They were invented decades ago.
They have fewer moving parts than wheelbois.
They require less maintenance.
There's obviously some bottleneck in expanding maglev technology, but what is it?
Why are maglev trains still rare?
3 years ago by frightful_hobgoblin to c/asklemmy
They were invented decades ago.
They have fewer moving parts than wheelbois.
They require less maintenance.
There's obviously some bottleneck in expanding maglev technology, but what is it?
A million times this. Mag-lev only works for either super dense routes where the added cost as you describe can be displaced by the immense value add of shorter and generally more comfortable travel. Or in nations that can force through decisions from the top down, such that cost becomes almost a non-factor like China. Rail in general across the western world is a weird mix of nationalized and privately owned companies and operators, such that introducing mag-lev with the intent to replace conventional rail would require compensation to the private companies who have invested billions in the current infrastructure else they simply won't be part of the new one, with all the issues that entail.
From an environmental standpoint it's also really hard to see an ROI in scrapping something that works in favor of mining, constructing and spending intense amounts of energy in all forms to build something better but only moderately so. The biggest improvement is moving from trucks to (electric) train for freight, going from electric train to mag-lev is only slightly better so the ROI just won't be there.
Also the fact that 'less moving parts' doesn't mean lower complexity or maintenance cost. Train wheels are a very robust and efficienct mechanism and most train designs are not being limited by them.
Very robust because they have 300 years of research, innovation, materials science and manufacturing in them. Making them incredibly stellar, well understood, damn near perfect technology for what they do.
Also them just being wheels in general which are one of the most efficient and simple ways to move stuff.
There are some concepts for hybrid maglev-rail tracks that would at least solve the first point, similar to how rail was electrified over time. It would still be very expensive though.
Recent demonstration https://www.youtube.com/watch?v=CQOEP7_euXQ
woah this is awesome!
maglevs need classical wheel systems anyway because there might be a power outage, so simply having wheels that are compatible with the local rail system is a brilliant idea.
add in a tiny propulsion system so they can use the normal tracks at low speed without the help of the maglev tracks and you can sort of blend the two systems together in critical locations like switches and train stations.
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Not to defend capitalism in general, but it’s really good at answering these sort of “is it worth the cost?” aquestions. The whole point is to allocate scarce resources efficiently; the problem is that it assumes nobody is a scumbag and all the costs are accounted for.
It isn't. Most decision makers of capitalism are very unaware of science. You'd know this if you work in research. The ideas that see light of day do so not because they're good in any quantifiable sense. It is because they convince the capitalists. This can be affected by so many things that aren't merit or even cost based.
Some things make sense from a cost perspective, but not a profitability perspective. Profit isn't just about cost. There's margins, competition, longevity, etc. Something can be of moderate costs, but if the margins are too low or it is too long term or a project, it is of low value to capitalists.
I'm really struggling to understand what you're getting at here.
Whether or not a decision maker is aware of science, their products will still be subject to the laws of physics.
Some things make sense from a cost perspective, but not a profitability perspective.
For example?
To simplify it, when capitalism answers "is it worth the cost?", it is not answering "is the benefit of this thing to society worth the cost?". They're answering "are the profits I would get out of this and the risk worth the cost?". And profits do not always agree with what's good for society.
One example of moderate-to-low cost investments that are of demand in society but not very profitable and hence does not see focus is low-income housing (at least in the US). Housing developments disproportionally target high income or even luxury housing, as the margins on those are far better (but the costs are also much higher). Even nowadays, that this trend has been going on for a while, and luxury housing has really fallen out of demand (which greatly increases the risk), it continues. Luxury housing still looks a better investment to investors, when society does not need more luxury housing. It needs more moderate and low income housing.
I think OP is just thinking of “cost” to mean capex. Whereas most real-world cost evaluations consider capex, opex, and opportunity cost, among others. Something having low cost but low margins will usually have a large opportunity cost, which increases the total real cost.
The current, dominant form of capitalism isn't and doesn't, though. It maximizes short-term profits and ignores all other medium and long-term costs. The efficient allocation of scarce resources doesn't happen when inefficient allocation yields greater short-term profit. The stock market ensures that high short-term yields with lower total returns will be favored over the inverse. In particular, it emphasizes competition over cooperation, which is more resource wasteful for the gestalt.
