The prominence of bollards has dramatically increased during the past decade because of heightened fears about security. These are a basic, practical, and cost-effective means of erecting anti-ram perimeter defense without creating a visual sense of a fortified bunker. Bollards are commonly used for traffic direction and control, as well as in purely decorative applications. However, steel security bollards can provide 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 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 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 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 created in a number of patterns to harmonize with a variety 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 made to fit as covers over standard steel pipe sizes, adding pleasing form towards the required function.
What Exactly Is A Bollard?
A bollard is really a short vertical post. Early bollards were for mooring large ships at dock, plus they are still in use today. An average marine bollard is produced in cast iron or steel and shaped somewhat such as a mushroom; the enlarged top was created to prevent mooring ropes from slipping off.
Today, the term bollard also describes many different structures used on streets, around buildings, and 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. If the availability of former cannons was used up, similarly shaped iron castings were created to fulfill the same functions. Bollards have since become many varieties that are widely employed on roads, specifically in urban areas, in addition to outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most frequent kind of bollard is fixed. The simplest is surely 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 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 selection of metallic, painted, and sturdy powder coat finishes.
Removable bollards are employed 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 therefore are designed and so 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 designed to be moved rarely, and after that simply with heavy machinery like a fork-lift.
Bollards generally fall into three types of applications:
Decorative Bollards – decorative bollards for architectural and/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 get an ornament. As standalone architectural or landscaping features, they are able to border, divide, or define an area. 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 latter lean toward visual simplicity – often straight-sided posts with a number of reveals near the top. Styles made to match various historic periods usually have more elaborate shapes and surface details. Such as flutes, bands, scrolls along with other ornamentation.The post-top is actually 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 contrary, they may be sometimes made flat and broad specifically to encourage seating. Common decorative bollard materials include iron, aluminum, stainless, and concrete.
Ornamental designs with elaborate detail are often made of iron or aluminum casting. Aluminum bollards are desirable for applications where weight is a concern, 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 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 frequently manufactured by sand-casting – a traditional foundry technique which 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 appealing to the attention. If high-finish consistency is desired, seek a manufacturer which will machine 100% from the surface after casting to generate units using a uniform surface for maximum looks.
Finish is a vital consideration in a decorative bollard, from functional along with aesthetic standpoints. Bollards are, by their nature, prone 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 an especially durable kind of painted finish. The applying process builds a coating with very consistent coverage. During coating, any bare metal has a tendency 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, plastic bollards made from aluminum may be a better choice than iron. When the finish coat is damaged, aluminum oxidizes to some color that is generally more acceptable compared to red rust produced by iron. Aluminum and stainless steel are also available in a variety of bare metal finishes. Functionality may be included in the otherwise decorative bollard. As an example, common choice is the chain eye – linking several bollards with chain, making a simple traffic direction system. A large 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 could 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 security and safety. The first function is achieved through the visual presence of the bollards, and to some extent by impact resistance, although, during these applications visual deterrence will be the primary function. Safety and security applications rely on higher levels of impact resistance. The key distinction between the two 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 the two, as an example, 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 lot entrance to your store, and at the mouths of streets changed into outdoor malls or ‘walk streets’. In designing bollard installations for any site, care should be come 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 never require impact resistance. A collection of bollards linked with a chain presents a visual cue not to cross the boundary, though it might be easy enough to get a pedestrian to travel over or beneath the chain if they choose. Bollards designed to direct traffic are occasionally created 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 often placed on the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes along with other installations that need 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 onto 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 extremely 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 control the flow of traffic into an intersection. Internet videos of ‘bollard runners’ graphically demonstrate the potency of also a low post at stopping cars.