MAGLEV trains on normal rails?

[Weaver]

An Italian company is claiming they're on the way to making a system whereby MAGLEV trains can tun on normal rails.

Seems to me that there's some significant pitfalls and hurdles here, some of which are addressed at the end of the video. I'd be interested to hear what others think, especially Kit...

[PR19_Kit]

Hmmm, yes, interesting...............

I couldn't figure what the electric motors were for at first, but later on it seems they must be providing the traction to move the thing along the track by rotating the laterally mounted rollers, although the commentary doesn't mention that anywhere. If they're doing that it's going to vibrate just as much as if they had conventional wheels! Why not use their maglev technology laterally and use a linear induction motor to shift it along  the track?

Oh hang on, BR did that in 1974., and so did the Tracked Hovercraft Project before then.

Besides all that how do they get the power to the vehicle to run the maglev pads? There doesn't seem to be any pantograph, or 3rd rail pickup either, and you can't run something like that on battery power for ever.

The point they raise in the commentary about 'switching stations' (I presume he means the point work.....) is pretty valid, and vital. Conventional railway systems generate their lateral forces to go through pointwork only on the INNER faces of the track, railway wheels only have flanges on the inside (these days anyway....) but their maglev system seemingly needs pads on the outside as well.

Why? There's a pad on the inside of the other rail that would generate opposing lateral forces that should work just as well. That's what the BR MagLev sort of did this in the 70s, but had the pads on the OUTSIDE of the track, I'm not sure why as it made the 'pointwork' the size of a large house! See the first BR maglev car below. Interestingly the mag lev 'track' was 4'8.5" gauge too, but I guess we were familiar with that figure by then. 



The problems with going through pointwork would apply on curves as well (my speciality....) but to a lesser extent, as the system would need to generate the lateral forces to yaw the vehicle into the curve. That could be generated by the opposing inner pads too, as well as their existing dual pad system I guess, but it's notable that they only demonstrated it on straight track.

Why? Watching it track through a curve would a lot more impressive.

All in all it seems to have gone off a little half-baked, there are still some fundamental things to sort out, despite the narrator saying constantly '....once the technology has been developed......' they say it will all be going ahead.

[PR19_Kit]

Hang on a minute, are they using PERMANENT magnets?

That's never going to work on a curve or pointwork as they'd need a control system to trim the lateral forces as the vehicle entered the curve. Permanent magnets produce a constant force depending on how far they ore from their 'base', and that distance won't be constant in a curve.

The BR Maglev car used a very complex control system to keep that distance constant, and it worked so well we used a sub-set of it on tilt systems later on.

[Weaver]

Thanks Kit.

As I understood it from the video, the magnets are NOT electromagnets, they're permanent magnets, with one big one above the track and two side ones underneath the top "T" of it, the attraction force of all of them to the rail balancing out. That's why they need structure on the outside of the track as well as the inside, and that's why it doesn't need power to levitate.

As well as the problems articulated in the video and your post, there's another thing that occurs to me. If you rub a permanent magnet along a steel bar for long enough, the bar will become magnetized. Would this system result in the track becoming magnetized, and if so, wouldn't that be a problem? Rail tracks are generally dirty and uncontrolled, and the debris on them gets regualrly disturbed by passing trains. Wouldn't a lot of metallic debris, everything from dust to nut & bolts, end up stuck to the track, and what would that do to the maglev train?

[Weaver]

Maybe the lateral forces in a corner are why they have the side wheels?

[Gondor]

What is it like going over points?

[PR19_Kit]

That's what he's on about when he talks about the 'switching stations' I think, as it is they can't traverse points at all with the double sided maglev pads. It'd need a RADICAL improvement in their technology to get over that.

I still reckon it'd work with just the inner pads though.