[blu42]

Propeller-based airplanes are not that much faster than this train -- current propeller world record stands at 855 km/h. For higher speeds jet/turbofan engines would be the choice, as they are among the few propulsion forms that can operate very efficiently with the atmospheric medium, rather than fully against it (up to certain speeds). So unless you equip that train with jet turbines (impractical for a number of reasons), you will be paying a huge energy price for airplane speeds at ground altitudes (holds true for any kind of ground transportation). As a result those trains are seldom operated at their peak speeds.