replacement. Barricades of plastics and composites have the advantage of being very lightweight, non hurting on impact, transportable, and high quality finishes including colour, night reflectivity -fluorescence. Plastic barricades are used in sporting events, fairs, amusement parks and festivals. Ropes, wires, woven tapes and plastic tapes are also used to create a visual boundary or symbolic barricades. Light beams, air curtains, water jets are some of the modern day innovations.

Barricades are effective through their shape, as much as they are through the materials of construction, and the terrain. RCC castings of variety of shapes and sizes are used as barricades.

Barricades for public gatherings have to be transportable and stable against heavy pushing by crowds. This are often called cycle stand barricades, due to the similarity of stable structure. Non rupturing plastic bags filled with water are used as barricades. Nets are stretched against building under construction to prevent accidents due to fall.

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4.0 OPENING SYSTEMS

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CHAPTER 4.0 INDEX

4.0.1 Nature of Openings

4.0.2 Types of Openings

4.0.3 Expression of Openings

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4.0.1 NATURE OF OPENINGS

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Keywords: NATURE OF OPENINGS / continuous entities / openings / junction / barrier system / domain defining elements / subordinated or minor systems / Japanese Gate Torii / eaves / Sanchi Stupa Gate / bands of eaves / toran / rounded arch / pointed arch / eaves is the essence of opening / the sides also mark an opening / metaphysical intervening element / connection / relationship / linkage / trade gateway / eaves and sides / formal opening system / marks a point of exchange with other domains / landmark a domain / power of domain / focus / links / nodes / gateways / linked openings / RELEVANCE OF OPENINGS / SCALE OF OPENINGS / finite size / small opening / large opening / multiple openings / significance of a small opening / contrasting scale / re-scaling / a large window / lites / ganged or multiple doors / wider but controlled opening / openings are spaced out / openings are concentrated or grouped / image projection / large opening means / smaller and fewer openings / large window vs small window / LEVEL OF OPENINGS / negotiable for egress / transit-able in emergency / french window / trapdoor or hatch door / barn door / warehouse gantry girder / high sill / low or zero sill / upper floor windows / THIRD DIMENSION OF OPENINGS / dual character / third facet / depth of the junction / threshold / real or notional / interim space or time / DESIGNING OPENINGS / basic design considerations / key issues for openings in buildings / devices / nature of relationships between spatial domains.

NATURE OF OPENINGS: Barriers are continuous entities, but can be experienced only through the openings within them, and at the junction formed by the end of one barrier and start of another barrier.

Doors, windows, gates, gateways, etc. are openings within a barrier system. These occur within domain defining elements such as: walls, fencings, fort walls, enclosures, partitions, dividers. Such opening systems are subordinated or minor systems as these must occur within a barrier system.

Openings often occur without the inevitable mothering barrier system. Japanese Gate Torii is placed alone anywhere in ‘wilderness’, in the middle of sea. According to the Japanese mythology, the essence of gate comes into being through the eaves. Torii is a metaphoric gate, formed by head bands, the ‘eaves’. The eaves need physical side supports, which are placed as minor elements of the Torii gate structure. The Sanchi Stupa Gate also has three emphatic horizontal bands of eaves, but placed over singular supports. The Toran, buntings, streamers, banners, all are forms of the eaves, and so constitute a gate. The head structure or lintel of an opening system is the place to mark gate deities and signs. The round arch can be considered as a relief to the ponderous horizontal lintel or the eaves. The pointed arch of the Gothic era relieves the opening more.

If the eaves are the essence of an opening, conversely, the sides, also mark an opening. Two posts alone, without any eaves, a head structure or a shutter can create an opening or gate. Set of parallel elements also define an opening. The twin elements are perceptually or conceptually linked by a metaphysical intervening element, that manifest a connection, a relationship or linkage. Petronas Towers, World Trade Centre twin towers, Brazil, electric transmission towers or pylons create gate like effect. Valleys between mountains provide a negotiable zone like a pass, the trough, gorge, etc. which are called gateways. Afghan valleys are considered the gateway to India. Suez Canal is considered a trade gateway to Europe. Silk Route opens a window to China.

The eaves and sides, both on their own, and all together create openings. In any formal opening system both are present. When one is absent or minor the openings tend to be notional.

An opening marks a point of exchange with other domains. Openings or such notional formations are placed to landmark a domain. Commemorative archways, Gateways, plaques, obelisks, pillars, moats, etc. not only denote the power of a domain, but also its focus.

Bridges, pathways, avenues etc. are links joining two points. Such links regulate the exchange occurring through them, so are considered gates. The ports, wharfs, moorings, runways of airports, plug-sockets, are nodes of connectivity and exchange. The nodes are gates. Computer nodes, the Gateways (a device or system that intervenes to provide an exchange) are linked openings.

RELEVANCE OF OPENINGS: Opening systems are also ineffective in transparent, obstructed or frequently interrupted (broken - discontinuous) barriers. A room with a lattice wall all around or a glass cabin has no need for a window. An open pavilion has no need for any door.

SCALE OF OPENINGS: An opening has finite 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.

A Small opening makes a barrier system very evident, whereas a large opening or multiple openings make barriers less effective. Significance of a small opening is due to the contrasting scale against the barrier system within which it occurs. 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 funnelling, filtration for selective processing acceleration and de-acceleration mechanisms. 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 wide doors to meet the functional carriage width, but are inserted with small openings for other uses. 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.

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.

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. A wall, the barrier system mothering the opening traditionally has been massive, but more insulating for radiation, so fewer openings disrupt a wall less.

LEVEL 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.

THIRD DIMENSION OF OPENINGS: All Opening systems have dual character: an inside and an outside one. But very often a third facet is recognised as the depth of the junction (cross section of the opening). Here the significant elements are: the thickness (or the duration of transiting through) of the barrier system, and the configuration of the opening system. The third facet or the dimension of the opening systems is the threshold. A threshold has two distinct worlds on either of the sides, one or both of which could be real or notional. A threshold could also be factual or abstract depending on the real or notional worlds across it. The threshold areas are resting zones, zone for transition, point of decision making, celebration, welcome or separation. The third facet however manifests from what happen in the interim space or time. Changes occur to things that pass through, such as filtration, elimination, mixing, alignment etc. Some of these changes are passive, but many use energy. A window airconditioner, air cooler, exhaust fans, enforces a change. Depth of the door or windows regulates the pattern of illumination and field of view. (For more on thresholds : see 4.1 Openings systems : Doors )

DESIGNING OPENINGS: Basic design considerations for an opening system are: width, height, depth, form (shape, configurations) and position (in the surroundings, angles, orientation). Key issues for openings in buildings are: the massing of openings, the relative size and position in reference to other openings, the contrast it creates against the surface of the barrier system, its height position in reference to eye level, adjoining terrains, ergonomic parameters, etc.

The openings in buildings are placed for the pattern, compositions, for scaling and proportioning, endowing graphical character, for reflecting styles, cultural ethos, religion and such other affinities and identities.

Openings are devices for allowing or restricting the sunlight, air, sounds, privacy and for framing the view of the outside. As a device openings have inbuilt systems to modify the elements transiting through it, such as air, moisture, dust particles, ion charge etc.

An opening in a barrier system primarily connects two distinct worlds, but their own presence assumes many different guises. An opening becomes a medium of investing the nature of relationship between spatial domains.

4.0.2 TYPES OF OPENINGS

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Keywords: CLASSES OF OPENINGS / touch the floor / higher sil level / gates and gateways / micro size openings / single function systems / fixed glazing / picture window / shop front windows / space dividers as partitions / computer gateways and ports / hub / protocol, converters and translators / universal architectural system / standard range of options / strict exterior architectural regimen / users / ELEMENTS OF OPENINGS / surrounds / parallel to the ground / perpendicular / head formations / foot entities , side members / fixed openings / hung shutter system / sliding shutter system / architectural aperture / pivots / architectural elements / hinges / sliding channels / wooden frames / Georgian sash windows / aluminium / integrated into the structural fabric.

CLASSES OF OPENINGS: There are two classes of openings in terms of their basic functions: Openings that touch the floor on one or both sides to facilitate floor level movement goods, people and animals; and Openings placed at higher sill level -away from the nominal floor level, and chiefly used for seeking illumination, view and ventilation. At other level gates and gateways besides serving the basic functions of door are used for grandiose. Micro size openings such as cracks or crevices of joints provide minor ventilation needs. Openings are designed as single function systems such as terrace level wind catchers, pip holes, delivery slots, etc.

Openings of fixed glazing serve the function of picture window framing a scenery or shop front windows to display items. Fixed openings also become space dividers as partitions or cover element like a curtain wall. Computer gateways and ports (air, sea, land) serve as a hub for transit, termination and re-connection. At this point one can have choice how, where, when a connection could be made. To provide such choices, the hubs are endowed with protocols, convertors or translators.

As opening is a very universal architectural system. Openings are often mass produced with standard range of options. The openings follow a very strict exterior architectural regimen without consideration of the interior use related needs. For the above two reasons openings of same size, shape and design are used on all orientations, floor levels, neighbourhood conditions and geographic locations. Users wish to mark the openings’ system with individual personality, cultural ethos, beliefs, affinities etc. These occur as appendages, add-ons or treatments.

ELEMENTS OF OPENINGS: A openings is formed by its surrounds. Surrounds are participating elements or just notional or casual elements that form the opening. The participating surrounds are either parallel to the ground defying the gravity or perpendicular following the gravity. Eaves, lintels, arches are head formations, ledges; floors and thresholds are foot entities; and jambs, ‘surrounds’ stiles etc. constitute the side members.

In case of fixed openings all sides are of equal importance, except the bottom one which may carry the load to the gravity. All sides ‘hold’ the glazing or panelling and provide sealing overlap. However, in case of hung shutter system, one side is used for fixing but in sliding shutter systems either the horizontal or vertical pair houses the channel for movement.

Primitive opening systems have no surround system, the shutter operates in the architectural aperture. But evolved systems the shutter is housed in a frame which in turn is fixed in the structural gap. The surround initially was a an overlap to seal the edges and restrict the shutter opening in one direction only. The shutters, if any were hung through pivots inserted in architectural elements. However, the pivots were difficult to insert, repair or replace, making way for development of hinges and to a small extent sliding channels. The other end of hinges could not be fixed to architectural element like masonry wall. Wooden frames became the unavoidable component of the opening systems. The Georgian sash windows used the sliding channel to avoid the problems associated with hinges. During industrial revolution era steel began to replace wood, and by mid 20^th C Aluminium became the favourite material for opening design. The frame, which was unavoidable component of the openings began to be integrated into the structure system in the form of curtain wall. The opening system and its surrounds all were well integrated into the structural fabric of the building.

4.0.3 EXPRESSION OF OPENINGS

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Keywords: EXPRESSION OF OPENING / descriptions, metaphorical expressions and as metaphysical entities / architectural, functional and visual interests / metaphorically / transition from one state of existence to another / metaphysically a triad: an inside, outside and as in-between / of being on one or the other side / being into neither of the two / third reality is the threshold / opening is like dream or thought / OPENINGS FRAME A VIEW / surreal / staging qualities / art, architecture and performing arts settings / foreshortening / C. Riley Auge / J. R. R. Tolkien treatments of doorways, gates, windows, and natural thresholds / constructs / physical boundaries / psychological transition points / point of transgression.

EXPRESSION OF OPENING: In literature openings occur as descriptions, metaphorical expressions and as metaphysical entities. As description, the opening systems occur as entities with architectural, functional and visual interests. Metaphorically an opening is a change. Doors, gates, windows, and other openings express the transition from one state of existence to another. Likewise passageways, bridges, ducts, also serve the function of transition. An opening is a line where the change occurs and the bridges lead a path to or away from such a line. The point of transition is a mark up, a demarcation. Metaphysically the opening constitutes a triad: an inside, outside and as in-between. The construct is a 3-way experience, of being on one or the other side and the state, or of being into neither of the two. The third reality is the threshold, the zone of indecision for some. The paired reality of inside and outside, or existing on one side vs. the other side creates a threshold or an edge. To stand upon the threshold allow time and space for contemplation before committing to circumstances, because the action once undertaken may not be undone. An opening is a relief from the enclosure or very constricting situation. It is a way to fulfill the expected, and a venture for the unexpected. The opening is like a dream or thought, so thin and efferent that one often does not realize if it is real or ethereal.

OPENINGS FRAME A VIEW: The framed view is available so far one is little away on either of the sides, but same frame gets dissolved when one reaches the threshold. The frame losses its arresting or picturesque quality when viewed in a wider context that is a very wide opening encountered very closely. An opening without any apparent framing seems surreal, as much as an opening that is without its adjacent wall or barricade. Both these staging qualities are used in art, architecture and performing arts settings. The framing provides a scale reference, but the third dimension of depth, remains ambiguous due to the foreshortening.

A change manifests on passing through an opening physically, through the depiction or psychical referencing. Architectural entities are three-dimensional constructs and so provide a time and space intervention. The inside or the womb is the origin, so human endeavours continue to revert there. The connecting thread or unbiblical chord continues to retract one to the inside, the womb.

‘Often crossing a threshold, real or implied, moves us between safety of the known and anxiety of the unknown. Thus, working on literal and symbolic levels simultaneously, doors and other passageways can provide, both, the physical reality of protection and represent the psychological idea of safety. Additionally, as 3-dimensional constructions, openings allow not only the dualistic reality of inside and outside, but also the possibility to exist within—being neither in nor out. Once one crosses the threshold, there is no going back to what was’.

‘Likewise, the psychological threshold provides an inner space for struggling with indecision, fear, and courage before passing into the unknown. The resulting experience changes forever (for good or ill) whoever crosses the threshold’. -‘Crossing the Threshold: Doors and Other Passageways in Tolkien’s Words and Images By C. Riley Auge`

J. R. R. Tolkien used doors, gates, and other passageways extensively and deliberately throughout both his literary and artistic works to explore and express these very ideas. In fact, many of his descriptions and treatments of doorways, gates, windows, and natural thresholds were worked and reworked numerous times in sketches and paintings before finalizing them within his written texts. Even in his landscape sketches, the focal point is almost always a doorway or other opening. Regardless of medium, the importance Tolkien placed upon these constructs, whether as physical boundaries or as psychological transition points (or both), is overwhelming when one closely examines collections of his artwork, The Hobbit, The Lord of the Rings, and The Silmarillion.

