Abstract: A steering apparatus and method are provided for a gantry crane with four corner-mounted wheel assemblies having steerable wheels. The crane is a type which drivable in either longitudinal or transverse directions, wherein steering control is automatically switched steering control to the “leading” wheels, or more particularly the wheels of the “leading” pair of wheel assemblies. The system detects which two of the wheel assemblies are leading, whether the crane is moving longitudinally frontwardly or rearwardly, or transversly rightward or leftward. The system includes a steering controller which controls steering actuators in such a manner that the wheels of the then-leading wheel assemblies are moved according to steering control input, while the wheels of a remaining pair of then-“trailing” wheel assemblies are moved to and/or held in, a straight alignment.

Abstract: A sway stabilizing system is provided for stabilizing sway of a grappler suspended by vertically movable hoisting cables on a gantry crane. The crane is a type which is particularly useful for lifting a standard container from a standard-height chassis, such as a standard road trailer. According to the invention, the system is designed to optimally dampen sway when the grappler is slightly higher than the top of a standard container resting on a standard chassis. More particularly, in order to cancel pendulum sway effect, the sway stabilizing system provides first and second anti-sway cables which are operably guided from the grappler to an overhead trolley of the crane in a longitudinally diagonal manner. The anti-sway cables are acted upon by respective hydraulic cylinder assemblies mounted on the grappler to apply appropriate tension in the respective anti-sway cables. The cylinder assemblies act in opposite directions to dampen grappler sway in both directions along a longitudinal axis.

Abstract: In a hydraulic cylinder actuation system for a crane having a conventionally charged main hydraulic pump, a supplemental pump or "charge boost" pump is provided. To efficiently achieve fast actuation speeds of the cylinder, the charge boost pump provides supplemental charge flow in response to a need in the system. The charge boost pump is driven independently from the main pump or may be driven by the main pump if the main pump is equipped with drive thru capability to provide a variable output and preferably includes a load sensing means for controlling the output.