The prominence of bollards has dramatically increased during the past decade because of heightened concerns about security. These are a basic, practical, and cost-effective way of erecting anti-ram perimeter defense without creating a visual sense of a fortified bunker. Bollards are popular for traffic direction and control, and in purely attractive applications. On the other hand, steel security bollards can provide many features 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 set up to permit pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different levels of access restriction for many different circumstances. They frequently tell us where we are able to 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 such as lighting, surveillance cameras, bicycle parking or even seating. Decorative bollards are created in a variety of patterns to harmonize with a wide range 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 towards the required function.
Exactly What Is A Bollard?
A bollard is really a short vertical post. Early bollards were for mooring large ships at dock, and they are still being used today. An average marine bollard is created in cast iron or steel and shaped somewhat like a mushroom; the enlarged top is designed 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. 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 availability of former cannons was applied up, similarly shaped iron castings were made to fulfill the same functions. Bollards have since become many varieties which can be widely employed on roads, especially in urban areas, as well as outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most common type 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 numerous decorative designs. Some feature square or rectangular cross-sections, but a majority of are cylindrical, sometimes using a domed, angled, or flat cap. They come in a number of metallic, painted, and durable powder coat finishes.
Removable bollards are utilized 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 easily 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 how much they weigh rather than structural anchoring to remain in place. They are designed to be moved rarely, and then simply with heavy machinery such as a fork-lift.
Bollards generally belong to three varieties of applications:
Decorative Bollards – decorative bollards for architectural and/or 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 can border, divide, or define a space. 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 a number of reveals close to the top. Styles made to match various historic periods will often have more elaborate shapes and surface details. Such as 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 include a simple rounded or slanted top to deter passersby from leaving trash or utilizing them for impromptu seating. On the contrary, they 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 concern, such as a removable bollard. Aluminum units are usually a little more expensive than iron. For applications in which a decorative bollard might be susceptible to destructive impact, ductile iron is actually a safer choice than more brittle metals, as force will deform the metal instead of shatter and transforming it into possible hazardous flying projectiles.
Iron and aluminum bollards are often manufactured by sand-casting – a traditional 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 attractive to the attention. If high-finish consistency is desired, seek a manufacturer that will machine 100% of the surface after casting to generate units with a uniform surface for max visual appeal.
Finish is a vital 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 – that is on iron, aluminum, and steel – is an especially durable form of painted finish. The applying process builds up a coating with very consistent coverage. During coating, any bare metal has a tendency 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 bollard manufactured from aluminum can be a better choice than iron. When the finish coat is damaged, aluminum oxidizes to a color which is generally more acceptable than the red rust produced by iron. Aluminum and stainless-steel are also offered in a variety of bare metal finishes. Functionality may be included in the otherwise decorative bollard. For instance, common choice is the chain eye – linking several bollards with chain, developing a simple traffic direction system. A big metal loop or arm on the side of the post allows parking and locking of bicycles, an extremely popular choice as increasing numbers of people seek alternative green transportation. Bollards might also contain lighting units or security devices, such as motion sensors or cameras.
Traffic and Safety Bollards
The most common bollard applications are traffic direction and control, along with safety and security. The very first function is achieved from the visual presence from the bollards, and to some degree by impact resistance, although, in these applications visual deterrence is definitely the primary function. Safety and security applications rely on higher levels of impact resistance. The main difference between the two is safety designs are worried 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 example, allows easy passage for humans and human-powered vehicles – including wheelchairs or shopping carts – but prevents the passage of cars. Such installations are frequently seen facing zcvjbu parking area entrance to your store, and also at the mouths of streets transformed into outdoor malls or ‘walk streets’. In designing bollard installations for a site, care has to be come 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 never require impact resistance. A line of bollards linked by a chain presents a visual cue never to cross the boundary, though it could be easy enough for a pedestrian to go over or under the chain when they choose. Bollards designed to direct traffic are occasionally 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 on the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes as well as other installations that should be shielded from accidental contact. A bollard at 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.
They are employed where U-turns and tight-radius turns are frequent. This kind of usage is particularly common at corners where vehicle drivers often misestimate turns, and pedestrians are especially near the roadbed waiting to cross. In certain 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 a low post at stopping cars.