The conventional train has been overtaken by a new technology that is both revolutionary as well as innovative and has opened up exciting possibilities.
The technology to run trains has advanced from the conventional rail track to a track where the wheels are not used in the conventional sense. The basic aim is to do away with friction which is part of the existing train systems and thus generate greater speeds. Such trains can run 3 to 4 times faster than a conventional train.They are also much faster than the new high-speed trains put into use in USA and China.
Current and Magnetic Field
We are all aware that when a current is passed through a coil it generates a magnetic field. This is referred to as Electromagnetic force. It means a magnetic field that is induced by an electric current. The only major condition that must be satisfied is that the coil must be a good conductor. It stands to reason that a bad conductor will not generate a magnetic field as the current will not pass through it.
When the two ends of the coil are connected to the source of the current like an accumulator or battery the magnet field that is generated will have will behave like a normal magnet and will have North and south poles. This is similar to a permanent magnet, with the exception that once the electric current is switched off; the magnet field will also lapse.
We are all aware of the Magical tricks of Houdini and our own Sorcar, both famous magicians who levitated human beings in full view of audiences. The human body floated in the air. In Maglev trains also the train floats in the air on a predetermined path. The predetermined path is not like a conventional rail track but something that is referred to as a guide way. A guide way is the path the train will follow while running. It will dispense with conventional wheels and as such with friction reduced to zero; the train is capable of much higher speeds.
Maglev Trains and Basics
Maglev trains have superconducting magnets on the train and the guideway has coils embedded in it. Thus the basic principle of creating magnetic force through an electric current is established.
The coils that are installed in the guide way have an 8 configuration and heavy current is passed through these coils. These generate a powerful magnetic field and interact with the super magnets on the train and allows the train to move ahead by lifting it few centimeters from the guide way or travelling path.
As I have written the electromagnets behave like permanent magnets and have the property of like poles and unlike poles. The repulsion force generated lifts the train and it glides forward.
Thus the basic ingredients to run a Maglev train is
a) A Source of electricity and its uninterrupted supply.
b) Metal coils to be embedded in the drive or guide way
c) Large magnets for guidance under the train.
India and Maglev Trains
Maglev trains will not have an electric or diesel engine as we understand, but it may have a control cabin that monitors the guide way, magnet force and measurement of resultant parameters.
The first Commercial use of a maglev train was in 2003 and rails all over the world are experimenting with this new technology. The Indian erstwhile Railway minister Lalu Prasad Yadav had received a proposal for a maglev track in India. Though it was costly proposition, yet it appealed to the rustic mind of the rail minister.
However after he left the rail ministry the matter has gone in Limbo. But recently a NRI consortium has proposed a Maglev train between Panvel and Pune and it is expected that this train will do the run in 20 minutes.
Maglev Trains and Aircraft
However Maglev trains though operating without friction cannot match aircraft as these fly at 30,000 ft and as such face no air resistance, which is not the case with Maglev trains which will have to deal with friction from the air. Hence they have to design to keep the drag coefficient low.
The fastest speed achieved on an experimental run by a Maglev train is 591 km per hour in Japan and that is well below the speed of an airliner and new generation super sonic transports that are on the anvil.
The Future and Limitations
All technology basically benefits the common man, like Duranto and the other superfast trains in India. One hopes that this technology is given due importance in India and once again India does not become a laggard in this field as well.
However Maglev trains do have some limitations and that concerns their size. Presently the technology does not permit multiple car trains and of more than 4/5 carriages. But perhaps the smaller trains can be offset by greater frequency