Seven Major Uses for Safety Bollards

Safety bollards are the workhorses of the security and traffic management world.  They serve an almost endless variety of roles, from directing traffic to protecting sensitive installations.  Here’s a look at seven of the most important ways in which they serve.

1. Traffic calming – Safety bollards are used to delineate car-free zones, prevent spillover parking on sidewalks, and reduce traffic speed by narrowing lanes.  Additionally, studies by the Transportation Research Institute of Israel have found that strategically placed safety bollards can reduce the frequency of automotive accidents.  In some cases, these purposes are best served by flexible metro bollards that bend upon impact.  In other instances, officials use heavily reinforced safety bollards made of steel with concrete cores.  In recent times, portable bollards have begun to replace traffic cones for use around roadway worksites.
   
2. Illuminating darkened areas – Wrongdoers typically seek dark, poorly lit places to commit crimes.  To discourage such behavior and enhance visibility, many modern safety bollards are outfitted with lighting devices.  In some cases, the bollard is a totally self-contained unit that operates via small solar panels, a built-in battery, and LEDs.  In other cases, safety bollards are connected to the power utility and joined in an electrical network.  Reflective bollards are often used to mark sensitive areas; officials rely on their ability to reflect oncoming headlights.
3. Deflecting vehicle tires – Bell-shaped safety bollards are used for this purpose in many parts of the world, including continental Europe and the United Kingdom.  They help to safeguard both property and pedestrians from stray vehicles.
4. Enabling periodic traffic control measures – Some facilities require concentrated traffic management during certain periods of time.  These include school zones, houses of worship, and factories that employ shift workers.  In such cases, portable safety bollards serve an important role.  Sometimes these products are temporarily mounted into permanently affixed metal sockets at road or ground level.  Other times, safety bollards are outfitted with electric or hydraulic mechanisms that operators can raise or lower as needed.  With advances in artificial intelligence, officials are using so-called “smart bollards” in some areas.  These devices can position themselves as needed based on incoming sensory data.
5. Enhancing driver safety during racing events – In some cases, sporting officials use safety bollards to mark sharp corners and other segments of raceways that might compromise the safety of the competitors.  These products are designed to break away from their base very easily, should a vehicle strike them.
6. Controlling access – Many types of safety bollards serve in this capacity.  They range from simple flexible structures joined together by yellow caution tape to substantial monuments that do double-duty as raised flowerbeds or sculptures.  Police officers use safety bollards to direct civilians away from crime scenes, as commonly shown on television and in motion pictures.  Permanent safety bollards can weigh many tons, and are designed to deflect oncoming vehicles traveling at high speeds.  This particular use for bollards has become increasingly common in the years since the 9/11 terrorist attacks.
   
7. Helping to preserve historic sites – In the United States, the National Register of Historic Places includes more than 90,000 buildings, objects, sites, districts and structures.  Many of these locations are easily damaged or defaced.  In such cases, officials often use safety bollards to discourage both careless activities and outright vandalism.  The bollards used range from lightweight portable structures to sizable fixtures, depending on budgetary priorities and changing circumstances.

Conclusion

The world becomes more crowded with each passing day, creating an ever-growing need for effective security measures.  Safety bollards serve an important role in this regard.  Their value as public protectors will only increase in the coming years.

Frangible Bollards for Structural Concrete

Protecting assets and pedestrians in a concrete structure often poses particular challenge to designers and architects.  Any bollard used must be strong enough and imposing enough to prevent errant vehicle traffic from causing damage, but yet cannot be a liability to the entire structure.  For this reason, embedded bollards are rarely used in pre- and post-tension concrete structures.  Should a vehicle impact and embedded bollard that does not give, potential for catastrophic structural failure exists.  Further, options to repair bent bollards are severely limited, leaving the property owner stuck with unsightly bollards.

This has left architects and property managers with only welded steel plate bollards as a safe option.  Even when used, often the anchor have to be design for shearing to avoid the possibility of damaging tendons. Unfortunately, as most parking garage owners know, welded-plate bollards are extremely weak and easily damaged, as this outdoor photo demonstrates.

Today there is a new type of bollard that offers the protection rivaling embedded bollard, while maintaining the integrity of the structural concrete.  The patented SlowStop Rebounding Bollard system is a surface mounted bollard that absorbs impacts using a unique energy absorbing disc hidden in the bottom of the bollard system.  This disc allows the bollard to tilt approximately 20 degrees upon impact, then rebound to upright (see DEMO VIDEO).  It is attached to concrete by way of concrete screw anchors, however the base of the bollard system, and the bollard pipe itself, are both designed to bend or break before the anchors pull out the foundation concrete.

