Post –by Gautam Shah
A hand rail is the topmost component of barricade systems like parapet or railing. Hand rails, without the barricading system, are provided in hotel lobbies, corridors, passages as a guide rail or an indicative element. The hand rail functions as guide rail as there no height related or other hazards are operative in such areas. As an indicative barrier it demarcates restricted areas. Such hand rails are not protective as a barricade but provide psychological support (assurance) for the hand or body. In this sense it has only a decorative function.
A wall-mounted 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 or oil circulation depending on the external weather conditions. Top hand rails or hanging rails are used in buses and metro trains for commuters to remain stable in high speed conditions and against breaking forces. Top hand rails also have hangers for grabbing to meet varied anthropometric profiles of commuters. 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 often used for resting against it, for placing hands, 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 profiles are required.
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.
Other Function of Hand Rail
A handrail serves many other functions, it often provides a lateral stability to the barricade system and joins pieces of barricade into a functional whole. Hand rails used for supporting the body may be designed to be non-continuous (for one or few persons), 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 non-continuous handrails are called post-to-post and newel-to-newel.
Positions or building elements that are likely to be unintentionally or abusively used as a hand rail, are designed or treated to prevent such a misuse. Some of the means used to discourage the usage are spikes, sharp knife edge profiles, sloped top face, or coating with non drying (green or ever-wet) paints. However, wider surfaces hand rails 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.