The popularity of bollards has dramatically increased in the past decade as a result of heightened worries about security. They are a simple, practical, and cost-effective method of erecting anti-ram perimeter defense without developing a visual sense of a fortified bunker. Bollards are commonly used for traffic direction and control, and in purely decorative applications. On the other hand, steel bollards can offer many functions beyond security. They can be used as purely aesthetic purposes, functioning as landscaping elements. Bollards can make visible boundaries of any property, or split areas within sites. They can control traffic and they are often arranged to allow 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 can and cannot drive, park, bike, or walk, protect us from crime, shield vehicles and property from accidents, and add aesthetic features to our own building exteriors and surrounding areas. Bollards can incorporate other functions like lighting, security cameras, bicycle parking or perhaps seating. Decorative bollards are produced in a selection of patterns to harmonize with an array of architectural styles. The prevalence of the very common kind of security bollard, the concrete-filled steel pipe, has encouraged the manufacturing of decorative bollards designed to fit as covers over standard steel pipe sizes, adding pleasing form to the required function.
What Exactly Is A Bollard?
A bollard is a short vertical post. Early bollards were for mooring large ships at dock, plus they are still being used today. A typical marine bollard is produced 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 applied to streets, around buildings, and then in landscaping. Based on 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. Once the supply of former cannons was utilized up, similarly shaped iron castings were created to match the same functions. Bollards have since evolved into many varieties that are widely employed on roads, particularly in urban areas, along with outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most frequent type of bollard is fixed. The most basic is surely an unaesthetic steel post, about 914 to 1219 mm (36 to 48 in.) above-grade. Specially manufactured bollards include not just simple posts, but in addition a multitude of decorative designs. Some feature square or rectangular cross-sections, but many are cylindrical, sometimes having a domed, angled, or flat cap. They are offered in a number of metallic, painted, and sturdy powder coat finishes.
Removable bollards are used where the necessity to limit access or direct traffic changes occasionally. Both retractable and fold-down styles are employed where selective entry is often needed, and they are designed so the bollard can be simply collapsed to ground level and quickly re-erected. Both retractable units may be manually operated or automated with hydraulic movements. Movable bollards are large, heavy objects – frequently stone or concrete – that depend on how much they weigh instead of structural anchoring in which to stay place. They are made to be moved rarely, then simply with heavy machinery for instance a fork-lift.
Bollards generally belong to three varieties of applications:
Decorative Bollards – decorative bollards for architectural or landscaping highlights;
Traffic and Safety Bollards – bollards which provide asset and pedestrian safety, along with 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 could border, divide, or define a place. They can 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 latter lean toward visual simplicity – often straight-sided posts with one or more reveals nearby the top. Styles designed 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 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 using them for impromptu seating. On the contrary, 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 usually manufactured from iron or aluminum casting. Aluminum bollards are desirable for applications where weight is a problem, for instance a removable bollard. Aluminum units are generally slightly more expensive than iron. For applications in which a decorative bollard could be susceptible to destructive impact, ductile iron is actually 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 often manufactured by sand-casting – a conventional foundry technique which is economical and well-suited to objects this size. However, sand-cast objects frequently bear surface irregularities that tend to leave the finished product less popular with the eye. If high-finish consistency is desired, seek a manufacturer that will machine 100% from the surface after casting to generate units using a uniform surface for max visual appeal.
Finish is an important consideration in a decorative bollard, from functional as well as aesthetic standpoints. Bollards are, by their nature, vulnerable to being scratched or nicked by pedestrians and vehicles. Those located near roadways are exposed to a reasonably aggressive environment; petrochemical residues and splashes of diluted road de-icing salts may compromise some painted finishes. Factory-applied powder coating – which can be seen on iron, aluminum, and steel – is definitely an especially durable kind of painted finish. The applying process builds up a coating with very consistent coverage. During coating, any bare metal is likely to attract the powder, eliminating pinholes in coverage. The baking process that completes the conclusion gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, plastic bollards made from aluminum might be a better option than iron. If the finish coat is damaged, aluminum oxidizes to your color that is generally more acceptable compared to red rust made by iron. Aluminum and stainless steel can also be found in a quantity of bare metal finishes. Functionality could be added to the otherwise decorative bollard. For example, common option is the chain eye – linking several bollards with chain, making a simple traffic direction system. A big metal loop or arm on the side in the post allows parking and locking of bicycles, a progressively popular choice as increasing numbers of people seek alternative green transportation. Bollards might also contain lighting units or security devices, including motion sensors or cameras.
Traffic and Safety Bollards
The most frequent bollard applications are traffic direction and control, together with security and safety. The first function is achieved through the visual presence of the bollards, and to some degree by impact resistance, although, within these applications visual deterrence will be the primary function. Security and safety applications rely on higher levels of impact resistance. The key difference between both is safety designs are involved with stopping accidental breach of any 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 example, allows easy passage for humans and human-powered vehicles – like wheelchairs or shopping carts – but prevents the passage of cars. Such installations tend to be seen before zcvjbu parking area entrance to a store, as well as at the mouths of streets converted to outdoor malls or ‘walk streets’. In designing bollard installations for a site, care should be taken to avoid locating them where they will likely 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 type of bollards linked with a chain presents a visual cue to not cross the boundary, though it could be easy enough for a pedestrian to travel over or beneath the chain when they choose. Bollards designed to direct traffic are often made 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 often placed on the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes as well as other installations that ought to be shielded from accidental contact. A bollard on the side of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can actually redirect a vehicle back on the roadway when its wheels hit the bollard’s sloped sides.
These are employed where U-turns and tight-radius turns are frequent. This type 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 strength of a low post at stopping cars.