The popularity of bollards has dramatically increased in the past decade due to heightened worries about security. These are a basic, practical, and cost-effective method of erecting anti-ram perimeter defense without developing a visual sense of a fortified bunker. Bollards are popular for traffic direction and control, as well as in purely attractive applications. However, steel bollard post can provide many features beyond security. They can be used for purely aesthetic purposes, functioning as landscaping elements. Bollards can make visible boundaries of any property, or separate areas within sites. They can control traffic and they are often set up 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 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, security cameras, bicycle parking as well as seating. Decorative bollards are produced in a selection of patterns to harmonize with a wide range of architectural styles. The prevalence of the very common kind 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 for the required function.
What Exactly Is A Bollard?
A bollard is actually a short vertical post. Early bollards were for mooring large ships at dock, and they are generally still being used today. An average marine bollard is manufactured 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 variety of structures utilized on streets, around buildings, and then in landscaping. According to 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. Once the supply of former cannons was utilized up, similarly shaped iron castings were created to fulfill the same functions. Bollards have since evolved into many varieties which are widely employed on roads, especially in urban areas, as well as outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most common type of bollard is fixed. The simplest is 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 numerous 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 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 often needed, and are designed therefore the bollard can be simply 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 as opposed to structural anchoring in which to stay place. They are created to be moved rarely, and after that just with heavy machinery such as a fork-lift.
Bollards generally belong to 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 could 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 latter lean toward visual simplicity – often straight-sided posts with a number of reveals nearby the top. Styles designed to match various historic periods usually have more elaborate shapes and surface details. These include flutes, bands, scrolls as well as other ornamentation.The post-top is actually a distinctive feature; traditional bollard design often includes elaborate decorative finials, whereas contemporary versions frequently come with a simple rounded or slanted top to discourage passersby from leaving trash or using 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-steel, and concrete.
Ornamental designs with elaborate detail are frequently made of iron or aluminum casting. Aluminum bollards are desirable for applications where weight is an issue, for instance a removable bollard. Aluminum units are generally a little more expensive than iron. For applications when 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 as opposed to 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 economical and well-suited to 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 will machine 100% from 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 in addition to 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 fairly 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 an especially durable type of painted finish. The applying process builds a coating with very consistent coverage. During coating, any bare metal tends to attract the powder, eliminating pinholes in coverage. The baking process that completes the conclusion gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, plastic bollard manufactured from aluminum can be a better choice than iron. In the event the finish coat is damaged, aluminum oxidizes to your color which is generally more acceptable compared to red rust made by iron. Aluminum and stainless steel can also be found in a number of bare metal finishes. Functionality can be added to the otherwise decorative bollard. As an example, common option is the chain eye – linking 2 or more bollards with chain, developing a simple traffic direction system. A big metal loop or arm on the side of 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, such as motion sensors or cameras.
Traffic and Safety Bollards
The most frequent bollard applications are traffic direction and control, together with safety and security. The very first function is achieved from the visual presence in the bollards, and at some level by impact resistance, although, in these applications visual deterrence is definitely the primary function. Security and safety applications rely on higher levels of impact resistance. The main distinction between the two is safety designs are worried 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 the two, for instance, 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 facing zcvjbu parking lot entrance to a store, and at the mouths of streets converted to outdoor malls or ‘walk streets’. In designing bollard installations to get a site, care has to be come 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 by a chain presents a visual cue to not cross the boundary, even though it may be easy enough for any pedestrian to visit over or beneath the chain should they choose. Bollards created to direct traffic are sometimes created 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 at the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes as well as other installations that need to be protected against accidental contact. A bollard at the side 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 type of usage is particularly common at corners where vehicle drivers often misestimate turns, and pedestrians are specifically near 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 potency of a low post at stopping cars.