Monorail

Monorail is a railway system in which the vehicle runs on a single rail. Most systems use an elevated beam, typically of steel or concrete, along which the train travels. Two common configurations exist: the straddle-beam type, where the car sits to the sides of the rail, and the suspended type, where the car is hung from the rail above.

Vehicles are usually electric and propelled by motors on the car. Guidance comes from wheels or rollers that touch the single track, with stabilizing wheels to prevent derailment. The track is typically a hollow or solid beam or girder that supports the train on an elevated right of way. Brakes combine mechanical, electric, and sometimes regenerative systems.

History of monorails dates to the 19th century, with early experiments in the United States and Europe. The Wuppertal Schwebebahn in Germany, opened in 1901, is among the oldest still operating. In the United States, the Disneyland Monorail began service in 1959. In Asia, Tokyo Monorail opened in 1964 and Kuala Lumpur Monorail in 2003; other networks exist in Japan, China, and the Middle East.

Advantages cited for monorails include a small land footprint, reduced ground-level disruption, and, in some cases, smooth operation with lower noise. Disadvantages include high capital costs, specialized maintenance, and limited capacity relative to traditional heavy-rail, as well as challenges integrating with other rail networks. They are most commonly used in urban corridors or theme parks rather than as primary intercity systems.

Notable systems: Wuppertal Schwebebahn (Germany); Tokyo Monorail (Japan); Osaka Monorail (Japan); Kuala Lumpur Monorail (Malaysia); and various Disney theme-park monorails.