Not only does this system provide for a superior safety in a structural concrete building, but it reduces damage to vehicles that may impact the bollard.  It also takes reduced damage itself, due to the shock absorbing properties of the rebounding bollard.  Should any part of the system become damaged, each part can be changed out in modular fashion.  The system is easy to install and usefully in retro-fit situations once tendon locations have been identified.

The system is available in 3", 4", and 6" sizes, each of which is specified based on quantifiable energy absorption testing data.  The 4" bollard is even particularly useful for creating bollard enhanced handicap parking sign posts.

Visit www.slowstop.com to learn more about this innovative new product and how it solves one of today's trickiest design problems for parking garages and structural concrete buildings.

Gaining Peace of Mind with Traffic Bollards

Traffic bollards are the most common bollards found today.  They’re used both to guide traffic and to help ensure public safety.  They accomplish the first objective by their visual presence, which alerts motorists to the need to follow a marked route or to avoid a prohibited area.  They fulfill the second purpose by forming physical barriers, strong enough to stop an errant motorist or out-of-control vehicle from striking passersby.

Traffic bollards are often painted bright yellow or orange to make them more prominent when viewed against the surrounding landscape. To aid nighttime visibility, traffic bollards often have reflective tape affixed to them.

Benefits of Traffic Bollards

1. Increased safety of city foot traffic – Bollards are used in many large urban areas to surround pedestrian islands.  There, they act as physical barriers against misguided and out-of-control vehicles.
2. Traffic calming – Several studies have shown that bollards cause motorists to drive slower and to pay more attention to their surrounding environment.  This leads to fewer vehicular accidents of all types.
3. Improved building access – Traffic bollards are also used to prevent vehicles from blocking entrances to buildings, by making it impossible for drivers to park too close to the entrance or for vehicles to park too closely together.
4. Psychological assurance – The vast majority of vehicle-related accidents are caused by a small minority of drivers, who fail to operate their automobiles in a responsible fashion.  However, traffic bollards act as a physical barrier between them and those who would otherwise be victims of their carelessness.  This allows both pedestrians and conscientious motorists to breathe a little easier as they go about their daily activities.  This enhanced level of mental comfort is far from the least of the many ways in which bollards benefit the public.

Conclusion

Traffic bollards play a vital role in today’s transportation systems.  Their use benefits drivers, pedestrians, and bike riders in innumerable ways.  For these reasons and more, urban planners should use them as integral components for helping to assure the public’s safety, comfort, and peace of mind.

When to Utilize the Safety Bollard

While all bollards are designed to promote public well-being to some extent, a safety bollard is intended specifically for this purpose.  Because of this, its construction is likely to be both permanent in nature and highly resistant to efforts to dislodge it.

While this can be beneficial in many ways, it increases the likelihood of damage to motor vehicles, cyclists, and even pedestrians that strike them.  It can also impede the entrance of emergency responders, such as fire and police units.  Given these facts, safety bollards should only be used when the circumstances warrant.  Such situations include the following:

1. When access to a particular area is likely to be especially hazardous.  A prime example is the typical construction site, where heavy equipment, falling objects, and scattered debris all pose significant dangers to unauthorized persons.  Scenes of recent motor vehicles collisions, places where sinkholes have opened, and areas where industrial accidents have occurred also fall into this category.
2. When ensuring the proper flow of traffic is vital to human safety.  For example, hospital entrances include dedicated lanes that are only meant to be accessed by ambulances.  However, on frequent occasions, misguided motorists drive their vehicles into these areas, preventing emergency vehicles from arriving.  In such locations, the prospect of damage to privately owned vehicles is outweighed by the potential harm caused to the sick and injured.  Hence, using safety bollards is thoroughly justified.
3. When a site is a likely target of terrorists or other criminals.  Nuclear facilities, for example, use safety bollards as well as other impediments to traffic.  This is because tight control of the location’s perimeter is of paramount importance to public safety.  Other locations at high risk of attack include police stations in high-crime areas, military installations, and hydroelectric plants. 

In summary, while a safety bollard is far from an ideal solution in many instances, it can serve a vital role in protecting sensitive areas from unauthorized access.  Use in accordance with sound judgment should be continued.

