Design Guide - Physical Element
Support posts
Free standing box section steel support posts with duct entry and inspection plates, concreted 1m plus into the ground, are always recommended. Masonry may be added for cosmetic reasons, but it should not be relied upon alone. Minor impact from a car almost certainly causes greater repair works with brick piers, than a gate supported by the right steel. Also the operator often has a more suitable fixing off steel than masonry. The support should be strong enough not just to hold up the gate, but also to withstand minor impact or a reasonable number of people climbing over it, without failing.
With installations carried out on suspect terrain, subterranean links may be necessary. A common form of link may be an RSJ across the drive at a suitable depth, preventing each support structure from moving.
Gate size
The size of gates, doors or barriers vary from site to site. Most are required to be as wide as possible and high enough to give adequate security. With most automatic systems the smaller the opening the lower the cost to install and maintain, also the more reliable the system is.
Gate width
Recommended vehicular widths are as follows:
Domestic swing gates | 3000mm – 4000mm |
Multi-user swing gates | 4000mm – 5000mm |
Commercial swing gates | 4500mm – 6000mm |
Sliding gates | 3000mm – 10000m |
NB. All subject to height, weight, shape and site survey.
Gate height
Within reason height is far less important than width, but it may have an effect on weight and hinge stress.
Domestic gates | 1200mm – 1800mm+ |
Multi-user | 1600mm – 2000mm+ |
Commercial | 1800mm – 2300mm+ |
NB. All subject to local planning and site survey.
Gate shape
Width has the most effect on the shape of gates recommended. The wider the gate the higher the load and stress that is on each hinge. The weight distribution of the gate will also determine stress at each hinge and as automatic gates are used far more than manual ones, hinge wear is an important consideration. General guide only, subject to site survey;
“Bow top” gates sweep up in the middle 2000mm leaf
“Flat top” gates are flat across the top 2500mm leaf
“Swallow top” gates dip in the middle 3000mm leaf
Gate material
As automation is of an engineering nature and requires stability within the material used, “Steel” is always recommended over “Timber”, With timber gates there is always a compromise between cosmetic looks and system reliability. Timber is a live material that is always moving and will often split and crack naturally even without automation. However automation of timber products can accelerate this natural process.
Gate construction
Each gate should be constructed to suit its opening size and method of control. Rectangular hollow section outer frame of 40mm+ square is recommended, together with medium/thick wall hollow section elsewhere (to avoid excessive weight and yet aid in stability). Close-board Infills, Sheeting or Cladding should be avoided where possible. They provide privacy but create problems with wind resistance and system performance, especially in exposed locations. Palisade gates and similar shaped Infills, create high levels of drag against the wind and as a result, have significant problems in windy conditions. The hinges should be of a high use type, suitable for the proposed method of control and adequately maintainable.
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