Tuesday, May 31, 2016


Post 142   by Gautam Shah

Corridors are formal transfer zones in buildings, but sometimes passages get formed with intense movement conditions between two points. Corridors are architecturally articulated built forms, whereas passages are marked or delimited sections. Corridors and passages are distinguished by barricades, flooring differences, sensorial markings, graphics and signages.

Meenakshi temple Corridor Madurai India Flickr image by Jean-Pierre Dalbyra
 A corridor as a built form is highly a formal entity and it is difficult to breach the discipline, but passages have no formal structure, and can be overstepped. A corridor is a passage, but a passage needs to be well modulated to become a corridor. A corridor without the traffic, will still remains a corridor, but a passage without movement just merges in the surrounding space. Corridors are more formal then passages, but passages allow greater public participation, and so ceremonial.
Corbet's Couloir -a ski run or passage Wikipedia image by Enricokamasa

Alleys, arteries, aisles, channels, lanes, couloirs (narrow passageway on a hill), tunnels, paths, lobbies, vestibules, avenues, all have one common element: a linear passageway. A labyrinth and maze, are entwined passageways, where the former one ‘has a single path -unicursal, reaching the centre; and the later is a complex branching -multicursal puzzle, with choices of a path and directions’.

Labyrinth Chartres Cathedral Wikipedia image by Maksim
Corridors and Passages, as transfer systems in buildings are well defined and functionally supported by other systems. Such transfer systems become ineffective, if design definitions are improper, have inaccurate capacities, or lose the validity due to the changed circumstances. When a transfer system becomes ineffectual, many other systems in the building become useless.

Books in Corridor Pixabay image by Unsplash

Corridors, are defined or recognized as passageways, connecting a point to point location, or several ones on the way. Corridors are defined by architectural features, distinctive materials and environment, sensorial recognition of their existence, signage, and preference for the shortest and easiest access route.

Corridors originate at points of transfer such as doors, other branch corridors, stairs, elevators etc. Corridors also occur where conditions for superior and efficient transfers are available, such as: shaded or protected areas, finer floorings, smoother gradient, pleasant surroundings, promise of fulfillment, expectancy, escape from hazards.

Passage Junctions Pixabay image by ujeans

Straight corridors provide a very efficient mode of transfer, but tend to be monotonous. Straight corridors allow continuous acceleration, which may pose problems to other transferees. Corridors with zigzag or variable movement directions heighten the expectancy. Circular or curved corridors tend to align the movement concentrically. Bidirectional movement corridors increase the social interactions among the users. Multi directional and multi velocity movements destroy the character of a corridor.
Main hall Brussels railway station > Wikipedia image by Saber68

Corridors are heavy movement areas, compared to many other spaces used for casual transit. Corridors, due to heavy traffic create environmental interference of noise, vibration, dust and spread pollutants and infections. Corridors enhance the fire hazards and security risks; however, if properly designed, may curtail such risks. A straight corridor can be policed from one point, but so an intruder (terrorist) also can command the entire corridor.

In complex buildings variety of work spaces, each with specific environment and controls are required; corridors as buffer zones isolate such spaces. Corridors create an intermediate or equitable zone of transfer for all such connected units. Corridors provide a strong cohesive identity among apparently very unrelated cells.

Main committee corridor Westminster London > Wikipedia+Flickr image by Mark Kobayashi-Hillary

 Corridors are ideal, if without any encumbrances, like cross passages, doors, and architectural transgressions (projecting out or receding in). But very long corridors, such as at Airports and underground metro services, without intervening interests become boring. Corridors are common utilities, so have several services attached to them, such as, toilets, drinking water fountains, fire fighting systems, emergency exits, air handling units for air-conditioning systems, seats, electrical mains, bulletin boards, exhibitions, first aids, security checkup systems, food and beverage dispensing systems and signs. A Tirupati temple (India) corridors are also used by devotees as a place to sleep, rest, eat, bathe and pray during the long wait for the Darshan.
Parikrama around Girnar Mountain Gujarat India > Wikipedia image by Nileshbandhiya
The word Corridor derives from Italian Corridore =place or space to run, which in turn has derived from correre or Latin currere='to run'. By association courier, meant a man or horse who could run to deliver messages, money or documents. Italian word corridoio is a place, or rather space for the courier (man or horse) to run.

