Monorail
A monorail is an urban rail transit type in which trains run on or are suspended above a single rail or beam structure to transport people. They have an intermediate transport capacity at the regional and metropolitan level, generally greater than that of the tram and less than that of the rapid transit.
Colloquially, the term "monorail" is often used to describe any form of elevated rail or people mover. More accurately, the term refers to the style of track. Monorail systems are most frequently implemented in large cities, airports, and theme parks.
Etymology
The term possibly originated in 1897 from German engineer Eugen Langen, who called an elevated railway system with wagons suspended the Eugen Langen One-railed Suspension Tramway.Differentiation from other transport systems
Monorails have found applications in airport transfers and medium-capacity metros. To differentiate monorails from other transport modes, the Monorail Society defines a monorail as a "single rail serving as a track for passenger or freight vehicles. In most cases, rail is elevated, but monorails can also run at grade, below grade, or in subway tunnels. Vehicles either are suspended from or straddle a narrow guide way. Monorail vehicles are wider than the guideway that supports them."Similarities
Monorails are often elevated, sometimes leading to confusion with other elevated systems such as the Docklands Light Railway, Vancouver SkyTrain, the AirTrain JFK and cable propelled systems like the Cable Liner people mover which run on two rails.Monorail vehicles often appear similar to light rail vehicles, and can be staffed or unstaffed. They can be individual rigid vehicles, articulated single units, or multiple units coupled into trains. Like other advanced rapid transit systems, monorails can be driven by linear induction motors; like conventional railways, vehicle bodies can be connected to the beam via bogies, allowing curves to be negotiated.
Monorails are sometimes used in urban areas alongside conventional parallel railed metro systems. Mumbai Monorail serves alongside Mumbai Metro, while monorail lines are integrated with conventional rail rapid transit lines in Bangkok's MRT network.
Differences
Unlike some trams and light rail systems, modern monorails are always separated from other traffic and pedestrians due to the geometry of the rail. They are both guided and supported via interaction with the same single beam, in contrast to other guided systems like rubber-tyred metros, such as the Sapporo Municipal Subway; or guided buses or trams, such as Translohr. Monorails can also use pantographs.As with other grade-separated transit systems, monorails avoid red lights, intersection turns, and traffic jams. Surface-level trains, buses, automobiles, and pedestrians can collide each one with the other, while vehicles on dedicated, grade-separated rights-of-way such as monorails can collide only with other vehicles on the same system, with much fewer opportunities for collision. As with other elevated transit systems, monorail passengers receive sunlight and views. Monorails can be quieter than diesel buses and trains. They obtain electricity from the track structure, whereas other modes of transit may use either third rail or overhead power lines and poles. Compared to the elevated train systems of New York, Chicago, and elsewhere, a monorail beamway casts a narrower shadow.
Conversely, monorails can be more expensive than light-rail systems that do not include tunnels. In addition, monorails must either remain above ground or use larger tunnels than conventional rail systems, and they require complex track-switching equipment.
Maglev
Under the Monorail Society's beam-width criterion, some, but not all, maglev systems are considered monorails, such as the Transrapid and Linimo. Maglevs differ from other monorails in that they do not physically contact the beam while moving.History
Early years
The first monorail prototype was made in Russia in 1820 by Ivan Elmanov. Attempts at creating monorail alternatives to conventional railways have been made since the early part of the 19th century.The Centennial Monorail was featured at the Centennial Exposition in Philadelphia in 1876. Based on its design the Bradford and Foster Brook Railway was built in 1877 and ran for one year from January 1878 until January 1879.
Around 1879 a "one-rail" system was proposed independently by Haddon and by Stringfellow, which used an inverted "V" rail. It was intended for military use, but was also seen to have civilian use as a "cheap railway". Similarly, one of the first systems put into practical use was that of French engineer Charles Lartigue, who built a line between Ballybunion and Listowel in Ireland, opened in 1888 and lasting 36 years, being closed in 1924. It used a load-bearing single rail and two lower, external rails for balance, the three carried on triangular supports. It was cheap to construct but tricky to operate. Possibly the first monorail locomotive was a 0-3-0 steam locomotive on this line. A high-speed monorail using the Lartigue system was proposed in 1901 between Liverpool and Manchester.
The Boynton Bicycle Railroad was a steam-powered monorail in Brooklyn on Long Island, New York. It ran on a single load-bearing rail at ground level, but with a wooden overhead stabilising rail engaged by a pair of horizontally opposed wheels. The railway operated for only two years beginning in 1890.
The Hotchkiss Bicycle Railroad was a monorail on which a matching pedal bicycle could be ridden. The first example was built between Smithville and Mount Holly, New Jersey, in 1892. It closed in 1897. Other examples were built in Norfolk from 1895 to 1909, Great Yarmouth, and Blackpool, UK from 1896.
