The popularity of bollards has dramatically increased during the past decade due to heightened concerns about security. They are an easy, practical, and cost-effective method of erecting anti-ram perimeter defense without creating a visual sense of a fortified bunker. Bollards are widely used for traffic direction and control, as well as in purely attractive applications. However, commercial bollards can offer many features beyond security. They can be used 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 they are often organized to permit pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different degrees of access restriction for many different 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 the building exteriors and surrounding areas. Bollards can incorporate other functions like lighting, surveillance cameras, bicycle parking as well as seating. Decorative bollards are made in a variety of patterns to harmonize with an array of architectural styles. The prevalence of the 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 towards the required function.
What Is A Bollard?
A bollard is really 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 created in cast iron or steel and shaped somewhat just like a mushroom; the enlarged top is made to prevent mooring ropes from slipping off.
Today, the term bollard also describes a variety of structures applied to streets, around buildings, and in landscaping. Based on 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. If the flow of former cannons was applied up, similarly shaped iron castings were created to fulfill the same functions. Bollards have since evolved into many varieties which can be widely employed on roads, specifically in urban areas, in addition to outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most frequent kind of bollard is fixed. The most basic is definitely 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 multitude 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 are available in a number of metallic, painted, and durable powder coat finishes.
Removable bollards are employed 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 therefore the bollard can be easily 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 count on how much they weigh as opposed to structural anchoring to remain in place. They are created to be moved rarely, and after that only with heavy machinery for instance a fork-lift.
Bollards generally belong to three varieties of applications:
Decorative Bollards – decorative bollards for architectural and 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
Some bollards are intended purely to be an ornament. As standalone architectural or landscaping features, they can border, divide, or define a space. 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 second lean toward visual simplicity – often straight-sided posts with a number of reveals nearby the top. Styles made 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 actually a distinctive feature; traditional bollard design often includes elaborate decorative finials, whereas contemporary versions frequently include a simple rounded or slanted top to deter passersby from leaving trash or using 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 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 usually a little more expensive than iron. For applications when a decorative bollard may be subjected to destructive impact, ductile iron is really a safer choice than more brittle metals, as force will deform the metal instead of shatter and transforming it into possible hazardous flying projectiles.
Iron and aluminum bollards are often manufactured by sand-casting – a regular foundry technique that is certainly economical and well-fitted to objects this size. However, sand-cast objects frequently bear surface irregularities that often leave the finished product less appealing to the eye. If high-finish consistency is desired, seek a manufacturer that can machine 100% of the surface after casting to create units using a uniform surface for optimum appearance.
Finish is a crucial 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 exposed to a relatively aggressive environment; petrochemical residues and splashes of diluted road de-icing salts may compromise some painted finishes. Factory-applied powder coating – which can be available on iron, aluminum, and steel – is surely an especially durable type of painted finish. The applying process builds a coating with very consistent coverage. During coating, any bare metal is likely 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. In the event the finish coat is damaged, aluminum oxidizes to your color that is generally more acceptable compared to the red rust created by iron. Aluminum and stainless are also offered in a number of bare metal finishes. Functionality may be added to the otherwise decorative bollard. For instance, common choice is the chain eye – linking several bollards with chain, creating a simple traffic direction system. A big metal loop or arm on the side in the post allows parking and locking of bicycles, a progressively popular choice as more 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 typical bollard applications are traffic direction and control, along with safety and security. The first function is achieved by the visual presence in the bollards, and to some degree by impact resistance, although, within these applications visual deterrence is the primary function. Security and safety applications depend on higher amounts of impact resistance. The main difference between the 2 is safety designs are concerned with stopping accidental breach of a 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 tend to be seen before zcvjbu parking area entrance to your 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 come to avoid locating them where they are going to 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 type of bollards linked by way of a chain presents a visual cue never to cross the boundary, although it might be easy enough for any pedestrian to visit over or under the chain should they choose. Bollards designed to direct traffic are occasionally made 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 and other installations that should be protected against accidental contact. A bollard on the edge of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can certainly redirect a vehicle 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 kind of usage is extremely common at corners where vehicle drivers often misestimate turns, and pedestrians are especially near the roadbed waiting to cross. In some cities, automatically retractable impact-resistant bollards are installed to control the flow of traffic into an intersection. Internet videos of ‘bollard runners’ graphically demonstrate the strength of also a low post at stopping cars.