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Monorail

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H-Bahn Dortmund
Tama-Monorail (Japan)
KL Monorail (Malaysia)

A monorail is a transit system, resembling a metro or railroad with a track nominally consisting of a single rail (actually a beam), as opposed to the traditional track with two parallel rails. Monorail vehicles are wider than the beam they run on.

The term monorail or industrial monorail is also used to describe any number of systems in which a chair or carrier is suspended from an overhead rail structure for the limited transportation of goods or workers.

Background

Gyroscopically Balanced Monorail (1907) by Brennan and Scherl

Attempts at creating unconventional railways have been made since the latter part of the 19th century. Usually these have been claimed to be more efficient, faster or cheaper to construct than conventional railways.

Several attempts have been made to create a system in which a double-flanged steel wheel operates on a single rail similar to the railroad type of rail. The Wuppertal monorail described below is the only surviving monorail to actually use a single rail as the means of contact with its right-of-way.

Monorails have both benefited and suffered from their novelty and concept of modernity. When The Walt Disney Company placed a monorail in their Disneyland theme park in 1955, it exposed large numbers of visitors to the transportation form in a credible though miniature transit setting. At the same time, however, the Disneyland monorail and others built at other Disney properties and amusement locations have tended to identify monorails with amusements rather than practical transportation.

The popular press in the U.S. in mid-20th-century often featured monorail ideas in a "transportation of the future" context but this same press also displayed images of personal "rocket backpacks" and popular space travel, creating interest but also confusion as to which ideas were fads and which might become reality.

Types and technical aspects

Modern monorails depend on a large solid beam as the vehicles' running surface. There are a number of competing designs divided into two broad classes, straddle-beam and suspended monorails.

The most common type of monorail in use today is the straddle-beam monorail, in which the train straddles a reinforced concrete beam in the range of two to three feet (~0.6-0.9m) wide. A rubber-tired carriage contacts the beam on the top and both sides for traction and to stabilize the vehicle. The straddle-beam style was popularized by the German company ALWEG.

There is also a form of suspended monorail developed by the French company SAFEGE in which the train cars are suspended beneath the wheel carriage. In this design the carriage wheels ride inside the single beam.

Power

Monorails today are powered by electric motors fed by dual third rails, contact wires or electrified channels attached to or enclosed in their guidance beams.

Switching

Switching has been a perennial issue with monorail systems since simple switching mechanisms associated with other systems are usually not feasible. Some early monorail systems--notably the suspended monorail of Wuppertal (Germany), dating from 1901 and still in operation--have a design that makes it difficult to switch from one line to another. Some other monorail systems avoid switching as much as possible, by operating in a continuous loop or between two fixed stations, as in Seattle, Washington.

Current operating monorails are capable of more efficient switching than in the past. In the case of suspended monorails, switching may be accomplished by moving flanges inside the beamway to shift trains to one line or another.

Straddle-beam monorails require that the beam structure itself be moved to accomplish switching, which originally was an almost prohibitively ponderous procedure. Now, however, the most common way of achieving this is to place a moving apparatus on top of a sturdy platform capable of bearing the weight of vehicles, beams and its own mechanism. Mulitiple-segmented beams move into place on rollers to smoothly align one beam with another to send the train in its desired direction. Some of these beam turnouts are quite elaborate, capable of switching between several beams or even simulating a railroad double-crossover.

In cases where it must be possible to move a monorail train from one beam to any of a number of other beams, as in storage or repair shops, a traveling beam not unlike a railroad transfer table may be employed. A single beam, at least long enough to carry a single monorail vehicle, is aligned at an entry beam to be mounted by the monorail cars. The entire beam then rolls with the vehicle to align with the desired storage beam.

Systems similar in appearance

The term 'monorail' is often applied by members of the public to any modern elevated railway, particularly automated ones such as the Docklands Light Railway, Vancouver SkyTrain and the JFK AirTrain, but this usage is erroneous; these systems use the same twin rails and electric third rail as most underground metros and some main-line railways.

Advantages and disadvantages

Sydney Monorail

Advantages:

  • The primary advantage of monorails over conventional rail systems is that they require minimal space, both horizontally and vertically. The width required is determined by the monorail vehicle, not the track, and monorail systems are commonly elevated, requiring only a minimal footprint for support pillars.
  • Due to a smaller footprint they are seen as more attractive than conventional elevated rail lines and visually block only a minimal amount of sky.
  • They are quieter, as modern monorails use rubber wheels on a concrete track (though some non-monorail subway systems, like certain lines of the Paris metro and all of the Montreal metro, use the same technique and are equally quiet)
  • Monorails are capable of climbing, descending and turning faster than most conventional rail systems.
  • Unlike conventional rail systems, straddle monorails wrap around their track and are thus not physically capable of derailing, unless the track itself suffers a catastrophic failure.
The Disneyland Monorail

Disadvantages:

  • A monorail switch by its very design will leave one track hanging in mid-air at any given time. An incorrectly positioned or jammed switch could thus cause the monorail to derail and fall, although the risk can be mitigated by careful design and there are no documented cases of this actually happening.
  • In an emergency, passengers cannot immediately exit because the monorail vehicle is high above ground and not all systems have emergency walkways. The passengers must sometimes wait until a fire engine or a cherry picker comes to the rescue. Newer monorail systems resolve this by building emergency walkways alongside the entire track (though this reduces the advantage of visually blocking only a minimal amount of sky).

Partial list of monorail systems

Monorail systems have been built in many countries around the world, many of them on elevated tracks through crowded areas that would otherwise require the construction of expensive underground lines or have the disadvantages of surface lines.

Tama Toshi Monorail Line, Tokyo, Japan
The Ueno Zoo Monorail carries passengers within the zoo in Tokyo.

Asia

  • Shanghai Maglev Train in Shanghai, China - Completed in 2004, the Shanghai Maglev Train is the first commercial monorail based on the German Transrapid maglev-monorail and runs for 30 km between Pudong International Airport and the Shanghai Lujiazui financial district. Designed for speeds up to 500 km/h (310 mph), its regular service speed is in the region of 430 km/h (267 mph) and is currently the fastest commercial railway system in the world.
  • South Korea - Lotte World, two station amusement park monorail.

Europe

The Schwebebahn Wuppertal crossing an intersection

North America

Newark Airport Monorail, Newark, New Jersey
File:LasVegasMonorail.1.jpg
The Las Vegas Monorail (Convention Center Station)

Monorails can be found in the following places in North America:

South America and Australia

  • Sydney, Australia has the Sydney Monorail originally designed as public transport but has found more use as a tourist attraction.
  • The Gold Coast, Queensland has two monorails:
    • A 2 km monorail around the Sea World Theme Park which was the first monorail in Australia.
    • A link between Conrad Jupiters Casino and the nearby Broadbeach shopping district.
  • Brisbane, Queensland once had a monorail, which was built for World Expo '88 and ran from the CBD across the river to Southbank. It was removed some time after the expo. The city now runs Airtrain, which is technically not a monorail, but a long elevated railway line to the airport.
  • Brazil has a monorail in Rio de Janeiro that links the large Barra shopping mall to its parking lot.

Planned monorails

Several new systems are being considered or built worldwide including:

See also

Monorails in general

Specific monorails

Monorail Advocacy Groups

  • Austin Monorail Project - a non-profit advocating monorail transit for Austin, TX
  • 2045 Seattle - a grassroots movement that supports the construction of rapid transit monorail in Seattle, WA

Organizations/Views Opposing Monorails

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