Machine and method of distributing ballast

A machine for distributing ballast on a ballast bed supporting a track, comprising

• (a) a machine frame supported on the track by undercarriages for movement along the track in an operating direction, the machine frame extending in a longitudinal direction, the undercarriages having wheels making point contacts with the track and the contact points defining a reference plane,
• (b) chutes arranged on the machine frame and spaced from each other in the direction extending transversely to the machine frame, each chute having
• (1) a discharge end for downwardly discharging ballast,
• (c) a vertically adjustable wiper unit downwardly projecting from the discharge end of each chute towards the track and extending the chute, the wiper unit
• (1) comprising a drive for adjusting the wiper unit relative to the discharge end, and
• (2) defining an inlet opening associated with the discharge end of the chute and an outlet opening defining a wiper edge, the wiper edge extending parallel to the reference plane, and
• (d) a flanged roller supporting the wiper unit on the track.