The popularity of bollards has dramatically increased during the past decade due to heightened concerns about security. They are an easy, practical, and cost-effective way of erecting anti-ram perimeter defense without developing a visual sense of a fortified bunker. Bollards are popular for traffic direction and control, as well as in purely attractive applications. On the other hand, steel security bollards can serve many characteristics beyond security. They can be used as purely aesthetic purposes, functioning as landscaping elements. Bollards can create visible boundaries of a property, or separate areas within sites. They can control traffic and 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 number 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 our own building exteriors and surrounding areas. Bollards can incorporate other functions like lighting, surveillance cameras, bicycle parking as well as seating. Decorative bollards are made in a variety of patterns to harmonize with an array of architectural styles. The prevalence of the most common form of security bollard, the concrete-filled steel pipe, has encouraged the manufacturing of decorative bollards created to fit as covers over standard steel pipe sizes, adding pleasing form towards the required function.
What Exactly Is A Bollard?
A bollard is a short vertical post. Early bollards were for mooring large ships at dock, and they are still being used today. A normal marine bollard is created in cast iron or steel and shaped somewhat just like a mushroom; the enlarged top is designed to prevent mooring ropes from slipping off.
Today, the term bollard also describes a variety 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 earth as boundary posts and town markers. If the flow of former cannons was applied up, similarly shaped iron castings were designed to match the same functions. Bollards have since evolved into many varieties that are widely employed on roads, especially in urban areas, in addition to outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most common form of bollard is fixed. The easiest is definitely an unaesthetic steel post, about 914 to 1219 mm (36 to 48 in.) above-grade. Specially manufactured bollards include not just simple posts, but also a wide variety of decorative designs. Some feature square or rectangular cross-sections, but a majority of are cylindrical, sometimes with a domed, angled, or flat cap. They are offered in a selection of metallic, painted, and sturdy powder coat finishes.
Removable bollards are utilized 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 therefore the bollard can be easily 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 rely on how much they weigh instead of structural anchoring in which to stay place. They are created to be moved rarely, and after that just with heavy machinery for instance a fork-lift.
Bollards generally fall into three kinds of applications:
Decorative Bollards – decorative bollards for architectural and/or landscaping highlights;
Traffic and Safety Bollards – bollards that offer 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 get an ornament. As standalone architectural or landscaping features, they can border, divide, or define a space. They may also be accents, sentries, or supporting players to larger, more dramatic architectural gesture.
Decorative bollards are manufactured to harmonize with both traditional and contemporary architectural styles. The second lean toward visual simplicity – often straight-sided posts with one or more reveals near the top. Styles designed to match various historic periods will often have more elaborate shapes and surface details. These include flutes, bands, scrolls and other ornamentation.The post-top is actually a distinctive feature; traditional bollard design often includes elaborate decorative finials, whereas contemporary versions frequently include a simple rounded or slanted top to discourage passersby from leaving trash or utilizing 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 a problem, like a removable bollard. Aluminum units tend to be a little more expensive than iron. For applications in which 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 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 that is certainly economical and well-fitted to objects this size. However, sand-cast objects frequently bear surface irregularities that have a tendency to leave the finished product less appealing to the eye. If high-finish consistency is desired, seek a manufacturer that can machine 100% from the surface after casting to generate units using a uniform surface for optimum visual appeal.
Finish is a crucial 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 relatively aggressive environment; petrochemical residues and splashes of diluted road de-icing salts may compromise some painted finishes. Factory-applied powder coating – which can be on iron, aluminum, and steel – is surely an especially durable type of painted finish. The application form 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 method that completes the conclusion gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, bollard covers manufactured from aluminum might be a better choice than iron. When the finish coat is damaged, aluminum oxidizes to your color which is generally more acceptable compared to the red rust created by iron. Aluminum and stainless-steel can also be found in a variety of bare metal finishes. Functionality could be included in the otherwise decorative bollard. As an example, common option is the chain eye – linking 2 or more bollards with chain, developing a simple traffic direction system. A sizable metal loop or arm on the side from 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, like motion sensors or cameras.
Traffic and Safety Bollards
The most typical bollard applications are traffic direction and control, in addition to safety and security. The very first function is achieved by the visual presence in the bollards, and to some degree by impact resistance, although, within these applications visual deterrence will be the primary function. Security and safety applications depend on higher degrees of impact resistance. The main distinction between the two is safety designs are concerned with stopping accidental breach of a 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 the two, for instance, allows easy passage for humans and human-powered vehicles – including wheelchairs or shopping carts – but prevents the passage of cars. Such installations tend to be seen facing zcvjbu parking lot entrance to some store, as well as at the mouths of streets changed into outdoor malls or ‘walk streets’. In designing bollard installations for a site, care has to be delivered to avoid locating them where they will likely turn into 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 collection of bollards linked by a chain presents a visual cue never to cross the boundary, though it might be easy enough to get a pedestrian to travel over or under the chain should they choose. Bollards designed to direct traffic are often designed to fold, deflect, or break away on impact.
Adding greater collision resistance allows a bollard to enforce traffic restrictions rather than merely suggesting them. Plain pipe bollards are frequently placed in the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes and other installations that ought to be protected from accidental contact. A bollard on the side 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 type 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 a few cities, automatically retractable impact-resistant bollards are installed to regulate the flow of traffic into an intersection. Internet videos of ‘bollard runners’ graphically demonstrate the strength of also a low post at stopping cars.