COVER STORY
REVOLUTIONIZING
Transport Through Maglev
The technology which we are featuring this time as our Cover Story is non-other than the Maglev Train which is also known as magnetic levitation train. It is a floating vehicle which is used as a mode of land transportation. The technology is supported either by electromagnetic attraction or repulsion. The magnetic field created by the electromagnetic waves helps the technology to carry on with its work with an amazing speed. The concept of Maglev was formulated during the early 1900s by American professor and inventor Robert Goddard and Frenchborn American engineer Emile Bachelet. The commercial use of the technology started in the year 1984 and since then, many networks and operators are working for the development of extensive networks proposed for the future for different countries especially the Asian ones. Maglevs incorporate a basic fact about magnetic forces—like magnetic poles repel each other, and opposite magnetic poles attract each other—to lift, propel, and guide a vehicle over a track. It is a basic science which is used in an advanced mode through the concept of electromagnetic waves. Maglev propulsion and levitation generally involves the use of superconducting materials, electromagnets, diamagnets, and rare-earth magnets as of now. Electromagnetic suspension known as EMS in short form uses the attractive force between magnets present on the train’s sides and the underside and on the guideway to levitate the train. A variation on EMS, called Transrapid, employs an electromagnet to lift the train off the guideway. The attraction from magnets presents on the underside of the vehicle that wraps around the iron rails of the
14
METRO RAIL NEWS | January 2020 | WWW.METRORAILNEWS.IN
Authored By..
Manoranjan Kumar Senior Editor METRO RAIL NEWS
guideway keep the train about 1.3 cm above the guideway as per the studies conducted on the technology. These magnetic fields interact with simple metallic loops set into the concrete walls of the Maglev guideway. The loops are made of conductive materials, like aluminium, and when a magnetic field moves past, it creates an electric current that generates another magnetic field. Electrodynamic suspension (EDS) systems are similar to EMS in several respects, but the magnets are used to repel the train from the guideway rather than attract them. These magnets are supercooled and superconducting and have the ability to conduct electricity for a short time after power has been cut. Unlike EMS, the charge of the magnetized coils of the guideway in EDS systems repels the charge of magnets on the undercarriage of the train so that it levitates higher (typically in the range of 1–10 cm) above the guideway. EDS trains are slow to lift off, so they have wheels that must be deployed below approximately 100 km per hour. However, these trains are not considered as much popular in comparison with the other ones. "Three types of loops are set into the guideway at specific intervals to do three important tasks: one creates a field that makes the train hover about 5 inches above the guideway; a second keeps the train stable horizontally. Both loops use magnetic repulsion to keep the train car in the optimal spot; the further it gets from the centre of the guideway or the closer to the bottom, the more