Find out more about our bollards at www.slowstop.com.

Reducing Damage from Vehicle-Bollard Impacts

Reposted from www.slowstop.com.

ABSTRACT

Bollards are short vertical posts, usually made of steel, typically used to prevent access and to protect pedestrians and assets from vehicle collision damage.  In so doing, vehicles (and their passengers) that impact bollards face damage (and injury) due to the collision, as well as damage to the bollard structure itself.  A new bollard system, known as SoftStop® in Europe and SlowStop® in the United States, solves this problem by allowing the bollard to give slightly upon collision, greatly reducing the maximum impact forces felt by both the colliding vehicle and the bollard system itself.

BOLLARD APPLICATIONS

Bollards are used in a myriad of applications, for one of several purposes:

• Equipment Protection
• Utility Protection
• Building Protection
• Access Restriction
• Pedestrian Safety

 One needs only to keep a sharp eye to see bollards around us every day.  In parking lots, driveways, and drive-thru lanes, bollards are used to protect buildings, teller machines, utilities such as gas meters, electrical equipment and fire hydrants, handicap parking signs, gate entry keypads, and to restrict access to undesired areas.  In factories and warehouses, bollards are important for protecting pedestrians as well as guarding storage racks and capital equipment from fork truck collisions.

Other industries which find a heavy use of bollards include automated car wash facilities, self-storage facilities, gas stations and convenience stores, propane dispensing, and parking garages, among others.

THE PROBLEM

Foundation mounted bollards are typically installed in one of two ways.  The first, least expensive way, is with a plate mounted bollard.  These bollards are steel pipes welded to a flat steel plate that can be anchored to a hard surface using concrete anchors.  This method of installation is quick and inexpensive, requiring the installer to drill four to eight holes in the concrete and bolt down the bollard with expansion or screw anchors.

The downside to this installation method, when used with a rigid bollard, is that the anchors are generally not strong enough to withstand anything more than a minor collision.  The plate anchors often are pulled up and possibly the plate bends, leaving a post which leans and is no longer able to properly serve its purpose.  Plate mounted bollards often require constant maintenance and replacement.

The second method for installing bollards involves using a longer steel pipe and burying a portion of it deep in the ground.  This method gives the bollard far more strength than surface mounted, however it can be very expensive to install if the surface is concrete and already poured.  Installation in this case requires coring a hole in the surface using an expensive diamond bladed coring saw.  These machines and their blades are expensive and require water cooling, creating a mess during installation.  Once the concrete is cored and the bollard is in place, the hole must be backfilled with concrete to secure the bollard.  For added strength, these bollards are often filled with concrete, as well.  Though the bollard pipe itself is relatively inexpensive, this installation method is costly and time consuming.

 

Although very strong, there are significant disadvantages to core installations.  Most importantly, there is no give to this system upon impact.  Though desired in high security applications, any vehicle impacting such a bollard will be significantly damaged and its passengers at risk of injury.  Loads carried by fork trucks can also be thrown given the jarring impact likely to occur.  Further, the bollard or its foundation can be damaged by such an impact, again leaving a tilted and less effective barrier requiring costly maintenance to correct.  Often the steel bollard itself is beyond repair and must be replaced with an entirely new bollard.

 

Another disadvantage of this type of installation is that it is a permanent installation with little flexibility for movement.  In factory applications, equipment is often moved and rearranged.  Bollards used to protect equipment or storage racks which are core-installed are not easily moved.  The concrete surrounding the bollard must be broken out and the large remaining hole filled, leaving a factory floor full of unsightly patches.  If the bollard itself is reusable after removal, the entire expensive installation process is started over at the new location.

Some designs have been created to attempt to solve these problems through the use of plastic or spring loaded bollards, however these designs suffer from a lack of strength.  If the plastic is of insufficient stiffness, the entire function of access denial is lost.  On the other hand, very stiff plastic designs have had difficulty with long term durability.  Minor collisions tend to wear away at such devices, and in outdoor applications UV degradation becomes a concern.

REVOLUTIONARY NEW DESIGN

 

Designed and patented by Belgian inventor Gerard Wolters as SoftStop® in Europe, the SlowStop® Bollard system is a unique design which solves many of the problems associated with traditional foundation mounted bollards.  Simply put, the SlowStop® system uses a compressed rubber base to act as an energy absorbing mass.  This elastomer allows the bollard to tilt slightly when impacted, in the range of 20° from vertical, then return upright while still stopping the colliding vehicle.

