Boom Barrier
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Boom Barrier
A boom barrier, also known as a boom gate, is a bar, or pole pivoted to allow the boom to block vehicular or pedestrian access through a controlled point. Typically the tip of a boom gate rises in a vertical arc to a near vertical position. Boom gates are often counterweighted, so the pole is easily tipped. Boom gates are often paired either end to end, or offset appropriately to block traffic in both directions. Some boom gates also have a second arm which hangs 300 to 400 mm below the upper arm when lowered, to increase approach visibility, and which hangs on links so it lies flat with the main boom as the barrier is raised. Some barriers also feature a pivot roughly half way, where as the barrier is raised, the outermost half remains horizontal, with the barrier resembling an upside-down ''L'' when raised. Automatic boom barrier There are various technologies for an automatic boom barrier. One of them is electro-mechanical, which is widely used due to its reliability. The o ...
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Crossbuck
A crossbuck is a traffic sign used to indicate a level railway crossing. It is composed of two slats of wood or metal of equal length, fastened together on a pole in a saltire formation (resembling the letter X). Crossbucks are sometimes supplemented by electrical warnings of flashing lights, a bell, or a boom barrier that descends to block the road and prevent traffic from crossing the tracks. Vienna Convention The Vienna Convention on Road Signs and Signals, a multilateral treaty of the United Nations with the intention of standardizing traffic signs around the world, prescribes several different regulations for the "crossbuck" sign. The sign should consist of two arms not less than long, crossed in the form of an . The first model may have a white or yellow ground with a thick red or black border. The second model may have a white or yellow ground with a thin black border and an inscription, such as "RAILWAY CROSSING". If lateral clearance obstructs the placement of the si ...
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Authorization
Authorization or authorisation (see spelling differences) is the function of specifying access rights/privileges to resources, which is related to general information security and computer security, and to access control in particular. More formally, "to authorize" is to define an access policy. For example, human resources staff are normally authorized to access employee records and this policy is often formalized as access control rules in a computer system. During operation, the system uses the access control rules to decide whether access requests from (authenticated) consumers shall be approved (granted) or disapproved (rejected). Resources include individual files or an item's data, computer programs, computer devices and functionality provided by computer applications. Examples of consumers are computer users, computer software and other hardware on the computer. Overview Access control in computer systems and networks rely on access policies. The access control process ...
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Road Infrastructure
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of roads, including parkways, avenues, controlled-access highways (freeways, motorways, and expressways), tollways, interstates, highways, thoroughfares, and local roads. The primary features of roads include lanes, sidewalks (pavement), roadways (carriageways), medians, shoulders, verges, bike paths (cycle paths), and shared-use paths. Definitions Historically many roads were simply recognizable routes without any formal construction or some maintenance. The Organization for Economic Co-operation and Development (OECD) defines a road as "a line of communication (travelled way) using a stabilized base other than rails or air strips open to public traffic, primarily for the use of road motor vehicles running on their own wheels", w ...
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English Inventions
English inventions and discoveries are objects, processes or techniques invented, innovated or discovered, partially or entirely, in England by a person from England. Often, things discovered for the first time are also called inventions and in many cases, there is no clear line between the two. Nonetheless, science and technology in England continued to develop rapidly in absolute terms. Furthermore, according to a Japanese research firm, over 40% of the world's inventions and discoveries were made in the UK, followed by France with 24% of the world's inventions and discoveries made in France and followed by the US with 20%. The following is a list of inventions, innovations or discoveries known or generally recognised to be English. Agriculture * 1627: Publication of first experiments in Water desalination and filtration by Sir Francis Bacon (1561–1626). * 1701: Seed drill improved by Jethro Tull (1674–1741). *18th century: of the horse-drawn hoe and scarifier by Je ...
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Railway Buildings And Structures
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a prepared flat surface, rail vehicles (rolling stock) are directionally guided by the tracks on which they run. Tracks usually consist of steel rails, installed on sleepers (ties) set in ballast, on which the rolling stock, usually fitted with metal wheels, moves. Other variations are also possible, such as "slab track", in which the rails are fastened to a concrete foundation resting on a prepared subsurface. Rolling stock in a rail transport system generally encounters lower frictional resistance than rubber-tyred road vehicles, so passenger and freight cars (carriages and wagons) can be coupled into longer trains. The operation is carried out by a railway company, providing transport between train stations or freight customer facili ...
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Protective Barriers
A separation barrier or separation wall is a barrier, wall or fence, constructed to limit the movement of people across a certain line or border, or to separate peoples or cultures. A separation barrier that runs along an internationally recognized border is known as a border barrier. David Henley opines in ''The Guardian'' that separation barriers are being built at a record-rate around the world along borders and do not only surround dictatorships or pariah states. In 2014, The ''Washington Post'' listed notable 14 separation walls as of 2011, indicating that the total concurrent number of walls and barriers which separate countries and territories is 45. The term "separation barrier" has been applied to structures erected in Belfast, Homs, the West Bank, São Paulo, Cyprus, and along the Greece-Turkey border and the Mexico-United States border. In 2016, Julia Sonnevend listed in her book ''Stories Without Borders: The Berlin Wall and the Making of a Global Iconic Event'' th ...
