Rebar (short for reinforcing bar ), known when massed as reinforcing steel or steel reinforcement , is a tension device added to concrete to form reinforced concrete and reinforced masonry structures to strengthen and aid the concrete under tension. Concrete is strong under compression , but has low tensile strength . Rebar usually consists of steel bars which significantly increase the tensile strength of the structure. Rebar surfaces feature a continuous series of ribs, lugs or indentations to promote a better bond with the concrete and reduce the risk of slippage.
106-619: The Valley Line is a low-floor urban light rail line in Edmonton , Alberta , Canada. The 13.1-kilometre (8.1 mi) line runs southeast from downtown at 102 Street stop to Mill Woods Town Centre at Mill Woods stop and connects to the Capital and Metro lines at Churchill station , downtown. The line is being constructed in phases, with phase 1 being the current open 12-station portion between 102 Street and Mill Woods that commenced operations on November 4, 2023. The second phase, consisting of
212-724: A "light rail" vehicle (it is a heavy rail vehicle), and is only included for comparison purposes. Low-floor LRVs have the advantage of a low-floor design, allowing them to load passengers directly from low-rise platforms that can be little more than raised curbs. High-floor light rail systems also exist, featuring larger stations. Historically, the track gauge has had considerable variations, with narrow gauge common in many early systems. However, most light rail systems are now standard gauge . Older standard-gauge vehicles could not negotiate sharp turns as easily as narrow-gauge ones, but modern light rail systems achieve tighter turning radii by using articulated cars . An important advantage of
318-458: A bus, there will be even more capacity when there is a combination of cars and light rail. Table 3 shows an example of peak passenger capacity. The cost of light rail construction varies widely, largely depending on the amount of tunneling and elevated structures required. A survey of North American light rail projects shows that costs of most LRT systems range from $ 15 million to over $ 100 million per mile. Seattle's new light rail system
424-520: A car-sized piece of concrete underneath the north berm of the Tawatinâ Bridge. The line's completion was subsequently delayed to late 2021, then to first quarter of 2022, and again to July 2022. On August 10, 2022, the City of Edmonton and TransEd announced another delay, as inspections in mid-July found cracks in three supporting piers on elevated portions of the line. Further inspections revealed that 30 of
530-403: A chaotic breakdown inflow and a dramatic drop in speed (a traffic jam ) if they exceed about 2,000 vehicles per hour per lane (each car roughly two seconds behind another). Since most people who drive to work or on business trips do so alone, studies show that the average car occupancy on many roads carrying commuters is only about 1.5 people per car during the high-demand rush hour periods of
636-1102: A common right-of-way (however, Link converted to full separation in 2019). Some systems, such as the AirTrain JFK in New York City, the DLR in London, and Kelana Jaya Line in Kuala Lumpur , have dispensed with the need for an operator. The Vancouver SkyTrain was an early adopter of driverless vehicles, while the Toronto Scarborough rapid transit operated the same trains as Vancouver, but used drivers. In most discussions and comparisons, these specialized systems are generally not considered light rail but as light metro systems. Around Karlsruhe , Kassel , and Saarbrücken in Germany, dual-voltage light rail trains partly use mainline railroad tracks, sharing these tracks with heavy rail trains. In
742-532: A device to reinforce arches, vaults , and cupolas . 2,500 meters of rebar was used in the 14th-century Château de Vincennes . During the 18th century, rebar was used to form the carcass of the Leaning Tower of Nevyansk in Russia, built on the orders of the industrialist Akinfiy Demidov . The cast iron used for the rebar was of high quality, and there is no corrosion on the bars to this day. The carcass of
848-416: A light rail train may have three to four cars of much larger capacity in one train under the control of one driver, or no driver at all in fully automated systems, increasing the labor costs of BRT systems compared to LRT systems. BRT systems are also usually less fuel-efficient as they use non-electrified vehicles. The peak passenger capacity per lane per hour depends on which types of vehicles are allowed on
954-499: A limited ability to carry tensile loads. When rebar is added they are known as "reinforced masonry". A similar approach (of embedding rebar vertically in designed voids in engineered blocks) is also used in dry-laid landscape walls, at least pinning the lowest course in place into the earth, also employed securing the lowest course and/or deadmen in walls made of engineered concrete or wooden landscape ties. In unusual cases, steel reinforcement may be embedded and partially exposed, as in
1060-435: A live rail. In outer areas, the trams switch to conventional overhead wires . The Bordeaux power system costs about three times as much as a conventional overhead wire system and took 24 months to achieve acceptable levels of reliability, requiring the replacement of all the main cables and power supplies. Operating and maintenance costs of the innovative power system still remain high. However, despite numerous service outages,
1166-536: A longer distance. Light rail cars are often coupled into multiple units of two to four cars. Light rail systems may also exhibit attributes of heavy rail systems, including having downtown subways, as in San Francisco and Seattle . Light rail is designed to address a gap in interurban transportation between heavy rail and bus services, carrying high passenger numbers more quickly than local buses and more cheaply than heavy rail. It serves corridors in which heavy rail
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#17330944373331272-631: A more diverse range of design characteristics than LRT, depending on the demand and constraints that exist, and BRT using dedicated lanes can have a theoretical capacity of over 30,000 passengers per hour per direction (for example, the Guangzhou Bus Rapid Transit system operates up to 350 buses per hour per direction). For the effective operation of a bus or BRT system, buses must have priority at traffic lights and have their dedicated lanes, especially as bus frequencies exceed 30 buses per hour per direction. The higher theoretical of BRT relates to
