The popularity of bollards has dramatically increased during the past decade because of heightened worries about security. They are a basic, 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. However, steel bollard post can provide many characteristics 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 are often set up 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 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 including lighting, surveillance cameras, bicycle parking or even seating. Decorative bollards are made in a variety of patterns to harmonize with a variety 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 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 a short vertical post. Early bollards were for mooring large ships at dock, plus they are still used today. A normal marine bollard is produced in cast iron or steel and shaped somewhat like a mushroom; the enlarged top is made to prevent mooring ropes from slipping off.
Today, the phrase bollard also describes many different structures applied to streets, around buildings, and 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. If the availability of former cannons was utilized up, similarly shaped iron castings were made to fulfill the same functions. Bollards have since evolved into many varieties which can be widely employed on roads, particularly in urban areas, in addition to outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most common 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 also numerous decorative designs. Some feature square or rectangular cross-sections, but most are cylindrical, sometimes using a domed, angled, or flat cap. They are offered in a variety of metallic, painted, and durable 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 frequently needed, and they are designed so 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 rely on their weight rather than structural anchoring to stay in place. They are made to be moved rarely, and after that only with heavy machinery for instance a fork-lift.
Bollards generally fall under three types of applications:
Decorative Bollards – decorative bollards for architectural and/or landscaping highlights;
Traffic and Safety Bollards – bollards that 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 become an ornament. As standalone architectural or landscaping features, they can border, divide, or define an area. They can 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 close to 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 along with 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 utilizing 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, and concrete.
Ornamental designs with elaborate detail are frequently made from 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 in which 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 instead of shatter and transforming it into possible hazardous flying projectiles.
Iron and aluminum bollards are usually manufactured by sand-casting – a traditional 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 that can machine 100% in the surface after casting to generate units having 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 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 – which is on iron, aluminum, and steel – is surely an especially durable type of painted finish. The application process increases a coating with very consistent coverage. During coating, any bare metal has a tendency 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, plastic bollard covers manufactured from aluminum may be a better option than iron. When the finish coat is damaged, aluminum oxidizes to your color that is certainly generally more acceptable than the red rust created by iron. Aluminum and stainless steel are also offered in a quantity of bare metal finishes. Functionality can be put into the otherwise decorative bollard. For example, common choice is the chain eye – linking several bollards with chain, developing a simple traffic direction system. A sizable metal loop or arm on the side in the post allows parking and locking of bicycles, an extremely popular choice as more people seek alternative green transportation. Bollards could also contain lighting units or security devices, like motion sensors or cameras.
Traffic and Safety Bollards
The most frequent bollard applications are traffic direction and control, along with safety and security. The initial function is achieved through the visual presence from the bollards, and to some extent by impact resistance, although, within these applications visual deterrence is the primary function. Safety and security applications rely on higher amounts of impact resistance. The major difference between the two is safety designs are worried with stopping accidental breach of any defined space, whereas security is approximately 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 – such as wheelchairs or shopping carts – but prevents the passage of cars. Such installations tend to be seen facing zcvjbu parking lot entrance to a store, and also 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 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 never require impact resistance. A type of bollards linked with a chain presents a visual cue not to cross the boundary, though it might be easy enough to get a pedestrian to go over or underneath the chain when they choose. Bollards created 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 instead of merely suggesting them. Plain pipe bollards are often placed on the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes along with other installations that should be shielded from accidental contact. A bollard at the edge of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can in fact redirect a vehicle 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 sort of usage is particularly common at corners where vehicle drivers often misestimate turns, and pedestrians are specifically close to 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 strength of even a low post at stopping cars.