The popularity of bollards has dramatically increased during the past decade because of heightened fears about security. These are an easy, practical, and cost-effective means 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. However, steel bollards for sale can serve many functions beyond security. They can be used for 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 arranged to permit pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different amounts of access restriction for many different circumstances. They frequently inform 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 like lighting, surveillance cameras, bicycle parking or even seating. Decorative bollards are created in a selection of patterns to harmonize with a wide range of architectural styles. The prevalence of the very 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.
What Is A Bollard?
A bollard is really a short vertical post. Early bollards were for mooring large ships at dock, and they are generally still in use today. An average marine bollard is created in cast iron or steel and shaped somewhat like a mushroom; the enlarged top was created to prevent mooring ropes from slipping off.
Today, the word bollard also describes a number of structures utilized on streets, around buildings, and in landscaping. According to legend, the initial 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 created to fulfill the same functions. Bollards have since become many varieties which are widely employed on roads, specifically in urban areas, as well as outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most typical form of bollard is fixed. The simplest 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 in addition a wide variety of decorative designs. Some feature square or rectangular cross-sections, but a majority of are cylindrical, sometimes having a domed, angled, or flat cap. They are available in a number of metallic, painted, and durable powder coat finishes.
Removable bollards are employed where the need to limit access or direct traffic changes occasionally. Both retractable and fold-down styles are employed where selective entry is frequently needed, and are designed so the bollard can easily be collapsed to ground level and quickly re-erected. Both retractable units might be manually operated or automated with hydraulic movements. Movable bollards are large, heavy objects – frequently stone or concrete – that rely on how much they weigh as opposed to structural anchoring in which to stay place. They are made to be moved rarely, then just with heavy machinery such as a fork-lift.
Bollards generally fall under three types of applications:
Decorative Bollards – decorative bollards for architectural and landscaping highlights;
Traffic and Safety Bollards – bollards which provide asset and pedestrian safety, in addition to traffic direction; and
Security Bollards and Post Covers – decorative, impact-resistant bollard enhancements
Some bollards are intended purely to get an ornament. As standalone architectural or landscaping features, they are able to border, divide, or define a place. They can be accents, sentries, or supporting players to larger, more dramatic architectural gesture.
Decorative bollards are made to harmonize with both traditional and contemporary architectural styles. The second lean toward visual simplicity – often straight-sided posts with several reveals near the top. Styles made to match various historic periods usually have more elaborate shapes and surface details. Included in this are flutes, bands, scrolls along with other ornamentation.The post-top is really a distinctive feature; traditional bollard design often includes elaborate decorative finials, whereas contemporary versions frequently come with a simple rounded or slanted top to deter passersby from leaving trash or utilizing them for impromptu seating. On the other hand, they may be 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 a problem, for instance a removable bollard. Aluminum units are usually a little more expensive than iron. For applications where a decorative bollard may be subject to destructive impact, ductile iron is a safer choice than more brittle metals, as force will deform the metal as opposed to 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 certainly economical and well-suitable for objects this size. However, sand-cast objects frequently bear surface irregularities that have a tendency to leave the finished product less popular with the eye. If high-finish consistency is desired, seek a manufacturer which will machine 100% in the surface after casting to create units using a uniform surface for optimum appearance.
Finish is an important consideration in a decorative bollard, from functional in addition to aesthetic standpoints. Bollards are, by their nature, vulnerable to being scratched or nicked by pedestrians and vehicles. Those located near roadways are in contact with a fairly aggressive environment; petrochemical residues and splashes of diluted road de-icing salts may compromise some painted finishes. Factory-applied powder coating – which is available on iron, aluminum, and steel – is an especially durable type of painted finish. The application form process builds up a coating with very consistent coverage. During coating, any bare metal tends to attract the powder, eliminating pinholes in coverage. The baking procedure that completes the finish gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, bollard covers made of aluminum can be a better choice than iron. If the finish coat is damaged, aluminum oxidizes to some color which is generally more acceptable compared to red rust made by iron. Aluminum and stainless steel can also be found in a number of bare metal finishes. Functionality may be put into the otherwise decorative bollard. For instance, common choice is the chain eye – linking two or more bollards with chain, developing a simple traffic direction system. A sizable metal loop or arm on the side in the post allows parking and locking of bicycles, an increasingly popular choice as increasing numbers of people seek alternative green transportation. Bollards might also contain lighting units or security devices, like motion sensors or cameras.
Traffic and Safety Bollards
The most frequent bollard applications are traffic direction and control, in addition to safety and security. The very first function is achieved through the visual presence of the bollards, and to some extent by impact resistance, although, in these applications visual deterrence is the primary function. Security and safety applications depend upon higher levels of impact resistance. The major difference between the two is safety designs are concerned with stopping accidental breach of the defined space, whereas security is approximately 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 tend to be seen in front of zcvjbu parking area entrance to some store, as well as at the mouths of streets converted to outdoor malls or ‘walk streets’. In designing bollard installations to get a site, care should be delivered to avoid locating them where they will become a navigational hazard to authorized vehicles or cyclists.
Some applications for traffic guidance depend on the cooperation of drivers and pedestrians and you should not require impact resistance. A line of bollards linked by way of a chain presents a visual cue never to cross the boundary, even though it could be easy enough to get a pedestrian to visit over or underneath the chain should they choose. Bollards made to direct traffic are often created to fold, deflect, or break away on impact.
Adding greater collision resistance allows a bollard to enforce traffic restrictions as opposed to 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 need to be shielded from accidental contact. A bollard in the fringe of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can certainly redirect a car back onto the roadway when its wheels hit the bollard’s sloped sides.
These are employed where U-turns and tight-radius turns are frequent. This kind of usage is extremely common at corners where vehicle drivers often misestimate turns, and pedestrians are especially near the roadbed waiting to cross. In a few 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 even a low post at stopping cars.