They're faster and more comfortable than traditional rail. They could help to reduce air and vehicle travel
And how about the actual speeds they are used with? Another poster suggested the maintenance costs of traditional speeds skyrocket as speed increases, while maglev doesn't really have a lot of stuff that wears down in the first place.
Then it's good that we don't have them, isn't it? Kool_Newt's post implies that it's due to a failing of capitalism, but this sounds like a win to me. I'd rather my money go towards food and housing than a faster or more comfortable experience doing something I rarely need.
One of the most common flights is US west coast to east coast. Normal high speed rail can't do this in a reasonable time frame. We need something faster if we want to get reduce those flights.
One of the features of capitalism is externalizing the costs, especially of pollution.
Sure, but if it lessens the impact on the climate from air travel and vehicles, then it's a good thing. Especially if they can become reliable and convenient enough that people don't need to have their own vehicles to drive everywhere.
Better acceleration, steeper inclines, tighter curves at same speed, better ride quality and less wear. As someone has mentioned below, normal trains could go a lot faster than they do in practice, because the ride quality, wear and wind resistance get atrocious, and the tracks need to be exceptionally straight. Making a maglev go fast is more feasible, though you still have the wind resistance issue obviously.
It's basically evolution. It's not that we don't get the best things, it's that when something evolves traits that require more energy than they are worth, they inevitably die out. I'm reminded of the film The Man in the White Suit.
It'd be nice to always have the "best" things, but the "energy" to support them has to come from somewhere.
Ultimately, their competition is regular trains, which are simpler, more tolerant to buying from multiple manufacturers, still significantly more efficient and faster than anything roadborne, able to switch over the course of seconds instead of minutes, able to interoperate with different tiers of intensity and speed, able to be built at grade, cheaper and having the better part of two hundred years of technological refinement behind it. Ultimately, maglev has specific, niche advantages that make it a hard sell for any system that already has regular rail.
On one side, it can mean this. And for lighter railway construction, such as trams, light rail and rural regional trains, this can be optional. Plus it makes yards and depots easier to build, just slap a few concrete plates for a few crossings and the staff will find their way around. This is not possible with some maglev technologies
On another, it can also mean that the infrastructure is built directly on the ground. Being able to do so is extremely useful, since you don't need to build (as many) bridges or tunnels to have rail going somewhere. Again, for some maglev technologies, this is not an option.
A lot of these arguments apply to high speed train. In France a completely separate line was build between Paris and Marseille for the TGV To reach its peak speed without being delayed by lines that stop at every station.
The problem is investment and shitty companies holding these technologies IMO.
To compare our bullet points for maglev and high speed & conventional rail:
High speed rail has enough compatibilities with regular rail to make sense.
EDIT: *this video pretty much starts out with footage of the switch points in question.
Also, you may see yellow tiles in the middle of the tracks, those are Eurobalises, European standard beacons for ETCS signalling, which is the current standard for train protection for new high speed lines in the EU, as well as general train protection in Luxembourg and Switzerland. The track in the vid is one of a few places in that country where the system is already in place on a regular mainline, though it's not yet in general use for regular domestic trains out there. That'll be another few years into the future.
To append, some examples of high speed systems with multiple manufacturers.
🇪🇺🇬🇧: Eurostar has, for the Channel Tunnel, two types of train built by two manufacturers. The old type by Alstom, the new type by Siemens.
🇪🇸: Just AVE has three different builders. The S-101 by Alstom, the S-102 by Talgo and the S-103 by Siemens. The S-102 is also used by Avlo, while OuiGo used Euroduplex sets by Alstom, and Iryo uses ETR 1000 sets built by Hitachi Italy.
🇮🇹: The ETR 500 is built by a consortium of manufacturers, several of which have been absorbed by others. The ETR 1000 has been built by a chain of builders due to mergers n stuff. And the NTV units are built by Alstom.
🇯🇵: Pretty much every major manufacturer of rolling stock has built at least some Shinkansen units. You'll find trains by Hitachi, Mitsubishi, Kawasaki and others all over the network.
🇨🇳: The first generations of CHSR trains were all imported designs, derived from others, both Shinkansen and European types. This allowed them to kickstart a domestic rolling stock industry for later generations of train.