1900s–1950s
Early designs used a double-flanged single metal rail alternative to the double rail of conventional railways, both guiding and supporting the monorail car. A surviving suspended version is the oldest still in service system: the Wuppertal monorail in Germany. Also in the early 1900s, Gyro monorails with cars gyroscopically balanced on top of a single rail were tested, but never developed beyond the prototype stage. The Ewing System, used in the Patiala State Monorail Trainways in Punjab, India, relies on a hybrid model with a load-bearing single rail and an external wheel for balance. A highspeed monorail using the Lartigue system was proposed in 1901 between Liverpool and Manchester.In 1910, the Brennan gyroscopic monorail was considered for use to a coal mine in Alaska. In June 1920, the French Patent Office published FR 503782, by Henri Coanda, on a 'Transporteur Aérien' -Air Carrier. One of the first monorails planned in the United States was in New York City in the early 1930s, scrubbed for an elevated train system.
File:Xlg russian monorail.jpg|thumb|300px|: "A new Russian type of monorail that runs in a chute on large spheres. Fragmentary and contradictory reports have appeared from Russia about a new revolutionary type of railway undergoing secret testing there, sparking the curiosity and interest of the American engineering world, who have recently received the first full confirmations about the details of the new system with photos of the working model in operation."
The first half of the 20th century saw many further proposed designs that either never left the drawing board or remained short-lived prototypes. Another project created on the layout was the ball-bearing train by Nikolai Grigorievich Yarmolchuk. This train moved on spherical wheels with electric motors embedded in them, which were located in semi-circular chutes under a wooden platform. A model train, built to 1/5 scale to test the vehicle concept, was capable of reaching speeds of up to 70 km/h. The full-scale project was expected to reach speeds of up to 300 km/h.
1950s–1980s
In the latter half of the 20th century, monorails had settled on using larger beam- or girder-based track, with vehicles supported by one set of wheels and guided by another. In the 1950s, a 40% scale prototype of a system designed for speed of on straight stretches and on curves was built in Germany. There were designs with vehicles supported, suspended or cantilevered from the beams. In the 1950s the ALWEG straddle design emerged, followed by an updated suspended type, the SAFEGE system. Versions of ALWEG's technology are used by the two largest monorail manufacturers, Hitachi Monorail and Bombardier.File:6308-DisneyLandHotelMonorailStation.jpg|thumb|The original Red Mark I Disneyland Monorail, with the additional car to make it a Mark II, as seen at the Disneyland Hotel station in August 1963
In 1956, the first monorail to operate in the US began test operations in Houston, Texas. Disneyland in Anaheim, California, opened the United States' first daily operating monorail system in 1959. Later during this period, additional monorails were installed at Walt Disney World in Florida, Seattle, and in Japan. Monorails were promoted as futuristic technology with exhibition installations and amusement park purchases, as seen by the legacy systems in use today. However, monorails gained little foothold compared to conventional transport systems. In March 1972, Alejandro Goicoechea-Omar had patent DE1755198 published, on a 'Vertebrate Train', build as experimental track in Las Palmas de Gran Canaria, Spain.
Niche private enterprise uses for monorails emerged, with the emergence of air travel and shopping malls, with shuttle-type systems being built.
1980s–present
From the 1980s, most monorail mass transit systems are in Japan, with a few exceptions. Tokyo Monorail, is one of the world's busiest, averages 127,000 passengers per day and has served over 1.5 billion passengers since 1964. China recently started development of monorails in the late 2000s, already home to the world's largest and busiest monorail system and has a number of mass transit monorails under construction in several of cities. A Bombardier Innovia Monorail-based system is under construction in Wuhu and several "Cloudrail" systems developed by BYD under construction a number of cities such as Guang'an, Liuzhou, Bengbu and Guilin. Monorails have seen continuing use in niche shuttle markets and amusement parks.Modern mass transit monorail systems use developments of the ALWEG beam and tyre approach, with only two suspended types in large use. Monorail configurations have also been adopted by maglev trains. Since the 2000s, with the rise of traffic congestion and urbanization, there has been a resurgence of interest in the technology for public transport with a number of cities, such as Malta and Istanbul, today investigating monorails as a possible mass transit solution.
In 2004, Chongqing Rail Transit in China adopted a unique ALWEG-based design with rolling stock that is much wider than most monorails, with capacity comparable to heavy rail. This is because Chongqing is criss-crossed by numerous hills, mountains and rivers, therefore tunneling is not feasible except in some cases due to the extreme depth involved. Today it is the largest and busiest monorail system in the world.
In July 2009, two Walt Disney World monorails collided, killing one of the drivers and injuring seven passengers. The National Transportation Safety Board found the cause of the accident to be human error by both the driver and controller, contributed to by a lack of standard operating procedures.
São Paulo, Brazil, is building two high-capacity monorail lines as part of its public transportation network. Line 15 was partially opened in 2014, will be long when completed in 2022 and has a capacity of 40,000 pphpd using Bombardier Innovia Monorail trains. Line 17 will be long and is using the BYD SkyRail design. Other significant monorail systems are under construction such as two lines for the Cairo Monorail, two lines for the MRT and the SkyRail Bahia in Brazil.