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Level Crossings
A level crossing is an intersection where a railway line crosses a road, path, or (in rare situations) airport runway, at the same level, as opposed to the railway line crossing over or under using an overpass or tunnel. The term also applies when a light rail line with separate right-of-way or reserved track crosses a road in the same fashion. Other names include railway level crossing, railway crossing (chiefly international), grade crossing or railroad crossing (chiefly American), road through railroad, criss-cross, train crossing, and RXR (abbreviated). There are more than 100,000 level crossings in Europe and more than 200,000 in North America. History The history of level crossings depends on the location, but often early level crossings had a flagman in a nearby booth who would, on the approach of a train, wave a red flag or lantern to stop all traffic and clear the tracks. Gated crossings became commonplace in many areas, as they protected the railway fro ...
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Street Furniture
Street furniture is a collective term for objects and pieces of equipment installed along streets and roads for various purposes. It includes benches, traffic barriers, bollards, post boxes, phone boxes, streetlamps, traffic lights, traffic signs, bus stops, tram stops, taxi stands, public lavatories, fountains, watering troughs, memorials, public sculptures, and waste receptacles. Description and use Street furniture is a collective term used in the United States, United Kingdom, Australia, and Canada. It refers to objects and pieces of equipment installed along streets and roads for various purposes. The design and placement of furniture should take into account aesthetics, visual identity, function, pedestrian mobility and road safety. For example, street furniture can be positioned to control overspill parking in addition to its primary purpose; for example a bench and a number of bollards may be used to block access to a sidewalk or verges for vehicles. Items * ...
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Toll Road
A toll road, also known as a turnpike or tollway, is a public or private road (almost always a controlled-access highway in the present day) for which a fee (or ''toll'') is assessed for passage. It is a form of road pricing typically implemented to help recoup the costs of road construction and maintenance. Toll roads have existed in some form since antiquity, with tolls levied on passing travelers on foot, wagon, or horseback; a practice that continued with the automobile, and many modern tollways charge fees for motor vehicles exclusively. The amount of the toll usually varies by vehicle type, weight, or number of axles, with freight trucks often charged higher rates than cars. Tolls are often collected at toll plazas, toll booths, toll houses, toll stations, toll bars, toll barriers, or toll gates. Some toll collection points are automatic, and the user deposits money in a machine which opens the gate once the correct toll has been paid. To cut costs and minimise time delay, ...
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Automatic Full Barriers
A four-quadrant gate or full-barrier equipment is a type of boom barrier gate protecting a grade crossing. It has a gate mechanism on both sides of the tracks for both directions of automotive traffic. The exit gates blocking the road leading away from the tracks are equipped with a delay, and begin their descent to their horizontal position several seconds after the entrance gates do, so as to avoid trapping highway vehicles on the crossing. In the United Kingdom, the exit-side barriers do not lower until the entrance-side barriers have lowered. Many people consider four-quadrant gates to be safer than two-quadrant gates because they prevent drivers from illegally and dangerously driving their vehicles around lowered gates, in an attempt to pass before the train does. However, these gates are only safer if there is a way of ensuring that the crossing is clear before clearing the train driver's signals and allowing them to pass, as is always the case in the United Kingdom. As a r ...
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Emergency Service
Emergency services and rescue services are organizations that ensure public safety and health by addressing and resolving different emergencies. Some of these agencies exist solely for addressing certain types of emergencies, while others deal with ad hoc emergencies as part of their normal responsibilities. Many of these agencies engage in community awareness and prevention programs to help the public avoid, detect, and report emergencies effectively. Emergency services are often considered first responders. Emergency services have one or more dedicated emergency telephone numbers reserved for critical emergency calls. In many countries, one number is used for all of the emergency services (e.g. 911 in the Americas, 999 in the United Kingdom, 112 in continental Europe Continental Europe or mainland Europe is the contiguous continent of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent, – which can conversely mea ...
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Vehicle
A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), watercraft (ships, boats, underwater vehicles), amphibious vehicles (screw-propelled vehicles, hovercraft), aircraft (airplanes, helicopters, aerostats) and spacecraft.Halsey, William D. (Editorial Director): ''MacMillan Contemporary Dictionary'', page 1106. MacMillan Publishing, 1979. Land vehicles are classified broadly by what is used to apply steering and drive forces against the ground: wheeled, tracked, railed or skied. ISO 3833-1977 is the standard, also internationally used in legislation, for road vehicles types, terms and definitions. History * The oldest boats found by archaeological excavation are logboats, with the oldest logboat found, the Pesse canoe found in a bog in the Netherlands, being carbon dated to 8040 ...
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