An elevated railway or elevated train (also known as an el train or el for short) is a railway with the tracks above street level on a viaduct or other elevated structure (usually constructed from steel, cast iron, concrete, or bricks). The railway may be broad-gauge, standard-gauge or narrow-gauge railway, light rail, monorail, or a suspension railway. Elevated railways are normally found in urban areas where there would otherwise be multiple level crossings. Usually, the tracks of elevated railways that run on steel viaducts can be seen from street level.
The earliest elevated railway was the London and Greenwich Railway on a brick viaduct of 878 arches, built between 1836 and 1838. The first 2.5 miles (4.0 km) of the London and Blackwall Railway (1840) was also built on a viaduct. During the 1840s there were other plans for elevated railways in London that never came to fruition. [1]
From the late 1860s onward, elevated railways became popular in US cities. New York's West Side and Yonkers Patent Railway opened in 1868 as a cable-hauled elevated railway [2] and was operated using locomotives after 1871, when it was renamed the New York Elevated Railroad. [3] [4] This was followed in 1875 by the Manhattan Railway Company, which took over the New York Elevated Railroad. [5] Other early elevated systems in the US included the Chicago "L", which was built by multiple competing companies beginning in 1892, [6] as well as the Boston Elevated Railway in 1901 and the Market–Frankford Line in Philadelphia in 1907. [7] Globally, the Berlin Stadtbahn (1882) and the Vienna Stadtbahn (1898) are also mainly elevated.
The first electric elevated railway was the Liverpool Overhead Railway, which operated through Liverpool docks from 1893 until 1956.
In London, the Docklands Light Railway is a modern elevated railway that opened in 1987 [8] and has since expanded. [9] The trains are driverless and automatic. [10] Another modern elevated railway is Tokyo's driverless Yurikamome line, opened in 1995. [11]
Most monorails are elevated railways, such as the Disneyland Monorail System (1959), the Tokyo Monorail (1964), the Sydney Monorail (1988–2013), the KL Monorail, the Las Vegas Monorail, the Seattle Center Monorail and the São Paulo Monorail. Most maglev railways are also elevated.
During the 1890s there was some interest in suspension railways, particularly in Germany, with the Schwebebahn Dresden, (1891–) and the Wuppertal Schwebebahn (1901). H-Bahn suspension railways were built in Dortmund and Düsseldorf airport, 1975. The Memphis Suspension Railway opened in 1982.
Suspension railways are usually monorail; Shonan Monorail and Chiba Urban Monorail in Japan, despite their names, are suspension railways.
People mover or automated people mover (APM) is a type of driverless grade-separated, mass-transit system. The term is generally used only to describe systems that serve as loops or feeder systems, but is sometimes applied to considerably more complex automated systems. Similar to monorails, Bombardier Innovia APM technology uses only one rail to guide the vehicle along the guideway. APMs are common at airports and effective at helping passengers quickly reach their gates. Several elevated APM systems at airports including the PHX Sky Train at Phoenix Sky Harbor International Airport; AeroTrain at Kuala Lumpur International Airport; and the Tracked Shuttle System at London Gatwick Airport, United Kingdom.
A people mover or automated people mover (APM) is a type of small scale automated guideway transit system. The term is generally used only to describe systems serving relatively small areas such as airports, downtown districts or theme parks.
Véhicule Automatique Léger or VAL is a type of driverless (automated), rubber-tyred, medium-capacity rail transport system. The technology was developed at the Lille University of Science and Technology, was marketed by Matra, and first used in the early 1980s for the Lille Metro system, one of the world's first fully automated mass-transit rail networks, preceded only by the Port Island Line in Kobe, Japan. The VAL technology is now marketed by Siemens, which acquired Matra in the late 1990s.
