this post was submitted on 24 Feb 2024
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Futurology

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[–] [email protected] 40 points 6 months ago (18 children)

Some people are skeptical this technology can ever work, but it appears CASIC's Phase 1 testing in a 2km tunnel has given them the confidence to proceed to Phase 2 testing in a 60km long tunnel.

Chinese railway engineering leads the world so I have a hunch that if any nation can pull this off, then it's China. However, lots of questions remain. A back-of-the-envelope calculation says that to achieve those speeds in the 2km test tunnel deceleration would have been about 3G. That's the same as a rocket at lift-off and not many people's idea of comfort.

[–] [email protected] 6 points 6 months ago* (last edited 6 months ago) (4 children)

I got an acceleration of 1.5G for the test, did you forget a factor of 2 or something? Still certainly not an enjoyable experience for passengers, but I assume it would accelerate over a much longer distance if a full track was built.

[–] [email protected] 2 points 6 months ago (1 children)

Did you also factor in that the train needs to come to a full stop in that 2km as well?

[–] [email protected] 2 points 6 months ago* (last edited 6 months ago)

Yes, I calculated the acceleration required to accelerate to 387MPH (173m/s) in 1km.
v^2 = 2ax
(173m/s)^2 = 2a(1000m)
a = 14.96m/s^2 = 1.53g

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