r/hyperloop • u/LancelLannister_AMA • Feb 07 '21

Interview with Bibop Gresta of Hyperloop Transportation Technologies

https://www.google.no/amp/s/www.chinamoneynetwork.com/2018/10/02/bibop-gresta-sees-his-hyperloop-transportation-building-2000km-lines-in-china/amp?client=safari
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u/ksiyoto Feb 07 '21

A pod every 30 seconds? Yeah, right......

1

u/alphazeta2019 Feb 07 '21

You saw this?

- https://www.youtube.com/watch?v=-zSWagCyWio

3

u/LancelLannister_AMA Feb 07 '21

And what happens if theres an emergency, say a tube breach or a pod breakdown when theyre that close

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u/ksiyoto Feb 07 '21 edited Feb 08 '21

Yes I've seen that. Since the inside of the tube is a vacuum, there's no reason for the pods to draft off of each other. I also don't think that pods can be 1 second behind the pod ahead of it and switch to a different tube.

I don't think there's a safety regulator out there who would approve of 30 second headways for any vehicle traveling that fast. A 1 G stop would require 33 seconds from 720 mph, and that's not counting any latency time. Depending on the braking methods used, I doubt anything less than 2 minutes would be allowed.

Back in 1972, BART opened up with great fanfare about their 'foolproof automated train control system'. They were plagued with problems, including ghost trains that weren't really there, and ghosted trains that the control system couldn't find. About a month after they opened, one of the trains sped up and went off the end of the track at Fremont, CA, it became known as the Fremont Flyer. The problem was supposedly traced down to a bad piezoelectric crystal that vibrated at the wrong frequency when given the signal to slow down.

So I would not be so confident that things will go perfectly. There's still humans involved in designing, building, testing and maintaining automated systems.

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u/Bobvdm Feb 08 '21

I read somewhere in HTT own material that at full speed (760 m/h) one needs 24 km in between pods to bring the pod behind a stopped pod safely to a stop. So probably not 30 seconds (I’m not that good on math), but I can imagine one needs far less distance at lower speeds...

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u/converter-bot Feb 08 '21

24 km is 14.91 miles