The publication relates to a depth compensated actuator, for a transportable inline depth compensated heave com-pensator for subsea lifting operations. The actuator comprises a cylinder shaped body and a piston with a piston rod, the piston rod being intended for exposure to external water pressure, a first and second connection means associated with the actuator. Further, the actuator comprises a depth compensator comprising a cylinder, a piston and a piston rod, the end of which being exposed to surrounding water; and conduit means between at least one volume in the actuator and one volume in the depth compensator. The pistons and piston rods are shaped as any of: hollow piston rod, ring shaped piston, ring piston rod. The depth compensated actuator solves the problem if improving depth compensation performance regarding size, weight, required fluid consumption, internal/inherent friction and adaptability. Further, use of a depth compensated actuator is claimed.

The publication relates to a depth compensated actuator, for a transportable inline depth compensated heave com-pensator for subsea lifting operations. The actuator comprises a cylinder shaped body and a piston with a piston rod, the piston rod being intended for exposure to external water pressure, a first and second connection means associated with the actuator. Further, the actuator comprises a depth compensator comprising a cylinder, a piston and a piston rod, the end of which being exposed to surrounding water; and conduit means between at least one volume in the actuator and one volume in the depth compensator. The pistons and piston rods are shaped as any of: hollow piston rod, ring shaped piston, ring piston rod. The depth compensated actuator solves the problem if improving depth compensation performance regarding size, weight, required fluid consumption, internal/inherent friction and adaptability. Further, use of a depth compensated actuator is claimed.

A damping mechanism may comprise a housing, a shaft, a spring arm assembly including a first spring arm, wherein the spring arm assembly is coupled to the shaft and configured to rotate in response to a rotation of the shaft, wherein the first spring arm extends relatively radially outward of the spring arm assembly toward the housing in response to the rotation of the shaft, and wherein the rotation of the shaft is damped in response to extending the first spring arm.

A damping mechanism may comprise a housing, a shaft, a spring arm assembly including a first spring arm, wherein the spring arm assembly is coupled to the shaft and configured to rotate in response to a rotation of the shaft, wherein the first spring arm extends relatively radially outward of the spring arm assembly toward the housing in response to the rotation of the shaft, and wherein the rotation of the shaft is damped in response to extending the first spring arm.

A wave-induced motion compensation crane and corresponding vessel and method are disclosed. The crane includes a motion compensation device at a tip end portion of the boom structure to compensate for X-Y wave-induced motion and a heave compensation device for Z-motion. The motion compensation device includes a moveable jib beam that extends in a substantially horizontal direction. The jib beam is slewable about a substantially vertical slew axis and translatable in a longitudinal direction of the jib beam. Preferably, the jib beam can be levelled based on the angular orientation of the boom structure.

A wave-induced motion compensation crane and corresponding vessel and method are disclosed. The crane includes a motion compensation device at a tip end portion of the boom structure to compensate for X-Y wave-induced motion and a heave compensation device for Z-motion. The motion compensation device includes a moveable jib beam that extends in a substantially horizontal direction. The jib beam is slewable about a substantially vertical slew axis and translatable in a longitudinal direction of the jib beam. Preferably, the jib beam can be levelled based on the angular orientation of the boom structure.

This overload preventing device is mounted on a mobile work machine, and is provided with: a storage unit which stores lifting performance data in which lifting performance is configured for each operation state, and performance region data in which switching angles are configured that define performance regions, including a front region, a back region, and a side region; and a work machine control unit which controls operation of the mobile work machine on the basis of the actual load and the lifting performance corresponding to the present operation state of the mobile work machine. The lifting performance includes a maximum deployment width performance configured for the front region and the back region, and the switching angles are configured for each operation state on the basis of stability calculations and strength factors such as jack strength.

Method for controlling a lifting device to move a load along a trajectory, to move the load in an efficient, automated, and collision-free manner between points, includes a start point and end point of the trajectory and prohibited zones are established which, during motion of the load are avoided. A computing unit calculates a geometric or rounded geometric or smooth geometric path, that kinematic and geometric limit values of the lifting device are predetermined, from which the computing unit, on the basis of the geometric or rounded geometric or smooth geometric path, calculates a dynamic or rounded dynamic or smooth dynamic path which provides time information about motion of the load along the geometric or rounded geometric or smooth geometric path. The geometric or rounded geometric or smooth geometric path and the dynamic or rounded dynamic or smooth dynamic path are combined for producing the trajectory.

Method for controlling a lifting device to move a load along a trajectory, to move the load in an efficient, automated, and collision-free manner between points, includes a start point and end point of the trajectory and prohibited zones are established which, during motion of the load are avoided. A computing unit calculates a geometric or rounded geometric or smooth geometric path, that kinematic and geometric limit values of the lifting device are predetermined, from which the computing unit, on the basis of the geometric or rounded geometric or smooth geometric path, calculates a dynamic or rounded dynamic or smooth dynamic path which provides time information about motion of the load along the geometric or rounded geometric or smooth geometric path. The geometric or rounded geometric or smooth geometric path and the dynamic or rounded dynamic or smooth dynamic path are combined for producing the trajectory.

A system and method for connecting a removable counterweight system to a crane including a lower assembly adapted to be connected to the counterweight system, an upper assembly adapted to be mounted to the crane, and a latch block assembly mounted to the upper assembly. The latch block assembly includes a plurality of blocks cooperating together to form a central counterbore for receiving a stud therein. The blocks are mounted within the upper assembly by at least one axle to allow for rotation of the blocks. A distal end of the stud is removably connected to the latch block assembly to attach the counterweight system to the crane.