Abstract: The invention relates to a mobile device for working and/or moving heaps, preferably stacked in the manner of an embankment, of compostable materials (ricks) or of materials which are suitable for a landfill, comprising travelling gear which can be moved on two tracks, an implement which can be driven in a rotating fashion essentially transversely with respect to the direction of travel within the space between the tracks of the travelling gear, and two clearing apparatuses which are mounted in front of the two tracks of the travelling gear in the direction of travel. Furthermore, the invention relates to a clearing apparatus for clearing material on a track of a mobile device. The invention is based on the object of developing a device and an associated clearing apparatus of the aforesaid generic type in such a way that they can be realized in a particularly compact fashion.