The prominence of bollards has dramatically increased during the past decade as a result of heightened concerns about security. These are a simple, practical, and cost-effective way 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, metal safety bollards can serve 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 separate areas within sites. They can control traffic and 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 inform 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 building exteriors and surrounding areas. Bollards can incorporate other functions like lighting, security cameras, bicycle parking as well as seating. Decorative bollards are created in a selection of patterns to harmonize with a variety of architectural styles. The prevalence of the very most common type 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 to 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, plus they are still in use today. An average marine bollard is manufactured 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 phrase bollard also describes a variety of structures used 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. Once the supply of former cannons was used up, similarly shaped iron castings were created to match the same functions. Bollards have since become many varieties which are widely employed on roads, specifically in urban areas, as well as outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most common form 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 merely simple posts, but in addition a wide variety of decorative designs. Some feature square or rectangular cross-sections, but most are cylindrical, sometimes using a domed, angled, or flat cap. They are available in a selection 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 frequently needed, and therefore are designed and so the bollard can be simply 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 depend on their weight as opposed to structural anchoring in which to stay place. They are made to be moved rarely, and then simply with heavy machinery like a fork-lift.
Bollards generally belong to 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, as well as traffic direction; and
Security Bollards and Post Covers – decorative, impact-resistant bollard enhancements
Some bollards are intended purely to be 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 several reveals near the top. Styles designed to match various historic periods will often have more elaborate shapes and surface details. Included in this are flutes, bands, scrolls and other ornamentation.The post-top is really a distinctive feature; traditional bollard design often includes elaborate decorative finials, whereas contemporary versions frequently come with a simple rounded or slanted top to discourage passersby from leaving trash or using 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 usually made of iron or aluminum casting. Aluminum bollards are desirable for applications where weight is a problem, for instance a removable bollard. Aluminum units tend to be slightly more expensive than iron. For applications where a decorative bollard could 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 usually manufactured by sand-casting – a conventional foundry technique that is economical and well-fitted to objects this size. However, sand-cast objects frequently bear surface irregularities that tend to leave the finished product less attractive to the eye. If high-finish consistency is desired, seek a manufacturer that will machine 100% in the surface after casting to generate units using a uniform surface for optimum looks.
Finish is an important consideration in a decorative bollard, from functional as well as aesthetic standpoints. Bollards are, by their nature, prone 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 – that is available on iron, aluminum, and steel – is definitely an especially durable kind of painted finish. The application form process builds up a coating with very consistent coverage. During coating, any bare metal tends to attract the powder, eliminating pinholes in coverage. The baking process that completes the finish gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, bollard cover manufactured from aluminum might be a better option than iron. In the event 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 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, developing a simple traffic direction system. A big metal loop or arm on the side in the post allows parking and locking of bicycles, an increasingly popular choice as more people seek alternative green transportation. Bollards could also contain lighting units or security devices, including motion sensors or cameras.
Traffic and Safety Bollards
The most common bollard applications are traffic direction and control, along with safety and security. The first function is achieved from the visual presence from the bollards, and to some extent by impact resistance, although, within these applications visual deterrence is definitely the primary function. Security and safety applications depend on higher levels of impact resistance. The major difference between the two is safety designs are concerned with stopping accidental breach of the 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, 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 before zcvjbu parking area entrance to some store, as well as at the mouths of streets converted to outdoor malls or ‘walk streets’. In designing bollard installations to get a site, care must be delivered to avoid locating them where they are going to 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 with a chain presents a visual cue not to cross the boundary, although it might be easy enough to get a pedestrian to travel over or under the chain if they choose. Bollards designed 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 often placed at the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes as well as other installations that need to be protected from accidental contact. A bollard in the fringe of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can certainly redirect a car back to the roadway when its wheels hit the bollard’s sloped sides.
These 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 particularly 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 potency of even a low post at stopping cars.