How can an electromagnet hold a train above its guideway?

In one type of magnetic-levitation train, electromagnets on the vehicle reach around parts of the guideway and attract its steel structure. The arrangement gives the vehicle an upward support force. Ordinary load-bearing wheel contact is not needed while it is levitating.

Magnetic attraction alone does not maintain a stable gap. If the magnet moves closer, attraction can become stronger and pull it closer still. Sensors therefore measure the gap, and controllers rapidly adjust current to keep the vehicle near the intended position as loads and track conditions change.

Support and propulsion are different jobs. In the Transrapid system, a long-stator linear motor creates a traveling magnetic field along the route. Interaction with the vehicle produces forward or braking force. Guidance forces also help keep it aligned sideways.

The train still needs energy, structural support and control. Avoiding wheel contact removes one source of mechanical wear, but air resistance remains and grows important at high speed. Other maglev designs use different magnetic arrangements, so one drawing should not be treated as the mechanism of every levitating train.