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: An upper bearing assembly for a pedestal crane comprises a partially dome-shaped kingpost head operably engaged by a bearing having a concave bearing face shaped to conform to a segment of said kingpost head, the bearing enclosed within a bearing retainer, the bearing retainer attached to the crane upper works.

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: A hydraulic boom stop for a crane that permits operation at angles greater than the normal maximum operating boom angle of the crane boom. The hydraulic boom stop has at least one hydraulic cylinder and a hydraulic control system that is user controlled. The user controls the hydraulic fluid pressure to a boom control valve that in turn regulates the movement of the boom. As the hydraulic cylinder ram moves, the hydraulic fluid displaced by the ram provides a back pressure in the boom control valve that opposes and slows the continued upward or downward movement of the boom. The back pressure bleeds off through restricting valves in the communication lines. A relief valve in communication with the line associated with the inward movement of the ram releases the pressure in that line when it attains a predetermined value. In this way, the ram movement is less rigid and the hydraulic cylinder acts as an effective damper of impact forces. The user also controls the outward movement of the ram.