The popularity of bollards has dramatically increased in the past decade due to heightened fears 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, as well as in purely decorative applications. On the other hand, commercial bollards can serve many features beyond security. They can be used as 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 are often arranged to permit pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different degrees of access restriction for a variety of circumstances. They frequently inform us where we can 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, surveillance cameras, bicycle parking or even seating. Decorative bollards are produced in a number of patterns to harmonize with an array 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 designed to fit as covers over standard steel pipe sizes, adding pleasing form to the required function.
Exactly What Is A Bollard?
A bollard is actually 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 manufactured 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 phrase bollard also describes a variety of structures utilized on streets, around buildings, and then in landscaping. In accordance with legend, the initial street bollards were actually cannons – sometimes said 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 designed to fulfill the same functions. Bollards have since evolved into many varieties which are widely employed on roads, especially in urban areas, along with 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 merely simple posts, but in addition a wide variety of decorative designs. Some feature square or rectangular cross-sections, but many are cylindrical, sometimes having a domed, angled, or flat cap. They come in a variety of metallic, painted, and sturdy powder coat finishes.
Removable bollards are used where the requirement to limit access or direct traffic changes occasionally. Both retractable and fold-down styles are employed where selective entry is often needed, and are designed and so 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 depend on how much they weigh instead of structural anchoring to stay in place. They are made to be moved rarely, then simply with heavy machinery for instance a fork-lift.
Bollards generally belong to 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, in addition to 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 a place. They may also 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 one or more reveals near the top. Styles designed to match various historic periods usually have more elaborate shapes and surface details. These include flutes, bands, scrolls as well as other ornamentation.The post-top is 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 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-steel, and concrete.
Ornamental designs with elaborate detail are frequently 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 generally a little more expensive than iron. For applications when a decorative bollard might be subjected 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 conventional foundry technique that is certainly economical and well-suited 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% from the surface after casting to generate units having a uniform surface for max visual appeal.
Finish is a vital consideration in a decorative bollard, from functional in addition to 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 – that is available on iron, aluminum, and steel – is surely an especially durable kind of painted finish. The application form 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 procedure that completes the conclusion gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, plastic bollard made of aluminum may be a better choice than iron. If the finish coat is damaged, aluminum oxidizes to some color that is certainly generally more acceptable compared to red rust made by iron. Aluminum and stainless are also available in a number of bare metal finishes. Functionality may be included in the otherwise decorative bollard. For example, common option is the chain eye – linking 2 or more bollards with chain, creating a simple traffic direction system. A sizable metal loop or arm on the side of the post allows parking and locking of bicycles, an increasingly popular choice as more people seek alternative green transportation. Bollards might also contain lighting units or security devices, including motion sensors or cameras.
Traffic and Safety Bollards
The most typical bollard applications are traffic direction and control, together with security and safety. The very first function is achieved from the visual presence of the bollards, and at some level by impact resistance, although, within these applications visual deterrence is the primary function. Safety and security applications depend on higher levels of impact resistance. The main distinction between the two is safety designs are worried 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 car park entrance to your store, and at the mouths of streets changed into outdoor malls or ‘walk streets’. In designing bollard installations for a site, care should be delivered to avoid locating them where they will likely become a navigational hazard to authorized vehicles or cyclists.
Some applications for traffic guidance depend on the cooperation of drivers and pedestrians and do not require impact resistance. A type of bollards linked with a chain presents a visual cue never to cross the boundary, although it might be easy enough for any pedestrian to travel over or underneath the chain should 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 as opposed to merely suggesting them. Plain pipe bollards are often placed in 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 on the fringe of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can in fact redirect an automobile back on 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 type of usage is extremely common at corners where vehicle drivers often misestimate turns, and pedestrians are particularly close 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 even a low post at stopping cars.