An automated guideway transit (AGT) or automated fixed-guideway transit or automatic guideway transit system is a type of fixed guideway transit infrastructure with a riding or suspension track that supports and physically guides one or more driverless vehicles along its length. The vehicles are often rubber tired or steel wheeled, but other traction systems including air cushion, suspended monorail and maglev have been implemented. The guideway provides both physical support, like a road, as well as the guidance. An automated line can be cheaper to run than a conventional line, due to the shorter trains and stations.
Urban rail transit is a wide term for various types of local rail systems providing passenger service within and around urban or suburban areas. The set of urban rail systems can be roughly subdivided into the following categories, which sometimes overlap because some systems or lines have aspects of multiple types.
Various terms are used for passenger railway lines and equipment; the usage of these terms differs substantially between areas:
Platform screen doors (PSDs), also known as platform edge doors (PEDs), are used at some train, rapid transit and people mover stations to separate the platform from train tracks, as well as on some bus rapid transit, tram and light rail systems. Primarily used for passenger safety, they are a relatively new addition to many metro systems around the world, some having been retrofitted to established systems. They are widely used in newer Asian and European metro systems, and Latin American bus rapid transit systems.
The Innovia APM 100 is an automated people mover (APM) rolling stock first developed by Westinghouse, intended mainly for airport connections and light rail in towns. They are operated by Automatic Train Control (ATC), making it fully automatic and driverless.
SelTrac is a digital railway signalling technology used to automatically control the movements of rail vehicles. It was the first fully automatic moving-block signalling system to be commercially implemented.
The Scharfenberg coupler is a commonly used type of fully automatic railway coupling.
Rapid transit or mass rapid transit (MRT) or heavy rail, commonly referred to as metro, is a type of high-capacity public transport that is generally built in urban areas. A grade separated rapid transit line below ground surface through a tunnel can be regionally called a subway, tube, metro or underground. They are sometimes grade-separated on elevated railways, in which case some are referred to as el trains – short for "elevated" – or skytrains. Rapid transit systems are railways, usually electric, that unlike buses or trams operate on an exclusive right-of-way, which cannot be accessed by pedestrians or other vehicles.
A suspension railway is a form of elevated monorail in which the vehicle is suspended from a fixed track, which is built above streets, waterways, or existing railway track.
Innovia APM is a rubber-tired automated people mover system (APM) currently manufactured and marketed by Alstom as part of its Innovia series of fully automated transportation systems. The technology was introduced in 1963 by Westinghouse and has been improved over three generations: the Innovia APM 100, Innovia APM 200, and the latest model, the Innovia APM 300. The license to use the technology has also passed hands several times, from Westinghouse to AEG in 1988, to Adtranz in 1996, to Bombardier Transportation in 2001, and most recently to Alstom in 2021.
In Singapore, the main lines on the Mass Rapid Transit system using the 1,435 mm standard gauge.
The Soekarno–Hatta Airport Skytrain is a semi-driverless 3.05 kilometre Automated People Mover System (APMS) which connects Soekarno-Hatta Airport Terminals 1, 2, 3 and SHIA railway station, free of charge. Trains are spaced 5 minutes apart, with 7 minutes needed to get from Terminal 1 to Terminal 3. The trains are only available on the landside.
SkyTrain is a proposed automated people mover line meant to serve the city of Makati and Bonifacio Global City area in Taguig, Metro Manila. Originally scheduled for completion in 2021, as of March 2022, construction has yet to begin.
The Gatwick Airport Shuttle Transit is a 0.75-mile (1.21 km) long elevated automated people mover that links the North and South Terminals at London's Gatwick Airport. The line is ground-side, and besides linking the two terminals also serves to link the North terminal to the airport railway station. Although sometimes colloquially, but erroneously, known as a "monorail", the transit vehicles are carried on rubber tyres running on a concrete track with twin running surfaces and are steered by separate guide rails.
The history of automatic train operation includes key dates for system introductions of different Grade of Automation. The lower grades, such as the German Punktförmige Zugbeeinflussung introduced in 1934 have been available earlier. Higher grades, such as the driverless operation have been introduced almost only in case automated guideway transit.