1378-407: A result, has many of the operating characteristics of a metro system rather than a light rail system. A capacity of 1,350 passengers per train is more similar to the heavy rail than light rail. Bus rapid transit (BRT) is an alternative to LRT and many planning studies undertake a comparison of each mode when considering appropriate investments in transit corridor development. BRT systems can exhibit
1484-530: A top speed of 55–71.5 miles per hour (88.51–115.1 km/h) depending on the system, while the trains on the all-underground Montreal Metro can only reach a top speed of 72 kilometres per hour (44.74 mph). LACMTA light rail vehicles have higher top and average speeds than Montreal Metro or New York City Subway trains. Many light rail systems—even fairly old ones—have a combination of both on- and off-road sections. In some countries (especially in Europe), only
1590-474: A tramway, a light metro, and, in a narrow sense, rapid transit. This is especially common in the United States, where there is not a popularly perceived distinction between these different types of urban rail systems. The development of technology for low-floor and catenary-free trams facilitates the construction of such mixed systems with only short and shallow underground sections below critical intersections as
1696-462: Is a generic international English phrase for types of rail systems using modern streetcars/trams, which means more or less the same thing throughout the English-speaking world . Light rail systems can range from trams runnig in streets along with other traffic, to semi-metro systems having portions of grade separated track. People movers are even "lighter", in terms of capacity. Monorail
1802-565: Is a separate technology that has been more successful in specialized services than in a commuter transit role. The use of the generic term light rail avoids some serious incompatibilities between British and American English . The word tram , for instance, is generally used in the UK and many former British colonies to refer to what is known in North America as a streetcar , but in North America tram can instead refer to an aerial tramway , or, in
1908-602: Is a significant amount of overlap between the technologies; similar rolling stock may be used for either, and it is common to classify streetcars or trams as a subcategory of light rail rather than as a distinct type of transportation. However, some distinctions can be made, though systems may combine elements of both. Low-floor light rail lines tend to follow a reserved right-of-way and with trains receiving priority at intersections, and tend not to operate in mixed traffic, enabling higher operating speeds. Light rail lines tend to have less frequent stops than tramways, and operate over
2014-424: Is also used in high-corrosion environments. It is available in many forms, such as spirals for reinforcing columns, common rods, and meshes. Most commercially available rebar is made from unidirectional fibers set in a thermoset polymer resin and is often referred to as FRP. Some special construction such as research and manufacturing facilities with very sensitive electronics may require the use of reinforcement that
2120-424: Is approximated as (bar size/9)² square inches. For example, the area of #8 bar is (8/9)² = 0.79 square inches. Bar sizes larger than #8 follow the 1 ⁄ 8 -inch rule imperfectly and skip sizes #12–13, and #15–17 due to historical convention. In early concrete construction bars of one inch and larger were only available in square sections, and when large format deformed round bars became available around 1957,
2226-560: Is by far the most expensive in the US, at $ 179 million per mile, since it includes extensive tunneling in poor soil conditions, elevated sections, and stations as deep as 180 feet (55 m) below ground level. This results in costs more typical of subways or rapid transit systems than light rail. At the other end of the scale, four systems (Baltimore, Maryland; Camden, New Jersey; Sacramento, California; and Salt Lake City, Utah) incurred construction costs of less than $ 20 million per mile. Over
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#17330944373332332-525: Is cast into it to carry the tensile loads . Most steel reinforcement is divided into primary and secondary reinforcement: Secondary applications include rebar embedded in masonry walls, which includes both bars placed horizontally in a mortar joint (every fourth or fifth course of block) or vertically (in the horizontal voids of cement blocks and cored bricks, which is then fixed in place with grout . Masonry structures held together with grout have similar properties to concrete – high compressive resistance but
2438-426: Is especially important for wheelchair access, as narrower gauges (e.g. metre gauge) can make it challenging or impossible to pass the tram's wheels. Furthermore, standard-gauge rolling stock can be switched between networks either temporarily or permanently, and both newly built and used standard-gauge rolling stock tends to be cheaper to buy, as more companies offer such vehicles. Overhead lines supply electricity to
2544-498: Is expensive. Similarly, the most expensive US highway expansion project was the " Big Dig " in Boston, Massachusetts, which cost $ 200 million per lane mile for a total cost of $ 14.6 billion. A light rail track can carry up to 20,000 people per hour as compared with 2,000–2,200 vehicles per hour for one freeway lane. For example, in Boston and San Francisco, light rail lines carry 9,600 and 13,100 passengers per hour, respectively, in
2650-575: Is hard to distinguish between what is called light rail, and other forms of urban and commuter rail. A system described as a light rail in one city may be considered to be a streetcar or tram system in another. Conversely, some lines that are called "light rail" are very similar to rapid transit ; in recent years, new terms such as light metro have been used to describe these medium-capacity systems. Some "light rail" systems, such as Sprinter , bear little similarity to urban rail, and could alternatively be classified as commuter rail or even inter-city rail. In
