Magnetic levitation
MAX
What is Magnetic Levitation (maglev) technology?
Magnetic Levitation, also referred to as Maglev, is a |
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mode of transportation where the vehicle is supported |
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by large electromagnets along a guideway. The vehicle |
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is then propelled at insane speeds by the magnetic |
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forces, which |
ride. |
Who uses maglev?
Maglev is used exclusively by high speed trains. Prototypes for other vehicles such as cars and trucks have been tested with maglev technology but in the end were found to be impractical. The first patent was created in 1902 but the first actual working model wasn’t around till 1940.
Countries that use maglev
The first maglev was built at the Birmingham airport, it could achieve speeds of 42km/h but it was shut down shortly due to instability. Japan is very successful with their maglevs creating some of the fastest trains in history. Their fastest train had a top speed of 603km/h. Germany is also another country that is having great success with their maglev systems, creating a train that can reach speeds of 434km/h.
How does a maglev system levitate?
The maglev system uses the basic principle of magnetic |
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repulsion and attraction to levitate trains. Large |
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electromagnets are placed on the bottom of the guideway and |
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on the top of the undercarriage that goes under the guideway. |
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The magnets on the bottom of the guideway are |
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-268 Celsius, increasing the strength of the |
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field by ten times. The guidance magnet on the side |
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train straight so it does not wiggle around. The two |
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are attracted to each other causing the |
train to lift |
usually creates a 10cm gap between the |
guideway |
bottom of the train. |
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How does a maglev system move forward?
We now know how a maglev train levitates but how does |
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it move forward? The answer is pretty simple. The walls |
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of the track are lined with electromagnetics that are split |
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into north and south poles. When the train comes along |
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side the magnets, the train is pulled forward and pushed |
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the same time creating fast and |
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. To slow down, the |
magnets are |
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train is pulled |
back. in emergency |
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are rubber |
pads along the bottom that |
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guideway to slow the train faster.
Cryogenics
The electromagnets are kept very cold by the use of cryogenics for the purpose of making the magnets stronger. Cryogenics is the science of anything below the freezing point of water. A cryogenic liquid is defined as a liquid with a boiling point less than -90°C. such liquids would include liquid helium or nitrogen. High speed maglev systems use a lot of cryogenic fluid too strength the attraction or the repulsion of the magnets. With extremely cold temperatures, the atoms inside the magnet will move more slowly, creating a much better alignment within the atoms producing a stronger magnetism force.
Energy consumption
At high speeds, the maglev train is much more efficient energy wise when compared to cars and planes. The trains, which do not rely on fossil fuels, are powered solely by solar panels. Start up is when most energy is consumed to get the train going. At 480km/h the train uses 0.4 megajoules of energy a mile, compared to 4 megajoules of a fossil fuel machine at that speed.
Danger with maglevs
Although maglevs are thought to be safer than planes, at such high speeds, anything is possible. In the case of an emergency the trains take a long time to stop as to not kill any of the passengers from the lateral force. The trains need ample time to slow down and accelerate. In the case of a derailment, the lips of the guideway would hold the train to the guideway so it doesn’t fly off the side.
Major problems
One of the biggest problems with maglev is the infrastructure involved. The guideways for these trains have to be completely straight. Passengers can only with stand 1/10th of a G of lateral force, meaning that for the train to turn it would need a radius of 65km. The guideways would run either high above the ground or underground. Tunneling would be a expensive solution. American cities that want to implement these systems run into the problems with the previous buildings. Many buildings set in place would have to demolished or moved to account for the space needed for the guideways. Another problem is if the guideway has to go through private property such as farm land, and the owner denies access for the train to go through.