A barrier separates one from what is beyond. It provides a zone where one has survived and will continue to do so eternally. The safe environment perpetuates the identity of the habitant and ‘its perception of the macrocosm unquestioned’. The edge of the barrier is the demarcation which when transgressed a new perspective is available. The point of transgression is the door or opening. Openings within the barriers like doors are the frames within which context the change is referenced. ‘The Sun god arrives through the Eastern gate and the past is always bounded by the door like the fake door of the Egyptian tombs.’ The fake door exists in spite of the knowledge that the dead will never return and the door will remain unused.

(For more refer to 4.1.9.2 Door Myths and Legends).

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4.1 OPENING SYSTEMS : DOORS

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CHAPTER 4.1 INDEX

4.1.0 Doors : general

4.1.1.1 Historical perspective : Doors

4.1.1.2 Historical perspective : Doors -Types

4.1.1.3 Historical perspective : Doors -Periods

4.1.2.1 Components of Doors

4.1.2.2 Materials and Technologies

4.1.2.3 Hardware

4.1.2.3.1 Basic Hardware

4.1.2.3.2 Secondary Hardware

4.1.2.3.3 Appendages and Attachments

4.1.2.4 Door Mechanisms

4.1.3.1 Door Styles

4.1.3.2 Commercial Categories of Doors

4.1.3.3 Varieties of Doors

4.1.3.4 Other types of Doors

4.1.3.5 Door like Utilities

4.1.4.1 Door like Presences

4.1.4.2 Real and Pseudo Doors

4.1.5.1 Door Sizes and Proportions

4.1.5.2 Doors Functional Sizes

4.1.6.1 Door Opening’s Structures

4.1.6.2 Door Openings in Thick and Thin Walls

4.1.7.1 Doors and Vastu Shastra

4.1.8.0 Functions of Doors

4.1.8.1 Illumination

4.1.8.2 Ventilation

4.1.8.3 Passage and Control

4.1.8.4 Safety and Security

4.1.8.5 Insulation

4.1.8.6 View through

4.1.8.7 Other Issues

4.1.9.1 Emerging Technologies

4.1.9.2 Door Myths and Legends

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4.1.0 DOORS: GENERAL

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Keywords: opening system / controllable opening / substantive barrier system / poor barrier system / poor door system / a finite size and specific functionality / regulators / Dwar / threshold / kiwad / door as a metaphor / symbolic endowments / forms and situations / allegorical connections / Sun / East / life, joy, brightness / West / false door / door of entrance / birth / door of exit / death.

A door is an opening system in a barrier system. The door as an opening system allows the exchange between the inside and outside, but it is a controllable opening. The need for an opening is very acute in strong barriers. A door comes into being if only a substantive barrier system exists. A poor barrier system, one that is transparent, translucent, broken, or uneven will have equally poor door system. An open pavilion cannot have an effective door system and a glass house or a latticed green house need not have an opaque door.

A door is effective if it is smaller in scale then the mothering barrier system. It can never be larger than the barrier system within which it resides. A door could be almost as large as the barrier system, but when it equals to the size of a barrier system, it loses the identity of a door. A door cannot exist without (or in spite of) a barrier system.

A door has a finite size and specific functionality. Doors serve a basic function of an entrance and exit, and are also regulators of privacy, security, environment, pollution, illumination, noise and fire. Such regulations are done by design, materials of construction, placement, and also by use of variety of fittings and hardware.

Sanskrit word for door is Dwar, which means ‘through which', ‘from', `by'. In Indian mythology the essence of a door is the threshold, here inside and outside, both manifest their differences. In Japan the door is an intervening spatial element -‘torii’ formed by the eaves, the head. Kiwad the hindi-urdu word nominally used for shutter of a door, is kim + wad = territory bounding or a movable barrier.

A door as a metaphor denotes entry, exit, change or transition, a switch, a control, identification, a nomination and intervening element between an enclosure and open or the free cosmos. Doors have symbolic endowments such as ownership, right of way, a new beginning, a portent of change, exit, departure or death. On the other hand certain forms and situations have allegorical connections with doors. Encounters with a different domain are through a door, or conversely a door or its representation marks the focal point of a domain or the section of its edge -the entrance or exit.

Ancient openings were associated with the Sun. The Sun entered from the East and passed out from the West. The East was associated with life, joy and brightness, and the West with darkness, gloom and death. Intaglios Babylonian seals show Sun god passing through a double valved gate of the East, and beginning to climb the mountain of the sky. The Veda says ‘the dawn shone with brilliance and opened for us the doors that are high and wide with their frames’. Even where four sides of a building have openings, it is the East door that is the great door or the gate of sunrise. The great Eastern door of the sun temple at Baalbek, 'city of the sun,' was 21' wide, and 40' high. Tombs in Egypt, Persia and Lycia have on West side a false door that was indicated like a real door. It is low and narrow, framed and decorated like the door of an ordinary house. Door of entrance marks the birth or new beginning and the door of exit marks the death or end of the world. Person with a door has the right of occupation and residence.

4.1.1.1 HISTORICAL PERSPECTIVE: DOORS

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Keywords: fire / social privacy / covering materials / skewed entry positions / monolithic panel / stiles / rails / shitomi / controlled barrier / pivots inserted into lintels and floor pieces / door frame / concealing it or integrating the door frame.

A door has been the most important element after fire for instilling a sense of security against intruders, wild animals and elements of weather. In cold climates keeping the warmth inside, in deserts the sand storms out, and in tropics protection from rainwater is mainly achieved by a door system. Social privacy is also a key factor in design of a door system.

Just as the hearth was the focus of the family, the door denotes a domain, the home. The first doors were plain gaps with additional facility of cover. A variety of covering materials like, hide, fabrics, woven matings, rubble heaps, sticks, wood logs and planks, metal casts, paper, grass and leaves, and stone slabs were used. These were dumped, heaped, hung or placed strategically. Stripes of hides, vines, ropes, animal guts, sticks, etc., were also used to support the cover materials. Skewed entry positions, such as: cliff faces, entwined passages, narrow or low height(crawling) passageways (like igloos of Eskimos), fall-down (pit houses of China) or climb-up (tree houses), etc., have been used to strengthen the functions of doors. From the period of ‘non built’ habitations (cave, open air, etc.) to early Harappan, Egyptian and Mesopotamia architecture, the ‘door’ was a gap that served the purpose of entry, exit and illumination. The earliest record of a door shutter is of a painting in an Egyptian tomb where it is shown to be a monolithic panel of wood. In reality such monolithic panels were technologically not feasible, so Vitruvius writes about doors built with stiles (scapi) and rails (impages), and the spaces enclosed were filled with panels (tympana).

Harappa’s main streets were straight walled with no openings, and all door-like openings were placed in the small side-lanes, passages or court yards. House rooms had entry gaps from such passages and court yards. The ‘doorway’ or gaps were covered with hides, fabrics and woven mats for privacy. The word ‘shitomi’ (Japanese) for the door literally means ‘a small woven mat’ recalling the hanging curtain forms of doors in ancient buildings.

The concept of a door as a controlled barrier with a shutter is only 7000 to 8000 years old. Doors of rigid and permanent materials first appeared with monumental architecture or public buildings. Doors for important chambers were made of wood or stone. All ancient doors of wood or stone were hung by pivots inserted into lintels and floor pieces of hard stones such as basalt, dolerites or granite. In later periods the wood pivots were sheathed in cast bronze.

Early doors had no frames, as these were hung by pivots inserted into the building element. When pivots began to be replaced by hinges, as the efficient hardware, door frames were required for fixing the hinge end. The door now had a doorframe a distinctive element from the masonry surrounds. The door shutters were rarely monolithic, but composed of stiles and insert panels. The framed door, and its panelled shutter, both made the system easy to replace system. In 20^th C once again better masonry or wall making techniques have eliminated the need for a door frame, by concealing it or integrating the door frame.

4.1.1.2 HISTORICAL PERSPECTIVE: DOORS - TYPES

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Keywords: PRIMITIVE DOOR COVERINGS / mat / shutter / WOOD DOORS / Pompeian wooden doors / Chinese wooden door / traditional Indian house doors / Indian palaces and fort doors / STONE DOORS / stone pivots / BRONZE DOORS / cast-bronze grilled doors / cast panels / IRON DOORS / nailing / rivetting / nut-bolting / iron hinges.

PRIMITIVE DOOR COVERINGS: Door coverings were made of reeds, straw, cane bamboos, and stalks as mat, often stiffened at the edge to form a shutter. Such door as cover rolled up or pushed aside, and as shutters were hung through leather, fabric ropes or vine straps. The mat or the shutter was secured in similar fashion. Such doors were mostly used in domestic architecture. For public buildings a formal and stronger door was required.

WOOD DOORS: The most preferred material for making doors, in all geographic locations, in ancient times, was timber. Archaeological and literary evidence indicates its prevalance in Egypt and Mesopotamia. Pompeian wooden doors were made of stiles and rails with in-fill planks or panels, and were equipped with locks and hinges. The Chinese wooden door usually consisted of two panels, the lower one solid and the upper one a wooden lattice backed with paper. The traditional Indian house doors were made of carved shutter frames, but with wood planks forming a backing rather than a panel insert. Indian palaces and forts’ doors were similar in construction.

According to a Chinese legend, a tomb located near the town of Sian and belonging to the first emperor of the Ch'in dynasty (221-206 BC) had a door that could not be cut with iron swords, because the door magnetically attracted the iron. Gates of a palace were also made of magnetic stone so warriors wearing iron armour were attracted and could not move.

King Solomon's temple doors were in olive wood, and besides olive wood, elm, cedar, oak and Cyprus were also used. These doors were carved, and overlaid with gold. The doors mentioned in Homer would appear to have been cased in silver or brass. Besides Olive wood, elm, cedar, oak and cypress were used. This Roman type of door was adopted in Islamic countries. In China the wooden door usually consisted of two panels, the lower one solid and the upper one a wooden lattice backed with paper. The traditional Japanese shoji was a wood-framed, paper-covered sliding panel.

STONE DOORS: Stone doors were used for tombs and such other sparingly to be opened buildings. The stone doors were heavy and like many other door systems of the time had stone pivots. In later periods stone doors with cast bronze pivots were also used. Stone doors do not accept add-on materials easily. Adding a bronze pivot was extremely difficult. Bronze, wood and steel were easy to include in a composition.

Stone doors have been found at Kuffeir near Bostra in Syria. Burckhardt found stone doors, 9 to 10 ft. high, as the entrance doors of the town. In Etruria many stone doors are referred to by Dennis. In Hauran in Syria, where timber is scarce, the doors were made in stone, and one measuring 5 ft. 4 in. by 2 ft. 7 in. is in the British Museum; the band on the meeting stile shows that it was one of the leaves of a double door.

BRONZE DOORS: Greek temples and Roman buildings had solid doors or cast-bronze grilled doors. Later bronze doors began to be made across Europe and parts of Asia, but by that time the art had died out in Rome. Cast bronze doors, as a tradition continued in Europe till middle ages. Later cast panels with patterns in relief made from a combination bronze, cast steel, and wood were used for assembling larger size doors.

The doors or gates at Balawat 895-825 BC. consisted of two leaves (each about 8 ft. 4 in. wide and 27 ft. high) were encased with bronze bands or strips, 10 in. high, and its tenons were sheathed with bronze. It seems the wood doors were about 3 in. thick, but the hanging stile was more than 14 inches in diameter. In the Hauran in Syria, where timber is scarce, the doors were made in stone, and one measuring 5 ft. 4 in. by 2 ft. 7 in. is in the British Museum; the band on the meeting stile shows that it was one of the leaves of a double door. At Kuffeir near Bostra in Syria, Burckhardt found stone doors, 9 to 10 ft. high, being the entrance doors of the town. In Etruria many stone doors are referred to by Dennis.

IRON DOORS: Iron began to substitute bronze as a tool and weapon material from about 1000 BC, and this must have been the period by which its use as door making material must have occurred. Bronze was more fusible (easy to melt and cast into shapes), harder than pure iron and far more resistant to corrosion. But Iron was more abundantly available. Bronze doors could form a lasting and protective layer of patina (rust) over the surface. Iron had problems of rusting. However, in many regions like Spain, China, etc., Iron Doors, lattices etc. were cast. Medieval churches throughout Europe were using wooden doors fitted with massive iron hinges and bands, to protect shrines and treasures. These doors were further embellished by slivering, gilding and later ceramic enamelling. Iron doors used nailing, rivetting and to a minor extent nut bolting as the joining technique. Forged joining of iron pieces came much later.

4.1.1.3 HISTORICAL PERSPECTIVE: DOORS - PERIODS

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Keywords: EARLY EGYPTIAN / lower and upper portions of the tall opening / GREEK DOORS / unifores / bifores or geminae / valvae / fixed and often open-able cast bronze grills / EARLY ROMAN DOORS / semi circular arched doorway / solid bronze double shutters / cast bronze panels / curtains / paginae / BYZANTINE PERIOD DOORS / Hagia Sophia’s cathedral / ROMANESQUE PERIOD / masonry vaulting / arched doorways / panelled squarish shutters / GOTHIC PERIOD / France and Germany / Italian doors / cast bronze doors / insert panels / Byzantine niello work / Lorenzo Ghiberti's doors / MEDIEVAL PERIOD / Lorenzo Ghiberti's Gates of Paradise / RENAISSANCE PERIOD / ‘bolection’ or projecting mouldings / INDUSTRIAL REVOLUTION PERIOD / iron structural sections / developments in glass manufacturing / new door systems / mass produced / door as integrated with the shell / POST INDUSTRIAL REVOLUTION PERIOD / National Standards and ISO / coordination of specifications / NEW AGE TECHNOLOGIES AND NEW DOORS / doors for automobiles / door frames / folded sheet sections / air curtains / invisible intelligent barrier systems.

EARLY EGYPTIAN: Early Egyptian temple doorways were tall (and so seemingly narrow) gaps stretching to the roof beam bottom. The lower and upper portions of the tall opening had distinctly different purposes. The upper part was left open to allow horizontal sun light to illuminate the altar in the early morning or evening. Seasonally moon light was also used for the same purpose. ‘From the upper portion of the cleavage, the powers or the spirits entered with the light, and the lower portion was the entry point for the mortals’. Closing the entire opening with a single shutter was not necessary and technologically feasible. The lower gap up to the functional height however was closed for security and privacy.

GREEK DOORS: The ancient Greek and Roman doors were unifores -single doors, bifores or geminae -double doors, or valvae -folding doors. The leaves of the folding doors were hinged, and folded back one over the other. The doors were tall, almost reaching about two-thirds the height of the lofty naos, and when open allowed ample light to illuminate the statue in the naos. The doors were of wood and cast bronze, often panelled with a lattice. The portals of Greek temples were fitted with fixed and often open-able cast-bronze grills. So doors even when closed, the grilles in the door panels admitted sufficient light for the ordinary purposes. The doors were placed behind a colonnade forming the East front face and often a secondary colonnade of the pro-naos.