2756-549: Is impractical. Light metro systems are essentially hybrids of light rail and rapid transit. Metro trains are larger and faster than light rail trains, with stops being further apart. Many systems have mixed characteristics. Indeed, with proper engineering, a rail line could run along a street, then go underground, and then run along an elevated viaduct. For example, the Los Angeles Metro Rail 's A Line "light rail" has sections that could alternatively be described as
2862-522: Is non-conductive to electricity, and medical imaging equipment rooms may require non-magnetic properties to avoid interference. FRP rebar, notably glass fibre types have low electrical conductivity and are non-magnetic which is commonly used for such needs. Stainless steel rebar with low magnetic permeability is available and is sometimes used to avoid magnetic interference issues. Reinforcing steel can also be displaced by impacts such as earthquakes , resulting in structural failure. The prime example of this
2968-480: Is one of the highest capacity ones, having been upgraded in a series of expansions to handle 40,000 passengers per hour per direction, and having carried as many as 582,989 passengers in a single day on its Line 1 . It achieves this volume by running four-car trains with a capacity of up to 1,350 passengers each at a frequency of up to 30 trains per hour. However, the Manila light rail system has full grade separation and as
3074-407: Is similar to that of a traditional tram, while operating at a higher capacity and speed, often on an exclusive right-of-way. In broader use, it includes tram-like operations mostly on streets. A few light rail networks have characteristics closer to rapid transit or even commuter rail , yet only when these systems are fully grade-separated are they referred to as light metros . The term light rail
3180-759: Is subject to the requirements of Australian Standards AS3600 (Concrete Structures) and AS/NZS4671 (Steel Reinforcing for Concrete). There are other standards that apply to testing, welding and galvanizing. The designation of reinforcement is defined in AS/NZS4671 using the following formats: Shape/ Section D- deformed ribbed bar, R- round / plain bar, I- deformed indented bar Ductility Class L- low ductility, N- normal ductility, E- seismic (Earthquake) ductility Standard grades (MPa) 250N, 300E, 500L, 500N, 500E Bars are typically abbreviated to simply 'N' (hot-rolled deformed bar), 'R' (hot-rolled round bar), 'RW' (cold-drawn ribbed wire) or 'W' (cold-drawn round wire), as
3286-703: Is the collapse of the Cypress Street Viaduct in Oakland, California as a result of the 1989 Loma Prieta earthquake , causing 42 fatalities. The shaking of the earthquake caused rebars to burst from the concrete and buckle . Updated building designs, including more circumferential rebar, can address this type of failure. US/Imperial bar sizes give the diameter in units of 1 ⁄ 8 inch (3.2 mm) for bar sizes #2 through #8, so that #8 = 8 ⁄ 8 inch = 1-inch (25 mm) diameter. There are no fractional bar sizes in this system. The "#" symbol indicates
Valley Line (Edmonton) - Misplaced Pages Continue
3392-535: The Cádiz TramBahia , where trams share track with commuter and long-distance trains from the main terminus in the city and curve off to serve cities without a railway connection. Some of the issues involved in such schemes are: There is a history of what would now be considered light rail vehicles operating on heavy rail rapid transit tracks in the US, especially in the case of interurban streetcars . Notable examples are Lehigh Valley Transit trains running on
3498-735: The London Underground and the New York City Subway . Conventional rail technologies including high-speed , freight, commuter , and rapid transit urban transit systems are considered "heavy rail". The main difference between light rail and heavy rail rapid transit is the ability for a light rail vehicle to operate in mixed traffic if the routing requires it. The world's first electric tram operated in Sestroretsk near Saint Petersburg , Russia , invented and operated on an experimental basis by Fyodor Pirotsky in 1880. The first tramway
3604-624: The Netherlands , this concept was first applied on the RijnGouweLijn . This allows commuters to ride directly into the city center, rather than taking a mainline train only as far as a central station and then having to change to a tram. In France, similar tram-trains are planned for Paris, Mulhouse , and Strasbourg ; further projects exist. In some cases, tram trains use previously abandoned or lightly used heavy rail lines in addition to or instead of still in use mainline tracks. In 2022, Spain opened
3710-831: The O-Train Trillium Line in Ottawa, Ontario , Canada, the River Line in New Jersey , United States, and the Sprinter in California , United States, which use diesel multiple unit (DMU) cars. Light rail is different from the British English term light railway , long-used to distinguish railway operations carried out under a less rigorous set of regulations using lighter equipment at lower speeds from mainline railways. Light rail
3816-673: The Philadelphia and Western Railroad high-speed third rail line (now the Norristown High-Speed Line ). Such arrangements are almost impossible now, due to the Federal Railroad Administration refusing (for crash safety reasons) to allow non-FRA compliant railcars (i.e., subway and light rail vehicles) to run on the same tracks at the same times as compliant railcars, which includes locomotives and standard railroad passenger and freight equipment. Notable exceptions in
3922-600: The West Edmonton Mall en route, is in the early stages of construction as part of the 27-kilometre (17 mi) Valley Line. The option approved by Council in 2010 has the west LRT extension run from downtown along 104 Avenue and Stony Plain Road to 156 Street, then south on 156 Street to Meadowlark Health & Shopping Centre, and then west along 87 Avenue to West Edmonton Mall and beyond. Proponents of this route cited opportunities for transit-oriented development . In 2016,
4028-530: The medians of roads . If run in streets , trains are usually limited by city block lengths to about four 180-passenger vehicles (720 passengers). Operating on two-minute headways using traffic signal progression, a well-designed two-track system can handle up to 30 trains per hour per track, achieving peak rates of over 20,000 passengers per hour in each direction. More advanced systems with separate rights-of-way using moving block signaling can exceed 25,000 passengers per hour per track. Most light rail systems in
