COMPONENTS of RAILINGS

Post 412 –by Gautam Shah 

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Railings are barricades against height related hazards, guides for pathways and grabbing elements for support while ascending, descending or any other physically difficult passage (such as slippery floors). Railings have a main holding or grabbing elements in the form of a continuous bar or rail, other in-fill components and support structures. The support structure is often designed as a spanning structural beam to reinforce the bridge, a waist of the stair or escalator. In very steep stairs such as ladders the sides of the stairs allow grabbing, and so are railing by themselves.

Mats Rope Ladders Sailboat

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640px-Approaching_the_Top_of_the_Ladder_to_Balcony_House,_Mesa_Verde_National_Park_(4851976994)

A railing is nominally a safety barricade used in a standing posture and so needs an optimum height provision. As a result the space between the passage and the railing requires some fill-up panel. This fill-up or in-fill could be of opaque, translucent to transparent material or a lattice. In stiff structures the in-fill could be of stiff construction, but rope bridges (catenary spans) need a flexible in-fill. Railings on roads are designed to take the impact of moving vehicles, and allow it to skid along it, but without an overturning. Railings in public places are designed to resist side thrust in case of pandemonium. Railings are designed with anti-ligature features to prevent suicides or unintentional injuries.

Railings are made of timbers, wood-composites, wrought iron, cast-iron, mild steel structurals or sections, stainless steels, glass, plastics, composites and masonry.

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Pontedellacostituzione

The components of the railing are identifiable in terms of their distinctive form, position and function. In some instances each of these has a perceptible presence, but it may not be a requirement of design. A proximate building element or an architectonic element may serve the functions of a railing. Railings, are bottom supported panel structures, wall supported linear elements, or suspended space entities.

Rope bridge flexible Hand rail

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Rail is the main grabbing and body support element of the railing system. This is a functional element which may not be the top member, but always at the optimum (for adults) height of 900 to 1200 mm. The rail may have an accompanying higher or lower barricading element. A rail could be an independent element of the other components of the railing. Rail can be a bar or an ergonomically conceived section or profiled top (cap-rail) of the in-fill panel or the barricade system. Rails are used with hand and so-called handrails, but a rail could support other parts or limbs of the body such as the buttock (metro trains and stations) or a foot (drink or snack bars). Informal rails are fabric or synthetic stripes that demarcate specific areas. Grab bars are placed in toilets, slippery or wet areas.

Bradbury Building Stairs ironwork

Support for Handrail: A handrail may be supported at end to end of flight of steps (usually negotiating 2 to 2.5 mts height) or may need intermediate supports called banisters.

Vienna state opera stairs Newels

A newel is a large picket or post that supports the handrail at the start and end or landing level. Newels are anchored to the floors or stair waists. Nominally the newel rests one step measure away from the last step. Newels may project upward then the rail level, and may be capped with an urn or finial. Volute is the end of a handrail, shaped like a spiral in a horizontal plane. A rail may not end as a free corner support of a newel, but may terminate into a wall or column as a rosette. A wall return is a bend that turns around a wall, column or a tall newel. Easement is the curved piece in the same plane or rising to form a turning transition of a rail. Similarly a goose-neck is a section between two differently sloped rail systems.

Villa Saint Cyr Staircase Newel Cap

Rail sections carved out of wood are curved against the normal grain of the wood, such as for the volute, rosette, goose-neck or easements. These require additionally under the layer support of wood.

Iron balusters

Baluster is a moulded shaft, square or circular, traditionally in stone, wood, metal, and now in plastics, supporting the coping of a parapet or the handrail of a staircase. The assembly is called the balustrade. Balusters are vertical mid pickets or members that hold the handrail. Sometimes these are simply called guards or spindles. Treads often require two balusters. The second baluster in such cases is closer to the riser and is taller than the first. A fillet is a decorative filler piece on the floor between balusters.

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RAILINGS AND PARAPETS

RAILINGS AND PARAPETS

Post 303⇒   by Gautam Shah  →

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Railings and Parapets are barricades against height related hazards. Railings and parapets both are important functional and architectonic elements. There are few characteristics and elements common to both. It is their nature of construction that places them in separate categories. Both are height-related hazards barriers, mainly for humans. Railings and parapets are invariably smaller than the human height, because most such elements are used for resting or grabbing with hands. For nominal usage 800-900 mm height is adequate, whereas difficult to negotiate (jump-over) conditions a height of 1400-1500 mm is considered. The later height is used for terraces of multi-story buildings to discourage suicides.

Patan Nepal

Design Parameters > Railings of nominal height ( 800-900mm) must have top 300mm as see-through face, so that children can see out. But if such a separation is likely to provide any toe space to climb up entire face should be see-through. All lattices should have preferably vertical bars and the clear gap must not exceed 100mm. For very tall railings (more than 900 mm) entire face must be of see-through elements and with a squared lattice. The squares in the lattice must not exceed 30 x 30 mm.

Parapets and Railings have sub elements such as: hand rail, Baluster or balustrade, banisters, volute, turn out, goose-neck, rosettes, easing, starting easing, over easing, core rail, newels, fillets, tandem caps, colonnettes.

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RAILINGS

Railings are translucent or latticed elements, placed at the edges of the floor and terraces. Railings are placed as safety barricade on the sides of stairs, ladders, ramps, and escalators. These are placed 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 near wells, tanks and other water bodies. 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.

Venice

Waverley Tram Depot Roof gable edge

The chief element of railings, are top rail, and secondary elements are posts that support the rail and latticed in-fill panels. A rail can be defined as any long member, usually of round section, fixed to posts, for resting hands, or for grabbing as a support. Railings have a top rail or hand rail used for holding, and a foot rail and mid rails. The hand rail in a masonry structure is a wider ‘table’.

Balusters

Masonry railings are often called parapets. In medieval castles, gapped parapets called crenellations or embrasures were formed to allow guns to fire through. On terraces and galleries of arid climates similar gaps are covered by pierced stones or metal lattice to allow the breeze to pass through at floor level of the terrace. This cooled the terraces faster, and provided comfort for occupants seating or sleeping on the floor. Latticed railing allows children to see through, and so discourage the climb-over.

Poole: wiggly barrier on the Twin Sails Bridge UK

PARAPETS

Parapets are opaque structures, often designed as an upward extension of the wall. Classical design of a parapet em-battlement of a coping at the top and corbel below. The top of the parapet often slopes towards the enemy to enable the defenders to shoot downwards, and this incline is called the superior talus. Parapets are placed at roof or terrace edges, or on embankments. Opaque parapets are used for deflecting winds, provide privacy to floor level activities, add weight to the edge to prevent lift-off forces. Parapets serve, besides defence-offence, other purposes, such as: to shield a view, as a noise barrier, barriers against splashes of storm-water, missiles or flying objects. Edge beams are designed as parapets. Parapets that are small in size are called curbs. Curbs are used as dividers.

Glass Parapet >Nottingham Castle Terrace

Essaouria Morocco

Fort walls have em-battlement parapets, which are pierced for styling, view beyond and for throwing defensive projectiles. Palaces and castles have decorative (non-defence) perforated parapets in various shapes such as circles, trefoils, quarter-foils.

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 crenels 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.

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