EARLY ROMAN DOORS: Early Roman doors were like the Greek doors, but with flat and a semi circular-arched doorway. The shutters were comparatively smaller in size but retained the vertical rectangular proportion. The Roman doors had solid bronze double shutters, supported by pivots fitted into sockets in the threshold and lintel. An early example of large cast bronze doors is of the 7.3 metres wide double shutter for the Roman Pantheon. The earliest large examples are the 24-foot (7.3-metre) double doors of the Roman Pantheon. The Romans perfected the technique of cast bronze panels for fabricating very large shutters. Panelled shutters were much lighter in the fabricated form, and so easy to transport, install and operate.

Doors of the ancient Temple of Divus Romulus are of two leaves each with two panels, and are framed in bronze; these were converted and reused in the Christian Church of SS Cosma and Damiano. The doors of the Pantheon are similar in design, with narrow horizontal panels in addition, at the top, bottom and middle. Two other bronze doors of the Roman period are in the Lateran Basilica. The doors of the church of the Nativity at Bethlehem (6^thC.) are covered with plates of bronze, cut out in patterns: those of St Sophia at Constantinople, of the 8^thand 9^thC, are wrought in bronze, and the west doors of the cathedral of Aix-la-Chapelle (9^th C), of similar type were probably brought from Constantinople, as also some of those in St Mark's, Venice.

Rooms of roman houses were separated from the entrance lobbies, porches and other rooms merely by curtains and only occasionally by wood shutters. The doors were made of cypress, oak, deal, box-tree, olive, or elm. For the bolts and pivots hardwoods and cast bronze were used. The wood was aged, and left in the press for years to prevent warping. Doors were panelled rather than made of boards to prevent warping of the wood, the doors were not constructed of boards but were of paginae -panels. The doors of the upper class were veneered and adorned with bronze, ivory, and other ornaments. Ancient roman doors had pivots of hardwood and sometimes of cast bronze.

‘The main entry into apartment houses typically took the shape of two wooden leaves that swivelled in pivots fixed into the doorsill and lintel blocks and opened inwards. Other doorways, for example those of the tavernae (shops) were secured every night by means of vertical wooden shutters that set into the travertine doorsill and lintel blocks, although at night and perhaps during midday break access might be made through a small entrance located inside the larger door.’

BYZANTINE PERIOD DOORS: The Roman panelled design and fabrication technique was continued through the Byzantine and Romanesque period. The bronze cast doors were used in the Hagia Sophia’s cathedral (838 C., Constantinople), St. Marks Venice, and the cathedral of Aix-la-Chapelle (9^thC.). The doors of the church of the Nativity at Bethlehem (6^thC.) are covered with plates of bronze, cutouts in patterns.

The art of casting doors was preserved in the Eastern Empire, the most notable example being double door (838 AD) of the Hagia Sophia’s cathedral in Constantinople (now Istanbul). In the 11th century bronze castings from Constantinople were imported into southern Italy. Bronze doors were introduced into northern Europe, notably in Germany, when Charlemagne installed a Byzantine pair (804 AD) for the cathedral at Aachen. The first bronze doors to be cast in one piece in northern Europe were made for the Cathedral of Hildesheim (1015 AD). They were designed with a series of panels in relief, establishing a sculptural tradition of historical narrative that distinguishes Romanesque and, later, bronze doors.

ROMANESQUE PERIOD: After 950 AD, well planned, grand scale buildings with excellent construction methods like masonry vaulting marked the Romanesque style. The Italian Romanesque architecture had large arched doorways. The straight and often angularly cut sides of the arched doorways were filled-in with columns, pilasters, flutes and other carvings. Actual doors were of much smaller size than the arched doorways. The Roman panelled design and mounting technique continued in Byzantine and Romanesque architecture. The door shutters still retained the squarish shape as panels were cast elsewhere. The panelled squarish shutters were fitted on the inside face of the arched gaps to avoid the mismatch of shapes. The door gap often had multilayered ‘traceried over patterns’. Gradually the shutters also began to be shaped matching the arched doorway gaps, requiring the reshaping of the top few panels of the door shutters.

‘The greatest works in the Romanesque style date from 1075 to 1125, after this period the style entered a florid baroque phase that lasted a generation and then was revivified as Gothic. A new type of ribbed groin-vaulted unit bay, using pointed arches to distribute thrust and improve the shape of the geometric surfaces produced vaulting that was light, strong, open, versatile, and applicable everywhere -a Gothic vaulting. A whole new aesthetic, with a new decorative system, the Gothic, was evolved as early as 1145.’

GOTHIC PERIOD: Gothic doors were of functional size, both of single and double leaves as well as dual doors. In the Romanesque period, the double shutter doors in the opening portal were separated by a column and the span was headed by a flat lintel, and than once again by a circular or pointed arch. In the Gothic period the spanning of opening was replaced by a pointed arch, giving a narrower look to the opening. The narrower look was further accentuated by the ribbed jamb and arch sides. In France and Germany, the main doorways were on the west face. The doorways were large, deeply recessed, intricately carved, and often with architectural elements such as columns, entablature, pediment and niches. Sculptural features such as statues of saints were placed in the arches in serried rows (e.g. Strasbourg and Rheims Cathedrals). Compared to this, the Italian doors were simpler, but doorways were elaborately treated.

In Italy, Germany and other areas of N. Europe cast bronze doors with an insert panels were used in many public buildings. The panels had designs, monograms and other ornaments in relief, frequently damascened (Ref: see notes on Surface Finishes) in silver and gold, and enriched with bosses and scrolls. From 12^th C onwards few churches in Italy had bronze doors inlaid with Byzantine niello work made by Byzantine crafts-persons. Lorenzo Ghiberti's doors for the Baptistery in Florence (1403–52) marked the beginning of a golden age of bronze casting in Florence and it lasted through the Renaissance and the Baroque era. Italian doors of the Renaissance period were simpler, with scale given by increasing the number of panels, as compared to France and Germany where doors had few or single panel but elaborately carved.

MEDIAEVAL PERIOD: The mediaeval period offers a wide variety of buildings with equally varied door styles, simply because many examples have survived or their records are available. A large variety of door head arches, such as flat, circular, 2,3, and 4 centred. The upper section of the doorway was flatter (of less depth), but its treatment was always elaborate. Wood was the chief door construction material. Iron hinges and spikes etc. were used. Woods of different varieties and metal sheets (bronze, copper, etc.) with plating and gilding were used. Typical Western medieval door for domestic architecture was of vertical planks backed with horizontals or diagonal bracing. It was strengthened with long iron hinges and studded with nails. In domestic architecture, interior double doors appeared in Italy in the 15th century and then in the rest of Europe and the American colonies. The craft of bronze casting, which was neglected till 12^thC., became now a thriving industry. Lorenzo Ghiberti's Gates of Paradise -Porta del Paradiso (1425) is the high point of this craft in Florence, it lasted through the Renaissance and right down to the Baroque era.

RENAISSANCE PERIOD: One of the masterpieces of Renaissance art -the bronze doors for the Baptistery of the Florence cathedral, which consist of 28 panels illustrating New Testament scenes of the life of Christ. Bronze doors inlaid with niello work were earlier produced mainly in Byzantine area (during 11^thand 12^thC.), now began to be produced everywhere in Europe.

In England in the 17th century the door panels were raised with ‘bolection’ or projecting mouldings, sometimes richly carved. In the 18^thC. the mouldings on the stiles and rails were carved with the egg and tongue ornament. Doors were also made of wood veneers and wood inlay.

The earliest Renaissance doors in France are those of the cathedral of St Sauveur at Aix (1503 AD.), the lower panels have 3 ft high figures in Gothic niches, and the upper panels have 2 ft niches canopies over them, all carved in cedar. The south door of Beauvais cathedral is in some respects the finest in France, the upper panels are carved in high relief with figure subjects and canopies over them. The doors of the church at Gisors (1575 AD.) are carved with figures in niches subdivided by classic pilasters superimposed. In St Maclou at Rouen are three magnificently carved doors, those by Jean Goujon have figures in niches on each side, and others in a group of great beauty in the centre. The other doors, probably about forty to fifty years later, are enriched with bas-relief, landscapes, figures and elaborate interlaced borders.

INDUSTRIAL REVOLUTION PERIOD: The industrial revolution period saw the use of new techniques of creating metal components. Steam powered machines were capable of handling heavy loads of forging, rolling, shaping and die-casting. Iron structural sections began to change the industrial buildings and public utilities. The openings in industrial buildings, railway stations were large and new door systems were developed. The developments in glass manufacturing methods also encouraged the large openings. New door systems such as: rolling shutters, multiple folding shutter doors, collapsible gates, goods elevators’ sliding upward doors, warehouse doors, etc. were fabricated of rolled or drawn iron. These doors were functional and without decoration or styling appendages. New doors required radically different hardware such as hinges and locking devices, and surface finishes. Colonies for new Industrial workers were developing in every urban centre, and required low-cost doors. Metal doors, timber flush doors and other alternative systems began to be mass produced. Railway cars, trams, buses and other automobiles required openings systems of different sizes, shapes and very often door as integrated with the shell (a structural component of the body). Industrial valves, oceanic vessels (ships, sail boats, etc.), chemical reaction vessels, processing chambers, steam boilers and other systems changed the age-old concepts about opening systems and provided new design insights. Massive demand from hotels, resorts, hospitals, army (barracks and other buildings), public housing schemes, commercial buildings, etc. supported development of standardized, mass produced, trimmed door systems that were not only easy to maintain but replaceable.

POST INDUSTRIAL REVOLUTION PERIOD: This is a period marked by the end of world war II. The old styles and building techniques gave way to new methods as Japan and Europe began to rebuild their war-torn economies. New developments in Materials Technologies, specifically plastics and other petroleum products began to offer new alternatives. Metal manufacturing now free of war preparations had large spare capacities of production offered better and diverse structural shapes and sizes. Coating, alloying, galvanizing, metalizing techniques offered steel and other metals with different options. National Standards and ISO helped develop a basis for world wide coordination of specifications. Several countries of the world achieved independence from colonial bondage. This created a huge market for the industrially developed countries.

NEW AGE TECHNOLOGIES AND NEW DOORS: New age doors include, both architectural and non architectural entities. Doors for automobiles were most radical in design, not only their size, shape and form were different but new materials were also being experimented. Composites of carbon, fibre glass, etc. were tried out here. Aircraft hangers, home garages, submarine vessels, pharmaceutical and other bio plants, food processing areas, hospital’s surgical areas, climate-controlled industrial plants (diodes and other electronic circuits), etc., provided new opportunities to reinvent the door. Laminated composites, surface hardened and alloyed materials, co-extruded plastics, foamed or air-entrained materials, stainless steel and aluminium sheet formations, wood waste products, powder coatings and other solvent-less systems, new varieties of glass and clear plastics, all have changed not only what a door was but how it could be constructed differently.

One of the major component to see a drastic change was the Door Frame. Traditional wood jamb + head frames have been nearly replaced by folded sheet sections (of mild steel, stainless steel, aluminum), drawn sections (mild steel, aluminium, bronze, other alloys and plastics), and formed units of (layered and particle composites of cellulosic materials, paper, plastics, cement concrete). Besides replacing a timber jamb with other materials, attempts began to have no jamb doors. Hinges and other door shutter fixing arrangements were sought to be replaced with floor pivots and sliding tracks. Glass doors without a stile or any other member supported on a floor pivot is an example of this. Frequently opened and closed gaps such as in public buildings (railway stations, airports, malls, office complex foyers, restaurants, industrial plants) have air-curtains (air cascading over the gap and thus forming a breach-able barrier) instead of traditional door frames. In areas where a door was required as a security check barrier, these nodes are replaced with almost invisible intelligent barrier systems that recognise, register and control the access.

4.1.2.1 COMPONENTS OF DOORS

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Keywords: shutter or leaf / frame / hardware / wall opening / barricade / door portal / doorway / sides / head / eaves / Hisashi / Torii / DOOR SIDES / DOOR FRAMES / closer or tighter shutting / JAMB / casings / DOOR SURROUNDS / CASINGS / sides of the gap /types of casings / door stop butt / double shutter set / multi shutter system / termination points / architraves / extra wide casings / air lock / PILASTER / anta ANCONES CONSOLE / Todla / FILLET / wall treatments / REVEAL / SPLAYED / DOOR PORTALS / splayed / Buland Darwaza / Tympanum / LITES / TRANSOM / horizontal bar / TRANSOM LITE / FAN LIGHT / classical revival and colonial revival / CIRCULAR LIGHT / rose windows / SIDE LITE / DOOR HEAD / PEDIMENT / Georgian and Greek Revival architecture / broken pediment / EMBRASURE / inward splaying / THRESHOLD / doorsill, or saddle / Shankhavati / TRACERY / plate type / bar type / SHUTTER OR LEAF OF A DOOR / Multi planked wood shutters / stiles / rails / wood joinery / spikes or nails / multiple panels / cast or hammered metal sheets’ cladding / cast bronze panels / cast or engraved designs / hinges / shelf supported pivots / STILE / hanging stile / latch stile / panel doors / stile and rail doors / MULLIONS / side-lite / RAILS / rows of panels / kick rail / lock rail / cross rails / PLANKS / slats / BATTENS / slats / braces / iron bars / PANELS / flat / rebated / raised design / SHEATHING / metal sheet or plate / cladding / BEADING / peg / tree-nail / architrave / HOOD / quarter sphere / awnings / MOULDING / ARCHITRAVE / COMPONENTS OF FLUSH DOOR SHUTTERS / FRAME OR EDGES / CORE MATERIAL / composite / monolithic / HOLLOW-CORE / LOCK-BLOCK: / concealed stile / SOLID-CORE / SKIN / embossed / moulded / architraves.

A door as a building element is made essentially of a shutter or leaf. The shutter sometimes requires an intermediating support structure or frame. The shutter and the frame are joined by hardware. The door system is placed in a wall opening, barricade, door portal or doorway.

The door portals have sides and a head, both of which are structurally formed and decoratively treated in many different ways. Structurally the sides are the edges of the gap in the wall, but are reinforced with better materials and construction techniques. The sides are configured to receive the door leaf or the frame. The sides are also shaped to form a frame. The sides are decoratively treated to add to the scale (size) and increase the perceptive importance of the door portal. The treatments on the sides visually ‘frame’ the door portal, making it a ‘stand alone’ element. The head is placed both as a structural element and a framing element. As a structural element it supports the overhead section and transfers the load to the side or base. The head is often a component of the roofing system, the eaves.

