The popularity of bollards has dramatically increased during the past decade because of heightened concerns about security. They are an easy, 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, as well as in purely attractive applications. On the other hand, steel traffic bollards can provide many features beyond security. They can be used purely aesthetic purposes, functioning as landscaping elements. Bollards can make visible boundaries of a property, or split areas within sites. They can control traffic and they are often organized to allow pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different amounts 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 including lighting, security cameras, bicycle parking as well as seating. Decorative bollards are made in a number of patterns to harmonize with an array of architectural styles. The prevalence of the very most common form 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.
Exactly What Is A Bollard?
A bollard is a short vertical post. Early bollards were for mooring large ships at dock, plus they are still in use today. A normal marine bollard is produced in cast iron or steel and shaped somewhat such as a mushroom; the enlarged top is made to prevent mooring ropes from slipping off.
Today, the phrase bollard also describes many different structures utilized on streets, around buildings, and then in landscaping. According to legend, the very first street bollards were actually cannons – sometimes reported to be captured enemy weapons – planted in the ground as boundary posts and town markers. When the flow of former cannons was applied up, similarly shaped iron castings were made to match the same functions. Bollards have since become many varieties which are widely employed on roads, especially in urban areas, in addition to outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most frequent form 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 most are cylindrical, sometimes having a domed, angled, or flat cap. They are available in a variety 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 frequently needed, and they are designed therefore the bollard can easily be 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 count on how much they weigh instead of structural anchoring to stay in place. They are made to be moved rarely, and then just with heavy machinery like 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 that offer asset and pedestrian safety, along with traffic direction; and
Security Bollards and Post Covers – decorative, impact-resistant bollard enhancements
Decorative Bollards
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 manufactured to harmonize with both traditional and contemporary architectural styles. The latter lean toward visual simplicity – often straight-sided posts with one or more reveals close to the top. Styles designed to match various historic periods usually have more elaborate shapes and surface details. These include 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 include a simple rounded or slanted top to discourage passersby from leaving trash or making use of them for impromptu seating. On the other hand, these are 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 usually made of iron or aluminum casting. Aluminum bollards are desirable for applications where weight is a concern, for instance a removable bollard. Aluminum units are usually slightly more expensive than iron. For applications where a decorative bollard may be subject 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 frequently manufactured by sand-casting – a traditional foundry technique that is 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 can machine 100% of the surface after casting to create units with a uniform surface for maximum visual appeal.
Finish is a vital consideration in a decorative bollard, from functional along with aesthetic standpoints. Bollards are, by their nature, susceptible to being scratched or nicked by pedestrians and vehicles. Those located near roadways are subjected 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 on iron, aluminum, and steel – is surely an especially durable form of painted finish. The applying process increases 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 bollard covers manufactured from aluminum may be a better choice than iron. When the finish coat is damaged, aluminum oxidizes to a color which is generally more acceptable compared to red rust produced by iron. Aluminum and stainless-steel are also available in a number of bare metal finishes. Functionality can be added to the otherwise decorative bollard. For instance, 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 of the post allows parking and locking of bicycles, a progressively popular choice as increasing numbers of 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 common bollard applications are traffic direction and control, along with security and safety. The very first function is achieved from the visual presence of the bollards, and to some degree by impact resistance, although, in these applications visual deterrence is the primary function. Security and safety applications depend upon higher degrees of impact resistance. The key difference between the two is safety designs are concerned 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, as an example, allows easy passage for humans and human-powered vehicles – like wheelchairs or shopping carts – but prevents the passage of cars. Such installations are frequently seen in front of zcvjbu car park entrance to your store, and at the mouths of streets converted to outdoor malls or ‘walk streets’. In designing bollard installations for any site, care has to be taken 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 collection of bollards linked with a chain presents a visual cue not to cross the boundary, even though it could be easy enough for any pedestrian to go over or underneath the chain if they choose. Bollards created to direct traffic are sometimes designed to fold, deflect, or break away on impact.
Adding greater collision resistance allows a bollard to enforce traffic restrictions instead of 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 should 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 actually redirect a car back onto the roadway when its wheels hit the bollard’s sloped sides.
They may be 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 especially close to the roadbed waiting to cross. In some 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.