Ponte Vecchio and Vasari Corridor from Galleria degli Uffizi > Wikipedia image by JasonF007

From later part of 16th C. Corridors were strategic spaces or routes of access in fortifications. Couriers and corridors were used for quicker deliveries by the military. It had military ramifications for defence or offense, but very little civilian relate. The space for a faster messaging, the corridoio was not a marked territory or a facilitated ground within a fortification or dense urban setting. It was simply a familiar-well travelled precinct. In late 16th C it denoted a military term for a narrow strip of land along the edge of a ditch or fort-wall sometimes protected by a parapet. It was also a narrow passageway along the slope of a hill and sea. Trails are marked passageways but in the wilderness. Trails are so narrow that most vulnerable or unafraid ones lead the way, and others must trail.
Secret passage between Vatican and Castel SaintAngelo Rome Italy Wikipedia image by Patnaik+ Alessio Damato

Thursday, May 26, 2016


Post 141   by Gautam Shah

Interior Design as a profession is changing at a very fast pace. Today many different forms of interior design practices exist, ranging from

Pure design (only),

Design + Supply,

Design + Supply + Execute (install-fabricate-operate).

Frank Lloyd Wright Pope-Leighey House > Wikipedia image by Cliff from Arlington Virginia USA

These classifications arise due to ethical reasons (professional bodies, governmental regulations, etc.), taxation, traditions and business convenience. There was a time when Interior designer or decorator worked on a site or few sites, within the travelable region. In very large, complex and remotely located projects, however, it was not feasible, for the designer or their representative to be present all the time on a site, and conduct the projects. Interior Designers, as a result, gradually began to limit their work to design matters only, and let other agencies handle the supply and execution. The practice of employing or appointing ‘third party venders or contractors’ serves varying degree of efficiency, reliability and satisfaction, for corporate or government types of organized clients.
Print 1833 of Dome of Rock Jerusalem > Wikipedia image by Georg Dehio/ Gustav von Bezold

In recent years large number of holistic Interior Items and systems have become available. These vendors (such as of modular kitchens, Toilets, Ceiling, Acoustics+Ceiling, Painting and other surfacing, Glazing, etc.) offer complete installation services. So Amateurs and Lay-users prefer services of such supply-install venders.

Vendor-Supply Interior Design Practice through use of Catalogues (by James Shoolbred & Co. 1876) Wikipedia image
 On the other hand, small practice designers found it more convenient to mange execution along with design. Designer self executing their own design often worked, without premeditated scheme. Designers, who lacked the capacity to detail out or document a project, preferred this route. These small time designers or amateurs have a capacity of creating design images (representations like Isometric, perspectives, 3D images, etc.) which are used as presentations for enticing a client. These amateurs rely on known craftspeople who can execute the design from such images and workout the lacking details.
Diagram of three corbel brackets at Chinese Hall by Official and architect Li Jie 1103 Wikipedia image by PericlesofAthens

There was a time when a Designer had to specify raw materials and the process of assembly or manufacturing to generate a product or a functional system. To check the suitability of the delivered product, and operative validity of the system, a series of tests and check parameters are also required. Very often these parameters remain worthless, because neither, the required level of manpower and testing equipments are available at a site, nor is it feasible to take the product or system from site to such locations.
Jasper Morrison Furniture in the Musee des Arts Decoratifs > Wikipedia image by Gael Chardon from Paris France
 Design needs are now documented in terms of ‘performance specifications’ or optimum operative functionality to be attained by the vendor or contractor, with their choice technological input (materials or manufacturing). This type of modern design documentation requires high level of skill input, technological knowledge-ability and professionalism. Amateur or untrained (hobbyists) interior designers do not have such proficiencies.
Documented design by Robert de Cotte 1700s

The separation of design and execution, is also favourable arrangement from point of view of Taxation. Pure Design practice is liable for simple taxation like Service Tax. In Design + Supply practice, a designer may be liable to pay other taxes (Sales Tax, etc.). Design + Build practice, is though an accepted norm in many countries of the world.