According to Japanese mythology a door portal is formed by the Hisashi (usually means eaves), whose character has the meaning ‘a space to see’. So a door occurs when a horizontal element like the eaves is formed. The horizontal element needs to be supported off the ground, so has sides. The gate Torii (Japanese) is an epitome of this. Torii can virtually occur anywhere in the space, and provide a metaphoric entrance. Torii frames a view or focuses presence.

DOOR-SIDES: The door-sides are distinctively of interior or exterior nature. Door sides are architectural or elements of its framing, but often it is often difficult to distinguish the purpose served by them. Door-side elements are also called door surrounds and are in the form of: casings, pilasters or half or demi-columns, flutes, niches, abutments, architraves, lites (side openings).

DOOR FRAMES: Frames are required primarily to hang a shutter, Frames for doors are used when the surrounding structural elements are incapable of receiving a hinge or such fixing mechanism. In very cold or rainy seasons, frames help closer or tighter shutting. Frames are made from wood, stone, cast or rolled metal sheets, Cement concrete, cement composites, extruded plastics, etc.

JAMB: The vertical support on either side of a door, window or other openings. A jamb is the vertical side member of a door frame. Jambs of extended width to cover the entire depth of the doorway are casings.

DOOR SURROUND: A surround is a decorative entity around a doorway. The term is also used for decorative elements around other openings such as windows and fireplaces.

CASINGS: Door frames have to be of functional size (width and depth) to economise the use of wood. Door gaps are often too deep and a frame cannot cover the entire width. The sides of the gap are covered by a Casing. Casing is a widened frame, or additional panelling that is placed on the remaining sides. The casing usually is placed on the interior face of the door frame, but for interior doors it can occur on any face. There are many types of casings: 1 a casing covers the entire gap and the door frame is mounted over it or is formed by placing a thin architrave that creates a door stop butt; 2 the casing is formed between two sets of frames, which marks the edge; 3 a casing or two sets of it are placed over the remaining portion, not occupied by the frame. Casings are single panel constructions, multi division panels, or in the form of stripes or flutes.

Deep door portals are used for accommodating a set of doors, with an interim space. In case of double shutter set (a set of shutters such ‘solid + glazed’, ‘glazed + louvred’, ‘glazed + mosquitos nett’ ) the doors are hung on the inside and outside edges. In a multi shutter system the casings are hollowed out to accommodate additional sliding shutters.

Casings become termination points for the skirting, wainscotting, dado or wall panelling system. The chief tools for such termination or integration of two elements are architraves.

Extra wide casings are created by having deeper door portals. Deep portals create a zone between the two shutters, to dampen the noise, provide insulation, create an air lock. To avoid deep casings the sides are architecturally or panelling wise chamferred or stepped (serrated as in Gothic doors).

PILASTER: A pilaster (anta in Greek and Egyptian architecture) is half a pillar that is attached to the side walls and projects to provide added support or is for ornamental decoration. Like a column, a pilaster often has a capital and a base. The depth of a pilaster is about one-sixth of its breadth, from a wall.

ANCONES CONSOLE: A bracket that is on either sides of a doorway to support a cornice or projected section of the lintel. A Todla (Gujarat, India) is often used for placing an oil lamp.

FILLET: A small band to separate the door frame or door casing from the adjoining wall panelling, dado or other wall treatments.

REVEAL: A small band or strip at a right angle to the side face of the opening (on the main face of the wall) used to seal the edge of frame or casing or border the opening gap.

SPLAYED: When the reveal is chamferred, or the corner edge of the masonry wall of the opening is diagonally cut, it is called splayed. Windows like openings have been splayed for ages. Door openings are splayed on sides and at head. The splay could be very wide to allow better distribution of illumination or have a wider view. Splay could be both on the interior and exterior faces.

DOOR PORTALS: Historically doors have been placed on the inner edge of the door portal, and front edges have been splayed to accentuate the sides (e.g. Fatehpur Sikri entrance to the main mosque complex is Buland Darwaza within which the actual door is much smaller). Similarly in Gothic architecture door portals are elaborate and serrated but an actual door is always much smaller. Fluting or serration is continued from both sides to over the door head portion (arched or flat lintels). In Mughal architecture additionally balconies and windows were placed in door portals. The angular portion above the door the Tympanum has been surface treated with carvings or fine lattices, and later as transom.

LITES: Lites or lights are the additional openings that occur over or on the side of a door. The lites are intended to illuminate the entrance foyer or vestibule. Lights were used as a characteristic style element for houses.

TRANSOM: The term refers to a fixed horizontal bar of wood or stone that is placed over a door to separate an opening or window above.

TRANSOM LITE: Flat arched, or square and flat headed lintels have an opening shutter (called a ‘ventilator’) often hinged to the horizontal crossbar or a transom (transom-lite). A transom lite is a window or fixed glazed panels positioned directly above a door or window, and shaped according to the archway (a segmental, semicircular etc.).

FANLIGHT: The lites in semi circular or other archways are shaped, or the lattice work within it is in the form of a fan (fanlights). It is a semicircular window above a door, often with distinctive radial shape. Fanlight doors were accompanied by sidelights. Fanlights illuminated an entry hall or vestibules. In the mid-1700’s the design of a fanlight gave a sense of an individuality to the facades of urban row houses. A fanlight is a key identifying feature of Federal style architecture. Fanlights were also found in Classical Revival and Colonial Revival houses.

CIRCULAR LIGHTS: These were left as round openings with delicately carved tracery patterns. These circular openings later in Gothic period became Rose windows. Rose windows were first filled with translucent marbles or small pieces of glass, and later with stained (coloured) glass. Circular lights with circular, segmental or elliptical archways were mounted on entire width comprising of the door and its sidelights. This was a common feature in Federal and Georgian style architecture.

SIDE-LITE: Sidelights are side openings on one or both sides of a door. These were popular in USA after the American Revolution.

DOOR-HEAD: A door head is the upper section of a door that is shaped flat, segmental or as a semi circular archway. Door head, as a term often includes the head of the opening, its treatments and appendages. The door-head as a structural component is a lintel, corbelled arches of various forms (semi circular, segmental, pointed, two points, a pointed trefoil, an ogee, shouldered, etc.), as a decorative system, it is a pediment or gable (triangular, cut triangular, circular, cut circular, etc.), flutes, and as a functional element has transoms, tympanums, fan light, rose windows, etc.

PEDIMENT: A low-pitched triangular gables over a doorway or other openings, often seen in Georgian and Greek Revival architecture. In a version known as a broken pediment, the peak of the triangle is interrupted, often with an ornamental curve and/or a decorative element in the centre. Pediments also occur as head decorations over the chair back, wall clocks and buildings’ fronts.

EMBRASURE: The inward splaying of openings such as doors and windows for wider distribution of illumination.

THRESHOLD: Thresholds have an origin since the days of pivot. Early doors were very heavy. Pivots for such doors were made with a metal casing, and placed in a hard wood or stone base. The thresholds, due to wear of the pivots, required frequent replacements. The threshold (a log of wood or other materials) was also used as the support base to hold the jambs, and maintain distance between them.

A threshold also separates two different types of floorings. The threshold serves as a barrier against crawling insects, storm and cold draughts. It is sometimes referred to as a doorsill, or saddle. A threshold is also used to insert a vertical cross bar or a stopper bar to secure the door. Most Indian temples have a high threshold called Shankhavati. Jain temples have doorway thresholds containing a set of Kumbha (urn).

TRACERY: Ornamental curved patterns in windows, doors and other openings often made of wood, stone or cast iron. Traceries are, plate type when cut out of a stone plate, or bar type with geometric patterns formed by narrower bands. Tracery was a typical element of Gothic Revival and Collegiate Gothic style architecture.

SHUTTER OR LEAF OF A DOOR: These were once made of monolithic material such as a single piece of stone or wood, but the limited size of the materials and heavy weight not only restricted the actual size of opening, but the control over its opening-closing mechanism. Multi planked wood shutters require a vertical member as stiles and horizontal rails, and both need to be held together through wood joinery and spikes or nails. Later during Greek and Roman period panelled door construction further reduced the weight of door and allowed construction of larger sized shutters. For large doors multiple panels were used. Large panels of single pieces of wood were not feasible, and panels of multiple planks were always weak. This weakness was removed with use of cast or hammered metal sheets’ cladding of bronze and copper over wood panels. In later Roman period and thereafter in Byzantine cast bronze panels (inserted in wood or metal frame work) with cast or engraved designs began to be used. These panels were produced at places far away from their use.

Door Shutters or leaves had inherent size limitation. As the door shutter construction became refined, weight was reduced, and door opening-closing became easier. The primitive doors were held by stacking, tying at the edge by ropes or leather straps. Later pivots were formed as an integral member of the shutter material. These pivot nodes were inserted into hard stone holes at floor and ceiling levels. Problems with pivot mechanisms were many: pivot nodes wore out fast -lowering and often tilting of the shutter, pivots broke frequently making shutter useless, and replacement of a worn or broken pivot required lot of structural changes. Pivots of cast bronze were a better option, but required special joining with wood and more so with stone shutters.

Sometimes during middle ages hinges began to replace the floor pivots. The first hinges were actually shelf-supported pivots. These were formed of wrought iron or bronze. Hinges were easy to fit or replace (in the first case without structural delays, and in later case without structural changes). Incase of pivots the bottom one carried the load whereas the top pivot was more of a holding element. But in case of hinges, all of them shared the carriage of loads.

Shutters are composed of many different materials and techniques: Stone sheets, metal plates, wood, glass, plastics, textiles, woven materials, leaves, leather, water and air jets, ultra sound.

STILE: Stiles are full height right and left vertical edges of a shutter. The hinges are mounted to the fixed side -known as the hanging stile, and the handle, lock, bolt, and/or latch, are mounted on the swinging side -known as the latch stile. Panel doors -doors built with frame and panel construction, also called stile and rail doors.

MULLIONS: Vertical members that run between two rails, and split the door into two or more columns of panels. A mullion is also a vertical member that divides a door and its side-lite.

MUNTINS: Thinner or minor members that divide the door into smaller panels.

RAILS: Horizontal members (similar to stiles) at the top, bottom and optionally in the middle of a door. Rails join the vertical edge members -the stiles. Rails also divide the door into two or more rows of panels. The top and bottom rails are named for their positions. The bottom rail is known as kick rail. A middle rail at the height of the bolt is known as the lock rail, other middle rails are commonly known as cross rails.

PLANKS: Vertical boards or slats that extend the full height of the door, and are placed side by side filling up the door's width.

BATTENS: Battens are smaller slats that extend horizontally across the door to which the planks are affixed. The battens hold the planks together. Sometimes, a brace, a long diagonal slat, or two are used to prevent the door from skewing (dropping down on free edge-corner). On some doors, especially antique ones, the battens are replaced with iron bars that are often built into the hinges as extensions of the door-side plates.

PANELS: Panels are large, wide boards used to fill up the space between the stiles, rails, and mullions. The panels typically have a tongue -a projecting element on one edge, and a groove at the other edge. Panels may be flat, rebated or of raised designs.

SHEATHING: A cover usually of metal sheet or plate applied over a door surface to protect it from moisture, impact denting, scratching, etc. Bottom section of Door shutters often have sheaths of metal, plastic or fibre sheets. Sheathing is also called cladding.

BEADING: A woodworking method used to join two pieces of wood. A mortise (cavity, hole, notch or slot) is cut into one piece of wood. The tenon is created by shaping the end of the second piece of wood so that it can slide into the mortise. After fitting the tenon into the mortise, the joint is made secure by drilling a hole through both the mortise and tenon, and driving a wooden peg, also called a tree-nail, into the hole. Beading is also a small architrave that holds the glazing pane or panel to stile or rail.

HOOD: A covering above a door or window that provides shelter as well as adds a decorative element to the doorway. Hoods are made with wood or metal frames and covered by pieces of slate, roofing tiles, metal sheaths, fibre cement sheets, canvas fibre glass sheets and fabrics, plastics’ sheets etc. One of the most used hoods during the last century was a quarter sphere over a semi circular archway of door or window. Modern hoods are manual or automatically collapsible or retractable mechanisms. An Indian bazar shop hood (for many centuries preceding the British Raj and till independence) was formed of canvas like heavy fabric stretched with bamboo poles. Hoods are also called awnings.

MOULDING: In England in the 17th century the door panels were raised with bolection or richly carved projecting mouldings. In the 18th century the mouldings were created on the stiles and rails with the egg and tongue carved ornamentation.

ARCHITRAVE: An architrave is a border that surrounds a door frame or door way. Often it covers the junction of a door frame and masonry wall, casing, panelling, etc. It is often a part of the moulding.

COMPONENTS OF FLUSH DOOR SHUTTERS:

FRAME OR EDGES: Edges on a flush door provide integrity to the structure and allow fixing of hinges, latches, etc. The edges are concealed behind a skin with only its side ends seen. Edges allow a door to be sized (by planning) for the opening.

CORE MATERIAL: Material that forms the core or body of the flush door. It fills up the space, but provides rigidity, reduce the druminess, enhances the insulation. The core material is a composite and sometimes a geometric composition but edged with a monolithic material.

HOLLOW-CORE: A hollow core construction has core formed of units arranged with space between them. Wood stripes, lattices, hollowed, honeycombed, corrugated, nodulated, or expanded forms of materials are used. Hollow-core flush doors are lightweight and have greater insulation capacity. Hollow core doors are used as interior doors.

LOCK-BLOCK: A lock-block consists of a wide edge or concealed stile for full height or for part of the door to facilitate insertion of mortice lock system.

SOLID-CORE: Solid-core doors have entire core area filled with pieces of wood or a panel of wood particles. Low-density particle boards or foams are also used to completely fill the space within the door. Solid-core flush doors (especially foam-core ones) are commonly used as exterior doors because they provide more insulation and strength.

SKIN: The front and back faces of the flush door are covered with a thin layer of materials such as wood veneer, plywood, sheet metal, fibreglass, or vinyl or polyester film. Multi layer skin materials such as veneers and plywoods are layered with the grain alternating direction between layers to prevent warping. The skin of a flush door is sometimes embossed moulded with patterns (in the case of metal, fibreglass, or vinyl). Additional mouldings and architraves are added (to wood) to give the appearance of a panel door. Fibreglass and metal-faced doors are coated to achieve stained wood looks.

4.1.2.2 MATERIALS AND TECHNOLOGIES

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Keywords: Nippur / Balawat / hanging stile / door frame / shutter / metal doors / embellishments and treatments / enamelling / malleable rolled sheets / cast door panels / tinning and galvanizing / oil painting / exotic woods / flush panel door / wood and wood-waste composites / door portals / glazed doors /clean -see through glass / French doors / folding and sliding doors / Shoji / canopy door / rolling door garages doors / modern doors / flexible shutters / vault doors / core-fill of mineral slabs.

