The prominence of bollards has dramatically increased during the past decade as a result of heightened concerns about security. They are an easy, practical, and cost-effective way of erecting anti-ram perimeter defense without creating 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, 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 organized to allow pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different degrees 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 the building exteriors and surrounding areas. Bollards can incorporate other functions such as lighting, security cameras, bicycle parking as well as seating. Decorative bollards are created in a selection 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 created to fit as covers over standard steel pipe sizes, adding pleasing form to the required function.
What Exactly Is A Bollard?
A bollard is really a short vertical post. Early bollards were for mooring large ships at dock, and they are still being used today. An average marine bollard is created in cast iron or steel and shaped somewhat such as a mushroom; the enlarged top is designed to prevent mooring ropes from slipping off.
Today, the phrase bollard also describes a number of structures applied to streets, around buildings, and then in landscaping. In accordance with legend, the first street bollards were actually cannons – sometimes said to be captured enemy weapons – planted in the ground as boundary posts and town markers. If the flow of former cannons was utilized up, similarly shaped iron castings were made 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 kind 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 only simple posts, but also 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 are available in a variety of metallic, painted, and durable powder coat finishes.
Removable bollards are utilized 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 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 rely on their weight instead of structural anchoring in which to stay place. They are designed to be moved rarely, and then only with heavy machinery like 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 which provide 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 become an ornament. As standalone architectural or landscaping features, they can border, divide, or define a space. 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 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 as well as other ornamentation.The post-top is 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, 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 usually made of iron or aluminum casting. Aluminum bollards are desirable for applications where weight is an issue, such as a removable bollard. Aluminum units are usually slightly more expensive than iron. For applications in which 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 as opposed to 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 economical and well-fitted to objects this size. However, sand-cast objects frequently bear surface irregularities that have a tendency to leave the finished product less attractive to the eye. If high-finish consistency is desired, seek a manufacturer that will machine 100% of the surface after casting to produce units using a uniform surface for optimum looks.
Finish is an important consideration in a decorative bollard, from functional as well as aesthetic standpoints. Bollards are, by their nature, vulnerable 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 available on iron, aluminum, and steel – is surely an especially durable type of painted finish. The application 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 finish gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, plastic bollards manufactured from aluminum might be a better option than iron. In the event the finish coat is damaged, aluminum oxidizes to your color which is generally more acceptable than the red rust made by iron. Aluminum and stainless steel can also be found in a variety of bare metal finishes. Functionality could be put into the otherwise decorative bollard. For example, common option is the chain eye – linking two or more bollards with chain, developing a simple traffic direction system. A big metal loop or arm on the side from the post allows parking and locking of bicycles, an increasingly popular choice as more people seek alternative green transportation. Bollards could also contain lighting units or security devices, such as motion sensors or cameras.
Traffic and Safety Bollards
The most common bollard applications are traffic direction and control, together with security and safety. The very first function is achieved by the visual presence from the bollards, and to some extent by impact resistance, although, during these applications visual deterrence is definitely the primary function. Security and safety applications depend on higher degrees of impact resistance. The main distinction between the 2 is safety designs are worried with stopping accidental breach of a 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 – like wheelchairs or shopping carts – but prevents the passage of cars. Such installations are often seen in front of zcvjbu car park entrance to a store, and also at the mouths of streets converted to outdoor malls or ‘walk streets’. In designing bollard installations for a site, care has to be delivered to avoid locating them where they are going to 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 line of bollards linked by way of a chain presents a visual cue to not cross the boundary, although it could be easy enough for a pedestrian to go over or underneath the chain if they choose. Bollards made to direct traffic are sometimes made 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 in the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes and other installations that ought to be protected from accidental contact. A bollard in the edge of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can actually redirect an automobile 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 sort of usage is especially common at corners where vehicle drivers often misestimate turns, and pedestrians are particularly near to the roadbed waiting to cross. In a few 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 potency of also a low post at stopping cars.