The present invention relates to a turn-about plough with a supporting wheel (3), in which the working depth guide can be set via a hydraulic cylinder (4). During the turn-about operation, the supporting wheel (3) swings around into the opposite working position in each case. An independent hydraulic system having a predetermined quantity of oil uses a valve unit (10) and a pressure accumulator (6) to enable the supporting wheel (3) to swing around into the opposite working position and, after the swing-around operation, to resume the predetermined working depth setting thereof. During the swing-around operation, oil is exchanged between the pressure spaces of the hydraulic cylinder (5) and the pressure accumulator (6).