The first doors were shutters of stone, wood, grass or reeds, leaves, hides or skins, woven mats and fabrics. The shutters, in order to close the opening, were made to swing, fold, collapse, slide or roll up. Ancient doors were primarily hung by pivots, formed as a protrusion of the door material at the top and bottom as the hanging edge of the stile. The pivot rotated in sockets in the lintel and sill or thresholds in the floor. The pivots and the sockets, both of them were later encased with harder material such as granite, basalt, hard woods, bronze, iron, etc.

Stone pivots, found at Nippur dating from 2000 BC., were in dolerites stone. The tenons of the gates at Balawat (now in the British Museum) were sheathed with bronze. These doors or gates were hung in two leaves, each about 8 ft.4 in. wide and 27 ft. high; they were encased with bronze bands or strips, 10 in. high, covered with repousse decoration of figures, etc. The wood doors would seem to have been about 3 in. thick, but the hanging stile was more than 14 inches diameters. Other sheaths of various sizes in bronze have been found, which proves this to be a common method to protect the wood pivots.

Floor pivoted doors were difficult to move or replace. Later pivots (hinged pivots) made of cast metals were wall-mounted instead of the floor and lintel. Wall pivots developed into hinges, when these were fixed to the surrounding frames instead of the masonry walls. The door frame became almost as inevitable an element as the shutter, for any opening system.

Metal doors of bronze, copper and later iron were used for public buildings. Metal doors were cast as panels and assembled into a larger size. Metal cast panels were cast with basic patterns, and later enriched by embossing, recessing, chasing or engraving. Bronze predominantly had patina (oxide - rust) as the finish. Metal surfaces were also plated, gilded or inlaid with Gold and Silver. Such precious metal embellishments and treatments were often plundered by the invaders. Metal panels were also suitable for enamelling (ceramic forming) but this technique was not exploited till 16^thC (similar ceramic enamelled panels were also used for ceilings). During the industrial revolution period malleable rolled sheets of mild steel, brass, copper alloys, replaced the heavy weight cast door panels. The sheet formed panels, however, continued to be finished with metal inlays, chasing, engraving and enamelling techniques. Tinning and galvanizing, were emergent technologies for protecting the metal sheets. Oil painting of metal doors began from 18^th C. onwards.

The external doors of the mosques in Cairo were cased with sheets of bronze or iron, cut out in decorative patterns, and incised or inlaid with bosses in relief. The internal doors were in wood framed and interlaced with Coptic designs of the square and diamond.

For internal doors and for domestic buildings wood has remained the most favoured material. Wood doors were lighter, receive wall pivots and with surrounding frames, regular hinges. Exotic woods (varieties in terms of colour, grain pattern, texture) were used to create contrasts between stiles and panels. Wooden panels were easy to finish and decorate. Lighter hinges with long arms (flanges) supported the members of the door frame. Such typical medieval doors were made of vertical planks and backed with horizontals or diagonal bracing, and the hinges were studded with nails or bolts. In domestic architecture, interior double doors appeared in Italy in the 15^thC. and then in the rest of Europe and the American colonies. The panelled effect was further simplified until, in the 20^thC., a single, hollow-core, flush panel door became common.

Wood is replaceable so it is an ideal material but forests cannot be regenerated fast enough to meet its heavy demand. Wood and wood-waste composites both are now sought to be replaced with alternative materials and technologies.

The size of a door shutter has always been prudent. Stone and metal cast doors were very heavy to install and operate. Metal panelled doors were easier to assemble, but were still heavy and difficult to maintain. The timber as a natural resource had size and supply limitations. Composite doors with elemental panels of rolled sheets were lighter, and with hinges were easy to install, repair, operate and decorate. Doors’ shutters have gradually become smaller and functional, but door portals have continued to be of grand size. Large door portals with functional sized door shutters have been common in buildings during middle ages and renaissance periods.

Historically doors have been of opaque shutters, with occasional small inset lattice openings, or few panels as lattice (e.g. Greek temples). Scattered examples of door panels of thin marbles or such translucent stones to brighten the interiors are found. To control the transparency curtains were used over door gaps or entire shutters of metal lattices were used. Glazed doors first appeared as window casements extended to the floor during the 17^thC. Early glazed doors were composed of very small glass panes cut out of blown bulbs. The quality was unclear or muddy. But it provided illumination inside. It was after the glass bed-casting and grinding (levelling and polishing processes) became better, a clean -see through glass was available. The glass panes replaced the wood panels.

French doors (double glazed) were incorporated into English and American architecture in the late 17^thand 18^thC. At about this time, the French developed the mirrored door. During the 19^th C., industrial production of complex hardware allowed folding and sliding doors as inspired by the Japanese shoji, the canopy door (pivoting at the top of the frame), the rolling door (of a tambour like construction), and garages doors opening to the top.

After wold war I, production of automobile, air-crafts and sea faring vessels helped developments of new types of specialized modern doors. These included 3D or spatial frame shutters, large shutters for air craft hangers and industrial plants, gates for dams, canals and dykes. Flexible shutters of stripes of polymer sheets are used in warehouses. Vault doors for: banks, high security storage areas (museums), bombing shelters are designed from alloy steel and metal composites and usually have a core-fill of mineral slabs, glass wool etc. for insulation, fire and radiation protection.

4.1.2.3 HARDWARE

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Keywords: three categories of hardware / Basic Hardware / Secondary Hardware / Appendages or Attachments.

Doors have Three categories of hardware: 1 BASIC HARDWARE attaches a shutter directly or through a frame to an opening or doorway, 2 SECONDARY HARDWARE provides control on the movement of a door, and at third level the hardware is 3 APPENDAGES OR ATTACHMENTS that endow various types of functionality.

Sub-Index for 4.1.2.3 HARDWARE

4.1.2.3.1 Baic Hardware

4.1.2.3.2 Secondary Hardware

4.1.2.3.3 Appendages and Attachments

4.1.2.3.1 BASIC HARDWARE

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Keywords: STRAPS / sparks of erosion / PIVOTS / end pivots / edge pivots -mid pivots / two-way swinging pivoted doors / pivot hinges / double acting floor hinges / hydraulic floor pivots / EARLY HINGES / wall-hung pivots / long armed hinges / flanged Hinges / MODERN HINGES / BUTT OR MORTISE HINGES / shangles / component / bearing / knuckles / hinge pin / pull out stress / push in stress / neutral stress / downward gravity stress / mouldings / casings / FLUSH HINGE / KNUCKLE HINGES / flush butt hinges / knuckle /PARLIAMENT OR BUTTERFLY HINGES / dovetail hinges / jewellery boxes / deep-set door frames / STRAP HINGE / wider flange / LIVING HINGE / thin flexible hinge / BACK FLAP HINGE / PIANO OR CONTINUOUS HINGES / INVISIBLE HINGES / CONCEALED HINGES / spring loaded / self-closing features / dampening system / H HINGES / HL hinges / BARREL HINGE / Lift-off butt hinges / LOOSE PIN HINGES OR BALL TIPPED HINGES / STOPPED HINGE / butt hinge / DOUBLE ACTION HINGE / middle flange / edge flanges / DOUBLE ACTION SPRING HINGES / UNEQUAL FLANGE HINGE / greater length of flange / reduced width of the flange / FRICTION STAYS / French door / ASKEW OR VERTICALLY MISALIGNED PIVOTS OR HINGES / Hydraulic or spring door-closer / CLASSIFICATION OF HINGES / FULL MORTISE HINGE / mortised / HALF MORTISE HINGE / FULL SURFACE HINGE / HALF SURFACE HINGE / STRUCTURAL HINGES / conditional movement / hinge like conditions / GATE HINGES / Building access hinges / FURNITURE OR CABINET HINGES / concealed hinges / butter fly hinges / piano hinges / butler tray and ambulance stretcher hinge / Drop Leaf Table Hinges / MICRO HINGES / ball-mortise / cylinder-pin system / FLOATING HINGES / two parallel axes of rotation / flatbed scanners.

Basic hardware for doors consists of shutter hanging mechanisms.

STRAPS: The first door shutter holders were straps of leather, ropes, vines, and threads, fabrics or synthetic materials’ (plastics and composites) are used as flexible hinges. Straps are still used in some conditions where metal friction is likely to cause sparks of erosion (petroleum solvent plants and cordite plants), but are made from new technology materials such as woven Fibre glass, Teflon, Cavalar, and carbon fibre composites.

PIVOTS: Doors with heavier materials such as stone, cast bronze and wood required pivots. Pivots were initially formed out of the shutter material itself, but later these were lined with metal sheaths. With better technologies of joining, the pivots were formed from cast bronze or iron steel and then attached to the shutters. By the time iron hinges began to be used, the door shutters had become lighter. Pivots allow the door to open inside, and a projection of the portal frame sealed the edges. Pivots are fixed at the corner of the door edge, and also on outside or inside the edge. Doors with outside the edge pivots -end pivots are expected to open to the inside, but can as well swing in both directions. Doors with inside the edge pivots -mid pivots open in both directions (e.g. Aluminium framed glass doors). For two-way swinging pivoted doors a door frame is an obstacle, and as a result such doors do not seal the gap completely. For pivoted doors no frames are necessary. Pivots are also called pivot hinges or double-acting floor hinges because opening movement is allowed in both directions as similar to hydraulic floor pivots used for glass doors in modern buildings.

EARLY HINGES: Early hinges were really wall-hung pivots, but the pin was hung off the side wall, and the girth or ring was fixed to the shutter. The ring had a long band which was fixed with nails to the stiles or rails. The early long armed hinges have become an expression of a medieval door. Flanged Hinges formed of steel, bronze and brass alloys are being used since middle ages.

MODERN HINGES: These are available of brass, bronze, mild steel, stainless steel, ABS and polypropylene plastics, carbon composites, etc. Most of the commercial hinges are made of several components (such as flanges, flange edge liners, pin, pin cylinder liners, coil springs, hydraulic cylinders, etc.), and these are again composed of many different materials.

BUTT OR MORTISE HINGES: These are also known as shangles in old Tudorian English (the large hinges on doors). Hinge like systems are employed in many types structures and movable bridges. In biology many body joints function as hinges. Butt or mortise hinges are made of hard wearing and stiff materials. Today hinges have a shaft or pin over which two flanges move. The pin is made of stainless steel, carbon steel, nylon and Teflon, some of these do not require any lubrication.

A hinge is component that attaches one edge of a door to the frame, while allowing the other edge to swing from it. A hinge can also be an arrangement. A type of bearing that connects two solid objects, and allowing a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation (the geometrical axis of the hinge). Hinges consist of a pair of plates, each with a set of open cylindrical rings (the knuckles) formed out of, or attached to them. The knuckles of the two plates are offset from each other and mesh together. A hinge pin is then placed through the two sets of knuckles to form a single unit.

One door usually requires minimum two, or more hinges. Nominally three bands (horizontal members of a panelled door) have three hinges, of which the top hinge is in ‘pull out stress’, the bottom hinge is in ‘push in stress’ due to the cantilever action of the shutter. The middle hinge is in ‘neutral stress’ state, but all three hinges have downward gravity stress. Butt or mortise Hinges are inset -mortised into the door stile and frame. The hinge is fixed with its pin section (cylinder) remaining out of the door face, to allow 180° of opening, i.e. the shutters can rest on the side of the door opening. However, sometimes mouldings over shutters, frames or casings interfere in the resting of the shutter, for such conditions hinges of larger width are used or fixed with greater outward projection of the pin section.

FLUSH HINGE: These hinges are surface-mounted and do not require a recess to be cut. They are not as strong as butt hinges but can be used for lightweight doors and small box construction.

KNUCKLE HINGES: These are flush butt hinges, fixed over the face of the door and its frame, and so not mortised. The pin cylinder or the knuckle is designed to be visible.

PARLIAMENT OR BUTTERFLY HINGES: These were known as Dovetail hinges and were used for cabinets from the 17th century onwards until the 18th century. The size and form of these hinges vary depending on the use, material and manufacturer. Very small ones are used for jewellery boxes or caskets and large ones used in public buildings. For deep-set door frames Parliament hinges are used to park a deep-set shutter along the corridor -at an opening angle of 180°.

STRAP HINGE: A strap hinge has a small height but a wider flange that accommodates two or three screws in a row on each flange.

LIVING HINGE: A living hinge is a thin strip moulded into a plastic part to create a line along which the part can bend. If properly designed and made, its closing and opening capacity lasts for more than a million cycles without failure. It is a thin flexible hinge with flexure bearing. It is formed during injection moulding process for plastics or a composite of it. Such hinges are used on lunch boxes and shampoo or hair oil bottles, and are formed of deformable plastics such as polyethylene, PVC, polypropylene, etc.

BACK FLAP HINGE: Back flap hinge is exactly the opposite version of the strap hinge. It has a squarish flange (height and width are nearly equal) Both are used in furniture items.

PIANO OR CONTINUOUS HINGES: These hinges are long enough to cover the entire length of the shutter, so support the shutter well against warping. Very thin sections of shutter boards (non panelled, without frames) require such hinges. These are used in cupboards, pianos, baueras, and desk top shutters.

INVISIBLE HINGES: These are used for joining two shutters. These are fully mortised as centred on the door shutter’s face. Door shutters seem like units of wall panelling as hinges are completely invisible.

CONCEALED HINGES: These are not seen outside a closed shutter and mainly used for furniture doors. These are often spring loaded with self-closing features and with or without a dampening system (slowing down the closing speed during the last few degrees). They are made of 2 parts: One part is the hinge cup and the arm; the other part is the mounting plate. These normally come in two sizes, 25 mm and 36 mm. The hinge is adjustable once fitted to correct the door alignment and planner straightness. These hinges are designed for use with chipboard and MDF.

H HINGES: These are shaped like an H, and used on the flush mounted doors. Small H hinges (75 to 100 mm) are used for cabinets and larger hinges (150 to 175 mm) are used for passage doors or closet doors. Large HL Hinges were common for passage doors, room doors and closet doors in the 17th, 18th and even 19th centuries. On taller doors H hinges were occasionally used in the middle along with the HL hinges at top and bottom.

BARREL HINGE: These Liftoff butt hinges have two components. The bottom section has a cylinder like projection over which a top hollow ring or cylinder is set. The shutter can be lifted off its position for servicing, cleaning etc. These are used in some kitchen cabinets.

LOOSE PIN HINGES OR BALL TIPPED HINGES: These serve the same purpose as the liftoff butt hinges. A removable pin holds two halves of the hinge knuckles together.

