Maglev trains are one of the most interesting new technologies in transportation.
They have been used for quite a few years in China and abroad. But their usage has always been limited for many reasons. Plus, planes are much faster and convenient. But things may be changing in China, where 50% of commercial Maglev applications (3 out of 6) of the world are present. The other three are in South Korea and Japan. Also some Western countries applied the technology, but not to the same extent.
How do Maglev trains work?
Maglev stands for Magnetic Levitation. It is a floating type of train that uses magnetic fields to reduce attrition. The concept comes from a century ago, but realization is technically difficult.
First, it requires certain materials – such as rare earths, superconductors, electromagnets and diamagnets. Second, the technology has seen limited use only since 1984 and in certain areas. For example, in Shanghai Pudong airport there is a Maglev train that connects the airport with Longyang Road, close to the city center. It is both the fastest and longest distance Maglev railway, at 430 km/h for about 30 km.
There are two types of Maglev trains: one that uses repulsion, the other uses attraction. While they work differently, the basic idea is the same: using magnets to remove attrition with the rails.
Regular trains already use very thin rails exactly to maximize their efficiency so they can travel at relatively fast speeds without consuming too much energy. But even a Maglev train has to fight a type of attrition – just like anything in the world – air attrition.
Until recently, the fastest speed Maglev trains could get to was 500 km/h. That is the speed achieved by the new trains planned to be used in Japan starting in 2027.
Will a New Silk Rail bring Carbon Neutrality?
Maglev trains are technically the most efficient type of train in terms of energy consumption. Furthermore, since there are technically no wheels having to touch the rails, these cannot be damaged or cause risk of derailment. Since they use electricity, they cause no pollution to the environment if supported by renewable energy, something that connects well with China’s recent commitments to carbon zero neutrality. The new Dam planned in Tibet could be a very good excuse to bring Maglev trains well into Western China, and perhaps one day connect China with central Asian countries and India. Such a massive project could literally be a New Silk Rail and change things for many Asian countries.
But that’s not all. Maglev trains have a technical lower need for tunnels, since the rails can move in ascension at about ten degrees, while conventional trains can only do so at four degrees. This means a Maglev train is more likely to avoid expensive and dangerous procedures of tunnel-building that already costed the lives of some technicians in the past.
But if the Maglev are so great, why we didn’t use them yet?
The cons of Maglev trains
The biggest problem is the already-existing infrastructure for trains. As a matter of fact, it would have to be either replaced or duplicated, as Maglev trains cannot travel on regular rails. The usage of rare earths and materials is also making the extensive adoption of Maglev harder. It is estimated that the costs per km are up to 50% higher to build Maglev infrastructure when compared with conventional high speed rails.
Furthermore, certain temperatures are needed in order to achieve the best results. Superconductivity can only happen at extremely low temperatures such as -269° C. That’s just 4 degrees away from absolute zero, the lowest temperature possible in theory.
There is still lots of room for improvement. As technology moves forward, it may make sense to invest in developing Maglev trains further.
The new generation comes in Chengdu
The 13th January 2021, in Chengdu, Sichuan, China presented a new prototype of next generation Maglev train.
The developers announced that they expect it to be cheaper and faster than previous Maglev trains. Their hopes are that the speed could even match with commercial planes. Their best hopes are that the trains can reach 800 km/h. Considering many planes operate at speed between 800 and 1000 km/h, this would be a game changer for many.
The train should reach a speed of 620 km/h. Furthermore, it can achieve levitation even when standing still – something that normally can happen only when traveling at a certain speed.
Chinese scientists also managed to achieve superconductivity at a higher temperature of -196° C. That’s not a small difference. As a matter of fact, the costs of refrigeration are just 2% of other Maglev trains. Furthermore, liquid nitrogen can be used instead of liquid helium, which is much more expensive to produce.
This train is still in an experimental phase. But scientists said they expect to have them commercially available in about 6 years.
Perhaps Maglev trains will be the new alternative to planes, after bullet trains?