It is a good thing that this is true, else the Earth could not manage to go around the Sun indefinitely!
Therefore the energy to keep a system like this going is entirely what is needed to replace various incidental losses like friction. With maglev technology there some electromagnetic drag, but the bulk of losses are air friction.
There is no way to keep a train like you describe going against air friction at 1200 mph. If you eliminated air friction, it would be very doable.
Would that eliminate enough of the air resistance to be feasible? Is a 1200km long contiguous structure feasible?