Maglev

Maglev
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This article is about transportation using magnetic levitation. For other uses, see Maglev (disambiguation).

JR-Maglev at Yamanashi, Japan test track in November 2005

Transrapid 09 at the Emsland test facility in Germany
Maglev (derived from magnetic levitation) is a system of transportation that uses magneticlevitation to suspend, guide and propel vehicles with magnets rather than using mechanical methods, such as wheels, axles and bearings. With maglev a vehicle is levitated a short distance away from a guideway using magnets to create both lift and thrust. Maglev vehicles are claimed to move more smoothly and quietly and to require less maintenance than wheeled mass transit systems. It is claimed thatnon-reliance on friction also means that acceleration and deceleration can far surpass that of existing forms of transport. The power needed for levitation is not a particularly large percentage of the overall energy consumption; most of the power used is needed to overcome air resistance (drag), as with any other high-speed form of transport.[citation needed]
In the public imagination, "maglev"often evokes the concept of an elevated monorail track with a linear motor. This can be misleading. While several maglev systems are monorail designs, not all maglevs use monorails,[1] and not all monorail trains use linear motors or magnetic levitation. Some railway transport systems incorporate linear motors but only use electromagnetism for propulsion, without actually levitating the vehicle.Such trains (which might also be monorail trains) are wheeled vehicles and not maglev trains.[2] Maglev tracks, monorail or not, can also be constructed at grade (i.e. not elevated). Conversely, non-maglev tracks, monorail or not, can be elevated too. Some maglev trains do incorporate wheels and function like linear motor-propelled wheeled vehicles at slower speeds but "take off" and levitate athigher speeds.[3][4]
The highest recorded speed of a maglev train is 581 km/h (361 mph), achieved in Japan by Central Japan Railway Company's (JR Central) MLX01 superconducting maglev in 2003,[5] 6 km/h (3.7 mph) faster than the conventional wheel-rail speed record set by the TGV.[6]
Differences in construction costs can affect chances for profitability. Maglev advocates claim that withconventional railway trains, at very high speeds, the wear and tear from friction along with the concentrated pounding from wheels on rails accelerate equipment deterioration and prevent mechanically-based train systems from achieving a maglev-based train system's high level of performance and low levels of maintenance.[7]
There are presently only two commercial maglev transport systems in operation, withtwo others under construction. In April 2004, Shanghai began commercial operations of the high-speed Transrapid system. Beginning March 2005, Japan began operation of the HSST "Linimo" line in time for the 2005 World Expo. In its first three months, the Linimo line carried over 10 million passengers. South Korea and the People's Republic of China are both building low speed maglev lines of theirown design, one in Beijing and the other at Seoul's Incheon Airport.
Contents[hide] * 1 History * 1.1 First patent * 1.2 Development * 1.3 New York, United States 1968 * 1.4 Hamburg, Germany 1979 * 1.5 Birmingham, United Kingdom 1984–1995 * 1.6 Japan 1985– * 1.7 Vancouver Canada and Hamburg Germany 1986–1988 * 1.8 Berlin, Germany 1989–1991 * 2Technology * 2.1 Overview * 2.1.1 Electromagnetic suspension * 2.1.2 Electrodynamic suspension * 2.2 Pros and cons of different technologies * 2.2.1 Propulsion * 2.2.2 Stability * 2.2.3 Guidance * 2.3 Evacuated tubes * 2.4 Power and energy usage * 2.5 Comparison with conventional trains * 2.6 Comparison with aircraft * 3 Economics...