The present invention further provides a controller which monitors the movement of each hydraulic actuator, and temporarily interrupts the operation of the leading actuator to ensure that {HEAD ~ both actuators} move in {TAIL ~ unison} 
The present invention further provides a controller which monitors the movement of each hydraulic actuator , and temporarily interrupts the operation of the leading actuator to ensure that { HEAD ~ both actuators } move in { TAIL ~ unison }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL