Urban Transport

China’s "Sky Train" levitates power-free on permanent magnet tracks

China’s "Sky Train" levitates power-free on permanent magnet tracks
China's new permanent-magnet maglev Sky Train
China's new permanent-magnet maglev Sky Train
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China's new permanent-magnet maglev Sky Train
China's new permanent-magnet maglev Sky Train
Up to 88 passengers per two-carriage Sky Train
Up to 88 passengers per two-carriage Sky Train

A new Sky Train test track in Southern China has debuted the world's first maglev transit system built using permanent magnets instead of electromagnets. It's capable of keeping its underslung carriages suspended indefinitely without a power supply.

The benefits of maglev public transport systems are fairly clear: they're nearly silent, they need little maintenance, and they eliminate rolling resistance, so they use less energy to accelerate. On the other hand, they don't show up in slow-speed transit services all that often, since the energy used to levitate a conventional maglev train adds somewhere around 15% to the overall energy bill at suburban speeds, as compared to a subway or light rail.

That's only if you use electromagnets, though. Permanent magnets deliver their magnetic forces 24/7, for free – well, provided you can afford the rare earth metals needed to make them permanent magnets in the first place. China has nearly 40% of the entire world's known reserves of rare earth elements – twice as much as its neighbor Vietnam in second place. It also mines far more of these metals than any other country, and it absolutely dominates the processing and supply chain – just six state-run Chinese companies produced 85% of the world's refined rare earths in 2020.

All this is to say that the experimental Sky Train unveiled last week in Xingguo county, Jiangxi province, looks very much like an "only in China" proposition.

Up to 88 passengers per two-carriage Sky Train
Up to 88 passengers per two-carriage Sky Train

At present, it's just an 800-meter (half-mile) single test track, built on steel poles that lift the track some 10 m (33 ft) in the air. A two-carriage train carrying up to a gratuitously lucky 88 passengers is suspended magnetically underneath the track, making no contact, and it glides along, silent and frictionless, between elevated passenger platforms at speeds up to 80 km/h (50 mph). Once test runs are finished, it'll be extended to a 7.5-km (4.7-mile) track, with a higher top speed around 120 km/h (75 mph).

Obviously, being raised up on poles, it requires less real estate on the ground than a light rail operation, and according to the South China Morning Post, these Sky Trains cost about a tenth of what a subway does – even accounting for the large amounts of neodymium involved. They'll certainly age well on the balance sheet, too – a neodymium-enhanced magnet loses less than 5% of its magnetism in a century, so these facilities could outlast filial piety.

Take a look in the video below.

China launches world’s first maglev ‘sky train’ that floats in the air using permanent magnets

Source: South China Morning Post

Bob Stuart
"they eliminate rolling resistance, so they use less energy to accelerate." Actually, they use the same energy to accelerate, mass of the hardware aside, but save on maintaining speed.
How many tons of rare-earth magnets does it take per mile? Even China could probably find better uses for its resources than this.
@BobStuart, So there would be two sets of magnets? The permanent magnets for levitation and electro-magnets for linear induction propulsion (as in current maglevs). The article isn't specific, but it seems logical to me.
Jim B
This could be built down the middle of city streets, then the street below could be pedastrianised, given the valuable city street space back to people and bike lanes and taking it away from cars. Without the need to put in a super expensive underground metro.

I wonder if the permanent magnet maglev track has lower mainentance costs and time than regular rail tracks?

I wonder how fast this system can go in straighter lines between cities?

The fact that it is ultra quiet should take away one objection of NIMBYs (although the NIMBYs never seem to mind road noise even though that is much greater than rail noise).

One one concern is that all suspended railways are basically monorails which struggle with track switching. I wonder if this maglev system deals with this weakness?
Sorry to break your bubble, the rest of the world has the rare earths in proven quantities, however, due to the environmental damage the mining does, the rest of the world chooses not to mine them.
Slowburn Fan
Reinvent the wheel
I wonder whatever happened to the Inductrack concept that used Halbach arrays of permanent magnets on tracks that used only coils of wire to generate an opposing force. That would require a much smaller amount of rare earth magnets.
more energy went into the permanent magnets than the trin will ever save by using them. It would be nice if these types of projects gave 100% real figures on the cost of the magnets & the damage to the environment, then 100% real expected $ savings expected
All this news is just so encouraging. We need to see and learn more of these positive developments.