Bollard
Contents
Bollard
A bollard is a short vertical post. Originally it meant a post used on a ship or a quay, principally for mooring. The word now also describes a variety of structures to control or direct road traffic, such as posts arranged in a line to obstruct the passage of motor vehicles.[1] In Securipedia, the meaning of the word bollard is limited to bollards meant to direct flows of traffic.[1][2]
Description
Bollards used to contribute to safety and security are extensive. The American Bar Association(ABA) state that bollards are used to contribute to homeland security.[3] Also the NIBS’s site—the Whole Building Design Guide (WBDG)—recommends in its Design Guidance that open spaces surrounding and contiguous to buildings be included as integral parts of a security design.[4] See Crime prevention through environmental design for more.
Security-related Bollard types
In the security industry physical site security bollards have assumed a prominent role, of which there are two main kinds:
- non-crash-resistant bollards
- crash- and attack-resistant bollards, a hardened barrier systems used to protect military, governmental and other buildings or compounds of higher security levels.[5] They are often used by retailers to prevent ram-raiding. Large concrete planters or art on solid pedestals are a decorative alternative to traditional bollards.
According to the National Institute of Building Sciences, non-crash resistant bollards are "perceived impediments to access" and address the actions of two groups.
- Law-abiding persons who comply with civil prescriptions of behavior as defined by the manner in which bollards are put to use;
- Potentially threatening and disruptive persons for whom bollard applications are proscriptive by announcing their behavior is anticipated and additional levels of security await them.[6]
Types of bollards
Road bollard
Bollards are rigid posts that can be arranged in a line to close a road or path to vehicles above a certain width or to separate traffic from pedestrians.[7] In the Netherlands, the city of Amsterdam became notorious for its Amsterdammertje.
The American Heritage Dictionary describes this use of bollard as "chiefly British", although the term has crept into the jargon of some American universities where dense traffic necessitates the use of bollards for access control.
Bollards can be mounted near enough to each other that they block ordinary cars, for instance, but wide enough to permit special-purpose vehicles, and bicycles through. Bollards can be used to enclose car-free zones: Removable bollards allow access for service and emergency vehicles. Bollards and other street furniture are used to control overspill parking onto sidewalks and verges.[8]
Tall (1.15 meter/4 foot) slim (10 cm/4 inch) fluorescent red or orange plastic bollards with reflective tape and removable heavy rubber bases are frequently used in traffic management where traffic cones would be inappropriate due to their width and ease of movement. Also referred to as delineators, the bases are usually made from recycled plastic, and can be easily glued to the road surface to resist movement following minor impacts from passing traffic. Sometimes called "T-top bollards" from the T-bar moulded into the top for tying tape, the bollard is an economical, cost effective, and safe delineation system designed especially for motorways and busy arterial roads. In conjunction with plastic tape, it is also effective in pedestrian control.
Movable bollard
Bollards may be hinged at ground level, allowing them to be folded flat to permit vehicles to drive over them. In such cases they are generally fitted with padlocks at the base, to prevent their being lowered without proper authorisation.
Retractable or "rising" bollards can be lowered entirely below the road surface (generally using an electric or hydraulic mechanism) to enable traffic to pass, or raised to block traffic. Rising bollards are used to secure sensitive areas from attack, or to enforce traffic rules that are time related or restrict access to particular classes of traffic. They are increasingly common around the world to hinder vehicle-based terrorist actions from achieving close proximity to buildings, and are also used to prevent ram-raiding such as in the 2007 Glasgow International Airport attack. They are also useful in mixed-use public spaces, which support both pedestrian use and emergency and or service vehicle use. These bollards are usually priced between $11,000 to $100,000 depending on its ability to ram vehicles based on speed. The most expensive bollards can stop vehicles at speeds of about 50mph.
Manually retractable bollards (lowered by a key mechanism) are found useful in some cases since they do not require retrofitting into existing landscapes, or any electrical hookups or hydraulic systems.[9]
The term "robotic bollards" has been applied to traffic barricades capable of moving themselves into position on a roadway.[10]
Self-righting bollards can take a nudge from a vehicle and return to the upright position without causing damage to the bollard or vehicle. They are popular in car park buildings and other areas of high vehicle usage.
Bell bollard
A bell bollard is a device that deflects vehicles' tires. The wheel mounts the lower part of the bollard and is deflected by its increasing slope. Such bollards are effective against heavy goods vehicles that can damage or destroy other types of street furniture.[11]
Footnotes and references
- ↑ this can be any kind of road traffic, ranging from pedestrians to heavy transport
- ↑ text on this page is adapted from wikipedia (Bollard - section bollards for physical security)
- ↑ Ernest B. Abbott and Otto J. Hetzel, Homeland Security Begins at Home: Local Planning and Regulatory Review to Improve Security, in Rufus Calhoun Young, Jr. and Dwight H. Merriam, in Chap. 5. A Legal Guide to Homeland Security and Emergency Management for State and Local Governments, American Bar Association, 2006
- ↑ Template:Cite web
- ↑ Security for Building Occupants and Assets, Whole Building Design Guide, December 14, 2010.
- ↑ Charles G. Oakes, The Bollard, Whole Building Design Guide, July, 23, 2010.
- ↑ Template:Cite web
- ↑ Template:Cite web Template:Dead link
- ↑ Template:Cite web
- ↑ Template:Cite news
- ↑ Template:Cite web
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