McElroy Octagon House on Gough st San Fransisco Cal 1891 Credit Library of Congress Prints & Photographs Division WIS,28-WATO,1-

 Interior Design like any other Design profession, is a dependent profession. Interior designers work in conjunction with other design professionals, needing interior design inputs in their projects, such as Architects, Building engineers, Landscape designers, Furniture and Product designers, Exhibition and Event managers. Interior designers also use expertise of other professionals for their work. These include environmental engineers, ecologists, furnishing experts, textile designers, painters, sculptors, and an array of crafts persons.

Pixabay Free image by stokpic
 Some degree of specialization is becoming apparent in Interior Design. Some of the major fields to have distinct identities within the ambit of Interior Design are: Hospitality or hotel design, Entertainment facilities, Public space design (air ports, railway stations), Exterior design or Street architecture, Exhibitions and events planning, Retail designing, Transport interior design. These fields naturally demand a varied manner of design approach and handling.

Sunday, April 10, 2016


Post 140   by Gautam Shah


Projects or their near independent systems, when nearly ready, begin to function or need to be operated early. Systems, for example, such as the load-bearing entities become operative as soon as installed or the supports are removed. Similarly systems like stairs and elevators or water supply etc. are made operative for use by construction personnel. Some systems need to be run-tested for certification, safety and other guarantees and warrantees to be effective

Towering inferno, a movie of 1974 showed how important are the Operations Manual and Specifications for fighting fires
 A system that is operative also becomes due for regular maintenance, servicing, repair, safety and security observance, and comes under the scope risk-management (such as insurance, fire, etc.). Operations’ Specifications relate to terms and conditions of operating and maintaining various systems of the project. For small, simple and projects of routine nature there may not be any acute need to create a set of such documents. Complex projects, however, require professional operators who may need not be the original contractor or vendors. These third party operators need a formal assignment of their work and responsibilities. The assignments delineating these are the operations manuals. Operations manuals are not just handed to assigned or contracted operators, but placed in an accessible location for emergency reference.

Escalator maintenance Operation > Wikipedia image by Dailongumuneka
Projects of routine and simple nature are distinctly delivered - handed over to the client or user, according to a defined process and schedule. The client or user, thereafter on their own, or through other agencies, manage and operate the system.

In case of complex projects, however, consist of several subsystems which begin to be operative as soon as these are installed. Contractors and vendors use such subsystems during the execution of the project (such as stairs, drainage & water supply system etc.), and sometimes manage them till the project is delivered. In cases like, turnkey projects, some of the subsystems must be operated for trial and verification.

Nose section of Boeing 747 tested with pressure tanks > Wikipedia image by Oliver Cleynen
Operations specification for traditional material specifications+ processes of construction or assembly are different from projects “delivered” through Performance Specifications. Projects conceived through Performance Specifications invariably have many built in provisions for care of the main and subsystems during their emergent phase. For routine projects, in many organizations, the job of operations and maintenance is handled through departmental facilities or out sourced to specialized agencies. In both cases, yet a strategy is required for dealing with probable conditions and also for less-predictable situations (disasters, crisis). Designers of the system may provide such a strategy, or specialist agencies are required to prepare the operational specifications.

Mech+Elec+Plumbing MEP area > Wikipedia image by Eric T Gunther 
Forms of Operations Specifications

Operations specifications become key instructions during crisis. The agency that evolves the operational specifications, such as Owner, Designer, or Operator of the systems, each may adopt a varied strategy, often lacking coordination to deal with the situation. Professionals are now available, who can independently assess a building system, and prepare a set of operations specifications.
During emergency there is little time for understanding a layout > Wikipedia image by Cpl Trent A. Randolph

Operations specifications are often more graphical then written to make its access non technical, and free of language barriers. Many specifications are in the form of signage, instructions or warning signals. These specifications may not occur as a single comprehensive document but distributed across the estate. Repairs and maintenance work, need to be scheduled with other plans of actions. Operations specifications also include methods of observance, supervision and feedback systems.
Complex entities require equally meticulous schemes for operations > Wikipedia image by Reinraum

Conditions for Creating and Providing the Operations Specifications

1          System Designer, System Provider (contractor, fabricator, vendor), and the System Operator, each of the roles should be clearly defined.

