Transport

China claims new speed record with vacuum-tube maglev train

China claims its T-Flight vacuum-tube maglev train has set a world speed record in prototype testing. It's eventually targeting at least 1,000 km/h, significantly quicker than an airliner
CASIC
China claims its T-Flight vacuum-tube maglev train has set a world speed record in prototype testing. It's eventually targeting at least 1,000 km/h, significantly quicker than an airliner
CASIC

China's biggest missile manufacturer is working on a hyperloop. CASIC claims it's clocked the fastest speed ever for a superconducting maglev vehicle – over 623 km/h (387 mph) – during tests in a low-vacuum tube just 2 km (1.2 miles) long.

Hyperloop trains have become more or less a punchline in certain parts of the tech world, shorthand for ultra-high-tech projects that make grandiose claims of immense speed and efficiency, while ignoring several large elephants in the room that leave them with little practical chance of success.

The idea is simple enough: take the vacuum-tube messaging systems of the 1800s, upsize them until they can fit whole maglev trains inside, then suck all the air out and blast those trains around at thousands of miles per hour, enjoying ludicrous levels of efficiency. There's no air drag or wheel contact to sap power and slow you down, so you can go Mach 5 through a long vacuum tunnel without so much as a sonic peep. New York to LA in a coffee and a dump.

Never mind that regular high-speed maglev trains and infrastructure are already hideously expensive to build and deploy, without needing hundreds or thousands of miles of perfectly air-tight tube, constantly being sucked at by vacuum pumps all day. Or the potential disaster if pretty much anything goes wrong at those speeds.

Still, it's one of those concepts that keeps popping up; Elon Musk famously proposed it, built one tiny example in Las Vegas, then farmed the concept out to other companies, one of which has just gone defunct. Indeed, Musk has been accused of whipping California and other states into a froth over the idea just to tank support for public transport projects.

Either way, there are companies still at it, and there's one that might have the right mix of population density, government co-operation and capital to get it done: China Aerospace Science and Industry Corporation, or CASIC. CASIC has built a 2-km test section of low-vacuum tube – the longest ever such facility – in Yanggao county, Datong, Shanxi province. For reference, if atmospheric pressure at sea level is about 1 bar, "low vacuum" is between 0.3 and 0.001 bar.

After numerous slower-speed tests over the last several months (one of which is the subject of the nine-month-old video below), the CASIC team recently sent its T-Flight "high-speed flier" down the track for its first stable magnetic levitation run, and while it's not yet releasing the exact speed, SCMP reports that it broke through the 623-km/h (387-mph) mark set last October for the fastest train run in history.

Let's break out the old back of the envelope for a second. Assuming we leave, say, about 500 m (1,640 ft) for safe stopping, that means the prototype vehicle might've accelerated at a little over 1 G – a tad quicker than freefalling, but without air resistance, for about 17 seconds before slamming on the brakes at about 3G of deceleration, however that works in a maglev situation. Or it might've accelerated significantly quicker at about 2G, hit its top speed halfway down the tube, then slowed down at a similar rate.

Either way, that is, as a man who sat in glitter might say, pretty nuts. CASIC says the flatness of its test track is within an 0.3 mm (0.01 inch) tolerance, that the 6 m (20 ft) diameter vacuum tubes have a geometric size error less than 2 mm (0.1 in), and that the entire pipeline can be returned to its normal pressure within five minutes.

CASIC is happy with this test, saying it validated the interaction between the test tube, the vehicle and the track. But it's certainly not done. Phase two calls for the track to be extended thirty-fold to 60 km (37 miles), which will allow the train to be tested at a target speed of 1,000 km/h (621 mph) – a decent whack faster than an airliner. After that, well, it might make sense to connect Datong with Beijing – a 346 km (215 mile), four hour-plus drive that might be slashed to less than half an hour in a hyperloop ride.

CASIC certainly has lofty and futuristic ambitions for the system – as the six-year-old video above shows, complete with a Wuhan-to-Beijing link claiming a 2,000 km/h (1,243 mph, or Mach 1.6) top speed. But the company seems to be realistic about the challenges and practicalities involved. This is a company that posted US$34 billion in revenue back in 2017, and the Chinese government certainly won't be wringing its hands over any landholder complaints or blue-bottomed grass frog habitats if it decides to get the thing built.

