What Happened to Hovertrains?

RobertDyck · 2019-10-23 13:05:32

I've long heard about maglev, but hadn't heard of hovertrains. This is an idea from the 1960s. Advantage: track is concrete, not steel or magnets. That makes the track simple and inexpensive.

Ps. Why were maglev trains designed with magnets to "pull" the train up to the track? Magnets get stronger when closer, so an oscillation will cause the train to lift up where the magnet will cause the trains lift magnet to slam into the track. That's unstable. It would be more stable to use "push" magnets. With the same pole on track and train facing each other so they repel. When an oscillation or "bump" pushes them together, magnetic force will push them apart more strongly. So it's inherently stable.

images?q=tbn:ANd9GcQDnuhz_bsUAZkJdEMPFXQ6SBcihw11S1ERhXp2BZUv0_J6mC-u&s

louis · 2019-10-23 13:14:45

Don't know about hovertrains, but I did cross the channel to France on a hovercraft when they were still in service. V speedy compared with a ship ferry but also, v noisy.Noise might be an issue for a hovertrain as well? Especially if you are travelling on it for a couple of hours rather than 20 minutes.

On the subject of train technology, I think we must be fast approaching the time when it becomes feasible to power trains by battery rather than expensive overhead lines.

tahanson43206 · 2019-10-23 13:36:08

For RobertDyck re #1

Henry Kolm is a name I can offer for insight into the very question you raised. He was a professor at MIT, and (as I recall from long ago) he and his students pursued this question. My recollection is that instability was impossible to overcome with the electronics of the time.

A quick search confirmed that the Japanese are using push technology, while (again, as I recall) the Germans went with pull.

When I inquired about Chinese maglev technology, this came up:

It was jointly developed by Shanghai Maglev Transportation Development Co. Ltd and a German consortium consisting of Siemens AG, Thyssen Transrapid GMBH and Transrapid International GMBH.

https://www.dailymail.co.uk/news/articl … 73mph.html

I would deduce the Chinese design might be using pull, but have nothing more concrete to report.

I will be interested in seeing further reports from other forum members as this topic develops.

Since tunnels are likely to be used for transportation at Mars, I can easily imagine the maglev technology showing up there in time.

***
For Louis ... I'm pretty sure a battery powered train is in operation, and I ** thought ** it was in England. it should not be difficult for you to discover if my recollection is correct.

(th)

Terraformer · 2019-10-23 15:42:49

Trains are relatively insensitive to weight (that is their great advantage), and efficient enough, that powering them by batteries has been feasible for a very long time. But catenary wires remove the cost of manufacturing the batteries and the time penalty for charging them. On the other hand, dual mode battery EMUs have been proposed for certain services currently run partway under wires (locally, the Manchester-Barrow service is an example), since they can charge whilst on the electrified portion. There are also diesel electric hybrids, such as the D-Train.

Regarding hovertrains, they are under-rated. The noise that hovercraft produce on water wouldn't be an issue, because they wouldn't be throwing up a lot of water to hit the rubber skirt. Hovertrains should be insensitive to weather conditions too, since they can glide over imperfections in the track. The track itself would be very cheap to manufacture.

I don't know why this is in human missions, though. Hovertrains only work on worlds with substantial atmosphere *and surfaces you can stand on*. The only other world that meets that description at the moment is Titan, and straight up flying there is so easy (4x denser atmosphere, 7x less gravity...) there would be no point laying a track.

louis · 2019-10-23 17:37:50

Yes, I think you're right TH but those are small local trains. Certainly until recently moving a huge train of 20 carriages with hundreds of people would not be possible using battery power. Of course one possiblity might be to have some induction sections for recharging of batteries on the move. The capital cost of overhead electric lines is huge and the gantries and cables look pretty unsightly as well.

tahanson43206 wrote:

***
For Louis ... I'm pretty sure a battery powered train is in operation, and I ** thought ** it was in England. it should not be difficult for you to discover if my recollection is correct.
(th)

louis · 2019-10-23 17:43:29

Thanks for the technical note on battery trains.

As regards hovercraft travel, I recall the Hovercraft being pretty noisy even before we got in the water, whilst still on the beach, but I am sure you are right that being in the water leads to additional noise.

Yes I wondered why this was in Human Missions...I think the Hyperloop is much more relevant to Mars. Would the 0.38 gravity cause any issues with the stability of trains on rails? Perhaps you'd need a wider guage.

Terraformer wrote:

Trains are relatively insensitive to weight (that is their great advantage), and efficient enough, that powering them by batteries has been feasible for a very long time. But catenary wires remove the cost of manufacturing the batteries and the time penalty for charging them. On the other hand, dual mode battery EMUs have been proposed for certain services currently run partway under wires (locally, the Manchester-Barrow service is an example), since they can charge whilst on the electrified portion. There are also diesel electric hybrids, such as the D-Train.
Regarding hovertrains, they are under-rated. The noise that hovercraft produce on water wouldn't be an issue, because they wouldn't be throwing up a lot of water to hit the rubber skirt. Hovertrains should be insensitive to weather conditions too, since they can glide over imperfections in the track. The track itself would be very cheap to manufacture.
I don't know why this is in human missions, though. Hovertrains only work on worlds with substantial atmosphere *and surfaces you can stand on*. The only other world that meets that description at the moment is Titan, and straight up flying there is so easy (4x denser atmosphere, 7x less gravity...) there would be no point laying a track.

New Mars Forums

Announcement

#1 2019-10-23 13:05:32

What Happened to Hovertrains?

#2 2019-10-23 13:14:45

Re: What Happened to Hovertrains?

#3 2019-10-23 13:36:08

Re: What Happened to Hovertrains?

#4 2019-10-23 15:42:49

Re: What Happened to Hovertrains?

#5 2019-10-23 17:37:50

Re: What Happened to Hovertrains?

#6 2019-10-23 17:43:29

Re: What Happened to Hovertrains?

Board footer