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| Sunday, 6 March 2005 |
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Junior Observer |  |
| News Business Features Editorial
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Trains powered by magnets
Maglev is short for magnetic levitation, which means that these trains will float over a guideway using the basic principles of magnets, which will replace the old steel wheel and track trains. The big difference between a maglev train and a conventional train is that maglev trains do not have an engine,at least not the kind of engine used to pull typical train carriages along steel tracks. Then, how does a maglev train work, you might wonder. The engine of maglev trains is hardly noticeable. Instead of using fossil fuels, the magnetic field created by the electrified coils in the guideway walls and the track combine to push the train forward. The magnetised coil running along the track, called a guideway, drive away the large magnets on the train's undercarriage, allowing the train to be raised between one and ten centimetres above the guideway. Once this happens, power is supplied to the coils within the guideway walls to create a unique system of magnetic fields that pull and push the train along the guideway. The electric current supplied to the coils in the guideway walls is constantly alternating to change the polarity of the magnetised coils. This change in polarity causes the magnetic field in front of the train to pull the vehicle forward, while the magnetic field behind the train adds more forward thrust. Maglev trains float on a cushion of air, eliminating friction. This lack of friction and the trains' aerodynamic designs allow these trains to reach unprecedented ground transportation speeds of more than 310 mph (500 kph). Developers say that maglev trains will eventually link cities that are up to 1,000 miles (1,609 km) apart. At 310 mph, you could travel from Paris to Rome in just over two hours. This technology is a popular topic of transportation conversation in several countries. Germany and Japan are both developing maglev train technology, and both are currently testing prototypes of their trains. In Germany, engineers have developed an electromagnetic suspension (EMS) system, called Transrapid. Japanese engineers are developing a competing version of maglev trains that use an electrodynamic suspension (EDS) system, which is based on the repelling force of magnets. The key difference between the Japanese and German maglev trains is that the Japanese trains use super-cooled, superconducting electromagnets. This kind of electromagnets can conduct electricity even after the power supply has been shut off. In the EMS system, which uses standard electromagnets, the coils only conduct electricity when a power supply is present. By chilling the coils at frigid temperatures, Japan's system saves energy. Maglev technology in use While maglev transportation was first proposed more than a century ago, the first commercial maglev train made its test debut in Shanghai, China in 2002, using the train developed by the German company Transrapid International. The same line made its first open-to-the-public commercial run about an year later, in December 2003. The Shanghai Transrapid line currently runs to and from the Longyang Road station at the city's centre and Pudong airport. Travelling at an average speed of 267 mph (430 kmh), the 19 mile (30 km) journey takes less than 10 minutes on the maglev train as opposed to an hour-long taxi ride. Despite U.S. interest in maglev trains over the past few decades, the expense of building a maglev transportation system has been prohibitive. **** Opposites attract! If you've ever played with magnets, you would know that opposite poles attract and like poles repel each other. This is the basic principle behind electromagnetic propulsion. Electromagnets are similar to other magnets, in that they attract metal objects, but the magnetic pull is temporary. You can easily create a small electromagnet yourself by connecting the ends of a copper wire to the positive and negative ends of an AA, C or D-cell battery. This creates a small magnetic field. If you disconnect either end of the wire from the battery, the magnetic field is removed. The magnetic field created in this wire-and-battery experiment is the simple idea behind a maglev train rail system. There are three components to this system: * A large electrical power source * Metal coils lining a guideway or track * Large guidance magnets attached to the underside of the train |
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| Politics | Produced by Lake House |
Have you ever seen or heard about maglev trains? Although this is not a
familiar word in Sri Lanka, countries like Germany and Japan are using
powerful electromagnets to develop high-speed trains called maglev trains.
