Figure 1: Bollards. Source: N Chadwick/CC BY-SA 2.0

The simple bollard has come a long way from its earliest days in use at piers for mooring ships. Modern bollards still provide essential functions at ports and docks in addition to their use in traffic and crowd control. Bollards provide critical functions including securing boats and ships, keeping people safe, providing lighting, and directing traffic.

Theory of Operation

Bollards are sturdy, short, vertical posts installed to control or direct road traffic and prevent vehicles from entering specific areas or to provide a secure tie-off point for ships. In either case, bollards are designed to be extremely sturdy and able to handle a large load. They serve as visual guides for drivers and provide physical separation between vehicle and non-vehicle areas. These posts are most often used to improve safety, but they can also serve aesthetic purposes.

Figure 2: Metal bollards. Source: Pixabay

Depending on their intended purpose, bollards can operate slightly differently. The main functions bollards provide include:

• Traffic guidance and control
• Security
• Marine docking
• Aesthetics

Bollards guide traffic by creating a clear distinction between areas where vehicles are allowed and where they are not. They ensure pedestrians can use sidewalks without fear of vehicle incursion, and they help direct traffic in parking lots. Bollards prevent vehicles from entering specific areas, like pedestrian zones or cycling paths. They are typically placed at the entrances of these areas.

Bollards are used to secure sensitive areas from potential vehicle attacks. In such cases, they are typically made of heavy-duty materials like steel and deeply anchored into the ground to withstand high-speed impacts. Such bollards are often found around government buildings, commercial areas, or any area where there's a risk of vehicle-based attacks.

Similar to their use for security, bollards used in marine settings are designed to withstand heavy loads. These bollards provide a secure point for ships to moor their lines, securing the boats in the port. The bollard must be able to resist any forces the ship may place on the mooring line.

In many urban and landscape designs, bollards are used as decorative elements. They can be designed to fit with the aesthetics of the area, sometimes being made to look like street furniture.

Bollards are either fixed, retractable, or collapsible. Fixed bollards are permanently fixed in place. They provide a consistent barrier for vehicles and are often used in areas where there is a constant need for protection. Fixed bollards are anchored strongly to the ground to allow any forces encountered to be quickly transferred into the ground. These bollards are the simplest and most common version

Retractable or "rising" bollards can be lowered below ground level when access is required and then raised again when the area needs to be secured. This is controlled manually or automatically. These bollards can still be made quite strong but do require a great deal more care in setting up and maintaining their operation.

Collapsible bollards can be folded down manually to allow vehicle access and then placed back upright afterward. These high-visibility bollards provide essential temporary functions for traffic control.

The effectiveness of a bollard in its intended role depends on its strength, visibility, and placement. The key idea behind their operation is to provide a physical and visual barrier to control traffic, secure ships, and increase safety.

Figure 3: A maritime bollard. Source: Pixabay

Specifications

The specifications for bollards can vary greatly depending on their intended use. Here are some general categories of specifications to keep in mind:

Material

Bollards can be made from a variety of materials, including steel, concrete, stainless steel, aluminum, iron, or even plastic. The choice of material will affect the bollard's durability, maintenance needs, and resistance to impact.

Size

Bollards typically range from 24 to 48 inches in height. Their diameter or width usually varies between 3.5 to 12 inches. This depends on the specific use and the environment where they will be installed. Bollards can also come in different shapes to blend with a building’s aesthetic.

Figure 4: Target bollards. Source: Robert T. Bell/CC BY-SA 2.0

Installation Method

This will depend on the specific type of bollard. Fixed bollards may be embedded into the ground, surface-mounted, or removable. Retractable bollards may be manually or automatically operated, while collapsible bollards can be locked in an upright or down position.

Impact Resistance

This is a key specification for security bollards. Some bollards are rated to stop a certain weight of vehicle at a certain speed, like a 15,000 pound vehicle traveling at 30 mph. These are often referred to as K-rated or M-rated bollards, with different levels of certification indicating higher levels of impact resistance.

Design and Finish

Bollards can have various finishes and designs, including painted, powder-coated, brushed, polished, or even ornamental features for aesthetic purposes.

Accessibility

Bollards should be appropriately spaced to maintain accessibility. For instance, regulations like the Americans with Disabilities Act (ADA) in the U.S. require a minimum space of 36 inches between bollards on accessible routes.

