Abstract: A mechanical digger comprises a wheel-supported frame, an hydraulically operated digging device mounted on the frame, an engine mounted on the frame and arranged to operate the digging device and a seat arranged on the frame to allow the operator to view and to control the operation of the digging device; the frame is also provided with two wheel mounting locations at either of which a set of wheels can be replaceably mounted. Preferably, the frame is provided with an intermediate mounting location which is capable of mounting replaceably a rear set of ground engaging feet and the front location is capable of mounting replaceably a set of ground engaging feet or the wheel set.