The SlowStop® design consists of four major pieces:

• Elastomer
•   Base
• Adapter
•  Post

This system is anchored to concrete using concrete anchor screws.  These anchors affix the base component over the adapter, which pre-compresses the elastomer against the ground.  The base and adapter pieces are made of a special ductile cast iron, which makes the pieces less brittle than typical cast iron, and also has a very low (-40°) brittleness temperature.  The steel pipe which serves as the bollard post is a typical steel pipe inserted into the adapter.  In the US, standard ANSI schedule 40 pipe is used to give the end user the flexibility to weld fencing using standard components if necessary.  Concrete fill is not required inside the bollard pipe, though is permitted.  In fact, sign posts can be inserted into the post and concrete filled in place.

Upon collision, the pipe and adapter are allowed to tilt within the base, forcing the adapter to further compress the elastomer in the direction of the impact.  The elastomer absorbs much of the energy of the impact and lengthens the deceleration time of the vehicle.  The elastomer is of sufficient strength to then rebound, usually pushing the vehicle away from the bollard and returning to an upright position.  The tilt of the pipe is limited to approximately 20° at which point the bollard will become rigid.

 

SlowStop Bollards® are designed in a variety of sizes, each of which is appropriate for various expected collision speeds and masses.  Further, they are available with modular connectors which can be used to create fencing and guards out of multiple base units.  By using multiple base units, the ultimate strength of the rebounding bollard unit can be increased.

PERFORMANCE ADVANTAGES

SlowStop® Bollards utilize the much simpler method of surface installation, greatly reducing installation costs, while maintaining the flexibility to move bollards as conditions warrant.  This is accomplished without the normal disadvantage of lack of strength, as the elastomer within the bollard system greatly reduces the maximum impact forces applied to the base anchors.  This is because deceleration of an impacting vehicle is much less severe than during an impact with a rigid bollard.  Energy is transferred to the elastomer instead of directly to a rigid post.  The chart show below demonstrates the difference in impact forces felt by impacting vehicles between a rigid bollard and the SlowStop® Bollard system.

This leads directly to the most important advantages of the SlowStop® Bollard system and that is the reduction of damage to both offending vehicles and to the bollard system itself.  Direct damage to vehicles is reduced due to the reduction of peak impact force seen by the vehicle.  Not only will this avoid damage to the vehicle, but also the chance of injury to a passenger is likewise reduced.  In the case of a fork lift in a factory or warehouse, the chance of a thrown load is also reduced, avoiding the potential for bystander injury and stock loss.

 

Finally, damage to the bollard and its foundation is reduced.  Because the post is constructed of Schedule 40 steel pipe, it maintains its strength, but because of its forgiving nature, much less force is transferred to the foundation.  This simplifies and eliminates maintenance while preserving an aesthetically pleasing facility.

LIMITATIONS

SlowStop® Bollards must be installed on concrete, as an asphalt surface is not of adequate strength to anchor the bollard system.  Considering the replacement costs of damaged bollards, however, it may be cost effective to pour a concrete pad and eliminate years of costly maintenance and asphalt repair.  As previously mentioned, each bollard is sized for expected loads in terms of mass and speed.  Should that limitation be exceeded, it is possible to break a component of the SlowStop® system.  Most likely that involves the post, adapter, or base.  Fortunately, the SlowStop® system is modular and easily repaired.  Posts can be replaced by loosening several set-screws, removing and replacing, and re-tightening the set screws.  Adapter and Base components can be replaced by carefully removing the concrete screw anchors and replacing the component.

CONCLUSION

The SlowStop® Bollard system is a revolutionary new product which solves many of the problems involved with bollard collisions as well as installation and maintenance issues.  Damage to vehicles, passengers, vehicle loads, and the bollards themselves is greatly reduced due to the absorption of impact energy by an elastomer hidden within the base of the bollard.  This elastomer allows the bollard to tilt when impacted and return upright afterward.  SlowStop® Bollards are quick and inexpensive to install, flexible as they are easily moved, and simple to maintain should there be the need.  Safety fencing and barriers are easily created using modular connectors, avoiding the need to weld pipe together.

Further information can be found at www.slowstop.com or by calling Impact Recovery Systems at 1-800-736-5256 (210-736-4477).