MAGLEV and the future

Maglev (Magnetic Levitation) was once touted as the "railway" of the future and in a way it is, though to date the principles of magnetic levitation have not been fully utilised on a commercial basis. A few systems have been tried, not always with success. Perhaps they were used in the wrong place at the wrong time. Those in use generally tend to be low-speed versions, which was not what the designers originally had in mind. The first commercial system was a 600-metre double track linking Birmingham airport to the nearby Birmingham International railway station and ran at only about 20 mph. It encountered many technical problems and was withdrawn from service in 1995.

The largest operating system currently in use is that in Shanghai (China) which links downtown Shanghai with its airport, 19 miles distant. The system, Transrapid, uses German technology developed by Siemens. The journey takes 7 minutes and 20 seconds, reaching a top speed of 268 mph (431 km/h). Acceleration is fairly rapid as the train reaches 220 mph in just two minutes – it is also incredibly cheap at just US$6 (£3.50) one way.

The Transrapid project is planned to be extended with a line eventually linking Shanghai and Hangzhou, a distance of 105 miles, which will be covered in just 27 minutes. Construction is expected to begin in 2010. In Japan the Linimo line runs for 9 kms and has nine stations. It can reach a top speed of 100 km/hr though runs at far less than that in daily operation. It has also suffered from serious technical problems. The experimental maglev in Japan holds the world speed record for a "train" of 361 mph, achieved on December 2nd 2003.

Japan is also testing maglev technology on a test track about 18 kms long (including tunnels to test the aerodynamics of high speed in tunnels). The test trains have reached a world land record of 361 mph (581 km/h) – the TGV in France running on conventional steel rail reached 357 mph (575 km/h) by comparison. Although tests are proving satisfactory the current economic conditions has led to the withdrawal of support fro a planned Tokyo-Osaka maglev line, obviously a very expensive project.

Maglevs do not run on conventional railway track but on specially built "tracks". In fact, they do not RUN on tracks at all but levitate about 15 mm above the track bed. Two different approaches to magnetic levitation train systems have been developed. The first, called electromagnetic suspension (EMS), uses conventional electromagnets mounted at the ends of a pair of structures under the train. The structures wrap around and under either side of the guideway. The magnets attract up toward iron rails in the guideway and lift the train. However, this system is inherently unstable; the distance between the electromagnets and the guideway, which is about 10 mm (3/8 in), must be continuously monitored and adjusted by computer to prevent the train from hitting the guideway.

The second design, called electrodynamic suspension (EDS), uses the opposing force between superconducting magnets on the vehicle and electrically conductive strips or coils in the guideway to levitate the train. This approach is inherently stable, and it does not require continued monitoring and adjustment. There is also a relatively large clearance between the guideway and the vehicle, typically 100 to 150 mm (4 to 6 in). However, the EDS maglev system uses superconducting magnets, which are more expensive than conventional electromagnets and require a refrigeration system in the train to keep the superconducting magnets cooled to low temperatures.

Trains are definitely a major part of the future for transport. In many ways they will become more important than now, with the extension of high-speed lines throughout Europe and other densely populated regions. By 2010 there should be over 5,000 miles of high-speed track in Europe. Maglev trains could play a part but an entirely new infrastructure would be needed, at massive cost, to create a new system. It is inevitable that most countries will opt for developing their traditional rail-based systems, even though the cost of building a high-speed line is pretty high.

Other ideas have been proposed but no working models are in operation. Perhaps the most ambitious was a plan hatched by an American businessman to build a system of vacuum tubes which would carry single car maglev trains at speeds of over 4000 mph, even under the sea between Europe and New York. As you might imagine no working models have yet been produced, although the idea was featured on a Discovery Channel show entitled "Extreme Engineering" in 2003. The most viable forms of rail transportation in the immediate future, especially in countries with fairly high population densities (much of Europe) involve extensions to the TGV and other high-speed conventional systems and the future development of maglev networks.

The biggest improvement that could, perhaps, be made in the not too distant future concerns freight. As we described earlier (see Freight Trains) massive amounts of freight are hauled over long distances by road. Transferring these to rail would cut pollution levels by huge amounts – as well as easing traffic congestion. The problem is that, at each end of a long journey, road is necessary between warehouse (origination of the freight and its final delivery point) and rail terminal. HGV drivers need to work too.