STOPPED HINGE: This is like any butt hinge but a square cut projection on a cylinder side of one flange restricts the opening of the shutter to 90° only.

DOUBLE ACTION HINGE: These have three flanges. The middle flange has hinged flanges on either side. The edge flanges are mortised into the side of the shutter, but the middle flange remains off the sides. The assembly leaves a space between the door shutter and its frame or other shutter. The hinge allows the shutter to open in both directions. Such hinges are used in saloon and bar doors.

DOUBLE ACTION SPRING HINGES: These are used on half height saloon doors. The hinge allows the shutter to open in both directions, but being a spring loaded mechanism, the closing action is automatic. In another version of such a hinge, it is fixed to the frame, and the other flange in the form of an arm has a roller at the edge. The shutter is often provided with a plate or channel for the roller arm to slide.

UNEQUAL FLANGE HINGES: These have unequal flanges in terms of width. A thin shutter has thin flange compared to wider flange for the frame side. Unequal hinges also have a greater length of flanges to compensate the reduced width of the flange.

FRICTION STAYS: Friction stays are fitted at top and bottom edges of the surface, and used on French door like systems. Such hinges allow a door to stay-put in its position in spite of the heavy winds, and so prove an ideal fixture on windy faces such as sea shores, mountain valleys etc. The hinge requires framing at least at the top and bottom, making it better suited for windows. It has a sliding channel within which a component fixed to the bottom of the shutter, for converting the rotational movement of opening into a linear thrust, through a collapsible triangular arrangement.

ASKEW OR VERTICALLY MISALIGNED PIVOTS OR HINGES: Fort doors had askew or vertically misaligned pivots or hinges, so in case of an emergency the door would be released from its catch to close fast, and automatically, but this also requires greater man power to open it and a stronger stay to keep it open. Similar systems are employed in modern hospitals, class rooms, garden, and toilets doors, where closed doors are preferred. Hydraulic or spring door-closer do the same function. In refrigerators a magnetic gasket pulls and keeps the door shut. Refrigerators often have doors locking hinges on both sides, allowing a door to be opened on left or right side. Salon and government offices have flap or mid door shutters, with a double flange hinge that can open it both-ways, and also has a spring-coil to bring the shutter to the closed position.

CLASSIFICATION OF HINGES:

FULL MORTISE HINGE: A full mortise hinge has one leaf mortised into the door edge, and the other leaf mortised into the door jamb. This is the most commonly used hinge configuration. Hinge sizes are specified with height first and open width second.

HALF MORTISE HINGE: This configuration is used for door jambs that do not allow mortising, e.g. a channel iron frame. One hinge leaf is fixed to the door edge, and other leaf is applied to the surface of the door frame.

FULL SURFACE HINGE: In this configuration, one hinge leaf is applied to the surface of the door, and the other leaf is applied to the surface of the door frame.

HALF SURFACE HINGE: In this configuration, one hinge leaf is applied to the surface of the door, and the other leaf is mortised into the door jamb.

STRUCTURAL HINGES include arrangements that link, two or more components of a structure but allow conditional movement but do not allow them to come apart or separate out in specific situations. The hinged condition also allows transfer of loads, stresses and transmission of energy. Such hinge like conditions occur in bridges, cranes, vehicles, dams, canal and dyke structures.

GATE HINGES are also called Building access hinges, and include heavy duty hinges for fort gates, estate gates, hanger shutter hinges.

FURNITURE OR CABINET HINGES: These include Concealed hinges with spring loading, controlled closures; butter fly hinges, piano hinges, etc. A butler tray and ambulance stretcher hinge (fold up the legs flat to 90E). Card Table Hinges are mortised into the edge and allow the top (shutter of card tables’ cavity) to fold onto itself. Drop Leaf Table Hinges are mounted under the surface of a table with leaves that drop down.

MICRO HINGES: Micro hinges are very small in size and used for jewellery boxes, wall clocks, travel suitcases, attach, bag, micro equipment and machinery cabinets. Many such hinges use ball-mortise arrangement rather than cylinder-pin system.

FLOATING HINGES: It is a hinge that, while able to behave as a normal hinge, enables one of the objects to move away from the other, hence ‘float’. Actually the hinge allows for two parallel axes of rotation, one for each object joined by the hinge, and each axis can be moved relative to the position of the other. Floating hinges are used in flatbed scanners designed to scan thick objects such as books. A sheet of paper is placed on the glass, and the cover is lowered over it. The scanner glass and the paper come together very close. If a thick book is placed on the glass, an ordinary hinge would leave the cover at an angle to the glass. A floating hinge raises the hinged edge of the cover to the level of the book, so that the cover remains parallel to the glass, but raised above it. Floating hinges are also used in two-plate electric cooking grills, as they allow for even heating of both sides of a thick piece of food without crushing it. Floating hinges are used for air craft doors, Suzuki (Maruti) delivery vans, etc.

4.1.2.3.2 SECONDARY HARDWARE

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Keywords: mechanics of opening and closing / PADLOCK CHAINS / chain / PARALLEL LOCKING RINGS / hooked rings / LATCH / ALDROP or HOLDROP / shaft / closing handle resting over cleat / BOLT OR NIGHT LATCH -TADI / LATCH-BOLT / DEADBOLT / HASP / chapras / SLAM LATCH / THUMB LATCH, NORFOLK LATCH or SUFFOLK LATCH / LOCKS / wedges or knots / wooden locks and keys / lock puzzles / pin locks / pin tumbler lock / mechanical / electro-mechanical / electronic / keys / levers / 2-lever lock / 6 to 9 lever lock / PADLOCKS / locking ring / LEVER LOCKS / MORTICE LOCK / cylinder locks / locking device / closing device / night or safety locks / lock body / lock trim / strike plate / keyed cylinder / mortise lock / bored cylindrical lock / CYLINDER LOCK / ALMIRAH LOCKS / DEADBOLT or DEADLOCK / spring-bolt locks / vertical deadbolt / COMBINATION LOCK / MULTIPLE-DIAL LOCKS / ELECTRONIC COMBINATION LOCKS / COMBINATION LOCKS ON DOORS / ELECTRICAL AND ELECTRONIC LOCKS / KEY SYSTEMS / INDIVIDUALLY KEYED SYSTEM (KD) / KEYED ALIKE (KA) / MASTER KEYED (MK) / single master-key / GRAND MASTER KEYED (GMK) / COMMON ENTRANCE SUITE / MAISON KEYING (CES) / individual key / COMPUTERISED OR CENTRALLY CONTROLLED SYSTEM / detection devices / electronic card / bio-metrics.

Secondary hardware provides specific characteristics to the door system in terms of control over mechanics of opening and closing. These include: stays, stoppers, locking mechanisms, pivot or hinge fixing -rivets and bolts, studs, nuts, housings, handles, doorstops or catch, door-closer, safety chains, peep holes, view glasses, ventilators, knockers, etc.

PADLOCK CHAINS: One of the simplest locking mechanisms is a chain. Chains are cast of brass, bronze or wrought iron and occasionally braided metal wire or fibre ropes. The chained loops formed of round or oblong rings, with a locking ring at one end, and a fixing hook at the other end, forms a primary locking device. The locking ring is placed over or besides a similar locking ring at the threshold, lintels or on side stiles. A padlock is hung from the junction of locking rings. Similar systems are used for locking bicycles.

PARALLEL LOCKING RINGS: The door and the frame, or two adjoining shutters have hooked rings, which when brought together to a parallel plane or in adjoining horizontal position, allow a padlock to pass through. Often a ring and a chain with multiple loops are used.

LATCH: A latch is a mechanical fastener that holds a shutter against the frame. A latch is functional through friction, a holding notch or a catch. Ball catch type of latch has a small sphere (ball-bearing) mounted on a coil spring. Strap latches have a retractable plastic or notch that is engaged in a slot.

ALDROP (HOLDROP): It is a latch in the form of a metal shaft with a closing handle resting over a cleat through which a padlock is set. The metal shaft, is round, square, flat or oblong in section. The shaft slides through cleats or a set of three ring brackets but its end enters into the jamb to fasten the shutter door.

BOLT OR NIGHT LATCH (TADI): Bolt is a straight sliding shaft with two / three cleats. The shaft has no closing handle (as in aldrop) but instead a notch or a small projecting holder is provided. Some latch shafts have a small aperture in the shaft to insert a padlock to prevent its sliding movement.

LATCH-BOLT: A bolt has an angled (chamferred) surface which acts as a ramp to push the bolt in while the door is being closed. With a latch-bolt, a door can be closed without having to operate the handle. A handle, however, is required to pull back the latch-bolt for opening the shutter.

DEADBOLT: Deadbolts usually extend deeper into the frame and are not retractable from outside except with a key. From inside the deadbolt can be retracted by either a latch or key. The bolt is often not angle cut or chamferred, so that no one from outside can open the bolt by stiff card like credit card. Deadbolts are fixed as add-on system over the inside face of the door. Such a fixing can be undone with a hard kick over the shutter or use a crowbar to break-in. For security purposes deadbolts are often concealed within the shutter body to prevent forceful breaking in. Deadbolts also have additional safety chain, which allows a door to be opened a little to receive a postal-currier delivery or talk to a visitor.

FLUSH BOLT: It is a sliding bolt housed in channel or pipe with projecting a holder pin mounted on a surface or concealed by mortising into the edge of a door or astragal that typically engages into the jamb head and sill to secure the door.

HASP: A hasp or Chapras in India, is a thin narrow plate hinged to a fixing flange. The plate, at its end has an elongated aperture which sits over a padlock placing ring. Hasps are used in small furniture items such as jewellery boxes, wall clocks, drawers, and interior doors.

SLAM LATCH: It uses a spring and is activated by the shutting or slamming of a door. Like all latches, a slam latch is a mechanism to hold a door closed. Slam latch derives its name from its ability to slam the doors and drawers shut without damaging the latch. A slam latch is rugged and ideal for industrial, agricultural and construction applications.

THUMB LATCH, NORFOLK LATCH OR SUFFOLK LATCH: These are stoppers used in vertical or horizontal position. The shaft is moved by thumb. These are often very thin, so can be fixed on the side of a stile of the first of two door systems, on sliding doors, etc.

LOCKS: A device that prevents access by those without a key or combination to open it. A lock nominally is a self-sufficient entity housed in a small chamber that houses its mechanism.

The first locks were perhaps wedges or knots (such as: a thief knot, Gordian knot) on fibre ropes. Wooden locks and keys were in use as early as 4,000 years ago in Egypt. The first known lock was strung on a rope hanging out of a hole in a door and a cylinder of wood with a hole drilled through its axis was its key. The key was inserted into the hole for a correct distance, the rope was pulled to extract the key cylinder and simultaneously pulling the bolt closed. Lock-puzzles were once used to obscure the locking mechanism or even provide a non-functioning lock for the thief to waste time on.

Early improvements in pin locks included increasing the number of pins to increase security, and changing the orientation of the pins to allow the key to provide the unlocking force instead of a rope, thus, establishing the principles of the modern pin tumbler lock.

Locks were mostly mechanical, but later electro-mechanical, and now electronic locks are available. The locks are operated by turning some form levers: through a removable key or such element, dialling in a combination which of activates opportunities, or commands directly or via electro-mechanical (magnetic or other cards). All locks are not intended to prevent unauthorised access. Some are used to control the accidental opening or closing of a door system.

Keys have ground slots and often shaped side channels, which in combination give it a nearly unique capacity. The keys are known by the ground or cut slots, which actuate components called levers. A two-lever lock is used for simple interior doors (no high security risk), whereas a 6 to 9 lever lock is used for outdoor entrances. Keys also have variety of conical projections and depressions all created through a computer programme, which by their position, diameter and depth or height provide a unique capacity. Such keys are virtually impossible to duplicate. Locks are fitted on the exterior and interior face of shutters.

PADLOCKS: Padlocks are portable locks, with their own body and foldable or a separable locking ring. Padlocks can be used over another ring or shackle, or with a chain to tie up separate objects. Inexpensive padlocks are susceptible to direct mechanical attacks which can release the shackle without the use of a key or a combination. Padlocks can be used almost over any type of opening, or with a chain on any vehicle wheel. Padlocks are used to tie up the wrapped around ropes on goods bundles or packages.

LEVER LOCKS: Levers are flat set of grooved or edge shaped devices which can be rotated or pushed by a matching key to operate or activate a mechanism. Insurance companies, police department and other security agencies desire at least a 5-lever lock for external doors of home security system. British Standard (BS 3621:2004) is the one recommended for insurance purposes. A new BS 3621 calls for a bolt throw of 20 mm rather than the 14 mm of the old British Standard.

MORTICE LOCK: (also Mortise in American English) A mortice lock is concealed into a cavity (mortice) in the stile or thickness of the door shutter (unlike a padlock which remains free). A square section pin projects out on one or both the faces to receive the operative handles. Older mortice lock had a large box, but new generation mortise locks are cylinder locks fitted from the front and back, and the locking devices as one, twin or multiple cylinders with projective that come out on the side of the door. The locking device is operated through a key, and an additional bolt -a closing device through a set of handles. The locking device is square ended but the closing device is tapered on one face for self closing but opening through handle movement. Night or safety locks have an extra slider which stops the lock being operative with key from outside.

A mortice lock unit consists of -a lock body (the part installed inside the mortise cutout in the door), the lock trim (such as doorknobs, levers, handle sets and pulls), and a strike plate or a box keep, which lines the hole in the frame into which the bolt fits and the keyed cylinder which operate the locking /unlocking function of the lock body.

Installation of a mortise lock weakens the structure of the typical timber door, but it is stronger and more versatile than a bored cylindrical lock, both in external trim, and functionality. For ornate doors, and for replacement of older locks, mortice locks are preferred, but for functional reasons cylinder locks are used.

CYLINDER LOCK: In these locks the locking mechanism and bolting are two separate systems. The components are standard so virtually any sub component, but importantly the cylinder and the keys are replaceable. Such locks are also available as sets which can be opened by their individual keys and also by a master or common key. Standard cylinder systems include key-in-knob-set cylinders, rim (also known as night-latch) cylinders. There are also many standards (Euro-profile or DIN standard, British oval profile and Swiss-profile) and company specific-patented cross-sectional profiles for lock cylinders, varying in lengths.

Cylinder locks are small in size and diameter, and are fitted from front and back side of a door shutter, rather than from the edge of a door stile (as in case of mortice lock), so are easier to fit and replace.