These are general categories of bollard specifications. Depending on their intended use and the specific context, other specifications may also be relevant. It's also worth mentioning that local or national regulations may require certain specifications for bollards used in specific contexts, so these would also need to be taken into account.

Figure 5: Security bollards. Source: CC BY-SA 2.0

Types

Bollards come in various types, serving different functions depending on their design and the specific needs of the area where they are installed. Here are some common types of bollards:

Fixed Bollards

Fixed bollards are permanently installed and immovable, providing a consistent protective barrier. They are often used in pedestrian areas, around buildings, or any areas where there is a constant need for protection from vehicles.

Removable Bollards

Removable bollards can be detached and moved to allow for temporary vehicle access. These bollards are usually placed in a ground socket and can be locked into place or removed as required. They are useful in areas where access needs may vary.

Retractable or Telescopic Bollards

Retractable bollards can be lowered into the ground when vehicle access is required and raised again when the area needs to be secure. These are typically controlled manually or automatically, and are often used for emergency vehicle access, entrances to businesses, or to control traffic flow.

Fold-Down Bollards

Also known as collapsible bollards, these can be manually folded down to allow vehicle access and placed back upright afterward. They are useful where occasional vehicle access is needed.

Anti-Ram or Security Bollards

These are designed to protect against vehicle-based attacks or accidents. They are typically made from robust materials, such as steel, and are deeply embedded into the ground. They may be fixed, removable, or retractable.

Lighted Bollards

These bollards include built-in lighting for better visibility and aesthetic appeal. They are often used in parks, pathways, or outdoor retail environments to increase safety and enhance the landscape design.

Flexible Bollards

These are designed to withstand impacts by bending or flexing upon collision, then returning to their original position. They are typically used in parking lots or along roadways to guide traffic and prevent vehicles from entering certain areas, without causing vehicle damage if they are hit.

Decorative Bollards

These bollards are designed with a focus on aesthetics and are often used in pedestrian areas or around public buildings, parks, and retail spaces. While they provide a decorative element, they can also function as barriers.

The type of bollard chosen depends on the specific needs and context of the area, whether the main concern is safety, security, traffic guidance, or aesthetics.

Figure 6: Bollards. Source: Infrogmation/CC BY-SA 4.0

Features

The features of bollards can differ depending on their purpose, design, and the location in which they're used. However, some general features that could be present in different types of bollards include:

Visibility Features

Bollards can have reflective tape or be brightly colored to enhance visibility, especially at night or during poor weather conditions. Some bollards also have built-in lighting.

Weather Resistance

Bollards are often designed to withstand various environmental conditions. They can be corrosion resistant and have features like water resistance and UV protection.

Locking Mechanism

Retractable, removable, and fold-down bollards typically have a locking mechanism that secures them in place when they're upright and keeps them secure when they're not in use.

Design

Some bollards are designed with aesthetics in mind. They can come in a variety of styles and finishes to complement the architecture and design of the surrounding area.

Flexibility

Some bollards, known as flexible or rebounding bollards, are designed to bend upon impact and then return to their original position. This feature can prevent damage to both the bollard and the vehicle in case of a collision.

Integrated Technology

In some advanced models, bollards can feature integrated technology such as sensors or automatic rising/lowering mechanisms.

The specific features of a bollard will depend on its intended use and the specific requirements of the location where it's installed.

Figure 7: Road bollards. Source: Pixabay

Manufacture

Bollard manufacturing can vary depending on the material used, the design of the bollard, and its intended application. Here is a general outline of the process for steel bollards, which are among the most common types.

Once the material is selected, it's cut to the desired length based on the height requirements of the bollard. This is usually done with a metal cutting saw or a plasma cutter for precision.

The cut material is then shaped into a cylindrical form, the most common shape for bollards. This might involve bending flat steel into a round shape or using pre-made steel tubing. If the bollard is made from a flat sheet of steel, the edges are welded together to form a cylinder. A top cap may also be welded onto the bollard for a finished look and to prevent accumulation of debris or water inside the bollard.

Depending on the type of steel used, the bollard may then be treated to prevent rust and corrosion. This could involve hot-dip galvanizing, where the bollard is dipped in a bath of molten zinc, or other types of coating or paint. The bollard may also be painted or powder-coated for aesthetic purposes and additional protection against weathering.

For more complex bollards, such as retractable or lighted bollards, additional steps would be necessary to install the mechanical components or wiring. The specific manufacturing process can vary based on the bollard type and manufacturer.

