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Maglev train

Encyclopedia : M : MA : MAG : Maglev train

Maglev can also mean general magnetic levitation.
Transrapid at the Emsland test facility
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Transrapid at the Emsland test facility

Maglev in Shanghai
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Maglev in Shanghai

Inside the Shanghai maglev
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Inside the Shanghai maglev

Inside the Shanghai maglev VIP section
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Inside the Shanghai maglev VIP section

Magnetic levitation transport, or maglev, is a form of transportation that suspends, guides and propels vehicles via electromagnetic force. This method has speed and ride comfort advantages compared to wheeled mass transit systems - potentially, maglevs could reach velocities comparable to turboprop and jet aircraft (500 to 580 km/h), and the lack of track-wheel friction allows for exceptional comfort - but although the idea is decades old, scientific and economic limitations have hindered the proliferation of the technology.

Maglev technology has minimal overlap with wheeled train technology and is not compatible with conventional railroad tracks. Because they cannot share existing infrastructure, maglevs must be designed as complete transportation systems. The term "maglev" refers not only to the vehicles, but to the vehicle/guideway interaction; each being a unique design element specifically tailored to the other to create and precisely control magnetic levitation and propulsion.

Due to the lack of physical contact between the track and the vehicle, the only friction exerted is that between the vehicles and the air. Consequently maglevs can potentially travel at very high speeds with reasonable energy consumption and noise levels. Systems have been proposed that operate at up to 650 km/h (404 mph), which is far faster than is practical with conventional rail transport. The very high maximum speed potential of maglevs make them competitors to airline routes of 1,000 kilometers (600 miles) or less. The world's first commercial application of a high-speed maglev line is the IOS (initial operating segment) demonstration line in Shanghai that transports people 30 km (18.6 miles) to the airport in just 7 minutes 20 seconds (top speed of 431 km/h or 268 mph, average speed 250 km/h or 150 mph). Other maglev projects worldwide are being studied for feasibility.

Contents

Technology

Maglev Propulsion
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Maglev Propulsion

See also: Fundamental Technology Elements in the JR-Maglev article, Technology in the Transrapid article, Magnetic levitation

Three types of technology

There are three primary types of maglev technology:

Inductrack

A newer, perhaps less-expensive, system is called "Inductrack". The technique has a load-carrying ability related to the speed of the vehicle, because it depends on currents induced in a passive electromagnetic array by permanent magnets. In the prototype, the permanent magnets are in a cart; horizontally to provide lift, and vertically to provide stability. The array of wire loops is in the track. The magnets and cart are unpowered, except by the speed of the cart. Inductrack was originally developed as a magnetic motor and bearing for a flywheel to store power. With only slight design changes, the bearings were unrolled into a linear track. Inductrack was developed by physicist Richard Post at Lawrence Livermore National Laboratory.

Inductrack uses Halbach arrays for stabilization. Halbach arrays are arrangements of permanent magnets that stabilize moving loops of wire without electronic stabilization. Halbach arrays were originally developed for beam guidance of particle accelerators. They also have a magnetic field on the track side only, thus reducing any potential effects on the passengers.

Lift and propulsion

Japan and Germany are active in maglev research, producing several different approaches and designs. In one design, the train can be levitated by the repulsive force of like poles or the attractive force of opposite poles of magnets. The train can be propelled by a linear motor on the track or on the train, or both. Massive electrical induction coils are placed along the track in order to produce the magnetic field necessary to propel the train.

Stability

Static magnetic bearings using only electromagnets and permagnets are unstable because of Earnshaw's theorem; on the other hand diamagnetic and superconducting magnets can support a maglev stably. Some conventional maglev systems are stabilized with electromagnets that have electronic stabilization. This works by constantly measuring the bearing distance and adjusting the electromagnet current accordingly.

Magnet weight

The weight of the large electromagnet is a major design issue. A very strong magnetic field is required to levitate a massive train, so conventional maglev research is using superconductor research for an efficient electromagnet.

''See also : transport applications of maglev.

Pros and cons of different technologies

Each implementation of the magnetic levitation principle for train-type travel involves advantages and disadvantages. Time will tell as to which principle, and whose implementation, wins out commercially.

