Maglev
Maglev is a system of rail transport whose rolling stock is levitated by electromagnets rather than rolled on wheels, eliminating rolling resistance.
Compared to conventional railways, maglev trains have higher top speeds, superior acceleration and deceleration, lower maintenance costs, improved gradient handling, and lower noise. However, they are more expensive to build, cannot use existing infrastructure, and use more energy at high speeds.
Maglev trains have set several speed records. The train speed record of was set by the experimental Japanese L0 Series maglev in 2015. From 2002 until 2021, the record for the highest operational speed of a passenger train of was held by the Shanghai maglev train, which uses German Transrapid technology. The service connects Shanghai Pudong International Airport and the outskirts of central Pudong, Shanghai. At its historical top speed, it covered the distance of in just over 8minutes.
Different maglev systems achieve levitation in different ways, which broadly fall into two categories: electromagnetic suspension and electrodynamic suspension. Propulsion is typically provided by a linear motor. The power needed for levitation is typically not a large percentage of the overall energy consumption of a high-speed maglev system. Instead, overcoming drag takes the most energy. Vactrain technology has been proposed as a means to overcome this limitation.
Despite over a century of research and development, there are only seven operational maglev trains today — four in China, two in South Korea, and one in Japan.
Two inter-city maglev lines are currently under construction, the Chūō Shinkansen connecting Tokyo and Nagoya and a line between Changsha and Liuyang in Hunan Province, China.
History
Development
In the late 1940s, the British electrical engineer Eric Laithwaite, a professor at Manchester University, developed the first full-size working model of the linear induction motor. He became a professor of heavy electrical engineering at Imperial College London in 1964, where he continued his successful development of the linear motor. Since linear motors do not require physical contact between the vehicle and guideway, they became a common fixture on advanced transportation systems in the 1960s and 1970s. Laithwaite joined one such project, the Tracked Hovercraft RTV-31, based near Cambridge, UK, although the project was cancelled in 1973.The linear motor was naturally suited to use with maglev systems as well. In the early 1970s, Laithwaite discovered a new arrangement of magnets, the magnetic river, that allowed a single linear motor to produce both lift and forward thrust, allowing a maglev system to be built with a single set of magnets. Working at the British Rail Research Division in Derby, along with teams at several civil engineering firms, the "transverse-flux" system was developed into a working system.
The first commercial maglev people mover was simply called "MAGLEV" and officially opened in 1984 near Birmingham, England. It operated on an elevated section of monorail track between Birmingham Airport and Birmingham International railway station, running at speeds up to. The system was closed in 1995 due to reliability problems.
First maglev patent
High-speed transportation patents were granted to various inventors throughout the world. The first relevant patent, , issued to Albert C. Albertson, used magnetic levitation to take part of the weight off of the wheels while using conventional propulsion.Early United States patents for a linear motor propelled train were awarded to German inventor. The inventor was awarded and . In 1907, another early electromagnetic transportation system was developed by F. S. Smith. In 1908, Cleveland mayor Tom L. Johnson filed a patent for a wheel-less "high-speed railway" levitated by an induced magnetic field. Jokingly known as "Greased Lightning," the suspended car operated on a 90-foot test track in Johnson's basement "absolutely noiseless and without the least vibration." A series of German patents for magnetic levitation trains propelled by linear motors were awarded to Hermann Kemper between 1937 and 1941. An early maglev train was described in, "Magnetic system of transportation", by G. R. Polgreen on 25 August 1959. The first use of "maglev" in a United States patent was in "Magnetic levitation guidance system" by Canadian Patents and Development Limited.
New York, United States, 1912
In 1912 French-American inventor Émile Bachelet demonstrated a model train with electromagnetic levitation and propulsion in Mount Vernon, New York. Bachelet's first related patent, was granted in 1912. The electromagnetic propulsion was by attraction of iron in the train by direct current solenoids spaced along the track. The electromagnetic levitation was due to repulsion of the aluminum base plate of the train by the pulsating current electromagnets under the track. The pulses were generated by Bachelet's own Synchronizing-interrupter supplied with 220 VAC. As the train moved it switched power to the section of track that it was on. Bachelet went on to demonstrate his model in London, England in 1914, which resulted in the registration of Bachelet Levitated Railway Syndicate Limited July 9 in London, just weeks before the start of WWI.Bachelet's second related patent, granted the same day as the first, had the levitation electromagnets in the train and the track was aluminum plate. In the patent he stated that this was a much cheaper construction, but he did not demonstrate it.
