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Bollard

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A mooring bollard.

A bollard is a short vertical post. Originally it only meant a post[1] used on a quay 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.[2]

The term may be related to bole, meaning a tree trunk.[3]

Mooring bollards

A bollard, a name inherited from the Norman-French name Boulard still often found in Normandy,[citation needed] is a short wooden, iron or stone post used on a quayside for mooring ships. Mooring bollards are seldom exactly cylindrical, but typically have a larger diameter near the top to discourage mooring warps (docklines) from coming loose. Single bollards sometimes include a cross rod to allow the mooring to be bent into a figure eight.

Road bollards

Internally illuminated traffic bollards used in the United Kingdom

Bollards are rigid posts that can be arranged in a line to close a road or path to vehicles above a certain width and to separate traffic from pedestrians.[4]

Bollards can be mounted near enough to each other that they block ordinary cars, for instance, but wide enough to permit special-purpose vehicles through. Bollards can be used to enclose car-free zones: Removable bollards allow access for service and emergency vehicles.

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 road traffic control 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.

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.

Movable bollards

A rising traffic bollard

Bollards are frequently used to direct traffic around a traffic island. A recent development is the "rising bollard" - a bollard that can be lowered entirely below the road surface 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.

A "manually retractable bollard", however is lowered by a key mechanism. A retractable bollard is a short post which can be lowered, either manually or automatically, into the ground when not needed. It is especially useful in a mixed-use public space which supports both pedestrian use and emergency and or service vehicle use. This flexible use creates opportunities for vehicular control as well as pedestrian accessibility in a mixed use public space. Manually retractable bollards are appropriate for new projects and especially for reconstruction projects since they do not require retrofitting into existing landscapes, or any electrical hookups or hydraulic systems. Similar systems, using bollards that are hinged at ground level, and fold flat allowing vehicles to drive over them, can be deployed in similar circumstances.[5] The term "robotic bollards" has been applied to traffic barricades capable of moving themselves into position on a roadway.[6]

Self-Righting Bollards can take a nudge from a vehicle and return to the upright position without causing damage to the Bollard or vehicle. Popular amongst car park buildings and other parking and high vehicle volume areas[7]

Bell Bollard

Bell bollard

A bell bollard is a device that acts as a vehicle barrier by deflecting vehicles' tires. The vehicle wheel mounts the lower part of the bollard, but is deflected by its increasing slope. Such bollards are effective even against heavy goods vehicles that can damage or destroy other types of street furnature

Other uses

Bollards are used as a form of permanent utility location. In the United States they are also placed next to warehouse garage door edges to prevent large trucks from hitting the door jambs.

Sculpture

In Australia, decorative bollards, designed and painted by Jan Mitchell, are placed in around the city of Geelong, Victoria, to enhance the landscape as a form of outdoor public sculpture. Usually they are made of timber, minimally modified from the traditionally cylindrical, wooden, maritime bollard shape, but brightly painted to resemble human figures. Such figures - which may be historical or contemporary, particular or generic - are sited singly or in clusters along the waterfront and in other areas where people gather. Decorative bollards have become a well-known feature of the city of Geelong and reflect its history as a major Australian port.[8]

Mountaineering

In mountaineering, a bollard is a large pile of snow or a block of ice shaped to form a secure anchor point. The size of a bollard anchor varies depending on the snow condition. Larger size is preferred for new snow which is soft and loose. While bollards can be quite strong, they are time consuming to build and not as commonly used as flukes, pickets, ice screws and Abalakov thread.

  • Wevie Stonder (under the pseudonym Wevie de Crepon) has a song called Ton Wah, in which bollards feature quite heavily.

Other meanings

See also

References