🇨🇭: Once we lower our standards of speed a touch, SBB uses two types, one by Alstom built in Italy, one by Stadler built domestically. And trains from neighbouring networks ride into particular areas, each of which has their own builders.
The same reason supersonic passenger jets are rare.
The extra speed comes with a massive increase in costs.
Travel 30% faster than high speed rail for 10-20 times the cost.
Is the claim about "10-20 times the cost" true? The internet says Shanghai maglev cost $1.33 billion for 30.5 km, i.e. less than $44 million/km. Compare https://transitcosts.com/new-data/ or https://transitcosts.com/...
Secondly, if it is true, why would it be true? Why would it be more expensive to build something with fewer moving parts?
Supersonic passeenger jets require more energy. Maglev trains require less energy.
all the other complex and important factors aside, air restistance is a formula of speed squared. Meaning for example if you bump speed up by 40% you double air resistance, and therefore double the energy cost of transport.
Isn’t that only applicable for identical trains? For sake argument, if you had two identical trains designed with poor aerodynamics, one at 100mph and one at 140mph then you can double the energy cost. But if you take two different trains with one designed to be more aerodynamic, at the same speed they wouldn’t have the same energy cost as the second has a better profile?
Plus theres less friction from needing to be on a rail.
So I think saying its double the cost of transport is too simplistic to be meaningful in this discussion
It's more than that - doubling air resistance only doubles the energy use if it's the only inefficiency on the train (e.g., no losses in the magnets, HVAC, lighting, etc.). Add onto that the fact that you're basically eliminating rolling resistance from traditional trains when switching to maglev, and the expected outcome should be much less than double.
Finally, the most important part, each high speed rail route of any meaningful distance has the opportunity to displace a certain amount of air travel, so big picture, HSR results in a significant decrease in overall energy consumption.
Maglev requires superconductors to work. They must be cooled to just a few degrees above absolute zero (typically ~ -270 celsius) and if they ever warm up beyond their critical temperature, catastrophic failure is the result. (this is called quenching which can destroy the superconductor permanently) So not only can you only drive maglev trains (which are expensive themselves) on maglev track and can only drive mag lev trains on maglev track, its far more expensive to build and maintain superconducting infrastructure than it is to lay down some steel rails. Maglev trains are used because the only friction that they experience is from air resistance. Theyre much faster than normal trains but it takes a lot of energy to keep the superconductor that makes them work cool, costs a lot more to build and requires a lot of electricity to get them up to speed. (They can use regenerative braking to recover much of this but its still an energy intensive process)
fwiw LN superconductors that operate at much higher temperatures are already being built https://eandt.theiet.org/...
Also, China manages to charge only $8/ticket for the shanghai maglev, so evidently it can be done cost effectively.
If you subsidize anything enough it can be cheap for people to buy. That doesnt mean that its actually cheap to build and maintain. And the reason why temperatures are kept far below the critical temperature is due to the critical magnetic field and critical current decreasing as temperature increases even below the critical temperature
Is the Shanghai maglev perhaps subsidized?
Well, if we look at actual maglev deployments in the real world, then they are much slower than conventional trains. All of them top out at 160kph, while conventional trains going below 200kph don't even count as high speed. There's only one Maglev line in the world which actually goes fast. So if we want to talk about regular speed representation, maglevs are slow and useless.
Maglev (derived from magnetic levitation) is a system of train transportation that uses two sets of electromagnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage of the lack of friction. Such trains rise approximately 10 centimetres (4 in) off the track. There are both high-speed, intercity maglev systems (over 400 kilometres per hour or 250 miles per hour), and low-speed, urban maglev systems (80–200 kilometres per hour or 50–124 miles per hour) under development and being built.
Despite over a century of research and development, there are only six operational maglev trains today — three in China, two in South Korea, and one in Japan. Maglev can be hard to economically justify for certain locations, however it has notable benefits over conventional railway systems, which includes lower operating and maintenance costs (with zero rolling friction its parts do not wear out quickly and hence less need to replace parts often), significantly lower odds of derailment (due to its design), an extremely quiet and smooth ride for passengers, little to no air pollution, and the railcars can be built wider and make it more comfortable and spacious for passengers.