More importantly, China's colossal population - 1.412 billion and rising – makes it one of the only countries in the world where public transit systems of this outrageous expense might be somewhere close to financially possible.

It's hard to know what to make of this thing, or how many grains of salt to take with it. For all we know, this might be an advanced railgun propulsion test by one of China's key military suppliers; CASIC is China's largest missile manufacturer, as well as a key contributor to the country's space program. But it seems it's also the world's leading hyperloop vacuum train company, with daylight second.

We'd love to see what 620-plus km/h looks like in some video, but it's unlikely; neither the outside nor the inside of a big white vacuum tunnel probably looks all that interesting.

Source: South China Morning Post

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9 comments
Username
It would be nice if reporters would mention that the original idea was not a maglev. It was a ground effect vehicle that required only a partial vacuum and was accelerated magnetically.
Aermaco
The original idea goes back to the Father of Modern Rocketry, Robert H Goddard, over 100 years ago, therefore the detail in operative systems are much less significant in a recent news article of the evolving history. Included in that history is the far less than genius claim that tunnels below will solve the traffic problem better than traffic in the air above.
TechGazer
By the time they get it working for actual passengers, AI may have reduced the number of people needing fast transport to the point where there's not enough market to support it. How many people need to spend hundreds of dollars more to cut trip time a bit? For those people whose expertise is critical, I could see a network of single-passenger planes distributed to handle those occasional needs.
Aermaco
@Techgazer you certainly present a wise gaze into the logic of transportation technology.
Jim B
The future of maglev is at low to medium speeds in cities, where it's low vibration and noise mean above ground rail can be put in more places.
windykites
Why is the train so pointy? I thought there was no air in the tube. This whole idea seems to be a huge waste of time, money and effort. You might get stuck in traffic at your destination.
martinwinlow
@ windykites - Oh, dear! There's still air in the tube - just not much, but at 1000kph+ "not much" equates to an awful lot (in aerodynamic terms) when you understand how aerodynamic drag works (exponential relationships between the key variables, 'n' all that).

@ TechGazer - Um... doesn't that ignore all the people who are not traveling for business purposes (85%+)? All the AI in the world is not going to be able to replicate the fact of actually *being there* however immersive that AI may be ... and besides, it's going be quite some time before AI advances that far... assuming we as a civilisation are prepared to let it do so in the first place.
martinwinlow
As Username says, why *massively* overcomplicate the idea )and cost) with maglev? I am quite sure that with some clever engineering, hyperloop pods would not have to be powered by anything other than initially magnetically and then maintain their speed by pod-mounted fans moving what little air there is inside the tube from in front to behind - leaving enough to be squirted out around the pod to keep it away from tube walls.

Perhaps a ring of simple wheels at each end of the pod constantly being powered to match the speed of the pod so that if, for whatever reason, the pod did knock against the inside wall of the tube the wheels would maintain separation and because their speed matched that of the tube, very little interaction forces would occur.

I would also question the need for pods any bigger than around 5 feet in diameter again massively reducing the cost of manufacture of both pods but especially the tube.
This would also be perfectly adequate for conveyance of freight.

Lastly my thoughts about where to put the track are simply that the twin-tube system (one tube for each direction) would be installed down the centre of every major motorway in the land. Given the much less demanding structural needs of comparatively small diameter tubes – ideally made of carbon fibre for lightness, strength and absence of corrosion issues - such a structure would require relatively little in the way of support and what support it needed would be relatively easy and cheap to install assuming my other idea relating to hyperloops was used i.e. that of having a huge moving structure straddling the motorway permitting the full use of the motorway whilst hyperloop construction took place, creeping along at 100m a day or whatever speed was necessary. Obviously some very cunning system would have to be deployed for negotiating intersecting bridges!

I'm quite sure such a system would cost a fraction of HS2 and be fully five times faster and use a fraction of the energy. In fact it's just a complete no-brainer!
Joe Boatman
I like windykites comment - why is the train pointy? Without air it doesn't need to be. And, at 623 km/h in only 2 km (1km to get going and another 1km to stop), what is the acceleration? Could anyone survive it? I remember my grandfather told me that the air would be sucked out of you travelling at 20 miles per hour. Ah, I forgot, there is no air in the tube. That should make the face masks drop from the overhead lockers 😊