4134-404: The number sign , and thus "#6" is read as "number six". The use of the "#" sign is customary for US sizes, but "No." is sometimes used instead. Within the trades rebar is known by a shorthand utilizing the bar diameter as descriptor, such as "four-bar" for bar that is four-eighths (or one-half) of an inch. The cross-sectional area of a bar, as given by πr ², works out to (bar size/9.027)², which
4240-711: The 14-kilometre (8.7 mi), 16-station portion between 102 Street and Lewis Farms, began construction in 2021 and is expected to be completed in 2028. Upon completion, the entire Valley Line is expected to serve more than 100,000 commuters daily, nearly matching the current Capital Line and Metro Line in terms of capacity and ridership. Unlike the other trains in the system, the Valley Line operates low-floor Bombardier Flexity Freedom trains, which were first designed for Line 5 Eglinton in Toronto. Forty other new low-floor light rail vehicles were ordered in 2021 from Hyundai Rotem for
4346-619: The 1970s was proven to have been a technical failure by the following decade. After World War II, the Germans retained many of their streetcar networks and evolved them into model light rail systems ( Stadtbahnen ). With the exception of Hamburg , all large and most medium-sized German cities maintain light rail networks. The concept of a "limited tramway" was proposed by American transport planner H. Dean Quinby in 1962. Quinby distinguished this new concept in rail transportation from historic streetcar or tram systems as: The term light rail transit
Valley Line (Edmonton) - Misplaced Pages Continue
4452-556: The 45 piers were cracked. An initial assessment named lateral thermal expansion as a potential factor in creating the cracks. Later analysis determined that the rebar was inadequate, and ideas were being tested as to how to best repair the piers. Before the damaged piers were discovered, trains were being tested on tracks between the Gerry Wright OMF and the Mill Woods stop. During pier remediation, testing took place only on portions of
4558-491: The French city of Bordeaux , the tramway network is powered by a third rail in the city center, where the tracks are not always segregated from pedestrians and cars. The third rail (actually two closely spaced rails) is placed in the middle of the track and divided into eight-metre sections, each of which is powered only while it is completely covered by a tram. This minimizes the risk of a person or animal coming into contact with
4664-642: The US are the NJ Transit River Line from Camden to Trenton and Austin's Capital MetroRail , which have received exemptions to the provision that light rail operations occur only during daytime hours and Conrail freight service only at night, with several hours separating one operation from the other. The O-Train Trillium Line in Ottawa also has freight service at certain hours. With its mix of right-of-way types and train control technologies, LRT offers
4770-455: The US as a whole, excluding Seattle, new light rail construction costs average about $ 35 million per mile. By comparison, a freeway lane expansion typically costs $ 1.0 million to $ 8.5 million per lane mile for two directions, with an average of $ 2.3 million. However, freeways are frequently built in suburbs or rural areas, whereas light rail tends to be concentrated in urban areas, where right of way and property acquisition
4876-634: The United States and in North America . In Britain, modern light rail systems began to appear in the 1980s, starting with the Tyne and Wear Metro from 1980 and followed by the Docklands Light Railway (DLR) in London in 1987, continuing into the 1990s including the establishment of the Manchester Metrolink in 1992 and the Sheffield Supertram from 1994. Due to varying definitions, it
4982-583: The United States are limited by demand rather than capacity (by and large, most American LRT systems carry fewer than 4,000 persons per hour per direction), but Boston's and San Francisco's light rail lines carry 9,600 and 13,100 passengers per hour per track during rush hour. Elsewhere in North America, the Calgary C-Train and Monterrey Metro have higher light rail ridership than Boston or San Francisco. Systems outside North America often have much higher passenger volumes. The Manila Light Rail Transit System
5088-529: The United States as an English equivalent for the German word Stadtbahn , meaning "city railway". Different definitions exist in some countries, but in the United States, light rail operates primarily along exclusive rights-of-way and uses either individual tramcars or multiple units coupled together, with a lower capacity and speed than a long heavy rail passenger train or rapid transit system. Narrowly defined, light rail transit uses rolling stock that
5194-472: The United States, "light rail" has become a catch-all term to describe a wide variety of passenger rail systems. Light rail corridors may constitute a fully segregated corridor, a dedicated right-of-way on a street, an on-street corridor shared with other traffic, a corridor shared with other public transport, or a corridor shared with pedestrians. The most difficult distinction to draw is that between low-floor light rail and streetcar or tram systems. There
5300-575: The United States, made a significant contribution to the development of reinforcing bars in concrete construction. He invented twisted iron rebar, which he initially thought of while designing self-supporting sidewalks for the Masonic Hall in Stockton, California. His twisted rebar was, however, not initially appreciated and even ridiculed at the Technical Society of California, where members stated that
5406-413: The United States, who produced and tested reinforced concrete beams. Joseph Monier of France is one of the most notable figures for the invention and popularization of reinforced concrete. As a French gardener, Monier patented reinforced concrete flowerpots in 1867, before proceeding to build reinforced concrete water tanks and bridges. Ernest L. Ransome , an English engineer and architect who worked in
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#17330944373335512-539: The Valley Line West received funding through the Government of Canada’s Public Transit Infrastructure Fund (PTIF) to review the preliminary design that was completed in 2013. The funding covers work to determine the most appropriate project delivery method (P3, for example) and to develop a business case for construction funding. Preparation work, such as the relocation of underground utilities and clearing of land along