Cute link to the Wikipedia Page
I am a curious human, beep boop
Plane maglev tracks are way more expensive than wheeled train tracks. It's slower to get expensive when the terrain stops being plane, but it takes a lot of roughness for it to become cheaper. Most countries just do without trains crossing rough terrain.
And the largest cost of almost any train is the tracks.
Look at HS2 in Britain and how people are against the cost for higher speed options, or California HSR. I'm all for it, it should absolutely be done, but getting taxpayers to see 10 years into the future is difficult.
Not entirely accurate. There's a lot of support for HS2 in the North as it would greatly improve the infrastructure - but it's increasingly obvious that HS2 will only be built out as far as is politically beneficial for the government so the project will deliver high speed rail in the south then be abandoned due to massive costs.
South England will reap the benefits (again) paid for by the tax money of all.
I'm not sure that it is really paid "by all". London brings in 25% of all UK taxes while having only 13% of the population. Londoners are paying twice as much as everyone else and yet everyone else complains about "South England/London reaping the benefits". Maybe try to fund something without our help for once? Or at least say thanks.
That's because HS2 is a totally flawed, Ill thought out, over budget and badly managed boondoggle - just like everything in the UK rail system since the Beeching cuts in the 60's. If it was properly run, well thought out - and actually made a significant difference in time (not approximately 15 minutes from Piccadilly to Euston), we'd support it.
I agree with all of that, but the thing is that faster journey times shouldn't be the main selling point of HS2 in the first place; it'll relieve capacity of the groaningly overused West Coast Mainline, allowing more freight and cheaper short journeys.
If it's properly managed.
Which it won't be.
Where existing transit infrastructure exists, cities prefer upgrading existing infrastructure, rather than installing new infrastructure in its place, and where transit does not exist cities prefer not to install anything at all and favor cars typically. Maglev trains are extremely expensive to install the infrastructure, so gathering the money out of local budgets to invest in the extremely expensive maglev infrastructure is typically very difficult.
In the US in particular, politicians, just don’t look at the picture in the long term, and only focus on short term investigator as it pertains to their election schedule, and that is sad and has long-term impact on the local population.
Think about it this way, OP: You know when they're working on the train network, how much you loathe commuting while a single line is out? How much of a pain replacement bus transportation is?
Now imagine having to do this for all train lines, everywhere, and you always have to switch trains (due to the difference in track) in between the blocks of replaced track. Plus you can't neatly fit maglev where conventional track fits and vice versa, plus you need the power infrastructure, plus you need to find a way to buy the rolling stock without already selling the old one.
Also for the US the automotive and oil industries have powerful lobbies and an obvious interest in preventing the proliferation of electric-powered public transport. They’ve spent decades centering personal automobiles as the default method of travel and attack these projects with enthusiasm.
I read it's the zoning and maintenance of the tracks. Since they probably have to be very precisely laid in order to support such a fast train.
That said I do wish for maglev trains to be accessible to all. I'd love to go across the states in a few hours on a train.
Plus, any maglev project has to be a new build and not outright replace existing lines. Replacing a line would require closing and removing the existing line, extensive reconstruction of the track bed, and probably delays or closure to tracks sharing the line. It's not an easy thing for the government to justify when it would be cheaper and easier to simply improve the existing rail infrastructure. Or..you know...ignore the problem which is what they seem to be doing anyways
You still need rubber wheels when it's stopped and at low speed. They retract when it's fast enough for the maglev to take over.
The electrical conductors are expensive as shit. The ones in the train need to be super cooled or something. The track ones need to be built along the entire length. On three sides, one vertically and two horizontally. Along with massive power lines along the whole length. They don't need to move to be expensive.
The right of way needs to be very straight. So compared to normal high speed, you have to spend much more on buying land, earth moving, tunneling, etc.
All this needs to be maintained to an extremely high degree because you can't accept a failure. The engine on a high speed rail fails and you just slow down, no biggie. HSR track is fairly robust and can easily be inspected visually. Since it has the same base as normal passenger and freight you have an entire industry knowledge and inspection machines. Any part of maglev fails and you have a catastrophic failure.
The ones in the train need to be super cooled or something
maglevs arent using fuckin superconducters to levitate, it's basic magnetic repulsion. Get whatever fictional version you've got in your head cleared up.
