How does hyperloop work? Everything you need to know about magnetic levitation
For the uninitiated, hyperloop is a high-speed passenger transport system that involves a sealed tube through which high-speed pods move, slashing travel times. For example, the journey from London to Edinburgh – which takes more than four hours on a train – would theoretically take just 30 minutes.
Musk has since encouraged startup firms and student-led projects to create their own versions of hyperloop. The high-speed system uses a version of magnetic levitation, but what is it and how does it work?
What is magnetic levitation?
Magnetic levitation, or maglev, is when an object is suspended in the air using only magnetic fields and no other support.
Along with super-fast maglev trains, magnetic levitation has various engineering uses including magnetic bearings. It can also be used for display and novelty purposes, such as floating speakers.
How does magnetic levitation work?
Magnetic levitation’s best-known use is in maglev trains. Currently, only in operation in a handful of countries, including China and Japan, Maglev trains are the fastest in the world, with a record speed of 375 mph (603 km/h). However, the train systems are incredibly expensive to construct and often end up languishing as little-used vanity projects.
There are two main types of maglev train technology – electromagnetic suspension (EMS) and electrodynamic suspension (EDS).
EMS uses electronically controlled electromagnets in the train to attract it to a magnetic steel track, while EDS uses superconducting electromagnets on both the train and the rail to produce a mutually repellent force that makes the carriages levitate.
A variant of EDS technology – as used in the Inductrack system – uses an array of permanent magnets on the underside of the train, instead of powered electromagnets or cooled superconducting magnets. This is also known as passive magnetic levitation technology.
How does Hyperloop use magnetic levitation?
In Musk’s original concept, the pods floated on a layer of pressurized air, in a similar way to pucks floating on an air hockey table. However, a more recent version of the technology from Hyperloop Transportation Technologies (HTT) – one of two companies leading the hyperloop race – uses passive magnetic levitation to achieve the same effect.
The technology has been licensed to HTT from Lawrence Livermore National Labs (LLNL), which developed it as part of the Inductrack system. This method is thought to be cheaper and safer than traditional maglev systems.
With this method, magnets are placed on the underside of the capsules in a Halbach array. This focuses the magnetic force of the magnets on one side of the array while almost entirely canceling out the field on the other side. These magnetic fields cause the pods to float as they pass over electromagnetic coils embedded in the track. Thrust from linear motors propels the pods forward.
HTT’s main rival, Hyperloop One is also using a passive magnetic levitation system where pod-side permanent magnets repel a passive track, with the only input energy coming from the speed of the pod.
For both systems, air pressure in the tunnels is lowered using air pumps in order to aid the pods’ movement. The low air pressure dramatically reduces drag so that only a relatively small amount of electricity is needed to achieve top speeds.
Now that we understand Magnetic Levitation, it’s time to look at the progress companies are making in expanding the technology for general use.
In exciting news, Virgin’s Hyperloop safely transported two passengers on the 2-seater Pod-2. This vehicle is a much smaller version of what we expect from the company later on. Per Virgin’s projections, we will someday see a 28-seat passenger vehicle.
The current model only reached 107 miles per hour but, they did so safely and we’ll call that a win for new technology.
Of course, Elon Musk isn’t letting Virgin take all of the Hyperloop glory. In July of this year, Musk tweeted that he was looking forward to building a 10 Kilometer long tunnel with several curves to better mimic real-life hyperloop travel.
With such great strides taking place in 2020 it’s natural to wonder when we’ll see the transportation system in full use. It’s still too early to tell honestly. The technology is incredibly expensive and it still has a long way to go to reach the projected speeds scientists and engineers think it is capable of.
As for now, we’ll continue to watch the progress and keep you updated on the latest developments in Magnetic Levitation based transports such as the Hyperloop.