The popularity of bollards has dramatically increased during the past decade due to heightened concerns about security. They are a basic, practical, and cost-effective means of erecting anti-ram perimeter defense without developing a visual sense of a fortified bunker. Bollards are widely used for traffic direction and control, as well as in purely decorative applications. However, metal bollards can provide many functions beyond security. They can be used as purely aesthetic purposes, functioning as landscaping elements. Bollards can create visible boundaries of a property, or separate areas within sites. They can control traffic and they are often arranged to allow pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different levels of access restriction for a number of 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 building exteriors and surrounding areas. Bollards can incorporate other functions such as lighting, security cameras, bicycle parking or even seating. Decorative bollards are created in a number of patterns to harmonize with a wide range 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 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 really a short vertical post. Early bollards were for mooring large ships at dock, plus they are still being used today. A typical 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 word bollard also describes a number of structures utilized on streets, around buildings, as well as in landscaping. Based on legend, the initial street bollards were actually cannons – sometimes reported to be captured enemy weapons – planted in the ground as boundary posts and town markers. If the supply of former cannons was utilized up, similarly shaped iron castings were designed to fulfill 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 only simple posts, but also a wide variety of decorative designs. Some feature square or rectangular cross-sections, but many are cylindrical, sometimes using a domed, angled, or flat cap. They are offered in a selection of metallic, painted, and sturdy powder coat finishes.
Removable bollards are employed 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 are designed therefore the bollard can easily be collapsed to ground level and quickly re-erected. Both retractable units might be manually operated or automated with hydraulic movements. Movable bollards are large, heavy objects – frequently stone or concrete – that rely on their weight instead of structural anchoring in which to stay place. They are made to be moved rarely, then just with heavy machinery such as a fork-lift.
Bollards generally fall under three varieties of applications:
Decorative Bollards – decorative bollards for architectural and landscaping highlights;
Traffic and Safety Bollards – bollards that offer 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 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 a number of reveals near the top. Styles created 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 actually 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 using them for impromptu seating. On the other hand, 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 often manufactured from iron or aluminum casting. Aluminum bollards are desirable for applications where weight is a problem, such as a removable bollard. Aluminum units are generally a little more expensive than iron. For applications where a decorative bollard may 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 usually manufactured by sand-casting – a conventional foundry technique that is economical and well-suitable for objects this size. However, sand-cast objects frequently bear surface irregularities that often leave the finished product less popular with 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 optimum visual appeal.
Finish is a crucial consideration in a decorative bollard, from functional along with aesthetic standpoints. Bollards are, by their nature, prone 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 application process increases a coating with very consistent coverage. During coating, any bare metal tends 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 bollards made of aluminum might be a better option than iron. If the finish coat is damaged, aluminum oxidizes to a color that is generally more acceptable compared to the red rust made by iron. Aluminum and stainless are also available in a quantity of bare metal finishes. Functionality may be put into the otherwise decorative bollard. For example, common choice is the chain eye – linking several bollards with chain, making a simple traffic direction system. A sizable 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 may also contain lighting units or security devices, including motion sensors or cameras.
Traffic and Safety Bollards
The most frequent bollard applications are traffic direction and control, together with safety and security. The initial function is achieved by the visual presence of the bollards, and to some degree by impact resistance, although, within these applications visual deterrence is definitely the primary function. Safety and security applications rely on higher amounts of impact resistance. The main distinction 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 facing zcvjbu parking area entrance to some store, as well as at the mouths of streets changed into outdoor malls or ‘walk streets’. In designing bollard installations to get a site, care has to be taken to avoid locating them where they will likely 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 line of bollards linked with a chain presents a visual cue never to cross the boundary, although it may be easy enough for any pedestrian to travel over or under the chain should they choose. Bollards made 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 as opposed to merely suggesting them. Plain pipe bollards are usually placed on the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes and other installations that should be shielded from accidental contact. A bollard on the side of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can certainly 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 specifically near 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 effectiveness of also a low post at stopping cars.