Abstract: A control device is designed for center pivot irrigation units of the type having an elongate water carrying pipe with a plurality of support vehicles spaced therealong, and wherein each of the vehicles includes a double acting hydraulic cylinder mounted thereon for moving the vehicle and the water pipe over the ground. The irrigation unit includes a device for aligning the vehicles, a hydraulic pump with pressure and return lines, and power and retract manifolds respectively interconnecting power and retract sides of the cylinders. The control device includes a hydraulic valve with three positions which communicate the pressure line with the power manifold, the retract manifold, and the pump return line respectively.