5618-502: The Valley Line, to be put in service when phase 2 to Lewis Farms opens. Planning studies for an LRT route from downtown to Mill Woods began in early 2009. In December 2009, Edmonton City Council approved a new low-floor train route that would leave a new ground-level station at Churchill Square on 102 Avenue between 100 and 99 Streets before stopping in The Quarters redevelopment on 102 Avenue between 97 Street and 96 Street. From here
5724-444: The Valley Line. Early construction work began in 2021 and the line formally commenced construction on May 27, 2022. It is expected to be completed in 2028. Valley Line trains run every 5 to 15 minutes, beginning at approximately 5:00 am daily. Service ends at approximately 1:00 am Monday through Saturday, and at approximately 12:30 am on Sundays. Trains run every 5 minutes during weekday peak hours, every 10 minutes during
5830-415: The ability of buses to travel closer to each other than rail vehicles and their ability to overtake each other at designated locations allowing express services to bypass those that have stopped at stations. However, to achieve capacities this high, BRT station footprints need to be significantly larger than a typical LRT station. In terms of cost of operation, each bus vehicle requires a single driver, whereas
5936-486: The bar into place, while the second makes use of the high compressive strength of concrete. Common rebar is made of unfinished tempered steel, making it susceptible to rusting . Normally the concrete cover is able to provide a pH value higher than 12 avoiding the corrosion reaction. Too little concrete cover can compromise this guard through carbonation from the surface, and salt penetration . Too much concrete cover can cause bigger crack widths which also compromises
6042-529: The bars and corrosion under the epoxy film have been reported. These epoxy-coated bars are used in over 70,000 bridge decks in the US, but this technology was slowly being phased out in favor of stainless steel rebar as of 2005 because of its poor performance. Requirements for deformations are found in US-standard product specifications for steel bar reinforcing, such as ASTM A615 and ASTM A706, and dictate lug spacing and height. Fibre-reinforced plastic rebar
6148-673: The beams at the columns. This type of failure manifested in the partial collapse of the Bixby Hotel in Long Beach, California and total collapse of the Eastman Kodak Building in Rochester, New York, both during construction in 1906. It was, however, concluded that both failures were the consequences of poor-quality labor. With the increase in demand of construction standardization, innovative reinforcing systems such as Kahn's were pushed to
6254-862: The case of the Disney amusement parks , even a land train . (The usual British term for an aerial tramway is cable car , which in the US usually refers to a ground-level car pulled along by subterranean cables .) The word trolley is often used as a synonym for streetcar in the United States but is usually taken to mean a cart, particularly a shopping cart, in the UK and elsewhere. Many North American transportation planners reserve streetcar for traditional vehicles that operate exclusively in mixed traffic on city streets, while they use light rail to refer to more modern vehicles operating mostly in exclusive rights of way, since they may operate both side-by-side targeted at different passenger groups. The difference between British English and American English terminology arose in
6360-421: The closure of Glasgow Corporation Tramways (one of the largest in Europe) in 1962. Although some traditional trolley or tram systems continued to exist in San Francisco and elsewhere, the term "light rail" has come to mean a different type of rail system as modern light rail technology has primarily post-WWII West German origins. An attempt by Boeing Vertol to introduce a new American light rail vehicle in
6466-406: The concrete, it can still be pulled out of the concrete under high stresses, an occurrence that often accompanies a larger-scale collapse of the structure. To prevent such a failure, rebar is either deeply embedded into adjacent structural members (40–60 times the diameter), or bent and hooked at the ends to lock it around the concrete and other rebar. This first approach increases the friction locking
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#17330944373336572-403: The day on weekdays and Saturdays, and every 15 minutes during evenings and on Sundays. Download coordinates as: Light rail Light rail (or light rail transit , abbreviated to LRT ) is a form of passenger urban rail transit that uses rolling stock derived from tram technology while also having some features from heavy rapid transit . The term was coined in 1972 in
6678-415: The day. This combination of factors limits roads carrying only automobile commuters to a maximum observed capacity of about 3,000 passengers per hour per lane. The problem can be mitigated by introducing high-occupancy vehicle ( HOV ) lanes and ride-sharing programs, but in most cases, policymakers have chosen to add more lanes to the roads, despite a small risk that in unfavorable situations an extension of
6784-750: The direct translation, which is city rail (the Norwegian term, by bane , means the same). However, UMTA finally adopted the term light rail instead. Light in this context is used in the sense of "intended for light loads and fast movement", rather than referring to physical weight. The infrastructure investment is also usually lighter than would be found for a heavy rail system. The American Public Transportation Association (APTA), in its Glossary of Transit Terminology, defines light rail as: ...a mode of transit service (also called streetcar, tramway, or trolley) operating passenger rail cars singly (or in short, usually two-car or three-car, trains) on fixed rails in
6890-655: The effects of corrosion, especially when used in saltwater environments. Bamboo has been shown to be a viable alternative to reinforcing steel in concrete construction. These alternative types tend to be more expensive or may have lesser mechanical properties and are thus more often used in specialty construction where their physical characteristics fulfill a specific performance requirement that carbon steel does not provide. Reinforcing bars in masonry construction have been used since antiquity , with Rome using iron or wooden rods in arch construction. Iron tie rods and anchor plates were later employed across Medieval Europe, as
