Maglev Suspension Systems

Shanghai Transrapid

In previous article, we discussed the Maglev technology and principle on which it is working. Here, we will discuss about the different technologies or suspension system used to levitate the train, although the basic concept remains same. Even though Maglev looks like new, futuristic mode of transportation, concept was first proposed about a century ago by Hermann Kemper. First commercial Maglev developed by German company Transrapid International was tested in Shanghai, China, in 2002. Shanghai Transrapid is functional since December 2003, with average speed of 430 Km/h.

Several other countries have started working on Maglev projects. Enough research is going on to improve the technology to levitate the train. Engineers are testing there prototypes of train for commercial use.

Electromagnetic Suspension System (EMS):

Electromagnetic Suspension  (EMS) System

In Germany, the company named, Transrapid International had developed Electromagnetic suspension (EMS) System. In this system, the bottom of the train wraps around a steel guideway. Electromagnets attached to train's undercarriage are directed up towards the guideway, which levitates the train about 1 centimetre above the guideway. The system keeps the train levitated even when it is not moving. The system is provided with emergency battery backup in case of power failure. Other guidance magnets embedded in the train's body keep it stable during the travel. The company also has train in commercial use implementing EMS, known as Transrapid and can reach the speed of 500 Km/h with people onboard.

Electrodynamic Suspension System (EDS):

Electrodynamic Suspension  (EDS) System

US & Japanese engineers are working on a competing version of Maglev trains SCMAGLEV, that uses Electrodynamic Suspension (EDS) System. The key difference is, Japanese trains uses supercooled, superconducting electromagnets, This kind of electromagnets can conduct electricity even after the power supply is shut off. The trains using this technology can levitate nearly 10 centimetres above the guideway. But, the train using EDS, must roll on the rubber tires until it reaches a lift off speed about 100 Km/h. Also, wheels have advantages during power failure of system to slow down the train.

EDS saves the energy by cooling coils, however, also the cryogenic system use to cool the coils can be expensive. Also, passengers with pacemakers would have to be shielded from magnetic fields generated by the superconducting electromagnets.

Inductrack:

Inductrack

Inductrack is a newer type of EDS that used permanent room temperature magnets to produce the magnetic field instead of super-cooled superconducting electromagnets. Inductrack also uses auxiliary wheels to accelerate until it begins to levitate. The permanent magnets made from neodymium- iron boron, which generates intense magnetic field are used. Magnets are arranged in a Halbach array so that, the intensity of magnetic field concentrates above the array to create enough levitating force.