New York, United States, 1968
In 1959, while delayed in traffic on the Throgs Neck Bridge, James Powell, a researcher at Brookhaven National Laboratory, thought of using magnetically levitated transportation. Powell and BNL colleague Gordon Danby worked out a maglev concept using static magnets mounted on a moving vehicle to induce electrodynamic lifting and stabilizing forces in specially shaped loops, such as figure-of-8 coils on a guideway. These were patented in 1968–1969.Japan, 1969
Japan operates two independently developed maglev trains. One is HSST by Japan Airlines; and the other, which is more well known, is SCMaglev by the Central Japan Railway Company.The development of the latter started in 1969. The first successful SCMaglev run was made on a short track at the Japanese National Railways' Railway Technical Research Institute in 1972. Maglev trains on the Miyazaki test track regularly hit by 1979. After an accident destroyed the train, a new design was selected. In Okazaki, Japan, the SCMaglev was used for test rides at the Okazaki exhibition. Tests in Miyazaki continued throughout the 1980s, before transferring to a far longer test track, long, in Yamanashi in 1997. The track has since been extended to almost. The world speed record for crewed trains was set there in 2015.
Development of HSST started in 1974. In Tsukuba, Japan, the HSST-03 became popular at the Tsukuba World Exposition, in spite of its low top speed. In Saitama, Japan, the HSST-04-1 was revealed at the Saitama exhibition in Kumagaya. Its fastest recorded speed was.
Construction of a new high-speed maglev line, the Chuo Shinkansen, started in 2014. It is being built by extending the SCMaglev test track in Yamanashi in both directions. The completion date expected to be 2034 and an extension to Osaka expected to be completed in 2037, with the estimate of 2027 no longer possible following a local governmental rejection of a construction permit.
Hamburg, Germany, 1979
05 was the first maglev train with longstator propulsion licensed for passenger transportation. In 1979, a track was opened in Hamburg for the first . Interest was sufficient that operations were extended three months after the exhibition finished, having carried more than 50,000 passengers. The Transrapid 05 was reassembled in Kassel in 1980.Ramenskoye, Moscow, USSR, 1979
In 1979 the USSR town of Ramenskoye built an experimental test site for running experiments with cars on magnetic suspension. The test site consisted of a 60-metre ramp which was later extended to 980 metres. From the late 1970s to the 1980s five prototypes of cars were built that received designations from TP-01 to TP-05. The early cars were supposed to reach the speed up to.The construction of a maglev track using the technology from Ramenskoye started in Armenian SSR in 1987 and was planned to be completed in 1991. The track was supposed to connect the cities of Yerevan and Sevan via the city of Abovyan. The original design speed was which was later lowered to. However, the Spitak earthquake in 1988 and the First Nagorno-Karabakh War caused the project to freeze. In the end the overpass was only partially constructed.
In the early 1990s, the maglev theme was continued by the Engineering Research Center "TEMP" this time by the order from the Moscow government. The project was named V250. The idea was to build a high-speed maglev train to connect Moscow to the Sheremetyevo airport. The train would consist of 64-seater cars and run at speeds up to. In 1993, due to the financial crisis, the project was abandoned. However, from 1999 the "TEMP" research center had been participating as a co-developer in the creation of the linear motors for the Moscow Monorail system.
Birmingham, United Kingdom, 1984–1995
The world's first commercial maglev system was a low-speed maglev shuttle that ran between the airport terminal of Birmingham Airport and the nearby Birmingham International railway station between 1984 and 1995. Its track length was, and trains levitated at an altitude of, levitated by electromagnets, and propelled with linear induction motors. It operated for 11 years and was initially very popular with passengers, but obsolescence problems with the electronic systems made it progressively unreliable as years passed, leading to its closure in 1995. One of the original cars is now on display at Railworld in Peterborough, together with the RTV31 hover train vehicle. Another is on display at Locomotion Museum in Shildon, County Durham.Several favourable conditions existed when the link was built:
- The British Rail Research vehicle was 3 tonnes and extension to the 8-tonne vehicle was easy.
- Electrical power was available.
- The airport and rail buildings were suitable for terminal platforms.
- Only one crossing over a public road was required and no steep gradients were involved.
- Land was owned by the railway or airport.
- Local industries and councils were supportive.
- Some government finance was provided and because of sharing work, the cost per organization was low.