the gripping action of gripping mechanism 23 the pre set distance is a function of the speed with which gripping mechanism 23 moves from the open position to the closed position when sensor 33 detects the container it is at the correct position to stop extension of arm 22 in this embodiment approximately three inches upon detection sensor 33 sends a signal which terminates the extension of arm 22 with the loader no longer extending gripping arms 28 and 29 engage the container as gripping arms 28 and 29 engage the container hydraulic pressure builds up in gripping actuation cylinder 30 this pressure is sensed by a pressure switch which switches the logic circuit from gripping movement to hoisting movement in the conventional way further also according to the previous convention the hoisting circuit actuates the circuits that operate and control to retract the loader and to dump the container the control system initiates these functions through operation of a valve assembly 40 as shown in fig1 and 3 valves 40 control operation of individual hydraulic cylinders by permitting or preventing fluid flow thereto thus fluid flows to cylinder 24 to extend arm 22 until the valve is closed upon the control system receiving a signal from sensor 33 cylinder 30 continues to close gripping arms 28 and 29 about container 14 until the pressure sensor located at or proximate the appropriate valve signals that a pre set pressure has been achieved as briefly mentioned previously the control system additionally includes a hydraulic movement measuring system hydraulic movement in this specific embodiment includes the extension or retraction of a hydraulic cylinder a counter is actuated to count.