<P> Two more stages are planned of 9.7 km (6.0 mi) and 37.4 km (23.2 mi). Once completed it will become a circular line . </P> <P> In the public imagination, "maglev" often evokes the concept of an elevated monorail track with a linear motor . Maglev systems may be monorail or dual rail and not all monorail trains are maglevs . Some railway transport systems incorporate linear motors but use electromagnetism only for propulsion, without levitating the vehicle . Such trains have wheels and are not maglevs . Maglev tracks, monorail or not, can also be constructed at grade (i.e. not elevated). Conversely, non-maglev tracks, monorail or not, can be elevated too . Some maglev trains do incorporate wheels and function like linear motor - propelled wheeled vehicles at slower speeds but "take off" and levitate at higher speeds . </P> <P> The two notable types of maglev technology are: </P> <Ul> <Li> Electromagnetic suspension (EMS), electronically controlled electromagnets in the train attract it to a magnetically conductive (usually steel) track . </Li> <Li> Electrodynamic suspension (EDS) uses superconducting electromagnets or strong permanent magnets that create a magnetic field, which induces currents in nearby metallic conductors when there is relative movement, which pushes and pulls the train towards the designed levitation position on the guide way . </Li> </Ul>

What is the bullet train made out of