The popularity of bollards has dramatically increased in the past decade as a result of heightened concerns about security. These are a basic, practical, and cost-effective method of erecting anti-ram perimeter defense without developing a visual sense of a fortified bunker. Bollards are widely used for traffic direction and control, and in purely decorative applications. On the other hand, bollards can serve many characteristics beyond security. They can be used purely aesthetic purposes, functioning as landscaping elements. Bollards can create visible boundaries of any property, or split areas within sites. They can control traffic and they are often organized to permit pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different levels of access restriction for a variety of circumstances. They frequently tell us where we could and cannot drive, park, bike, or walk, protect us from crime, shield vehicles and property from accidents, and add aesthetic features to the building exteriors and surrounding areas. Bollards can incorporate other functions such as lighting, security cameras, bicycle parking as well as seating. Decorative bollards are made in a selection of patterns to harmonize with a wide range of architectural styles. The prevalence of the most common type of security bollard, the concrete-filled steel pipe, has encouraged the manufacturing of decorative bollards made to fit as covers over standard steel pipe sizes, adding pleasing form for the required function.
Exactly What Is A Bollard?
A bollard is a short vertical post. Early bollards were for mooring large ships at dock, and they are generally still used today. An average marine bollard is manufactured in cast iron or steel and shaped somewhat just like a mushroom; the enlarged top was created to prevent mooring ropes from slipping off.
Today, the term bollard also describes a number of structures applied to streets, around buildings, and then in landscaping. According to legend, the very first street bollards were actually cannons – sometimes said to be captured enemy weapons – planted in the ground as boundary posts and town markers. If the supply of former cannons was used up, similarly shaped iron castings were designed to match the same functions. Bollards have since evolved into many varieties which can be widely employed on roads, particularly in urban areas, in addition to outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most typical kind of bollard is fixed. The most basic is an unaesthetic steel post, about 914 to 1219 mm (36 to 48 in.) above-grade. Specially manufactured bollards include not only simple posts, but additionally numerous decorative designs. Some feature square or rectangular cross-sections, but many are cylindrical, sometimes with a domed, angled, or flat cap. They are available in a selection of metallic, painted, and sturdy powder coat finishes.
Removable bollards are used where the requirement to limit access or direct traffic changes occasionally. Both retractable and fold-down styles are employed where selective entry is frequently needed, and they are designed so the bollard can be simply collapsed to ground level and quickly re-erected. Both retractable units could be manually operated or automated with hydraulic movements. Movable bollards are large, heavy objects – frequently stone or concrete – that count on their weight as opposed to structural anchoring to remain in place. They are created to be moved rarely, and then simply with heavy machinery such as a fork-lift.
Bollards generally fall under three kinds of applications:
Decorative Bollards – decorative bollards for architectural and landscaping highlights;
Traffic and Safety Bollards – bollards that provide asset and pedestrian safety, as well as traffic direction; and
Security Bollards and Post Covers – decorative, impact-resistant bollard enhancements
Some bollards are intended purely to become an ornament. As standalone architectural or landscaping features, they are able to border, divide, or define an area. They may also be accents, sentries, or supporting players to larger, more dramatic architectural gesture.
Decorative bollards are produced to harmonize with both traditional and contemporary architectural styles. The second lean toward visual simplicity – often straight-sided posts with several reveals close to the top. Styles made to match various historic periods will often have more elaborate shapes and surface details. These include flutes, bands, scrolls as well as other ornamentation.The post-top is really a distinctive feature; traditional bollard design often includes elaborate decorative finials, whereas contemporary versions frequently feature a simple rounded or slanted top to deter passersby from leaving trash or making use of them for impromptu seating. On the contrary, these are sometimes made flat and broad specifically to encourage seating. Common decorative bollard materials include iron, aluminum, stainless-steel, and concrete.
Ornamental designs with elaborate detail are frequently made from iron or aluminum casting. Aluminum bollards are desirable for applications where weight is an issue, like a removable bollard. Aluminum units are generally slightly more expensive than iron. For applications when a decorative bollard may be susceptible to destructive impact, ductile iron is really a safer choice than more brittle metals, as force will deform the metal rather than shatter and transforming it into possible hazardous flying projectiles.
Iron and aluminum bollards are usually manufactured by sand-casting – a regular foundry technique that is economical and well-suitable for objects this size. However, sand-cast objects frequently bear surface irregularities that tend to leave the finished product less attractive to the eye. If high-finish consistency is desired, seek a manufacturer that can machine 100% in the surface after casting to produce units using a uniform surface for maximum appearance.
Finish is an important consideration in a decorative bollard, from functional as well as aesthetic standpoints. Bollards are, by their nature, susceptible to being scratched or nicked by pedestrians and vehicles. Those located near roadways are exposed to a fairly aggressive environment; petrochemical residues and splashes of diluted road de-icing salts may compromise some painted finishes. Factory-applied powder coating – that is seen on iron, aluminum, and steel – is an especially durable form of painted finish. The application form process builds a coating with very consistent coverage. During coating, any bare metal is likely to attract the powder, eliminating pinholes in coverage. The baking method that completes the finish gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, bollard cover manufactured from aluminum might be a better option than iron. If the finish coat is damaged, aluminum oxidizes to some color which is generally more acceptable than the red rust produced by iron. Aluminum and stainless are also offered in a number of bare metal finishes. Functionality may be included in the otherwise decorative bollard. For instance, common option is the chain eye – linking several bollards with chain, creating a simple traffic direction system. A sizable metal loop or arm on the side in the post allows parking and locking of bicycles, a progressively popular choice as more people seek alternative green transportation. Bollards may also contain lighting units or security devices, such as motion sensors or cameras.
Traffic and Safety Bollards
The most frequent bollard applications are traffic direction and control, along with safety and security. The initial function is achieved through the visual presence of the bollards, and at some level by impact resistance, although, during these applications visual deterrence is the primary function. Safety and security applications depend on higher degrees of impact resistance. The major distinction between both is safety designs are concerned with stopping accidental breach of the defined space, whereas security is all about stopping intentional ramming.
Closely spaced lines of bollards can form a traffic filter, separating motor vehicles from pedestrians and bicycles. Placing the posts with 1 m (3 ft) of clearance between them, for instance, allows easy passage for humans and human-powered vehicles – such as wheelchairs or shopping carts – but prevents the passage of cars. Such installations are frequently seen facing zcvjbu car park entrance to your store, as well as at the mouths of streets changed into outdoor malls or ‘walk streets’. In designing bollard installations to get a site, care has to be delivered to avoid locating them where they will be a navigational hazard to authorized vehicles or cyclists.
Some applications for traffic guidance depend on the cooperation of drivers and pedestrians and do not require impact resistance. A type of bollards linked with a chain presents a visual cue not to cross the boundary, though it might be easy enough for any pedestrian to travel over or beneath the chain when they choose. Bollards made to direct traffic are sometimes designed to fold, deflect, or break away on impact.
Adding greater collision resistance allows a bollard to enforce traffic restrictions instead of merely suggesting them. Plain pipe bollards are frequently placed at the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes as well as other installations that should be protected against accidental contact. A bollard on the side of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can in fact redirect a car back to the roadway when its wheels hit the bollard’s sloped sides.
They are employed where U-turns and tight-radius turns are frequent. This sort of usage is particularly common at corners where vehicle drivers often misestimate turns, and pedestrians are particularly near to the roadbed waiting to cross. In some cities, automatically retractable impact-resistant bollards are installed to manage the flow of traffic into an intersection. Internet videos of ‘bollard runners’ graphically demonstrate the potency of a low post at stopping cars.