2          A System Provider must distinctly (formally) handover (deliver) the System (whole or self-sufficient parts of it) to the Client or appointed System Operators, as provided in the contract.

3     A System Designer and System Provider, together evolve the Operations Specifications. Only one of them is made responsible for Formal Transfer of the Operations Specifications' Documents to the operative agency.

4          System Designer (or the client) must see those necessary guarantees as available from Vendors and Sub contractors, and as provided by the main System Contractor, are transmitted to the Client. Alternatively a third party agency is appointed to create them afresh, and also affect such a transmission of guarantees.

Wednesday, April 6, 2016


Post 139   by Gautam Shah

We need to move, along, away or towards the gravity. These modalities form transfer systems. The transfer systems along the gravity include paths, corridors, passages, etc. Transfer systems away or towards the gravity are perpendicular or inclined, and include firemen sliding poles, garbage chutes, emergency evacuation tubes, steps, stairs, ladders, slides, escalators, ramps and elevators. Some can be of both categories, like automated walkways, cable hung cars, roller coasters, conveyers, etc.
Climbing up the rock face at Angel's landing (Zion National Park) > Wikipedia image by Alex Proimos from Sydney Australia

All movements are essentially directional but transfer systems occur in unison, for two way movements. The other segment, however, manifests in some other situation, occasion, location or format. An escalator as an unidirectional system is more efficient than a mixed movement system like a stair. The gravity accelerates the down-movement, and inclination retards the rate of passage.

Jain Pilgrims on Shatrunjaya hill, Palitana Gujarat India > Flickr image by Arian Zwegers
Regularized transfer systems are uninterrupted services, and have width or passage way as the restrictor. Other restraining factors include speed of movement (goods or people, etc.), acceleration-de-acceleration, intermediate entry-exit openings, and safety. Carriage transports such as elevators are discontinuous services, and restrained by the frequency of service and capacity of the module.
Stairs and Escalators at Cabot Circus Shopping Centre, Bristol England > Wikipedia image by Arpingstone

Stairs and Escalators are stepped and inclined, transfer systems. Both provide uninterrupted transfer services. Use of stairs requires some orthopaedic proficiency and cautious posturing, but automated escalators allow freedom to see around during the passage. Stairs can take mixed traffic of accent and descent, but escalators require different sets. Reverse escalator services are often not provided as stairs are not very strenuous to climb down.
142 Mts long Potemkin stairs Odessa (1834-41) made famous by movie The battle of Potemkin 1925 > Wikipedia image by Dezidor

Film shot of The Battle of Potemkin on Odessa steps
Stairs and escalators are point to point passageways, as there is no midway interference, except at landings. Mountain side steps when comparatively wide show midway disturbance when people climb up diagonally to increase the negotiated distance and thereby reduce the steepness. Escalators are designed to be intermittent systems reaching floor to floor. Escalators transiting multiple floors are not perceived to be safe. Similarly multi floor escalators combined with landing level automated walkways are not favoured.
Streets of Cusco Peru > Road Ramp and matching step gradient > Wikipedia image by Rod Waddington from Kergunyah Australia

Steps and Stairs generally have a pitch higher than ramps. Stairs are safer than ramps provided the person is fully mobile and orthopaedically fit, but ascent or descent over stairs, more strenuous than the ramps. A ramp can have gradually variable pitch, but a stair has to have a one continuous grade of pitch.
Grand Staircase of RMS Olympic > Wikipedia image
The inclination of steps is defined by the relationship of tread versus the riser of the steps. This relationship varies for steps and stairs used for different purposes, ranging from steep ladders to flatter ramps like foot-ways. The dimensions of tread and riser are proportional and can be plotted on a hyperbola. Certain formulas also provide such proportions: 2T + R = 650 to 680 mm or R x T = 43000 to 45000. For steeper pitch the additional effort required to work against the gravity reduces the efficiency.
Steps with alternating treads over steel rock slope of Pinnacles National Park California USA > Wikipedia image by Wing-Chi Poon
Stairs have a pitch of not less than 17.30° (5:16), and of not more than of 48.30° (9:8). Below these limits it becomes a ramp or foot-ways, and above it a ladder. A ladder is not a comfortable utility. Step-ladders are lower in pitch, less than 75° and require flat treads. Risers may be open or closed, for toe accommodation and handrails may or may not be provided. In the ladders’ class of stairs, some are easier to climb than others. Ladders are used for fire escapes, boiler rooms, fly galleries, attics, decks, etc. Rung ladders are pitched more steeply, above 75°, and have extremely narrow treads or round rungs to accommodate the foot. In certain cases, the space to accommodate the knee between steps may be necessary. Rung ladders usually do not require additional handrails as the side members of the ladder can be used for holding grips. Rung ladders are often caged for safety, though such cages are more useful for ascent then for descent. It is safer to climb down facing the ladder. Swimming pools, water tanks, and sewers have rung ladders. Manhole steps are very narrow in widths, but the width is otherwise compensated by its staggered placement. The same holds true, for climbers for bunk beds, whether in railways, buses, barracks or homes.