{| cellspacing=0 cellpadding=0 width=100% | colspan=5 |

|- | width=20% | Technology || rowspan=7 |    || width=35% | Pros || rowspan=7 |    || width=45% | Cons |- | colspan=5 |
|- valign=top | EMS (Electromagnetic) || EMS is a propulsion system that trains do not have to carry; can attain very high speeds (500 km/h); magnetic fields inside and outside the vehicle are insignificant; highly reliable computer controlled operations; proven, commercially available technology || Guideway includes stator packs along entire length which add cost to construction, but do enable high speeds without vehicle weight penalty. |- | colspan=5 |
|- valign=top | Superconducting EDS (Electrodynamic) || Powerful onboard superconducting magnets enable highest recorded train speeds (581 km/h) and heavy load capacity; has recently demonstrated (Dec 2005) successful operations using high temperature superconductors (HTS) in its onboard magnets, cooled with inexpensive liquid nitrogen || Strong magnetic fields onboard the train make the train inaccessible to passengers with pacemakers or magnetic data storage media such as hard drives and credit cards; vehicle must be wheeled for travel at low speeds; system per mile cost still considered prohibitive; the system is not yet out of prototype phase. |- | colspan=5 |
|- valign=top | Inductrack System (Permanent Magnets) || Failsafe Suspension - no power required to activate magnets; can generate enough force at low speeds (around 5 km/h) to levitate maglev train; in case of power failure cars slow down on their own in a safe, steady and predictable manner before coming to a stop || Requires wheels. New technology that is still under development (as of 2006) and has as yet no commercial version or full scale system prototype. |- | colspan=5 |

The Inductrack and the Superconducting EDS are only levitation technologies. In both cases, vehicles need some other technology for propulsion. A Jet engine and a linear motor are being considered, such as the linear motor used for propulsion in the Japanese Superconducting EDS MLX01 maglev.

The German Transrapid electromagnetic maglev uses a linear motor for both levitation and propulsion.

Neither Inductrack nor the Superconducting EDS are able to levitate vehicles at a standstill, although Inductrack provides levitation down to a much lower speed. Wheels are required for both systems, whereas EMS systems are wheel-less.

The German Transrapid, Japanese HSST (Linimo), and Korean Rotem maglevs levitate at a standstill, with electricity extracted from guideway using power rails for the latter two, and wirelessly for Transrapid. If guideway power is lost on the move, the Transrapid is still able to generate levitation down to 10 km/h speed, using the power from onboard batteries. This is not the case with the HSST and Rotem systems.

Alleged theft of maglev technology

In a serious incident in December 2004, Chinese engineers broke into the Transrapid maintenance room in the middle of the night in Shanghai, took measurements of the train, and even filmed the whole incident, according to the German Economic Weekly, Wirtschaftswoche. Wirtschaftswoche further speculated that it was a case of Transrapid technology theft. Furthering the Transrapid Consortium's unease, the Chengdu Aircraft Industrial Group has announced it has developed its own high speed maglev technology, which it claims to be superior to that of Transrapid's, less than 2 years after the break-in. Trials are supposed to begin this year of the new 'Chinese' maglev technology in Shanghai. According to the Spiegel Online however, the Chengdu Aircraft Industrial Group has been tinkering with maglev technology since 1986, so it is unknown if the maglev train about to run test trials in Shanghai is the result of technology theft or actual domestic research culminating in the creation of this new maglev train system.

However, the Changchun Railway Vehicles company announced in 2001, before the Transrapid maglev was in operation in Shanghai, that it was developing a competing maglev system and project in northeastern China. It is one of a few Chinese companies now extensively and independently researching maglev technology.

Recently new announcements by Chinese officials planning on cutting maglev rail costs by a third have stirred some strong comments by various German officials and more dipomatic statements concern from Transrapid officials. The Deutsche Welle reports that the China Daily quoted the State Council encouraging engineers to "learn and absorb foreign advanced technologies while making further innovations." *[link]

Bavarian Premier Edmund Stoiber commented, "What's happening in China smells suspiciously like technology theft," shortly after learning of the new Chinese plans to build their own maglev train. The Premier suggested that the G8 take up the issue of Chinese intellectual property rights violations at their next meeting.

