Maglev Train Exceeds 600km/h For World Record

nojayuk writes: An experimental Japanese magnetic levitation train has reached a speed of 603 km/h, breaking the world speed record the same train set last week of 590 km/h. "Central Japan Railway (JR Central), which owns the trains, wants to introduce the service between Tokyo and the central city of Nagoya by 2027. The 280km journey would take only about 40 minutes, less than half the current time. However, passengers will not get to experience the maglev's record-breaking speeds because the company said its trains will operate at a maximum of 505km/h. In comparison, the fastest operating speed of a Japanese shinkansen, or "bullet train" is is 320km/h. ... Construction costs are estimated at nearly $100bn (£67bn) just for the stretch to Nagoya, with more than 80% of the route expected to go through costly tunnels, AFP news agency reports."

Comments

80% through tunnels?

[Rich0]

If you're putting 80% through tunnels, I'd wonder if it would almost make sense to make it 100% tunnels and have it in a vacuum. You could reach absurd speeds with such a design, though only if your stops are sufficiently distant (you would want a hub/spoke model).

Re:80% through tunnels?

[jandrese]

Then every car (and the tunnel itself!) needs to be a pressure vessel and you need oxygen masks if there is a leak. Plus you have to turn every station into an airlock. Depressurizing the tunnel is a lot of extra work.

It might be easier (although not much more sane) to have two large ventilation systems for the tunnel. One working at high negative pressure (near vacuum), and the other working at a high positive pressure. The vents would be shutters that could be opened and closed rapidly, so you're always pulling air from the front of the train and introducing it behind the train. Basically you would always have a strong tail wind, reducing the heating effects of compressing that much air. The energy required to move the air would be substantial though, and it might not make sense. The high speed shutter system would be relatively complex too, and making it reliable would be a challenge.