Temple steps Thanjavur Tamil Nadu India Wikipedia image by Thamizhpparithi Maari

 Steps are components of stairs. Stairs when open (to sky -not covered on sides or top) are considered steps. Steps are freer architectural appendage or inset elements to negotiate small height differences. Steps traditionally have had abutting walls on either side. Steps could have same tread-riser relationship but steps are less steeper. A staircase is an enclosed or caged set of steps to several floors.

High pitch Bathing Ghat steps of ChetSingh Ghar Benaras India > Wikipedia image by Patrick Barry from San Francisco USA
Minimum width required for low intensity unidirectional traffic is 600 mm, however most standards specify 900 as minimum width for escape in a hazardous situation. A two-way lane stair should be at least 11200 mm. Sufficient width space for movement is required at torso level, otherwise at feet level a minimum width of 250 mm is required. Where same step is to be used for placing either one of the feet, both, the step and passage widths of minimum width of 500 mm are necessary. Stairs less than 500 mm width are generally emergency stairs rarely to be used, or service stairs to be used by experienced persons. For single lane traffic 750 mm width is an accepted standard. Most of the building bylaws allow minimum 900 mm widths for private buildings. For public buildings a stair width of 1200 mm to 1500 mm is recommended. For pedestrian over bridges and other public thoroughfares, a stair width of 2400 is recommended. On public thoroughfares where traffic is totally segregated or is only one directional, the minimum stair width could be 1800 mm.
Stepped Caen Hill Locks of the Waterway on Kennet and Avon Canal Devizes Wiltshire England > Wikipedia image
 Many stepping arrangements are used for emergency and special purposes. Simplest is a knotted rope or a rope ladder secured to a wall or column. In many countries older buildings were required to confirm to new bylaws, open iron stairways on the building's exterior were placed. Open iron stairs, though are rendered useless by smoke from windows, so must be placed against a blank wall. One of the best fire escape stairs is a fully enclosed stairway in the building itself or in an adjoining tower. Uncoated or unprotected steel is highly hazardous during a fire as it expands and deforms the stairway. Wood though combustible catches fire slowly, and allows more escape time compared to an unprotected steel stair.
Fire exit stairs in Soho NYC > Wikipedia image by Jorge Royan


Friday, March 11, 2016


Post 138   by Gautam Shah

       BLOG SITE >> https://interiordesignassist.wordpress.com/

229 CORRIDORS AND PASSAGES (Part – I) (30 Oct 2014) https://interiordesignassist.wordpress.com/2014/10/30/corridors-and-passages-part-i/

230 CORRIDORS AND PASSAGES -as Transfer Systems in Buildings (Part – II) DESIGN PARAMETERS (31 Oct 2014) https://interiordesignassist.wordpress.com/2014/10/31/corridors-and-passages-part-ii/

261 CORRIDOR SPACES (1 Dec 2014) https://interiordesignassist.wordpress.com/2014/12/01/corridor-spaces/

276 CORRIDORS and PASSAGES Transfer Systems in Buildings (Part – III ) Passages (16 Dec 2014) https://interiordesignassist.wordpress.com/2014/12/16/corridors-and-passages-transfer-systems-in-buildings-part-iii-passages/

