Method and apparatus for controlling and operating a container crane or other similar cranes

摘要

The crane comprises a generally horizontal boom or other supporting structure having at least one rail thereon, a trolley having a reversible drive for moving the trolley in either direction along the rail, a wire rope hoist suspended from the trolley, and a load carrying device suspended from the hoist for selectively grasping and releasing a freight container or some other load. The crane has a control system which causes the trolley drive to stop the trolley momentarily at a first stopping position. Due to the control system, the drive then restarts the trolley and stops it at a second stopping position directly over a transfer position where the load is to be delivered and released. If the load is a freight container, the transfer position may be directly over a cell of a container ship. The control system includes an encoder for determining the length of the pendulum comprising the trolley, the hoist, the load carrying device and the load. The stopping of the trolley at the first stopping position causes the load to swing forwardly into the first quarter of a pendulum swinging cycle. The control system includes means for adjusting the distance between the first and second stopping positions to correspond with the horizontal component of distance traveled by the load during the first quarter of the pendulum cycle.