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Comment by comrade1234 | Hacker News Reader

The Shanghai airport maglev used to go around that speed too (~430km/h) over twenty years ago. But these new trains are regular trains running on regular (but specialized and high quality) tracks. There's probably no more need for maglev now that you can run on regular (well not exactly) tracks.

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Did it? I took a ride on the Shanghai airport maglev around a month ago, and it never went above 300 km/h, which was a real bummer, to be honest.

I remember there were different speeds at different times last time I went, but it seems they reduced it in 2021 permanently.

https://en.wikipedia.org/wiki/Shanghai_maglev_train

I was there 20 years ago and it was ~500km/h, if I remember correctly.

Yes it did, at least earlier. I rode it in 2010.

At these speeds, how are they guaranteeing that the tracks are in PERFECT working order?

e.g. even a small earthquake that shifts the tracks a few inches would probably cause, at minimum, a degradation in service.

It does require really good maintenance-of-way work.

Having all trains inspect the track is feasible. The latest round of Shinkansen trains does that. They're moving away from running a Dr. Yellow track inspection train every 10 days.[1]

[1] https://www.railway.supply/n700s-trains-to-be-equipped-with-...

Japan has solved that 60+ years ago in a much more seismically active zone, it's not a major issue.

That’s fascinating, what do they do?

seismometers installed along the coast and near the tracks. Senses the earthquake and trains respond if necessary. I believe if the epicenter of the quake occurred directly under a moving train this system would fail(or too close react). However, that appears never to have happened and is probably extremely unlikely.

Sensors all over the tracks? There’s probably many different sensor strategies you could use to detect imperfections.

I know that modern roller coasters are outfitted with a bunch of stress, vibration, conductivity, etc sensors. There’s a theme park near me where huge fast roller coasters run all day every day all season. The speeds aren’t as high but I bet given the twists and turns the stresses and tolerances are worse.

There are high fps cameras that monitor the overhead lines on every carriage, maybe also pointing at the rails? It is a engineering marvel though, the rides are so smooth, in my home country the trains have issues with leafs on the tracks … lol

This sounds like a Plainly Difficult moment.

I suspect ~200 years ago in England people were saying pretty similar things!

In my country there are special trains equiped with sensors that drive around at night to measure the tracks. Would have prevented that disaster in Spain.

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