The China Aviation Industry Corporation said in their defense that the new "Zhui Feng" maglev train is not based or dependent on foreign technology. They claim it is not only a much lighter train, but also has a much more advanced design.

Noise

In April 2004, a peer-reviewed article in the Journal of the Acoustical Society of America stated that the noise from maglev trains are considerably more annoying than standard steel on steel intercity train noise and are approximately as annoying as road traffic. The difference between equal annoyance levels of maglev and traditional trains was 5 dB. This counters claims from maglev proponents that maglev trains have acoustic benefits over standard trains. [link] Maglev is characterized by high noise levels and brief duration, which may startle those underneath the track. The type of noise a maglev emits is similar to a jet engine. [link]

Existing maglev systems

JR-Maglev at Yamanashi
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JR-Maglev at Yamanashi

Birmingham 1984–1995

The world's first commercial automated system was a low-speed maglev shuttle that ran from the airport terminal of Birmingham International Airport (UK) to the nearby Birmingham International railway station from 1984 to 1995. The length of the track was 600 m, and trains "flew" at an altitude of 15 mm. It was in operation for nearly eleven years, but obsolescence problems with the electronic systems made it unreliable in its later years and it has now been replaced with a cable-drawn system.

Berlin 1989–1991

Main article: M-Bahn
In West Berlin, the M-Bahn was built in the late 1980s. It was a driverless maglev system with a 1.6 km track connecting three stations. Testing in passenger traffic started in August 1989, and regular operation started in July 1991. Although the line largely followed a new elevated alignment, it terminated at the U-Bahn station Gleisdreieck, where it took over a platform that was then no longer in use; it was from a line that formerly ran to East Berlin. After the fall of the Berlin Wall, plans were set in motion to reconnect this line (today's U2). Deconstruction of the M-Bahn line began only two months after regular service began and was completed in February 1992.

Emsland, Germany

Transrapid, a German maglev company, has a test track in Emsland with a total length of 31.5 km.

Shanghai Maglev Train

Main article: Shanghai Maglev Train
Transrapid constructed the first operational high-speed conventional maglev railway in the world, the Shanghai Maglev Train from downtown Shanghai, China to the new Shanghai airport at Pudong. It was inaugurated in 2002. The highest speed achieved on the Shanghai track has been 501 km/h (311 mph), over a track length of 30 km. Transrapid uses EMS technology. The track will be extended by 160 km before the 2010 World Expo begins in Shanghai.

JR-Maglev

Main article: JR-Maglev
Japan has a test track in Yamanashi prefecture where test trains JR-Maglev MLX01 have reached 581 km/h (363 mph), faster than wheeled trains. These trains use superconducting magnets which allow for a larger gap, and repulsive-type "Electro-Dynamic Suspension" (EDS). In comparison Transrapid uses conventional electromagnets and attractive-type "Electro-Magnetic Suspension" (EMS). These "Superconducting Maglev Shinkansen", developed by the Central Japan Railway Co. ("JR Central") and Kawasaki Heavy Industries, are currently the fastest trains in the world, achieving a record speed of 581 km/h on December 2, 2003.

Linimo (Tobu Kyuryo Line)

Main article: Linimo
The world's first commercial automated "Urban Maglev" system commenced operation in March 2005 in Aichi, Japan. This is the nine-station 8.9 km long Tobu-kyuryo Line, otherwise known as Linimo. The line has a minimum operating radius of 75 m and a maximum gradient of 6%. The linear-motor magnetic-levitated train has a top speed of 100 km/h. The line serves the local community as well as the Expo 2005 fair site. The trains were designed by the Chubu HSST Development Corporation, which also operates a test track in Nagoya. Urban-type maglevs patterned after the HSST have been constructed and demonstrated in Korea, and a Korean commercial version Rotem is now under construction in Daejeon and projected to go into operation by April of 2007.

