Japanese rail operator Central Japan Railway Co. (JR Central) has announced it will build the world's fastest maglev system, with 310mph (500km/h) vehicles running along a 180-mile (290km) track between Tokyo and central Japan. According to Reuters, the 5.1 trillion yen ($44.7bn) project will be completed by 2025, and while JR …
And there was John Prescott looking all cock-sure about his high-speed 1.
Hm... didn't the Transrapid achieve 510 km/h on the Shanghai tracks during testing? It is running at *only* 430 km/h because 510 km/h was its max speed, and usually vehicles don't run at actual max speeds but at set "cruise" speeds. So is 500 km/h its max speed, or cruise speed?
Oh, and which maglev tech are they using? I distinctly remember that the Japanese project involved some superconductors and weird stuff that required a "minimum takeoff speed" (they don't hover at low speeds) and had the slight problem of generating a strong magnetic field inside the train. If you got a pacemaker, don't go into that train!
What is the fuel efficiency?
How efficient is a maglev compared to a normal diesel engine? I would have hoped that it is much better, since, obviously, it depends on zero resistance to move.
I expect the rolling resistance will be pretty much insignificant to the air resistance and motor efficiency.
re. How efficient?
"How efficient is a maglev compared to a normal diesel engine?
In theory, "much, much, much better"; in practice, "much, much better" - but then, if you choose diesel to compare with, that's not much of a challenge!
At 500 kph air resistance >> rolling friction of steel wheel on rail, so any advantage of maglev would be minimal.
Zero resistance? They are running it in a vacuum tube?
No train vs. ground friction, maybe but zero total resistance is impossible. At 310mp/h, I'd imagine that the wind resistance generated by even the sleekest of trains would be pretty intense.
Japanese vs Transrapid German maglev technology
Daniel B is right, the German Transrapid system employed in Shanghai did reach over 500km/h during testing. Its 501km/h remains the world record for unmodified public service ground transport vehicles on a public service system. The Japanese maglev system, which has reached over 550km/h is still only at the test track phase. The French TGV world record for wheel-on-rail trains was only achieved with a heavily modified train, using about twice as much energy per km as a Transrapid maglev.
He is also right, the German system is much simpler than the Japanese version. Transrapid levitates at 0km/h using conventional electro-magnetic techniques. It wraps around a simple guideway, underneath which the linear induction motor is mounted.
The Japanese system, by contrast, uses super-cooled, super conducting magnets in the vehicles, which suspend the vehicle in a much more complex manner within a U-shaped concrete trough. The Japanese version cannot levitate until 100km/h is reached. It therefore carries the weight of wheels and brakes, which Transrapid does not. It is also much more complex to brake, being fitted with aircraft-style air-brakes amongst other deceleration systems. Transrapid brakes more simply: as the power the induction motor is reduced, the vehicle, which is a 'slave' of the track, slows with it.
Another point of comparison. The Transrapid system generates tens to hundreds of times less electromagnetic radiation than using a hairdryer, watching TV or using a domestic cooker. As a consequence passengers can approach within centimetres of the vehicle when it is at rest in stations; and are frequently to be seen doing so, taking photographs of each other in front of the nose cone in Shanghai. The superconducting Japanese system, however, has long used lead-shielded 'boarding tunnels' (similar to jetways at airports) to get passengers on an off the train.
Work has been done by UK Ultraspeed on a potential application of the Transrapid system on an intercity scale in Britain. The technical complexities of the Japanese system seem to be coming home to roost in the capital cost.
JR Central's published capex estimate equates to USD155m or GBP78.2m per route km. UK Ultraspeed estimates a total capital cost including land of between GBP33m and GBP37m per route km. Ultraspeed's numbers also compare favourably to the GBP56.42m per route km capital cost of the UK's only TGV-style railway, the long overdue 'High Speed 1' link from London to the Channel Tunnel.
Air restiance vs rolling friction
At these seeds air restiance is more important than rolling friction for fuel economy.Still it should have an impress k/l/passenger figure.
Magnetic fields? Leave the laptop at home!
"But honest, boss, I finished the report! It was on my laptop just before I boarded the train. But now my disk has been wiped..."
What a difference
At least they take safety seriously enough, unlike in the UK, leaving it to god for safety , plus when they say 2025, they are most likely to finish on time, unlike in the UK, 2025 either meant its half done by 2025, or it will finish in 2025, but with the budget jump 44b to 440billion and just expect the public to swallow it.
