The invention relates to a method for load monitoring of a tamping unit of a track maintenance machine, wherein at least one sensor is arranged for recording a load on the tamping unit. In this, measuring data recorded by means of the sensor are stored over a time period (T) in an evaluation device, wherein at least one load-time progression for cyclical penetration operations of the tamping unit into a ballast bed is derived from the stored measuring data. With this, conclusions can be drawn as to the load stress situation of the tamping unit and the condition of the ballast bed.

A machine for repairing a ballast bed has an undercutter that defines a direction of movement of the repairing machine, and a distributor for dividing a flow of ballast entering from the undercutter into a rear flow of exiting ballast and a separate front flow of exiting ballast. At least one rear screening machine is positioned behind the undercutter in the direction of movement and is fed by the rear flow of exiting ballast. At least one front screening machine is positioned in front of the undercutter and fed by the front flow of exiting ballast, and the distributor has a variator for varying the ratio between the separate first and the second flows of exiting ballast.

A machine for repairing a ballast bed has an undercutter that defines a direction of movement of the repairing machine, and a distributor for dividing a flow of ballast entering from the undercutter into a rear flow of exiting ballast and a separate front flow of exiting ballast. At least one rear screening machine is positioned behind the undercutter in the direction of movement and is fed by the rear flow of exiting ballst. At least one front screening machine is positioned in front of the undercutter and fed by the front flow of exiting ballast, and the distributor has a variator for varying the ratio between the separate first and the second flows of exiting ballast.

The invention relates to a method for load monitoring of a tamping unit of a track maintenance machine, wherein at least one sensor is arranged for recording a load on the tamping unit. In this, measuring data recorded by means of the sensor are stored over a time period (T) in an evaluation device, wherein at least one load-time progression for cyclical penetration operations of the tamping unit into a ballast bed is derived from the stored measuring data. With this, conclusions can be drawn as to the load stress situation of the tamping unit and the condition of the ballast bed.