Underground Railroad, referred to the subway, also referred to as the Mass Transit Railway, the narrow sense refers to mainly run underground urban railway system or rapid transit system; a broad sense, because many of these systems with the construction of the environment may also be ground of the road exist, and it usually covers the metropolitan areas all kinds of underground and high-density transport system on the ground.
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The world’s first underground railway system is the London Metropolitan Railway, opened in 1863 in order to solve the problem of London traffic jams built. At that time electricity is not yet universal, so even the Mass Transit Railway (MTR) can only use the steam locomotive. Locomotive release the exhaust gas is harmful, so the tunnel at some distance they have to get through and ground ventilation slots. In 1870, London opened the first passenger bored subway, across the River Thames near the Tower of London. But the railway is not successful in a few months after the close. The earliest extant bored underground railway opened in 1890, also in London, connecting the city center and southern regions. The initial construction of the railway who plan to use a similar cable car, driven by, but in the end of the electric locomotive, making it the first electric subway. In the city of London in the early opening of the subway in 1906, the full electrification.
The vast majority of urban rail transit systems are used to carry passengers of the city commuter, urban rail transit systems in many occasions as the backbone of the urban transport. Typically, urban rail transit system is the method of many cities to solve traffic congestion problems.
Chicago had the underground railway used to transport goods; Mass Transit Railway Corporation of London, England also specialized to carry messages. The two railway has to be disabled in 1959 and 2003. All city underground railway passenger services only. Moscow underground railway in the war (World War II), the Mass Transit Railway (MTR) will be used as a factory or air-raid shelter. Many countries such as South Korea’s subway system, has in the design of war may be calculated in the design, so it is the depth of the railway, crowd control, taking into account the needs of the daily traffic and defense. For some parts of the underground railway construction in the ground not only to avoid ground traffic and housing, as well as by the outdoor severe weather damage in order to avoid the railway system, the negative teaching material Moscow subway ground line: on the 4th and L1 line by the extreme cold weather the ravages of the maintenance costs have been far higher than the line of construction and maintenance costs.
In addition, urban rail transit system was also used for the display of the national indicators in the economic, social and technically superior. For example, the former Soviet Union’s underground railway system they Station ornate known, while the North Korean capital Pyongyang’s underground railway system has been a grand decoration.
Vehicles: the first urban rail system compartments are made of wood, later converted into steel in order to reduce the event of the dangers posed by fire. Toronto’s underground railway opened in 1953, then the train began to re-modified aluminum, effectively reducing maintenance costs and weight.
A lot of underground railway tunnel running than in the main trunk is small; Generally speaking, the Mass Transit Railway train volume generally relatively small. Sometimes the tunnel and even can affect the shape of the design of the train, for example, part of the London Underground train is.
Most of the urban rail systems are dynamic distributed (EMU), instead of using the power centralized. If using a power centralized, often with push-pull operation.