Very much in brief,
Matthew, Andrew, others,
it isn't any 'more effective'. Actually, it is less effective.
I've written up the whole matter in detail elsewhere, and want to be brief in here:
1. Chris is very much correct: At these speeds, rolling takes an insignificant part in the overall energy 'loss' compared to air resistance.
2. The need to mount the track above ground (stilts) makes the construction vastly more costly than for conventional trains (TGV)
3. The need to mount the track above ground makes the construction vastly more ugly than one on the ground
4. AC is wrong on 'motor'. Motor means friction of wheels against rails or asphalt. The idea of maglev is floating on a magnet cushion; that is nothing to apply your force to. Maglevs are propelled by traveling fields. When one does enough multidimensional integrals of vectors, about 3 pages, one finds out that the electromagnetic propulsion field eats itself up over distance. So what you need is a propeller or jet engine.
In short: the one and only argument for maglev is the Hai-Tec-Feel-Good.
For any other reason it's just crap out of the box.
Proud to be British
We gave the world the railway.
In the late 1940s, professor Eric Laithwaite of Imperial College in London developed the first full-size working model of the linear motor.
Anyone travelled on GNER recently?
Speed brings cities closer together
I've ridden on the old Japanese bullet train. The most striking thing is the quiet smoothness. There is no clakety clakety and very little wiggle or vibration in the coaches. That is why they can go so fast. The tracks are welded and the ties are concrete, unlike the old wooden ones we use here in Canada which would rattle the train apart at any speed fast enough to get you home by suppertime.
I would guess that the reason for using maglev and getting rid of the rails is to get rid of vibration so that higher speeds can be acheived. You can always apply more power to overcome resistance, but you can't do it safely if there is vibration. Effiency is not the issue here. Speed is. The reason for higher speeds is so that it takes less time to get somewhere, effectively bringing cities closer together.
As others have pointed out, rolling resistance is always low. Air resistance, however, goes up as the cube of the speed. It takes 8 times more energy to go 20mph than it does to go 10mph. Anybody who has ever tried to go fast on a bicycle will know this first hand!
Hmm, I wonder what the *estimated* cost per km of High Speed 1 was *before* it was started (after adjustment for subsequent inflation) and before the inevitable budget creep set in. That would be a more accurate comparison (and I'll bet a stack of cash a somewhat less favourable one as well). Our Anon Cow is way off into comparing apples and pears land here.
Air restiance vs rolling friction
Trains that use rolling wheels still encounter air resistance just the same as a maglev train. At the same speed they would have similar air resistance but the wheeled train would also have the rolling resistance to contend with.
"an elite world club after Japan, France and Germany"
Rather crushing for the inventors of the railway (and maglev), but I guess we should be used to it by now. Anyone remember the APT..?
TeeCee could try google....
"On time and on budget."
Even though the government stole back the railways from the shareholders half way through the development and a gazillion other idiotic Blair/Prescott fuckups throughout the build.
If we left running the railways to people who know what they are doing and didnt move the goal posts every 2 years things would be better. Ho hum you get what you pay for i guess and the Brits a re too cheap to afford decent trains.
"Bored of idiots down talking British Railways when its twats in government fucking it u"p.
any better than the Disco and Break dancing DLR. It might be fast but no fun. We should give them a tour here. will be shaken and stirred at the same time.
It's all about bringing cities closer, I think on the Mainland the longest it'll take to get to Tokyo is 3 hours. Oh And Japan isn't small. Just the main island is is about 1200miles long if you streightened it out.
Also the reason for using their own technology is so they don't need to pay the Germans to build it they can do it all themselves. Something we Brits will never be able to do becouse we don't invent anything anymore.
Anyway here is what a weeks rail works turns into in Britain
"engineering work will be finished by new year"
"engineering work is overrunning and will be finished in january"
"we currently expect the engineering work to be finished by february"
"the engineering work is still ongoing..."
Was finished in June.
What's a train
Is that the thing that often fails to turn up leaving you stranded on a freezing platform for an hour (if your lucky), journeys take 10x longer, charges high prices and is full of chav w******s who decide they like everyone to listen to some gobshite music on their stolen phones?
The stations should be sealed up and labeled "In Emergency Use only"
Yes that's a train.
"... but the wheeled train would also have the rolling resistance to contend with."
So what's your point? A train travelling at 500kpm has 1000 times the air resistance of one traveling at 50kpm. The rolling resistance becomes insignificant.
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