Abstract: A prime mover having a central body with a plurality of elongated legs pivotally connected to said central body for movement both up and down and sideways and individual steerable drive means on each elongated leg to enable the prime mover to move over a wide variety of terrains. The drive means include ground supporting wheels or tracks. Carried on the prime mover are electro hydraulic control means for steering each of the drive means and electric control means for actuating each of the drive means for moving the prime mover along the ground. A work platform is supported on the central body, which is appropriately levelled and stabilized in work position by proper extension or retraction or vertical depression or elevation of the respective elongated legs. The prime mover has four independently mounted drive means or wheels, unconnected by common axles or mechanical linkage and having no fixed track, that are controlled in such a manner that the geometry of steering produces a coherent effect.