Mag-Lev's

[GNER 373]

Sorry if this has been debated before...

I was watching a program the other day that had a section on about the Mag-Lev Trains that run in Germany and more recently Japan.

It made me start to think if Mag-Lev's take off (not literally of course) would it spell the end for 'Traditional Railways'?

It has no Track Wear, can reach crazy speeds and looks almost failsafe (as the program stated).

I can see the appeal to Rail Companies but I'd personally be devastated not to see a set of rails cutting through a countryside!

What do you guys make of it, and does anyone think this is a fad or indeed the future of Rail?

And furthermore is it really a Train? (I think its more of a monorail!!!)

 

[90019]

What do you guys make of it, and does anyone think this is a fad or indeed the future of Rail?

IMO, it's a fad.
Haven't the Germans given up on it though?
Even in Japan, it seems more of a novelty than anything else.

It's not exactly viable in this country anyway, because you need long distances needed to get up to a properly high speed, and considering the size of the UK, it's not really that viable. We're still better off with conventional trains, unless maglev technology makes huge leaps forward in the next few years.

 

[GNERman]

looks almost failsafe (as the program stated).

Safe?

http://en.wikipedia.org/wiki/2006_Lathen_maglev_train_accident

 

[NSEFAN]

I think that in concept, maglev is great, but even if it does 'take off' as you say, it will be a long way off. Especially in a very traditionalist country like this one.

Despite the advantages, it does have its complications, the biggest one being cost, not just to install, but also to run. Floating trains cost a lot of money to keep in the air! This running cost would be helped if we could acheive superconductivity at 'normal' temperatures, but we don't even know if this is possible (a bit like cold fusion).

Another issue is changing tracks. 'Points' would be much larger and complex, so would be few and far between. The fiendishly complicated routes we see in some areas, around Clapham Junction for example, wouldn't be able to fit in the same space.

As for tracks in the countryside, I can agree there. You'd certainly hear the train though! Whilst there's no physical contact between the train and the line, the aerodynamics produce a lot of noise!

I'd argue it is a train, a set of propelled cars moving in one unit together. For some people, it's not a train until it's loco hauled, allows heads-out, or has been in Loadhaul livery.

 

[starrymarkb]

I think the Japanese are giving up on it too, china certainly has chosen conventional LGVs for future high speed builds

 

[Mvann]

Mag lev has been tested in this country before. It now sits outside railworld in Peterborough.

 

[GNER 373]

Cheers Guys! I suppose I can sleep easy now!

 

[A60K]

Mag lev has been tested in this country before. It now sits outside railworld in Peterborough.

Yep - Birmingham Airport to Birmingham International station, ceased operation around 1994.

 

[Peter Mugridge]

Isn't the one at the Nene Valley actually a hovertrain rather than a maglev?

 

[jopsuk]

it is. Very different beast. Quite odd. It is properly outside, too- you can wander round and under it even when Railworld is shut.

 

[LE Greys]

We now have the Shanghai Maglev.

That doesn't seem to be a great success either, but I think there are plans to extend it.

 

[Oracle]

I thought that the Gatwick shuttle to the North Satellite was a Maglev?

 

[jopsuk]

Nope. Rubber tired people mover. The old one to the sattelite at the South terminal and the still in place one connecting the two terminals were the same technology. Similar people movers at Stansted and now connecting Heathrow Terminal 5 to its sattelites

 

[j0hn0]

Regarding safety. If you leave something on the track, a train is likely to crash into it. The accident was merely human error.

I have been on the Shanghai maglev and I have to say that it is amazing, although not as smooth as I anticipated. There were puddles lying on the track that morning and I swear you could feel the train hitting them.

The technology works, the technology is safe, clean and proven. Its far too expensive though and we all know how much we love our cost-benefit ratios in the UK :roll:

If HS2 was built all in one go, it would make sense to make it maglev as the stations will be seperate and they will use their own tracks into the city centres and will not needed to operate on classic lines.

 

[ChrisCooper]

Most conventional rail accidents are human error, and a lot are caused by things on the track. Maglev is also far too new and limited to know what other possible failure modes there are. It also depends on what you call "safe" anyway. Maglev has killed 23 people, yet must have a very low number of passenger miles compared to conventional railways.

