Chinese Maglev Breaks Speed Record (Patreon)

[This is a transcript with links to references.]

News from China say the Chinese have broken their own, and the global, speed record for magnetically levitating trains, which you might know under the name hyperloop. Let’s have a look.

I find news coming out of China generally somewhat difficult to interpret. In this case all we have to go by is an article that appeared in the South China Morning Post. They report that the China Aerospace Science and Industry Corporation, CASIC for short, has made “a significant breakthrough” with its latest test.

There are no further documents to support this supposed breakthrough. But while I don’t have much trust in the Chinese government,  I have a huge lot of respect for Chinese scientists and engineers, which is what makes me think it’ll probably be mostly correct. What it means though it a different question.

The new transport system from CASIC is a magnetically levitating train that travels in a vacuum tube. These trains are also known as “maglev”,  short for “magnetic levitation”, and yes that is basically what Musk means by hyperloop.

Such transport systems dramatically reduce friction both with the ground or rails and, most importantly with air. The test facility is located in the northern part of China and is for all we know it’s the biggest of its kind with a tunnel of about 2 kilometres  length.

Construction on the test facility officially began in April 2022. Last year in the summer they reportedhaving reached 452 kilometres per hour , which made the Chinese maglev the fastest train in the world. In October they said they’d reached 623kilometers per hour  under non-vacuum conditions. They now report that they have exceeded this speed, presumably with some amount of vacuum, but don’t say exactly what speed they’ve reached.

 Their goal is to reach 1000 kilometres per hour. Just for comparison, a typical passenger plane flies something like 800 kilometres per hours.

 The China Post also says that the test allowed them to check that various components of their technology are working as desired,  most importantly the magnets. This is all very good news.

The biggest challenges for those systems are:  maintaining the vacuum in long tubes over potentially hundreds of kilometres, and avoiding accelerations. Getting such systems up to speed is no small feat. It isn’t easy to maintain good vacuum in a tube that long, that needs very precisely shaped parts. And at that high speed even the smallest bump or wiggle could be a disaster.

If you have tubes over long distances and you put them on the surface  you will have to cope with the .  expansion and contraction due to temperature changes  If you put it underground, you have to cope with geological tensions. Both of these are small effects, but at 1000 kilometres an hour even the smallest deformation can be an issue. And the issue is that inside the thing it might get very rough.

You can actually see this in this footage from a Virgin Hyperloop test in 2020.  Pay attention to the vibration. It’s noticeable, but you may say it’s not too bad. Then again, they reached a velocity of merely 100 miles per hour. So I think It would be very interesting to get some data on what’s going on in that Chinese maglev.

Does it make sense to build such a transport system? Well, that depends on how expensive it is. But generally I tend to think if you have a country as large as China it does make sense. Even if you don’t use it to transport people, there’s a lot of stuff you might want to transport that doesn’t care very much about vibrations. Wood, steel, concrete, clothes.

 Indeed the company Virgin Hyperloop of which we saw the test footage, decided two years after the test to focus on transporting freight. However, in December last year they announced they’d be shutting down, quoting financial problems.

So, I am somewhat sceptical about the passenger friendliness off those machines,  but I still think the Chinese might be getting something out of it. If nothing else it’s a very prestigious project that brings them good press.