The super-speed Transrapid maglev system has no wheels, no axles, no gear transmissions, no steel rails, and no overhead electrical pantographs. The maglev vehicles do not roll on wheels; rather, they hover above the track guideway, using the attractive magnetic force between two linear arrays of electromagnetic coils—one side of the coil on the vehicle, the other side in the track guideway, which function together as a magnetic dipole. During levitation and travelling operation, the Transrapid maglev vehicle floats on a frictionless magnetic cushion with no mechanical contact whatsoever with the track guideway. On-board vehicle electronic systems measure the dipole gap distance 100,000 times per second to guarantee the clearance between the coils attached to the underside of the guideway and the magnetic portion of the vehicle wrapped around the guideway edges. With this precise, constantly updated electronic control, the dipole gap remains nominally constant at . When levitated, the maglev vehicle has about of clearance above the guideway surface.