ALMIRAH LOCKS: These are found on commercial Mild Steel sheets (CRCA) cupboards. These are housed in a box fixed on the inside face of a shutter. The closing device has three components, a locking lever that is moved through a handle, and accompanying it is two vertical locking bars that move upward and downward. Such devices are also concealed on a street side of main doors of buildings for security purposes.

DEADBOLT OR DEADLOCK: It is a special kind of locking mechanism that provides more security than an ordinary key-operated lock. Unlike most spring-bolt locks, in which the bolt is held in place only by the pressure of a spring and can easily be retracted, a deadbolt lock cannot be opened except by rotating the lock cylinder. A variant of the standard deadbolt is the vertical deadbolt, which generally rests on top of a door. ‘Vertical deadbolts resist jimmying (in which an intruder inserts a pry bar between the door and the frame and tries to pry the bolt out of the jamb)’.

COMBINATION LOCK: It is operated by setting a sequence of numbers or symbols, instead of key in a nominal lock. The sequence is entered by a single rotating dial which interacts with several discs or cams, by using a set of several rotating discs with inscribed numerals which directly interact with the locking mechanism, or through an electronic or mechanical keypad. A combination lock requires a correct permutation and not merely the correct combination of digits.

‘The first known combination lock was invented in 1206 by the Arab scholar, inventor and mechanical engineer al-Jazari. He documented the device in his book al-Ilm Wal-Amal al-Nafi Fi Sina'at al-Hiyal (The Book of Knowledge of Ingenious Mechanical Devices). Muhammad al-Astrulabi (ca 1200) also made combination locks, two of which are kept in Copenhagen and Boston Museums. Gerolamo Cardano later described a combination lock in the 16th century. In 1852 a German man by the name of Joseph Loch was said to have invented the modern combination Lock for Tiffany's Jewellers in New York City. However the rights to his invention were stolen from his business associate who thereby attained all credit of the discovery’.

MULTIPLE-DIAL LOCKS: One of the simplest types of combination lock, as seen in low-security bicycle locks, in briefcases and baggage, etc. uses several rotating discs with notches cut into them. The lock is secured by a pin with several teeth on it which hook into the rotating discs. When the notches in the discs align with the teeth on the pin, the lock can be opened.

ELECTRONIC COMBINATION LOCKS: These are better then their mechanical counterparts. Such locks are used on safes and drawers. Electronic locks work with power-assisted mechanisms.

COMBINATION LOCKS ON DOORS: Combination locks for doors require one to enter a numeric sequence (pre fixed or dynamic-variable with every use) or a punched, slotted, magnetically or electronically charged key cards to facilitate entry. These locks are often designed for entry by a class of people (e.g. common door entry for members of an apartment), and for conditional access (e.g. in a hotel room the lock becomes unopenable after a guest checks out).

ELECTRICAL AND ELECTRONIC LOCKS: These work with an electric current. Plain-electric locks had magnetic lever system working on the correct voltage or sometimes an electrically controlled-switched lever. Many electric locks are connected to a central access control system of the plant or building complex.

KEY SYSTEMS

Keys have variety of configurations such as: a diameter, the length, shape of the shaft (flat, cylinder, tapered, etc.), and size and shape of slots or cuts, grooves, etc. Modern keys have conical projections and depressions created through a computer programme, which due to their position, diameter and depth or height, are impossible to duplicate.

INDIVIDUALLY KEYED SYSTEM (KD): Here each cylinder lock can be opened by its individual key.

KEYED ALIKE (KA): Many cylinder locks have one key, such as all drawers of a cabinet or many rooms of a mansion, guest rooms on a floor or of a wing. It is also ideally suited to residential applications such as same ley for front and back doors.

MASTER KEYED (MK): A master-keyed system involves each lock having its own individual key which will not operate any other lock in the system, but all locks can be still be operated by a single master-key. This is useful for the concierge or floor in charge of a hotel lobby to access all rooms.

GRAND MASTER KEYED (GMK): This is an extensive version of the master-keyed system where each lock has its own individual key and all the locks are operated by one grand master-key.

COMMON ENTRANCE SUITE / MAISON KEYING (CES) This system is widely used for main entrance door of apartment block, office block and hotels. Each apartment has its own individual key which will not open the doors to any other apartments, but can open the common entrance door and other common service areas.

COMPUTERISED OR CENTRALLY CONTROLLED SYSTEM: It controls the access to all doors. It may also include the detection devices to register the presence (active, resting and sleeping) of a guest or occupant of a room; the status of the rent paid and misuse of various gadgetry or services, etc. The key system in the form of an electronic card or bio-metrics can be reset. The guest or visitors need not surrender the access card at the lobby counter while going out or even on checking out (as the entrance door and many other points in hotel trace and note the movements).

4.1.2.3.3 ATTACHMENTS AND ADORNMENTS FOR DOORS

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(Click here to go to Chapter 4.1.2.3 sub-Index)

Keywords: add-on and integrated systems / fuzzy logic / additional or sub doors / very large doors / small auxiliary doors / DOOR STOPS / dampen the noise / absorb the impact damage / shutter opening beyond certain limit / self closing / askew hinge or pivot alignment / primitive door stops / cotton and fodder stock rooms / self closing doors / door strikes / buffers / door catch / fork pin / a magnet / foot door stop / ESCUTCHEON / STRIKE / SAFETY CHAIN OR DOOR CHAIN / PEEPHOLES, VIEWERS / magnifying glass / one way mirror / fisheye lens / STRIKERS OR KNOCKERS / right of asylum / LETTER SLITS OR MAIL SLOTS / mail receptacle / mailbox / THRESHOLDS / Indian mythology / shankhavati / threshold devices / HANDLES / door handle serves purposes / hand operated / TYPES OF HANDLES / hinged and pivoted doors / horizontal and radial movement / horizontal pull or push / pulled and pushed / NATURE OF DOOR SHUTTER OPENING-CLOSING / DOORKNOB / spherical objects / crystal glass blobs / DOOR HANDLE / horizontal or vertical lever / C shaped static type / Hospital doors handles / Restaurant pantry doors / concealed / fold down / CRASH BAR / crash or panic bar / FASTENERS / CROSSBAR / bolt / reinforce the shutter / prevent break-in by force / GLAZING / putty or mastic compound / transparent to translucent material.

Attachments and adornments endow additional functions and meanings to a door. Modern doors have many add-on and integrated systems, ranging from simple tools, devices to intricate gadgets and complex equipments. These are manual, automatic (mechanical, electrical and electronic), or synergetic, and are programmed with fuzzy logic. Such systems control: opening size, duration, frequency, speed, location, selection, etc. and ergonomically facilitate the working of a door system.

Doors are fitted with additional or sub doors to regulate the traffic and environmental exchange. Very large doors are required for occasional heavy traffic, prestige and for architectural effect, but such doors are difficult to manage in terms of frequent opening or closing. Small auxiliary doors are included within the shutter or besides the main door, for specific functions. Non functional or decorative elements are added to doors as expression, for confirmation to a faith or belief, for solace and other reasons. (For more refer to: chapter 4.3 Opening Systems : Treatments).

DOOR STOPS: A door stop is used with door shutters to dampen the noise and absorb the impact damage to shutter itself, its frame, nearby wall or furniture. Door stops prevent shutters opening beyond certain limit and thereby protect the hanging mechanisms such as hinges. Doorstops also prevent self closing of the shutter due to askew hinge or pivot alignment or wind pressure.

Primitive-door stops were in the form of wedges of wood or metal inserted under the shutter. A door was held open by simply placing a heavy object such as a brick or stone placed in the path of the door. Historically, lead bricks, when available, were popular. In traditional Indian houses of yester years a small piece of wood hinged to the door jambs was placed as a door stop, to prevent a shutter closing due to the winds. Doors were tied to the side walls by ropes or leather straps, which were cut with a sharp blade (in an emergency) to allow a door to close on its own. Cotton and fodder stock rooms have self closing doors, held open by a thin rope, which on catching flame would close the door and prevent spread of the fire.

Doorstop hinges with a rising butt designed to close a door automatically came in use about 1775. Doorstops were made of metals like wrought iron, brass until about 1850. A handle or some other means of lifting the stop easily were incorporated in the design. Doorstops in earthenware and a few in glass were also made. Many took the form of figures of famous persons, such as Napoleon, Shakespeare, Wellington, Gladstone, and Disraeli. Animal forms were also popular.

Modern doorstops include: door strikes of rubber like material or a spring loaded buffer that absorbs the impact and noise of door striking a wall. Such door strikes also have a door catch in the form of a spring metal fork pin or a magnet to hold the shutter. Doorstops are fitted either on the shutter, wall or on the floor. A foot door stop is fitted at the bottom of a stile and has a rubber vacuum buffer, which can be released or pushed with a foot toe.

ESCUTCHEON: it is a decorative base surrounding an eye piece, keyhole or lock cylinder. Escutcheons are mainly decorative, they provide a setting so that an eye piece or the keyholes are easily located. Escutcheons prevent the eye piece or lock cylinder from rotating and prevent damage to the peripheral area.

STRIKE: A plate with a hole in the middle made to receive a bolt. If the strike is for a latch-bolt, it typically also includes a small ramped or mitred area to help the bolt move inward while the door is being closed (also known as a strike-plate).

SAFETY CHAIN OR DOOR CHAIN: Safety chains are used to restrict the opening of a shutter, just enough to see the visitor’s face or exchange small articles. Safety chains are often lock-able so an outsider cannot open it. The chain is made of hardened metal which cannot be cut easily by a splicing instrument.

PEEPHOLES, VIEWERS: A peephole is a small opening (or glass windows) placed in a door at eye level to allow people to see who is outside the door without opening it. A simple peephole is an aperture with a metal rim, often with a small grill and a shutter on the inside face. Some have a magnifying glass or one way mirror. Glass peepholes are often fitted with a fisheye lens to allow a wider view of the field from inside with little to no visibility from outside. Micro camera systems are fitted within such devices and connected to viewing screen and intercom system.

STRIKERS OR KNOCKERS: A knocker is a functional entity but often used as an ornamental item on the door. Under medieval English common law, this instrument supposedly afforded the right of asylum to anybody who knocked the door of a church. Bells and chimes operated by rope are also used with doors as calling device.

LETTER SLITS OR MAIL SLOTS: A letter slit is a mail receptacle covered with a swinging flap door and a base plate for its fixing in a door or wall. The slot has limited opening, to allow mail to be delivered and sometimes return the receipt note. The flap door is spring-loaded or relies on gravity to remain shut when not in use. It also restricts straight view of the interior. Many mail slots also have a secondary flap, on the inside to offer further protection from the elements, or have a box or baskets on inside to catch the inserted articles. Mail slots are typically horizontal, but on a small width door this could be vertical. A mail slot is an alternative to the mailbox.

ASTRAGAL: A vertical member attached to the less used or inactive door, of a double door system at the meet point of the lock stiles. It helps seal the junction.

THRESHOLDS: Thresholds are not very evident in modern day door systems, but still have a functional necessity. Doors on windy porches, dusty passages, storm (rain) exposed fronts require a threshold. Thresholds were once a necessary component of door system to fix the bottom pivots and keep apart the lower ends of jambs. Such thresholds were of stone and wood. According to Indian mythology a threshold stops bad effects coming into the interiors. Jain temple thresholds are called Shankhavati due to inclusion of a conch like form in it.

Thresholds often have a small central hole to receive the vertical bolting shaft of door closing mechanism. Modern door mechanisms incorporate a ventilation and air curtain like devices as thresholds. Modern thresholds also have sensors to register the weight of things passing over it. All sensing devices associated with openings are called threshold devices, even if these do not occur at floor level. Gurudwaras and temples have feet wash-pits as thresholds. In pharmaceutical plant an extended threshold mechanism can have water jets to wash of feet or dust the shoes, and dry them out with hot air. Thresholds are used for edge fixing of carpet near door gaps.

HANDLES: Doors require handles in certain conditions. Doors’ handles assist mainly opening-closing of the door, but in some instances trigger locking and unlocking mechanisms. A door handle serves purposes like: a grip for closing and opening of the shutter, reduce the wear, staining of the surface of shutter, and spread of infection, through frequent touching. Doors’ handles are nominally hand operated but could be elbow, shoulder, knee or feet operated. Automatic doors do not require handles. Less used door may not have a set of handles but instead a key to the lock system may provide a grip.

TYPES OF HANDLES: Handles have many forms. Handles are horizontal or vertical and occasionally inclined. Handles have a grab bar, knob or a niche. Handles are fixed or rotating knobs, bulbs and bars, fixed, folding or shift-able bars, pins with rings, ‘L’ shaped sections and ‘J’ type or butterfly hooks. Sliding shutters often have a small slit engraved in the shutter surface for gripping. Aldrops, latches, hasps, tadis, and even padlocks are used as handles. Other forms of handles include buttons, knotted ends of a rope, chains, holes, grab-able edges or projections.

Handles for hinged and pivoted doors require horizontal and radial movement for closing, handles for sliding shutters need horizontal pull or push whereas rolling shutter handles are pulled and pushed in vertical plane. Glass shutters rest on a push-back mechanisms that with a push throw open the glass shutter slightly. Mortice locks, hospital door handles, etc. have locking-unlocking system integrated into the handle.

NATURE OF DOOR SHUTTER OPENING-CLOSING:

● Push-in from outside to open inward

● Push-out from inside to open outward

A handle is nominally not required, but for preventing staining or wearing of the door shutter surface.

● Pull-in from outside to close

● Pull-in from inside to close

A handle is required to get a grip on the shutter. Though, one can hold the shutter from the side of the edge but may injure own-self near the jamb.

DOORKNOB: First door knobs were perhaps rope knots that were used for pulling a shutter close and lock it. Doorknobs either are spherical objects fixed over a base plate or attached to an axle that rotated to release the bolt. Door knobs often have an inset push-button or key hole to activate the locking mechanism. Door knobs with human, dwarfs, demonic, animal heads cast in brass, copper and steel, are still popular. Doorknobs also have crystal glass blobs and shaped precious stones. Door knobs require heavy gripping and so are less preferred by infirm people.

DOOR HANDLE: A door handle is a horizontal or vertical lever, attached to rotating pin at one end, which with 30° movement retracts the latch bolt. Doors handles are also C shaped static type, fixed by a set of screw pins from the back side or a plate from a front side. Doors handles are often very long, stretching from shutters’ edge to edge, such as in plate glass doors. Hospital doors’ handles move up and down to open-close the latch bolt. Restaurant pantry doors have no handles, because waiters push the two-way opening shutter by shoulder. Automatic doors require no handles as the sensor opens and shuts the door. Handles over sliding doors are either concealed or fold down to level of shutters’ surface.