6996-457: The end of August. The remaining section south to Mill Woods was slated to be done after the line opened, with the work undertaken at night when no trains are running. On October 24, the City of Edmonton announced that the line would open on November 4 after testing resumed and independent certifiers submitted final approval. The inaugural train had later departed from Mill Woods stop at 5:15 am that morning. An expansion to Lewis Farms , with
7102-436: The federal government invested $ 250 million, and $ 235 million would come from the provincial government, leaving a $ 515 million funding gap delaying the project. On March 11, 2014, it was announced that the project would be completely funded with an additional $ 150 million from the federal government and $ 365 million from the provincial government. Land procurement began in 2011 and utility relocation began in 2013, completion of
7208-414: The first stage was expected in 2020. The official groundbreaking of the Valley Line was on April 22, 2016. In September 2019, it was revealed that the segment of the line was a year behind schedule of its projected December 2020 opening date. The 2019 construction season posed a challenge to crews due to frequent rain. In December 2019, completion of the line was pushed back until 2021 after TransEd found
7314-405: The idea that Kahn's reinforcing system in concrete beams would act as a Warren truss and also noted that this system would not provide the adequate amount of shear stress reinforcement at the ends of the simply supported beams, the place where the shear stress is greatest. Furthermore, Turner warned that Kahn's system could result in a brittle failure as it did not have longitudinal reinforcement in
7420-929: The industry manufactured them to provide the cross-sectional area equivalent of standard square bar sizes that were formerly used. The diameter of the equivalent large format round shape is rounded to the nearest 1 ⁄ 8 inch to provide the bar size. For example, #9 bar has a cross section of 1.00 square inch (6.5 cm ), and therefore a diameter of 1.128 inches (28.7 mm). #10, #11, #14, and #18 sizes correspond to 1 1 ⁄ 8 inch, 1 1 ⁄ 4 , 1 1 ⁄ 2 , and 2-inch square bars, respectively. Sizes smaller than #3 are no longer recognized as standard sizes. These are most commonly manufactured as plain round undeformed rod steel but can be made with deformations. Sizes smaller than #3 are typically referred to as "wire" products and not "bar" and specified by either their nominal diameter or wire gage number. #2 bars are often informally called "pencil rod" as they are about
7526-453: The late 19th century when Americans adopted the term "street railway", rather than "tramway", with the vehicles being called "streetcars" rather than "trams". Some have suggested that the Americans' preference for the term "street railway" at that time was influenced by German emigrants to the United States (who were more numerous than British immigrants in the industrialized Northeast), as it is
7632-524: The latter is described as light rail. In those places, trams running on mixed rights-of-way are not regarded as a light rail but considered distinctly as streetcars or trams. However, the requirement for saying that a rail line is "separated" can be quite low—sometimes just with concrete "buttons" to discourage automobile drivers from getting onto the tracks. Some systems such as Seattle's Link had on-road mixed sections but were closed to regular road traffic, with light rail vehicles and buses both operating along
7738-455: The light rail concept was the "Shaker Heights Rapid Transit" which started in the 1920s, was renovated in 1980-81 and is now part of RTA Rapid Transit . Many original tram and streetcar systems in the United Kingdom , United States , and elsewhere were decommissioned starting in the 1950s as subsidies for the car increased. Britain abandoned its tram systems, except for Blackpool , with
7844-493: The line is at the Gerry Wright Operations and Maintenance Facility (opened in 2018), at Whitemud Drive and 75 Street. On June 1, 2011, City Council approved $ 39 million in funding to proceed with preliminary engineering for the Valley Line. In November 2011 City Council voted to allocate $ 800 million to the project, with the hopes of starting construction by 2014 and an expected completion date of 2018. A funding plan
7950-426: The line is lifted onto an elevated guideway over Davies Industrial. Finally, the line proceeds south along 75/66 Street until it reaches Mill Woods Town Centre. Within this line the proposed stops are: Quarters, Muttart, Strathearn, Holyrood, Bonnie Doon, Avonmore, Davies (to include a bus terminal and park & ride), Millbourne/Woodvale, Grey Nuns, and Mill Woods Town Centre. The maintenance and storage of vehicles for
8056-429: The line that were not elevated. On January 3, 2023, the structural repairs of the cracked pillars were complete, and testing expanded to all sections of the line, including the elevated portions. On June 26, 2023, TransEd announced they were replacing 140 kilometres (87 mi) of signalling cables in ducts, as some were oxidized. The work started immediately, and was expected to be done from downtown to Whitemud Drive by
8162-682: The local guard. As rust takes up greater volume than the steel from which it was formed, it causes severe internal pressure on the surrounding concrete, leading to cracking, spalling , and, ultimately, structural failure . This phenomenon is known as oxide jacking . This is a particular problem where the concrete is exposed to salt water, as in bridges where salt is applied to roadways in winter, or in marine applications. Uncoated, corrosion-resistant low- carbon / chromium (microcomposite), silicon bronze , epoxy -coated, galvanized , or stainless steel rebars may be employed in these situations at greater initial expense, but significantly lower expense over
8268-446: The nominal bar diameter in millimeters, as an "alternate size" specification. Substituting a true metric size for a US/Imperial size is called a hard conversion , and sometimes results in the use of a physically different sized bar. bar size size (soft) Metric bar designations represent the nominal bar diameter in millimeters, rounded to the nearest 5 mm. bar size (kg/m) (mm) Area (mm ) Metric bar designations represent