277 CORRIDORS and PASSAGES Transfer Systems in Buildings (Part – IV ) Vasari Corridor of Florence (17 Dec 2014) https://interiordesignassist.wordpress.com/2014/12/17/corridors-and-passages-transfer-systems-in-buildings-part-iv-vasari-corridor-of-florence/

522 VERANDAHS and equivalent architectural forms (26 Sept 2015) https://interiordesignassist.wordpress.com/2015/09/26/verandahs-and-equivalent-architectural-forms/
548 VERANDAHS and equivalent architectural forms Part – II (19 Nov 2015) https://interiordesignassist.wordpress.com/2015/11/19/verandahs-and-equivalent-architectural-forms-part-ii/

153 TRANSFER SYSTEMS 14 Aug 2014 https://interiordesignassist.wordpress.com/2014/08/14/transfer-systems/

MOVING out of the BUILT FORM (26 July 2014) https://interiordesignassist.wordpress.com/2014/07/26/moving-out-of-the-built-form/

Sunday, February 21, 2016

DOORS -SECONDARY HARDWARE (Latches, stays and stoppers)

Post 137   by Gautam Shah

Doors have THREE categories of HARDWARE:

1 BASIC HARDWARE attaches a shutter directly or through a frame to an opening or doorway. (Basic-Hardware)

2 SECONDARY HARDWARE provides control on the movement of a door such as Latches, Stoppers, Locks-keys, stays.

3 APPENDAGES OR ATTACHMENTS that endow various types of functionality.


Secondary hardware provides 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 formed of braided metal wire or fibre ropes. The chains are primary locking devices with loops formed of round or oblong rings, a locking ring at one end, and a fixing hook at the other end. 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.

Padlock Pixabay image by tpsdave

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 or another shutter. 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. 

Strapped Latch > Pixabay image by Hans

Latch arrangement over Soda water bottle > Wikipedia image by Arthur Ccyyrree

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.

Latch or Aldrop > Wikipedia image by Palagiri
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.

Door Latch > Pixabay image by TryJimmy

LATCH-BOLT: A bolt has an angled (chamfered) 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.

Door safety chain > Wikipedia image by Santeri Viinamaki

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 chamfered, so that no one from outside can open the bolt with stiff card like credit card. Deadbolts are fixed as add-on system over the inside face of the door. Such 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.

Door with two locks in the knob and deadbolt > Wikipedia image by Brian Katt

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.

Hasp or Chapras > Wikipedia image by Ajmint

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.


DOOR STAYS are mechanisms to keep a door shut or stay it in a particular open position. Normally stays are used to keep a shutter closing down, and so used on the internal (opening) face of the shutter, whereas latches and such mechanisms are used for preventing the opening of the shutter. Some stay mechanism is required to restrict movement of a pivoted door in one direction. Stays can be placed at the bottom, midway or at the top of the shutter. Other staying mechanisms are: stoppers, door restrictor door-stops, door catch, door closer and friction stays.

Door stay wedge > Wikipedia image by Bozembla

WEDGE STAY: A wedge is one of the oldest stay systems. It is made from wood, metal or stone. Wedges function due to friction from the floor surface.

WINGED STAYS: These are hinged flaps that can be opened out over the side of the stile of the shutter to prevent the door closing. These are fixed at handle height and so comfortable to operate.

PRESSURE STAYS work with vacuum or suction created in a hollowed rubber rim. These are at floor level and so foot operated. Some stays when not used have an extra mechanism that turns to the closing edge of the door to keep it slightly ajar. These makes, it safer for children and old persons hurting their knuckles.

DOOR HOLDERS: These are fixed at the back of the door (where a wall or such striking face is available). The door side attachment is held by vacuum, magnet or mechanical snapping.

Door Catch with magnet > Wikipedia image by Brokensphere 
SHUTTER HOLDERS or PREVENTORS: These are essentially restrictive arrangements that prevent a shutter from opening to full width. These are used for hinged, pivoted and sliding doors to regulate the entry or exit. The mechanisms include stretchable ropes, chains or armed levers. Automatic doors have sensors that judge the width of the passage required and regulate the opening width.

Old style Door closer Wikipedia image by Norbert Schnitzler


 Read about> Locks

(https://interiordesignassist.wordpress.com/2014/08/15/locks/ )