CRASH BAR: A crash bar is a mechanism that unlatches a door for an emergency exit. In some countries this is a mandatary requirement for all doors recognised as emergency exit points. It is called crash or panic bar, because when someone pushes against it, the door gets opened. Such bars are normally placed on the interior face of the door.

FASTENERS: A door fastener is a long armed hook device with a pin joint at one end and a ring for insertion at the other end. Fasteners are fixed at top or the middle of the shutter to prevent a door or windows’ shutter from closing automatically or due to wind.

CROSSBAR: It is sometimes called a bolt. It is simple plank, bar or beam of wood or metal inserted on the back side of a door to reinforce the shutter and prevent break-ins by force. The insertion is either in the cavities on jamb sides or through special cleats fixed on jambs. Often the bar is pin jointed at one end to keep it from misplacement or theft. On double doors, the bar extends over both shutters.

CROSS BUCK: Horizontal bars are bolted across the vertical planks and used in place of the rails to strengthen the door shutter.

GLAZING: Glazing refers to the panes of glass set into windows, doors and other openings. It can also refer to the putty or mastic compound used to seal the glass. Glazing today refers to any transparent to translucent material used as a panel within an opening or a shutter in it. Glazing is also a process that provides a glossy surface through a coating or through rubbing and polishing an existing surface.

4.1.2.4 DOOR MECHANISMS

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Keywords: DOOR MECHANISMS / rotated / hung / opening downward / moat doors / leaf opening upward / pulley based mechanical leverages / pocket doors / counter weights / sloped guide-ways / modern garages / old style warehouse elevators / collapsible or folding type / folded assembly slides / push-shut / doors of public spaces / fire and emergency exit doors / ACTIVE DOOR / dual shutters / secondary or less active or inactive door / MANUAL DOORS / mechanism and configuration / counter balancing and coiled spring / MECHANICAL DOORS -SEMI AUTOMATIC DOORS / wide door / mechanical automatisation / AUTOMATIC DOORS / control and security system / Sensor powered doors / Switch operated doors / Pressure detection doors / Delay mechanism synchronous doors / DOOR SWINGS / left hand LH / right hand RH / left hand reverse LHR / right hand reverse RHR / dual opening doors / bidirectional-mixed traffic / circular swinging doors / sliding or pushing doors / CONSTRUCTION OF DOORS / reinforced by mid bulging / doors of fragile materials / side impact thrust / auto opening and closing system / foot operated handles / automatic opening-closing sensors / buffer or banging plates / SCALE OF DOORS / very wide doors / barricades to channelize / multiple door system / tall doors / tall opening like effects / architectural door portals / functional door / large doors / additional lateral framing / dams and canal gates / 3D entities / extra lateral stability / DOOR MOVEMENT / holder or retainer / load bearing unit / self pivots / hinges / wood door frames / masonry surrounds / space to open shutter / sliding doors / demountable shutters / crossbars / shutters sliding in guides / Stacking of shutters / sliding and folding stack / DOOR HEADS / double shutters / gothic twin doors / Ganged or multiple doors / side lites.

DOOR MECHANISMS: Modern doors have many shapes, sizes and configurations. Traditional doors rotated on pivots or were hung by hinges from sides. Shutter opening downward from top, used gravity for fast closing in emergencies, but fall required a pit for parking and it hindered the surface movement, so was rarely used. Top hung doors or moat doors of medieval English castles opened to form a bridge over the pit. Door leaf opening upward is an action against gravity, and so it is difficult to handle, unless the lift is assisted by pulley based mechanical leverages. Sideways moving of shutters or pocket doors are aided by counter weights or sloped guide-ways. Such mechanisms are still used in cotton godowns doors where a fire could burn a fabric ring holding the door against sliding to a shut position, automatically. Utility delivery vehicles have doors sliding sideways. Modern garages have automatic doors with leaf opening upward and sliding parallel to the roof underside. Old style warehouse elevators have, part of the door sliding up and the other half sliding downward. Industrial units where large size goods and equipments are frequently transferred, door shutters are of collapsible or folding type. The folding action is either in horizontal or vertical directions. In case of very heavy vertical folds, the folded assembly slides while being supported and guided.

Doors nominally open on inside or the side that is controlled or protected by the owner. It is easier to push-shut a door and keep it shut against an intruder forcing against it. However, doors of public spaces such as stadia, cinema, etc. must open out towards a street or open space. Fire and emergency exit doors must also open out.

ACTIVE DOOR: When a door has dual shutters, the first shutter to enter or leave the house, nominally the right side one, is called an active door. These shutters have the locking device and the key hole. The other shutter is called secondary or less active or an inactive door. The secondary shutter is opened when the flush bolt (stopper) is released.

MANUAL DOORS: Manual doors are operated by a person, and in few cases by a trained pet. Manual doors have mechanism and configuration that are within the anthropometric capacity of the user. A heavy door shutter, but with well lubricated and balanced movement system can be operated by a child or infirm adult. Systems that have shutters (inclined or upward), opening against gravity, are difficult to handle. These categories include shutters sliding upward, hatch doors, etc. However, such shutters are made easier to operate by counter balancing and coiled spring mechanisms.

MECHANICAL DOORS -SEMI AUTOMATIC DOORS: Such doors have an assisting mechanism that helps make their opening, closing, locking and unlocking, easier. A wide door requires less pull, but the reach to the shutter due to a larger radius of opening makes it difficult, especially for a wheel chaired, infirm, or a person with crutches or walking sticks. Lever armed handles, double shutters in place of one, askew fixing of hinges for towards gravity auto closing or opening, double hinges, auto (hydraulic) door closer, floor springs, etc. are some of the common methods of mechanical automatisation.

AUTOMATIC DOORS: Automatic doors are single or dual shutters and often operate as multi door system. Such doors usually operate as a sub system of a larger control and security system of the building.

Sensors powered doors activated by some photo-voltaic or infra red sensors that detect the presence of a person or an object, coming into its path, open the door and keep it open for prefixed duration, opening width, and scans the path again.

Switch operated doors are manually operated such as when a person pushes a button to open the door or certain conditions such as the identity checks have been confirmed.

Pressure detection doors operate when: the pressure increases or decreases beyond prescribed levels, by temperature or moisture level settings of the room and by the weight of the person or object through a floor mounted weighing scale.

Delay mechanism synchronous doors do not allow the paired door to open out till the other door has closed properly and an adequate seal is achieved, and other intermediate operations have been completed. Intermediate operations include scanning, cleaning, pressure equalization, disinfection, etc.

DOOR SWINGS: Door swings or Handing, are always specified as from the outside, i.e. outside to inside or public to private.

Left Hand LH: If the hinges are on the left and the door opens in, it's a lefthand door. You push the door with your left hand.

Right-hand RH: If the hinges are on the right and the door opens in, it's a right-hand door. You push the door with your right hand.

Left-hand Reverse LHR: If the hinges are on the left and the door opens out, it's a left-hand reverse door. You pull the door with your left hand.

Right-hand Reverse RHR: If the hinges are on the right and the door opens out, it's a right-hand reverse door. You pull the door with your right hand.

Dual opening doors: Doors for bidirectional-mixed traffic like, a restaurant’s pantry, laboratories, etc. need to open both ways, and here the pivot that provides ideal mechanism for dual opening. Salon and flap doors also open both ways.

Circular swinging doors: Revolving doors for office entrance foyers, railway stations and other public places are circular swinging doors, though here movement is restricted to clock or counter-clock wise.

Sliding or pushing doors: Sliding doors have left and right sideways movements. In counter balanced and automatic doors a slight push opens both the shutters simultaneously.

CONSTRUCTION OF DOORS: Sliding panels of doors need to be stiff and could be reinforced by mid bulging or assisted by guide channel or rail, at top or bottom, or both. Fire prone areas have doors of fragile materials, (easily to break in an emergency such as, ordinary -non toughened glass, no fixed grills, thin body shutter leaves) which in case of an emergency can be broken. Car and other vehicle doors are designed to absorb the side impact thrust through provision of extra depth and reinforcement.

Certain doors need to be opened without touching them, as both the hands are occupied (kitchen-pantry service) or hands are likely to get contaminated (operation theatres), such doors have an auto opening-closing system or have a foot operated handles. Similarly doors with high degree of wheelchair commuters, heavy and long trolleys (hospital patients, industrial plants) require automatic opening-closing sensors. Warehouse doors have touch sensitive buffers or banging plates that help the door to open out and away from the direction of pressure or push.

SCALE OF DOOR: Historically very wide doors have been a necessity, for functional as well as for splendour. Wide openings are provided for ceremonies, processions, etc. but wide doors are incapable of regulating the traffic. Such openings have either barricades to channelize the traffic, or multiple door system is used.

Tall doors were less of a functional necessity but a compulsion in monumental structures with royal or public patronage. For very tall doors, the construction of strong shutter and relevant opening control mechanism has been the greatest deterrent. Tall opening like effects are created with architectural door portals, where the functional door is very much smaller.

Large doors require lateral stiffening, as the usual thin shutter leaf construction is insufficient against buckling forces, wind, blasts, and often sonic boom pressures. Aircraft hangers’ and spaceships’ assembly workshops (Apollo, Columbia, USA) have very large doors with additional lateral framing. Similarly dams and canal gates have to resist not only the pressure of retained water but dynamic pressures of waves and eddy currents. Such doors are designed as a 3D entities. Stadia and such public spaces where people are likely to push the gates, extra lateral stability is required.

DOOR MOVEMENT: Doors have shutters, and the variety of ways these are fixed show the nature of functions that can be served and the level of technology available. In the pivot system, the upper unit is a holder or retainer one and the bottom one is the load-bearing unit. Pivots are still considered ideal for very heavy shutters. Replacing an old style pivot on a shutter was difficult, often requiring reconstruction of the door frame and surrounding structures. Over the years, for lighter panelled doors, shelf-pivots were used. The shelf-pivots became hinges, but later more hinges were used to keep a thin shutter straight. It was possible to fix metal hinges to wood and cast metal door shutters, but to fix the other end of the hinge to a stone or masonry wall was difficult. Wood door frames replaced the masonry surrounds.

For side-hung shutters, a space to open the shutter is required on inside or outside. This is not available in small rooms, narrow passages and also where the immediate terrain is upward-downward-sloping or stepped. For such situations sliding doors or doors with demountable shutters are preferred. Side hung shutters with latches or backside closing crossbars cannot resist an intruder pushing in, for such situations shutters sliding in guides (rails or channels) at sides, top or bottom are ideal. Stacking of shutters by using multiple channels or guide rails allow larger opening. Where multiple tracks are not, feasible shutters are joined together like the bellows of an accordion to form a sliding and folding stack. Folding or collapsible doors were first used in cabinets and cupboards. For a folding or collapsing shutter stack the first or primary shutter is supported on pivot and other shutters are hinged to them.

DOOR HEADS: Doorway width was restricted by the spanning lintel or the arch, but width of the door shutter depended on the materials and technology used for shutter construction and mechanisms of movements such as a pivot, hinges, slider guides, etc. Large doorways require equally large shutters. Double shutters remained a common choice for wide openings. Gothic twin doors had an intermediate support elements. Ganged or multiple doors became popular due to the size restrictions imposed by the glass panes. In verandahs and public places such multiple doors provide the localised choice of controlled opening. Doorways’ gaps are also narrowed by placing side lites or side windows. Small shutters were inset within large shutters (such as fort doors). A door within a door is also provided for pets, delivery of milk and postal articles.

The gates at Balawat (now in the British Museum) were of two leaves, each about 8 ft.4 in. wide and 27 ft. high; they were encased with bronze bands or strips, 10 in. high, covered with repousse decoration of figures, etc. The wood doors would seem to have been about 3 in. thick, but the hanging stile was more than 14 inches diameters. Other sheaths of various sizes in bronze have been found, which proves this to have been the universal method adopted to protect the wood pivots. In the Hauran in Syria, where timber is scarce the doors were made in stone, and one measuring 5 ft. 4 in. by 2 ft. 7 in. is in the British Museum; the band on the meeting stile shows that it was one of the leaves of a double door.

4.1.3.1 DOOR STYLES

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Keywords: GOTHIC REVIVAL STYLE / Revival Style Architecture in America / Collegiate Gothic / CLASSICAL DOOR / Federal, Georgian, Classical Revival and Greek Revival / MEDIEVAL DOOR / horizontal and diagonal braces / RUSTIC DOORS / rough hewn / INDIAN SHOP (MARKET - BAZAR) SHUTTERS / lock bar or rail bar / INDIAN SHOP (MARKET - BAZAR) SHUTTERS / GEORGIAN STYLE / crown or pediment / pilasters / ADAM or FEDERAL STYLE / fanlights / MOAT DOORS.

GOTHIC REVIVAL STYLE: Gothic style of high middle ages used in cathedrals in Western Europe was used as Revival Style Architecture in America in the 19^thC. It was widely used for churches and universities, where it was called Collegiate Gothic. Gothic Revival buildings often feature a panelled front door set into an arch, partially glazed with Gothic motifs, tracery or a simple rectangular or diamond-shaped pattern.

CLASSICAL DOOR: A general term referring to a door constructed according to the architectural style based on classical Roman or Greek forms. Examples of classical door styles include Federal, Georgian, Classical Revival and Greek Revival.

MEDIEVAL DOORS: European medieval wood doors typically consisted of vertical planks backed with horizontal and diagonal braces. These were strengthened with long flanged iron hinges and stud nails.

RUSTIC DOORS: Rustic doors are similar to medieval in construction but the wood is unfinished or rough hewn (or saw cut) and fixed as the panels but without the framing.

INDIAN SHOP (MARKET - BAZAR) SHUTTERS: These shutters are formed of loose wood planks that are inserted in the top and bottom grooves within a wooden door frame, stone or other masonry. The planks are held together by a lock bar or lock rail of wood or steel.

GEORGIAN STYLE: A style of architecture that took its name from the Kings of England and it was prevalent in the American colonies from 1700 AD until about 1780. Georgian houses usually displayed a strict symmetry with a panelled door as a centerpiece. Typically the door was capped by an elaborate crown or pediment, and often bordered by pilasters (flattened columns) on each side. The style lost favour after the American Revolution, when the Federal and Classical Revival styles gained more widespread use.

ADAM OR FEDERAL STYLE: A style named for British architect Robert Adam, who introduced the use of fanlights, semicircular windows integrated over the door section, to accentuate the doorways of London townhouses.

Adam or Federal style (It is also style of architecture) that was popular in post-colonial North America from 1780 to 1820. Both the Federal style and the Classical Revival style came into favour following the American Revolution, symbolizing the new republic and replacing the earlier Georgian style and its association with England. It is characterized by elegance and lightness compared with the Georgian style.