FTA's UMTD program

In the US, the Federal Transit Administration (FTA) Urban Maglev Technology Demonstration program has funded the design of several low-speed urban maglev demonstration projects. It has assessed HSST for the Maryland Department of Transportation and maglev technology for the Colorado Department of Transportation. The FTA has also funded work by General Atomics at California University of Pennsylvania to demonstrate new maglev designs, the MagneMotion M3 and of the Maglev2000 of Florida superconducting EDS system. Other US urban maglev demonstration projects of note are the LEVX in Washington State and the Massachusetts-based Magplane.

Southwest Jiaotong University, China

On December 31, 2000, the first crewed high-temperature superconducting maglev was tested successfully at Southwest Jiaotong University, Chengdu, China. This system is based on the principle that bulk high-temperature superconductors can be levitated or suspended stably above or below a permanent magnet. The load was over 530 kg and the levitation gap over 20 mm. The system uses liquid nitrogen, which is very cheap, to cool the superconductor.

The first, the German patent (1941)

The first patent for a magnetic levitation train propelled by linear motors was German Patent 707032, issued in June 1941.

Economics

High-speed maglevs can be expensive to build, but are comparable to the capital costs of building a traditional high-speed rail system from scratch, a highway system or a system of airports.[[Citing sources citation needed]] More importantly, maglevs are significantly less expensive to operate and maintain (O&M) than traditional high-speed trains, planes or intercity buses. The data coming out of the Shanghai maglev demonstration project indicates that O&M costs are quite low, and are indeed covered by the current relatively low volume of 7,000 passengers per day.[[Citing sources citation needed]] Ridership on this Pudong International Airport line is expected to rise dramatically once the line is extended from Longyang Road metro station all the way to Shanghai's downtown train depot.

The Shanghai maglev cost US$1.2B to build which means that at 20,000 passengers a day at US$6 per passenger it will take around 30 years to pay off just the capital costs, not accounting for track maintenance, salaries and electricity (see solar power). This computes to US$60 million per mile. However, it should be noted that the total $1.2B indicated includes one-time capital costs such as manufacturing and construction facilities and operational training, largely distorting the per-mile costs of the short track. It is predicted that the per-mile costs of the extension to Hangzhou will be significantly lower.

The proposed Chuo Shinkansen line is estimated to cost approximately US$82 billion to build.[[Citing sources citation needed]]

However, when one considers the cost of airport construction (e.g. Hong Kong Airport cost US$20 billion to build in 1998) and 8-lane Interstate highway systems that cost around US$50 million per mile, it becomes immediately apparent that maglev's costs are competitive, especially considering that they can handle much higher volumes of passengers per hour than airports or 8-lane highways and do it without introducing any air pollution along the right of way.

Low-speed maglevs (100 km/h), such as the Japanese HSST or Korean Rotem, are expected to cost somewhere around US$30 million per mile.[[Citing sources citation needed]] Besides offering improved O&M costs over other transit systems, these low-speed maglevs provide ultra-high levels of operational reliability and introduce zero noise or air pollution into dense urban settings.

As maglev systems are deployed around the world, experts expect construction costs to drop as new construction methods are perfected.

Under construction

Old Dominion University

A track of less than a mile in length has been constructed at Old Dominion University in Norfolk, Virginia. The system is not operational, but research is currently ongoing to resolve some stability issues with the system. This system uses a "smart train, dumb track" that involves most of the sensors, magnets, and computation occurring on the train rather than the track. This system will cost less to build per mile than existing systems.

Proposals

Europe

Munich

A Transrapid connection of the Bavarian capital Munich to its international airport (37 km) is now being planned. It would reduce the current connection time via S-Bahn (German city railroad system) from about 40 minutes to 10 minutes.

Berlin - Hamburg

A 292 km Transrapid line linking Berlin to Hamburg. It has been deleted due to lack of funds. Instead the existing railway line has been upgraded to 230 km/h for ICE train sets.

London - Edinburgh and/or Glasgow

A maglev line has recently been proposed in the United Kingdom from London to Edinburgh and/or Glasgow with several route options through the Midlands, Northwest and Northeast, and is reported to be under favourable consideration by the government. A further high speed link is also being investigated as an option between Glasgow to Edinburgh though there is no settled technology for this concept yet, ie (Maglev/Hi Speed Electric etc) [link] [link]

Asia

Tokyo - Osaka

If a proposed Chuo Shinkansen is built, connecting Tokyo to Osaka by maglev, the existing test track in Yamanashi prefecture would be part of the line.

