Abstract: An elongated, generally horizontal frame is provided with latch means at each end. An equipment mounting frame is mounted on the elongated frame for movement to selected positions therealong from adjacent one end to adjacent the other end of the elongated frame; a hydraulic cylinder is pivotally mounted on the equipment mounting frame, about a generally horizontal axis proceeding transversally. Piston rods extend in opposite axial directions from a piston slidingly received in the cylinder. Cooperating latch means are provided on the outer ends of the two piston rods. The equipment mounting frame is moved along the elongated frame by latching one piston rod end or the other in one of the latch means of the elongated frame and applying hydraulic fluid to the cylinder to relatively extend or retract the latched piston rod. Latching and unlatching are accomplished by temporarily tilting the cylinder from horizontal (e.g.