It's also worth noting that different materials would require different manufacturing processes. For example, concrete bollards would involve casting in a mold, while plastic bollards might be created through a process like injection molding.

Applications

Bollards are used in a variety of applications due to their versatility. They can serve functional purposes, like traffic control and security, or aesthetic purposes, enhancing the visual appeal of a space. Here are some common applications:

Traffic Control

Bollards are used in parking lots, on sidewalks, and around buildings to guide vehicles and pedestrians. They can help designate pedestrian zones, bike lanes, and fire lanes, or they can be used to restrict access to certain areas.

Figure 8: Bollards. Source: Kenneth Allen/CC BY-SA 2.0

Security

Anti-ram bollards can protect people, property, and infrastructure from vehicle-based attacks or accidents. They're often used around government buildings, stadiums, schools, and other areas where security is a concern.

Storefronts

Bollards are commonly used in front of stores or restaurants to protect against vehicle incursions. This is especially common where parking or a drive-thru lane is close to the building.

Landscaping

Decorative bollards can enhance the visual appeal of parks, city streets, university campuses, and other public spaces. They can also serve as a place to attach hanging baskets, lights, or banners.

Figure 9: Metal bollards. Source: Pixabay

Cycling Paths

Bollards can be used to separate cycling lanes from vehicle lanes, offering protection to cyclists and guiding traffic.

Parking Garages and Lots

Bollards can be used to direct traffic flow in a parking garage, to protect parking equipment, or to designate certain parking areas.

Boat Mooring

The oldest use of bollards, they can be used to provide a mooring point for boats in port. Boats and ships of all different sizes require mooring to secure the ships at the dock.

Figure 10: Bollards can be used to provide a mooring point for boats in port. Source: Pixabay

Stadiums and Event Venues

Bollards can be used to control and guide crowds, protect pedestrian areas, and prevent unauthorized vehicle access.

Airports

Bollards can protect against unauthorized vehicle access in sensitive areas, guide traffic, and protect buildings and other infrastructure.

Utilities Protection

Bollards can be used to protect utilities such as gas meters, electrical equipment, and HVAC units from accidental impact.

These are just a few examples of where bollards can be used. Their applications are vast and varied, depending on the specific needs and requirements of the location.

Figure 11: Traffic bollards. Source: Liaoning Deren/CC BY-SA 4.0

Standards

Standards for bollards are set by various organizations and can vary by country, state, or even city. These standards may govern aspects like the materials used, the size and design of the bollard, and its ability to withstand impact. Some of these standards include:

• ASTM F3016
• ASTM F2656
• BS 8442:2006
• PAS 68
• IWA 14-1

The American Society for Testing and Materials sets various standards for bollards. For instance, ASTM F3016 specifies the standard test method for small, low-speed vehicles (like a car or small pickup truck) at a speed of 10 mph, while ASTM F2656 specifies the standard test method for crash testing for vehicle security barriers.

The Department of State's K-Rating system is used for crash-tested barricades. K4-rated bollards can stop a 15,000 pound vehicle going 30 mph, K8-rated bollards can stop the same weight at 40 mph, and K12-rated bollards can stop the vehicle at 50 mph.

British Standards BS 8442:2006 covers miscellaneous road traffic signs and devices, including specifications for passive traffic control devices like bollards.

International Workshop Agreement (IWA 14-1) is an international standard specifying the essential impact performance requirement for a vehicle security barrier and a test method for rating its performance.

These standards are designed to ensure that bollards are effective in their role, whether that is to protect people and property, guide traffic, or enhance aesthetics. However, standards can vary, and it's important to follow the standards that apply in the specific location and for the specific application of the bollards.

References

Reliance Foundry—A Complete Guide to Bollards—Bollard Definition, History, Uses, and More

McCue—What are bollards and why do I need them?

Crowd Control Warehouse—What are Bollards Used For? Bollard Definitions & Types of Bollards

Tampa Steel & Supply—What Is a Bollard in Construction?

Bollard Shop—Types of Bollards and their uses

B&B Roadway & Security Solutions—Why use bollards

1-800-BOLLARDS—5 Safety Uses For Bollards

ASTM F3016/F3016M-19—Standard Test Method for Surrogate Testing of Vehicle Impact Protective Devices at Low Speeds

BS 8442:2006—Miscellaneous Road Traffic Signs And Devices. Requirements And Test Methods (British Standard)

Related Information

GlobalSpec—Barcelona Attacks Highlight the Need for More Bollards and Terrorist Countermeasures