The prominence of bollards has dramatically increased during the past decade due to heightened concerns about security. These are a simple, practical, and cost-effective method 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 attractive applications. On the other hand, bollard post can serve many features beyond security. They can be used for purely aesthetic purposes, functioning as landscaping elements. Bollards can create visible boundaries of a property, or split areas within sites. They can control traffic and are often organized to permit 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 tell 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 such as lighting, surveillance cameras, bicycle parking or even seating. Decorative bollards are created in a number of patterns to harmonize with an array of architectural styles. The prevalence of the very common type 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 a short vertical post. Early bollards were for mooring large ships at dock, and they are generally still in use today. An average 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 word bollard also describes a variety of structures used on streets, around buildings, and in landscaping. In accordance with legend, the 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 flow of former cannons was utilized up, similarly shaped iron castings were made to match the same functions. Bollards have since become many varieties that are widely employed on roads, specifically in urban areas, as well as outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most frequent type of bollard is fixed. The simplest 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 a majority of are cylindrical, sometimes having a domed, angled, or flat cap. They come in a number of metallic, painted, and sturdy powder coat finishes.
Removable bollards are used where the need 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 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 depend on their weight rather than structural anchoring in which to stay place. They are designed to be moved rarely, then only with heavy machinery for instance a fork-lift.
Bollards generally fall under three kinds of applications:
Decorative Bollards – decorative bollards for architectural and 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 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 second lean toward visual simplicity – often straight-sided posts with several reveals near the top. Styles created to match various historic periods usually have more elaborate shapes and surface details. These include 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 include a simple rounded or slanted top to discourage passersby from leaving trash or making use of 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 steel, and concrete.
Ornamental designs with elaborate detail are usually manufactured from iron or aluminum casting. Aluminum bollards are desirable for applications where weight is an issue, for instance a removable bollard. Aluminum units are usually slightly more expensive than iron. For applications when a decorative bollard could be subjected to destructive impact, ductile iron is really 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 certainly economical and well-suitable for objects this size. However, sand-cast objects frequently bear surface irregularities that often leave the finished product less attractive to the eye. If high-finish consistency is desired, seek a manufacturer which will machine 100% in the surface after casting to produce units using a uniform surface for maximum appearance.
Finish is an important consideration in a decorative bollard, from functional in addition to aesthetic standpoints. Bollards are, by their nature, prone to being scratched or nicked by pedestrians and vehicles. Those located near roadways are in contact with a relatively 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 an especially durable type of painted finish. The application process builds a coating with very consistent coverage. During coating, any bare metal tends 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 bollards made of aluminum may be a better choice than iron. In the event the finish coat is damaged, aluminum oxidizes to a color that is certainly generally more acceptable compared to the red rust created 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. For example, common option is the chain eye – linking two or more bollards with chain, making a simple traffic direction system. A big metal loop or arm on the side from the post allows parking and locking of bicycles, an extremely popular choice as more 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 typical bollard applications are traffic direction and control, along with security and safety. The very first function is achieved by the visual presence in the bollards, and at some level by impact resistance, although, within these applications visual deterrence will be the primary function. Safety and security applications depend on higher amounts of impact resistance. The major distinction between the two is safety designs are involved with stopping accidental breach of a defined space, whereas security is 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 – such as wheelchairs or shopping carts – but prevents the passage of cars. Such installations are frequently seen before zcvjbu parking lot entrance to a store, and at the mouths of streets changed into outdoor malls or ‘walk streets’. In designing bollard installations to get a site, care should be delivered 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 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 visit over or underneath the chain should they choose. Bollards designed to direct traffic are often 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 at the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes along with other installations that need to be protected from accidental contact. A bollard on the edge of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can in fact redirect a car back onto the roadway when its wheels hit the bollard’s sloped sides.
These are employed where U-turns and tight-radius turns are frequent. This type of usage is particularly 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 effectiveness of also a low post at stopping cars.