Track maintenance machine and method for tamping sleepers of a track

The invention relates to a track maintenance machine having a tamping unit for tamping sleepers of a track lying in a ballast bed, including a tool carrier which is mounted for vertical adjustment on an assembly frame and on which tamping tools are arranged so as to be squeezable towards one another, wherein the tool carrier is coupled to a vertical adjustment drive actuated by means of a control device. In this, a control circuit is set up for controlling a lowering motion of the tool carrier, the control circuit including a controller, a setting device for the vertical adjustment drive and a measuring device for recording the lowering motion. With this, it is possible to provide an optimal course for the lowering motion.