Abstract: A system and method are provided that allow for direct measurement of relative movement and relative velocity of movement of a crane (10) boom tip (14) in relation to a target load (24) on an adjacent vessel deck (20) allowing real-time determination of work load parameters under then-current conditions. A rangefinder (32) is located proximate boom tip (14) without requirement of a device on the target load or load vessel. A method accumulates relative movement, environmental data and as-built crane design to determine rated capacity of crane (10).

Abstract: A system and method are provided that allow for direct measurement of relative movement and relative velocity of movement of a crane (10) boom tip (14) in relation to a target load (24) on an adjacent vessel deck (20) allowing real-time determination of work load parameters under then-current conditions. A rangefinder (32) is located proximate boom tip (14) without requirement of a device on the target load or load vessel. A method accumulates relative movement, environmental data and as-built crane design to determine rated capacity of crane (10).

Abstract: A movable pedestal or kingpost type luffing crane that includes an upperworks, having a crane boom, rotatably mounted on a crane support. The crane support extends below the upperworks. The movable crane is constructed to be selectively maintained in or removed from a receiving socket. Movement prevention means prevents the radial and vertical movement of the crane support in the receiving socket. Anti-rotation means prevents the rotation of the crane support in the receiving socket. A centering means is also provided which facilitates the centering of the crane support means within the receiving socket. Providing a plurality of receiving sockets located at predetermined locations provides a system wherein the movable crane may be moved from socket to socket and from location to location.

Abstract: An inverted kingpost crane is disclosed, the crane including an upperworks supporting a crane boom, the upperworks supported on a rotating kingpost, the kingpost supported in a sleeve, an upper radial bearing structure intermediate an upper section of the kingpost and the sleeve, a lower bearing structure comprising a thrust bearing and a radial bearing disposed intermediate a lower section of the kingpost and the sleeve. The upper bearing and the lower bearing structure are constructed of a relatively soft bearing material, the bearing material providing a sacrificial wearing surface between the rotating kingpost and the stationary sleeve.

Abstract: A crane design which permits limited rotation in the plane of loading of the upperworks of a pedestal crane independently of the central support thereof, and independently of the thrust and radial bearings about an extension of such central support. Means for centering the vertical loading vector and horizontal overturning moments by restricting the possible displacements thereof are disclosed, as are methods for accomplishing the same.

Abstract: A crane design which automatically self-compensates for misalignment between the longitudinal axis of the central support for such crane and the actual axis of rotation of the upperworks thereof when under load. Means for accomplishing both translational and rotational correction as needed are disclosed. Also, method for accomplishing the same.

Abstract: A bearing assembly for a pedestal crane including at least one arcuate shoe adapted to be disposed about the pedestal and mounted with the upperworks of the pedestal crane, with mounting members for releasably mounting the arcuate shoe with the upperworks of the pedestal crane, and further having bearing means with the arcuate shoe for engaging the outer surface of the pedestal for reducing friction between the upperworks and the pedestal when rotating the upperworks of the pedestal crane about the pedestal.

Abstract: A new and improved anti-two block system adapted to be used with a crane for the prevention of damage to the boom tip of the boom of the crane by the travelling member wherein the two block system of the present invention includes an engaging mechanism movably mounted with the boom tip for engaging the travelling member when the travelling member moves into close proximity to the boom tip during lifting operations of the travelling member with the crane for the prevention of damage thereto.

Abstract: The method for removing a bearing assembly disposed between a revolving turntable of a pedestal crane assembly and the pedestal and a removable bearing assembly for a pedestal crane, wherein the method includes activating a support member coacting between the revolving turntable and the upper end of the pedestal for raising and supporting the pedestal crane assembly from the support column of the pedestal, centering the revolving turntable about the support column of the pedestal with alignment structure, removing a retainer plate that secures thrust and radial bearings in position with respect to the revolving turntable and the upper end of the pedestal to permit access and removal of the bearings.

Abstract: An anti-two block system adapted to be used with a crane having a sensor device mounted with the boom point of the crane in communication with a hoisting actuator mechanism such that the sensor device effects movement of the hoisting lever of the crane to discontinue the lifting force exerted on the lifting line when the travelling member engages the sensor device.

Abstract: In a crane having a boom adapted to be mounted on a pedestal, a crane mounting system having a crosshead assembly and a bearing means, the crosshead assembly for connection to the crane boom and adapted to be rotatively mounted in proximity to the upper end of the pedestal and the bearing means allowing rotation and limited pivotal movement of the crosshead assembly with respect to the pedestal.

Abstract: In a crane having a boom, a load cable, a traveling block and multiple sheaves for the cable, an improved sheaving arrangement for preventing spinning of the traveling block and twisting of the cable when raising and lowering the traveling block.