They absolutely can, the one currently being built in Japan does: http://www.ejrcf.or.jp/jrtr/jrtr68/pdf/14-25.pdf page 19-20
Here's the one I was thinking of, superconducting magnets for the japanese one SCMaglev https://youtu.be/XjwF-STGtfE?si=jrnttpIrmHBXMtUF
One other thing I've not seen mentioned yet is capacity. Switching a maglev track is difficult and very slow, which reduces the number of trains you can get through a switch and therefore the number of people your system can carry.
They're very expensive to build. That's it, really.
If it had a significant advantage the expense would be worth it, but steel wheels on steel rails already have a coefficient of friction 10x lower than rubber tires on asphalt, so it's not worth it.
You do save money on them in the long-run. I just assume it takes decades to get all that return on investment back out, thus any entity interested mainly in quarterly profits has little incentive to make the investment, which would be disruptive to their finances in the near-term.
Is that assuming there will not be major repairs?
Fewer major repairs is the way they save you money. Fewer moving parts, less friction, less wear and tear. All the energy savings gets tossed out the window in the interest of going faster, in the ones we've made so far anyway.
If we somehow remove the friction of air on train body. Then maglev would be zero friction transport.
Edit : Oh my. My little joke comment has ballooned into a full on debate. And I'm not even aware of any of these things they're all saying.
I just made a comment guys, I'm not serious or not in any agenda.
You mean that hyper idiotic Hyperloop idea that’s just a warmed up remix of the vacuum train idea from the 1920s and will efficiently kill all passengers if a little thing goes wrong (if you can get a hundreds of kilometres long vacuum chamber airtight anyway)?
Technically.... We actually do, but not simultaneously room temperature AND room pressure. There's one known material known to be superconducting at absolutely insane levels of pressure. That's not sustainable for any reasonable usecase of superconductors.
Not replicated, they found some anomalies in the samples skewing the results
As others here have already mentioned the infrastructure costs alone are a huge problem, where I live we are currently just trying to electrify the corridor and it’s not even the entire system, once again the overall rail infrastructure is already there (it’s just electrification) yet this is still going to take a minimum of a decade and the minimum cost is going to be more than $11bn, technically this saves money as you don’t need to buy a new fleet of rolling stock just upgrade the old ones.
So ya for a maglev you would need a completely different infrastructure and the rolling stock
I remembered seeing a video by Real Engineering that explained a lot on Maglev and it's pros and cons but one of the summaries that really hit it off for me and if I remember correctly is that it cost 11 times more to build per kilometre compared to conventional high speed rail, for about 70% more top speed while using 30% more energy.
https://www.youtube.com/watch?v=S4L_0CDsd1I
Personally I feel unless they come up with better superconductors, there's still a long way to go before it really takes off.
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Here's an interesting write-up about an attempt to develop a large-scale urban maglev system in the 1970s: https://en.wikipedia.org/...
tl;dr: there were so many technical issues that when the West German company developing the tech lost funding and the Ontario government took over the project, they immediately abandoned the maglev concept and replaced it with linear-induction propulsion with steel wheels on rails (the mag, without the lev).
Even this tech, which does have a few advantages over conventional rail and is still used today in cities like Vancouver, is falling out of favour due to general logistical issues with using bespoke technology over conventional rail -- fewer people know how to build and maintain it, you're relying on usually just one company to supply your trains and infrastructure until the end of time, you can't reuse any existing infrastructure, etc. I'd imagine these issues still get in the way of maglev development today -- even more so because you can't even reuse existing rails
It's very sad tbh if it's the reason. It means the companies are unable to teach their knowledge, expand their market and attract investment by themselves despite clear advantages. I wouldn't be surprised, but it's still sad imo.
More likely just the shear cost of building the tracks.
Still cheaper than maglev rails I’d guess.
This argument may be true in regards to rail in general. This specific question is “why not maglev instead of rail”. That’s not car’s fault - it’s just extremely expensive to build maglev and that’s compared even to regular high speed trains.
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If you introduce a new rail type into your rail network you can't use your existing fleet of trains on that section reducing the ROI on that train engine or carriage. Also, any train you purchase for the new rail type will only ever work on that system lowering their profitability in the long term.
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