As people have said, a big problem with maglev is the energy consumption, both from levitating the train and from overcoming air resistance. At very high speeds air resistance becomes a big issue, leading to increased energy consumption, increased noise (studies have shown that much beyond current top conventional rail speeds, aerodynamic noise begins to overcome wheel-rail noise), and even heating. Maglevs have not even shown any significant speed increase compared to conventional trains. The current Maglev record is only just faster than the record for a conventional train. I can only see Maglevs really being sucessful if built underground where they could travel at very high speeds in low pressure tunnels. Trans-Atlantic for example. Unless we can come up with some sci-fi anti-gravity system, I can't see levitating trains (or anything else) replacing conventional transport for most journies.

 

[j0hn0]

Most conventional rail accidents are human error, and a lot are caused by things on the track. Maglev is also far too new and limited to know what other possible failure modes there are. It also depends on what you call "safe" anyway. Maglev has killed 23 people, yet must have a very low number of passenger miles compared to conventional railways.

As people have said, a big problem with maglev is the energy consumption, both from levitating the train and from overcoming air resistance. At very high speeds air resistance becomes a big issue, leading to increased energy consumption, increased noise (studies have shown that much beyond current top conventional rail speeds, aerodynamic noise begins to overcome wheel-rail noise), and even heating. Maglevs have not even shown any significant speed increase compared to conventional trains. The current Maglev record is only just faster than the record for a conventional train. I can only see Maglevs really being sucessful if built underground where they could travel at very high speeds in low pressure tunnels. Trans-Atlantic for example. Unless we can come up with some sci-fi anti-gravity system, I can't see levitating trains (or anything else) replacing conventional transport for most journies.

No need for anything too sci fi, just put it in a vacuum. Air and weather variables eliminated.

well, I guess that is a bit too Logans Run actually

but possible nonetheless, china have the technology, the finance and capability of building a maglev from Beijing to Bombay to London. Sucking all the air out in those quantities quick enough would be the challenge.

Been a while since physics lessons but would heat be generated by a passing train in the same way as in the channel tunnel if the air was removed?

sorry tangent

 

[ChrisCooper]

If you take all the air out their would be no friction at all, so no heat generated by that. The only heat generated would be waste heat from the motors and electrical systems, and from the passengers themselves. Actually, one problem with total vacume would be that getting rid of this heat would be harder, as it could only be done through radiation. Low pressure would probably be best, the sort of pressure at aircraft cruise altitude. Evacuating air from the tunnel would take time, but if air locks were provided then it would just be a case of maintaining the low pressure. Oviously there would need to be a way of maintaining normal atmospheric pressure for passengers to board and alight. That could either be done through sealed retractable bridges, or by having the stations at atmospheric pressure and then lowering the pressure before entering the tunnels. The former would be good for intermediate stations, the latter for termini or major stations, especially as it would allow them to be on the surface. For the latter, to enter the tunnel the train would just need to go into an airlock and once the outer door was sealed the inner door could be opened, evacutating the air into the tunnel. The volume of air entering the tunnel would be tiny compared to the volume of the tunnel and make no difference to overall pressure. To exit the tunnel the opposite would be done.

The reason I've thought about this a lot is that i'm writing a sci-fi story where this sort of maglev system is the main form of long distance intraplanetary travel, with air travel almost none existant other than for getting into space. Still uses conventional electric railways for shorter distances. It is a real consideration for the future when the oil runs out as we are still a long way from developing an onboard energy source that gives the energy and power to weight and size ratio of fossil fuels.

 

[j0hn0]

nice 1 Chris, someone else has thought about it, and with greater knowledge too!!

For me it IS the transport of the future to usurp air travel and has the potential to be way faster and way more efficient.

 

[WatcherZero]

You could use heat sinks to store the heat and then at stations dump that heat either by exchanging cooling liquids or replacing a thermal battery.

 

[ChrisCooper]

Only problem with heat sinks is the weight and size, the more heat you want to absorb the more mass is required. Water would be good as it's got a high specific heat capacity, over 4000J/kg/deg C and of cource can be quickly replaced (hence why it's typically used for cooling). It's fairly low density though (about 1kg/l) so size will probably be the limiting factor. Denser materials would give more compact heatsinks but typically have lower specific heat capacities, so weight would be the issue. It's important to consider that these trains could be travelling for hours without stopping (for example trans-atlantic). Each person onboard is giving out around 100J every second, therefore 360kJ per hour enough (if my late night calculations are right) to heat up 90kg of water by 1deg an hour. That's before the electrics are taken into account.