Japanese National Railways diagram showing how a 'Maglev' (magnetic levitation) system works. Instead of travelling on wheels on a track, the car hovers up to 2 cm above a metal track and is pulled along by magnets. The advantages of the maglev system are there are no moving parts to wear out, no maintenance is required and it hardly makes any noise. However, building the track for a train like this is very expensive.
© National Railway Museum / Science & Society Picture Library -- All rights reserved