Shanghai - Hangzhou

China has decided to build a second Transrapid maglev rail with a length of 160 km from Shanghai to Hangzhou (Shanghai-Hangzhou maglev line). Talks with Germany and Transrapid Konsortium about the details of the construction contracts have started. On March 7th, the Chinese Minister of Transportation was quoted by several Chinese and Western newspapers as saying the line was approved. Construction will probably start towards the end of 2006 and is scheduled to be completed in time for the 2010 Shanghai Expo, becoming the first inter-city Maglev rail line in commercial service in the world. The line will be an extension of the Shanghai airport Maglev line.

USA

Southern California, Los Angeles - Las Vegas

Main article: California-Nevada Interstate Maglev
High-speed maglev lines between major cities of southern California and Las Vegas are also being studied via the California-Nevada Interstate Maglev Project. This plan was originally supposed to be part of a I-5 or I-15 expansion plan, but the federal government has ruled it must be separated from interstate work projects.

Since the federal government decision, private groups from Nevada have proposed a line running from Las Vegas to Los Angeles with stops in Primm Nevada, Baker California, and points throughout Riverside County into Los Angeles.

Unfortunately, Southern California politicians have not been receptive to these proposals, many concerned that a high speed rail line out of state would drive out dollars that would be spent in state "on a rail" to Nevada.

Baltimore - Washington, D.C.

Main article: Baltimore-Washington D.C. Maglev
A 64 km project linking Camden Yards in Baltimore and Baltimore-Washington International (BWI) Airport to Union Station in Washington, D.C. It is in demand for the area due to its current traffic/congestion problems. The project is in contention for the same federal grant as the Pittsburgh project.

Honolulu

The city of Honolulu, Hawaii is said to be planning a Linimo class urban Maglev for its main mass transit train.

San Diego

San Diego is considering a high-speed maglev line to serve as a passenger transportation node to remote airport sites under consideration. The cost estimate is approximately $10 billion U.S. for the 80-100 mile run, not including the cost of construction of the airport. [link]

Pittsburgh

A 75 km project linking Pittsburgh International Airport to downtown Pittsburgh to Monroeville, PA and ending in Greensburg, PA. The Pittsburgh route is favored by some on the basis that it would test the durability and endurance of the maglev technology over more hilly terrain and more variable winter weather conditions. The project is in contention for the same federal grant as the Baltimore-Washington, D.C. project.

The Cascadia MagLev

Long-proposed but not on any official drawing boards would be a MagLev line along the Interstate 5 corridor, its core component from Portland, Oregon to Vancouver, British Columbia, with eventual extensions to Eugene, Oregon (in the south) and Whistler, British Columbia (in the north). The initial phase of the project would link Tacoma to Seattle, mirroring the old interurban line between those two cities. The same idea has re-surfaced with a conventional high-speed rail proposal, although its extension into British Columbia has been largely blocked by opposition on the part of the City of White Rock, British Columbia, which would sit astride the line.

Vactrain

see also Swissmetro
More exotic proposals include maglev lines through vacuum-filled tunnels (see Vactrain), where the absence of air resistance would allow extremely high speeds, up to 6000-8000 km/h (4000-5000 mph) according to some sources. Theoretically, these tunnels could be built deep enough to pass under oceans or to use gravity to assist the trains' acceleration. This would likely be prohibitively costly without major advances in tunnelling technology. Alternatives such as elevated concrete tubes with partial vacuums have been proposed to reduce these costs. If the trains topped out at around 8000 km/h (5000 mph), the trip between London and New York would take a breathtakingly short 54 minutes, effectively supplanting aircraft as the world's fastest mode of public transportation.

UniModal

UniModal is a proposed personal rapid transit system using Inductrack suspension to achieve speeds of 160 km/h (100 mph).

References

See also

External links

General

Transrapid

Japanese maglev

Linear motor car

Maglev train companies

These websites contain further information provided by companies building maglev trains (alphabetical order).

 

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