8374-508: The nominal bar diameter in millimetres. Preferred bar sizes in Europe are specified to comply with Table 6 of the standard EN 10080 , although various national standards still remain in force (e.g. BS 4449 in the United Kingdom). In Switzerland some sizes are different from European standard. bar size density (kg/m) diameter (mm) area (mm ) Reinforcement for use in concrete construction
8480-465: The old and new systems. Since the 1980s, Portland, Oregon , has built all three types of system: a high-capacity light rail system in dedicated lanes and rights-of-way, a low-capacity streetcar system integrated with street traffic, and an aerial tram system . The opposite phrase heavy rail , used for higher-capacity, higher-speed systems, also avoids some incompatibilities in terminology between British and American English, for instance in comparing
8586-659: The peak direction during rush hour. Rebar The most common type of rebar is carbon steel , typically consisting of hot-rolled round bars with deformation patterns embossed into its surface. Steel and concrete have similar coefficients of thermal expansion , so a concrete structural member reinforced with steel will experience minimal differential stress as the temperature changes. Other readily available types of rebar are manufactured of stainless steel , and composite bars made of glass fiber , carbon fiber , or basalt fiber . The carbon steel reinforcing bars may also be coated in zinc or an epoxy resin designed to resist
8692-510: The qualification of “tentative” was removed when the updated standard ASTM A305-49 was issued in 1949. The requirements for deformations found in current specifications for steel bar reinforcing, such as ASTM A615 and ASTM A706, among others, are the same as those specified in ASTM A305-49. Concrete is a material that is very strong in compression , but relatively weak in tension . To compensate for this imbalance in concrete's behavior, rebar
8798-540: The required clearance height can be reduced significantly compared to conventional light rail vehicles. Reference speed from major light rail systems, including station stop time, is shown below. However, low top speed is not always a differentiating characteristic between light rail and other systems. For example, the Siemens S70 LRVs used in the Houston METRORail and other North American LRT systems have
8904-432: The right-of-way that is often separated from other traffic for part or much of the way. Light rail vehicles are typically driven electrically with power being drawn from an overhead electric line via a trolley [pole] or a pantograph ; driven by an operator onboard the vehicle; and may have either high platform loading or low-level boarding using steps." However, some diesel-powered transit is designated light rail, such as
9010-415: The road network might lead to increased travel times ( Downs–Thomson paradox , Braess's paradox ). By contrast, light rail vehicles can travel in multi-car trains carrying a theoretical ridership up to 20,000 passengers per hour in much narrower rights-of-way , not much more than two car lanes wide for a double track system. They can often be run through existing city streets and parks , or placed in
9116-401: The roads. Typically roadways have 1,900 passenger cars per lane per hour (pcplph). If only cars are allowed, the capacity will be less and will not increase when the traffic volume increases. When there is a bus driving on this route, the capacity of the lane will be higher and will increase when the traffic level increases. And because the capacity of a light rail system is higher than that of
9222-558: The route enters a tunnel and travels beneath 95 Street descending into the river valley to cross the North Saskatchewan River on the new Tawatinâ Bridge , east of Louise McKinney Park . The route then climbs the hill adjacent to Connors Road then proceeds east along 95 Avenue and southbound at 85 Street. The route travels southbound along 85 Street, crossing the intersection north of Bonnie Doon Mall and shifting to 83 Street, continuing south and east. Just north of Argyll Road,
9328-406: The route, began in 2019. The Government of Canada provided approximately $ 948 million for the Valley Line West expansion, and the Government of Alberta in 2020 committed approximately $ 1.04 billion for the project. As of 2020 the expansion was projected to cost approximately $ 2.67 billion in total. In 2020, the City of Edmonton selected Marigold Infrastructure Partners to build the western section of
9434-613: The same as the German term for the mode, Straßenbahn (meaning "street railway"). A further difference arose because, while Britain abandoned all of its trams after World War II except in Blackpool , eight major North American cities ( Toronto , Boston , Philadelphia , San Francisco , Pittsburgh , Newark , Cleveland , and New Orleans ) continued to operate large streetcar systems. When these cities upgraded to new technology, they called it light rail to differentiate it from their existing streetcars since some continued to operate both
9540-491: The same size as a pencil. When US/Imperial sized rebar are used in projects with metric units, the equivalent metric size is typically specified as the nominal diameter rounded to the nearest millimeter. These are not considered standard metric sizes, and thus is often referred to as a soft conversion or the "soft metric" size. The US/Imperial bar size system recognizes the use of true metric bar sizes (No. 10, 12, 16, 20, 25, 28, 32, 36, 40, 50 and 60 specifically) which indicates
9646-413: The service life of the project. Extra care is taken during the transport, fabrication, handling, installation, and concrete placement process when working with epoxy-coated rebar, because damage will reduce the long-term corrosion resistance of these bars. Even damaged epoxy-coated bars have shown better performance than uncoated reinforcing bars, though issues from debonding of the epoxy coating from
9752-519: The side in favor of the concrete reinforcing systems seen today. Requirements for deformations on steel bar reinforcement were not standardized in US construction until about 1950. Modern requirements for deformations were established in "Tentative Specifications for the Deformations of Deformed Steel Bars for Concrete Reinforcement", ASTM A305-47T. Subsequently, changes were made that increased rib height and reduced rib spacing for certain bar sizes, and
