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How does a maglev train work?

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Quick answer

A maglev train floats above a guideway using magnetic levitation, either by electromagnets attracting it up toward a steel rail or by superconducting magnets repelling it from coils. Coils in the guideway then create a moving magnetic field that pulls the train along. With no wheel friction, speeds above 400 km/h are possible.

A maglev train works by using powerful magnets to lift the train a few millimetres or centimetres above its guideway and a moving magnetic field to pull it forward. With no wheels touching rails at speed, there is no rolling friction, so maglevs can travel smoothly at well over 400 km/h.

Step by step

  1. Magnets on the train interact with rails or coils in the guideway to produce an upward lifting force.
  2. Sensors measure the gap many times per second, and controllers adjust currents to keep the train floating steadily.
  3. Side-facing magnets keep the train centred so it cannot drift sideways off the guideway.
  4. Guideway coils switch on in sequence, creating a magnetic wave that travels along the track and pulls the train.
  5. To slow down, the field is reversed, using the same linear motor to brake the train smoothly.

Key things to understand

  1. Maglev is short for magnetic levitation, meaning magnetic forces hold the train up instead of wheels.
  2. Electromagnetic suspension systems wrap magnets under a steel rail and use attraction to pull the train upward.
  3. Electrodynamic systems use superconducting magnets whose motion induces currents in guideway coils, pushing the train up by repulsion.
  4. Computers adjust magnet currents continuously to keep the gap steady and the train centred on the guideway.
  5. A linear motor in the guideway creates a travelling magnetic wave that drags the train forward or slows it.

Labelled diagram

  1. Guideway

    A raised concrete track containing rails or coils that interact with train magnets.

  2. Levitation magnets

    Lift the train using magnetic attraction or repulsion, so nothing touches at speed.

  3. Guidance magnets

    Side magnets keep the train centred on the guideway through curves.

  4. Gap sensors

    Measure clearance constantly so controllers can correct the magnet currents.

  5. Linear motor

    Sequenced guideway coils create a travelling field that pushes and brakes the train.

How a maglev floats and moves

Real-world examples

  • The Shanghai maglev links the city to Pudong International Airport over about 30 km and has carried passengers at around 430 km/h.
  • Japan's experimental superconducting maglev set a world rail speed record of 603 km/h in 2015.
  • Japan's Chuo Shinkansen, under construction, will use superconducting maglev between Tokyo and Nagoya.
  • Low-speed maglev shuttles in Changsha, China, and Incheon, South Korea, connect airports with nearby districts.

Common mistake

✗ Myth: Maglev trains have zero friction, so they need almost no energy to run.

✓ Fact: Removing wheel contact eliminates rolling friction, but air resistance grows rapidly with speed and dominates at maglev speeds. Powering the levitation and propulsion systems also takes substantial electricity.

People also ask

How does a maglev train float?
It floats on magnetic force. In one design, electromagnets under the train are attracted upward toward a steel rail, with computers controlling the gap. In the other, superconducting magnets moving past guideway coils induce currents that repel the train upward. Either way, nothing touches the track at cruising speed.
How fast is a maglev train?
The Shanghai maglev has run passenger services at around 430 km/h, among the fastest commercial trains anywhere. Japan's superconducting test train reached 603 km/h in 2015, the world speed record for a railed vehicle. Low-speed urban maglevs travel at about 100 km/h.
Does india have a maglev train?
India has no maglev line in operation. Proposals have been discussed over the years, but none has been built. Indian Railways is instead developing conventional high-speed rail, such as the Mumbai to Ahmedabad corridor, which uses wheeled Shinkansen-style trains rather than magnetic levitation.
How high does a maglev train float?
It depends on the design. Attraction-based systems like the Shanghai line hold a gap of roughly 10 millimetres, while Japan's superconducting system floats around 10 centimetres above the guideway once it reaches speed.
Does a maglev train have wheels?
Some do. Japan's electrodynamic maglev only levitates above about 150 km/h, because induced currents are too weak at low speed, so it rolls on rubber wheels until then. Attraction-based maglevs can hover even when stationary.
Why are there so few maglev lines?
A maglev needs an entirely new, precisely built guideway that cannot share track with ordinary trains. That makes construction very expensive, and conventional high-speed rail already reaches about 300 km/h on cheaper, compatible tracks.
What stops a maglev train?
Mainly the linear motor itself. Reversing the travelling magnetic field slows the train and can return energy to the grid; air resistance helps, and wheels or skids with mechanical brakes serve as backup at low speed.

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