Abstract: A heave compensator includes a main hydraulic cylinder including a first connection device located at an upper end of the main hydraulic cylinder and a first piston having a piston rod. The interior of the main hydraulic cylinder is divided by the first piston into an upper first chamber and a lower second chamber filled with hydraulic liquid. The piston rod has a second connection device located at a lower end of the piston rod. The heave compensator includes a lifting accumulator comprising a second piston dividing the interior of the lifting accumulator into a third chamber filled with gas and a fourth chamber filled with hydraulic liquid. The fourth chamber is fluidly connected to the second chamber by a first liquid conduit having a first actuator controlled valve regulating the flow of hydraulic liquid in the first liquid conduit.

Abstract: A heave compensator for heavy lifts with adjustable dampening characteristics is able to operate above and below the water line in environmental pressures ranging from the atmospheric up to several hundred atmospheres pressure. A method for automatic regulation of the available stroke length of the heave compensator during the lifting operation, based on the realization that heave compensating devices utilising a slideable piston as a volume expanding mechanism to reduce the tension forces upon relative movements between crane and load, may obtain a simple compact construction able to execute a range of different compensation functionalities by registering the pressure and temperature in the gas filled chambers of the device, and employing this information to regulate the amount of gas in the single gas filled chambers.

Abstract: A heave compensator for heavy lifts with adjustable dampening characteristics is able to operate above and below the water line in environmental pressures ranging from the atmospheric up to several hundred atmospheres pressure. A method for automatic regulation of the available stroke length of the heave compensator during the lifting operation, based on the realization that heave compensating devices utilising a slide-able piston as a volume expanding mechanism to reduce the tension forces upon relative movements between crane and load, may obtain a simple compact construction able to execute a range of different compensation functionalities by registering the pressure and temperature in the gas filled chambers of the device, and employing this information to regulate the amount of gas in the single gas filled chambers.