9858-408: The standard gauge is that standard railway maintenance equipment can be used on it, rather than custom-built machinery. Using standard gauges also allows light rail vehicles to be conveniently moved around using the same tracks as freight railways. Additionally, wider gauges (e.g. standard gauge) provide more floor clearance on low-floor trams that have constricted pedestrian areas at the wheels, which
9964-533: The steel tie bars that constrain and reinforce the masonry of Nevyansk Tower or ancient structures in Rome and the Vatican. Steel has a thermal expansion coefficient nearly equal to that of modern concrete . If this were not so, it would cause problems through additional longitudinal and perpendicular stresses at temperatures different from the temperature of the setting. Although rebar has ribs that bind it mechanically to
10070-551: The system was a success with the public, gaining up to 190,000 passengers per day. Automatic train operation is employed on light rail networks, tracking the position and speed of a train and hence adjusting its movement for safety and efficiency. One line of light rail (requires 7.6 m, 25' right of way) has a theoretical capacity of up to 8 times more than one 3.7 m (12 foot) lane on a freeway, excluding busses, during peak times. Roads have ultimate capacity limits that can be determined by traffic engineering , and usually experience
10176-548: The tower was connected to its cast iron tented roof , crowned with one of the first known lightning rods . However, not until the mid-19th century, with the embedding of steel bars into concrete (thus producing modern reinforced concrete ), did rebar display its greatest strengths. Several people in Europe and North America developed reinforced concrete in the 1850s. These include Joseph-Louis Lambot of France, who built reinforced concrete boats in Paris (1854) and Thaddeus Hyatt of
10282-450: The trams, making it safe on city streets. Several systems in Europe and a few recently opened systems in North America use diesel -powered trains. When electric streetcars were introduced in the late 19th century, conduit current collection was one of the first ways of supplying power, but it proved to be much more expensive, complicated, and trouble-prone than overhead wires . When electric street railways became ubiquitous, conduit power
10388-649: The twisting would weaken the iron. In 1889, Ransome worked on the West Coast mainly designing bridges. One of these, the Alvord Lake Bridge in San Francisco's Golden Gate Park, was the first reinforced concrete bridge built in the United States. He used twisted rebar in this structure. At the same time Ransome was inventing twisted steel rebar, C.A.P. Turner was designing his "mushroom system" of reinforced concrete floor slabs with smooth round rods and Julius Kahn
10494-455: The vast majority of light rail systems. This avoids the danger potentially presented by an electrified third rail . The Docklands Light Railway uses an inverted third rail for its electrical power, which allows the electrified rail to be covered and the power drawn from the underside. Trams in Bordeaux , France, use a special third-rail configuration where the power is only switched on beneath
10600-434: The widest range of latitude of any rail system in the design, engineering, and operating practices. The challenge in designing light rail systems is to realize the potential of LRT to provide fast, comfortable service while avoiding the tendency to overdesign that results in excessive capital costs beyond what is necessary to meet the public's needs. The BART railcar in the following chart is not generally considered to be
10706-671: Was approved in October 2012 in which the city would contribute $ 800 million into the project with the remaining $ 1 billion coming from the provincial and federal governments. On February 15, 2012, city council approved the Downtown LRT concept plan. The Downtown LRT Project became part of the Southeast to West LRT project. The city hoped to have money in place by the end of 2013 for the $ 1.8-billion LRT line from downtown to Mill Woods to start construction in 2016. City council committed $ 800 million,
10812-527: Was coined in 1972 by the U.S. Urban Mass Transportation Administration (UMTA; the precursor to the Federal Transit Administration ) to describe new streetcar transformations that were taking place in Europe and the United States. In Germany, the term Stadtbahn (to be distinguished from S-Bahn , which stands for Stadtschnellbahn ) was used to describe the concept, and many in UMTA wanted to adopt
10918-560: Was experimenting with an innovative rolled diamond-shaped rebar with flat-plate flanges angled upwards at 45° (patented in 1902). Kahn predicted concrete beams with this reinforcing system would bend like a Warren truss , and also thought of this rebar as shear reinforcement. Kahn's reinforcing system was built in concrete beams, joists, and columns. The system was both praised and criticized by Kahn's engineering contemporaries: Turner voiced strong objections to this system as it could cause catastrophic failure to concrete structures. He rejected
11024-662: Was introduced in North America in 1972 to describe this new concept of rail transportation. Prior to that time the abbreviation "LRT" was used for " Light Rapid Transit " and " Light Rail Rapid Transit ". The first of the new light rail systems in North America began operation in 1978 when the Canadian city of Edmonton, Alberta , adopted the German Siemens-Duewag U2 system, followed three years later by Calgary, Alberta , and San Diego, California . The concept proved popular, with there now being numerous light rail systems in
11130-610: Was the Gross-Lichterfelde tramway in Lichterfelde near Berlin in Germany, which opened in 1881. It was built by Werner von Siemens who contacted Pirotsky. It initially drew current from the rails, with overhead wire being installed in 1883. The first interurban to emerge in the United States was the Newark and Granville Street Railway in Ohio, which opened in 1889. An early example of
11236-517: Was used in those cities that did not permit overhead wires. In Europe, it was used in London, Paris, Berlin, Marseille, Budapest, and Prague. In the United States, it was used in parts of New York City and Washington, D.C. Third rail technology was investigated for use on the Gold Coast of Australia for the G:link light rail, though power from overhead lines was ultimately utilized for that system. In
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