A deepwater hoisting system includes a synthetic fibre rope winch assembly including a motor driven first winch and a length of synthetic fibre rope driven by said first winch. The synthetic fibre rope has an end remote from the first winch. The system further includes a steel wire winch assembly including a motor driven second winch and a length of steel wire driven by said second winch. The steel wire has an end remote from the second winch. At least the second winch is an active heave compensation motor driven winch. The system further includes a lifting block having a lifting block sheave, through which the synthetic fibre rope is run. The end of the synthetic fibre rope is connected to the end of the steel wire, so that the lifting block is suspended in a double-fall arrangement.

There is disclosed a retrieval system for retrieving a vessel from water to a deck of a recovery vessel, comprising: a lifting device mounted on the deck of the recovery vessel, the device comprising a substantially vertically extending structure and a lifting hook mounted to said substantially vertically extending structure so as to be raised and lowered therefrom by way of a first winch; a connection lead having a free end configured to detachably connect to a connection link of the vessel to be retrieved from the water an opposing end of the connection lead being located on the recovery vessel; a capture member mounted with respect to the lifting hook to capture the connection link of the vessel when the free end of the connection lead is raised towards the lifting hook; and a control member mounted with respect to the lifting hook of the lifting device and configured to receive at least a portion of the connection lead so as to direct the connection link to the capture member to be captured thereby as the free end of the connection lead is raised towards the lifting hook; wherein upon capture of the connection link by the capture member the winch is operated to facilitate lifting of the vessel from the water to the deck of the recovery vessel.

A system for bridle bite adjustment can include a tow rope coupled to a paravane at a first position on a lever arm and a spur line coupled to the paravane at a second position on the lever arm. The system can also include a winch to adjust a deployed length of the tow rope. The tow rope and the lever arm can adjust a bridle bite of the paravane by when the deployed length of the tow rope is adjusted by the winch, thereby balancing tension between the tow rope and the spur line.

A system for bridle bite adjustment can include a tow rope coupled to a paravane at a first position on a lever arm and a spur line coupled to the paravane at a second position on the lever arm. The system can also include a winch to adjust a deployed length of the tow rope. The tow rope and the lever arm can adjust a bridle bite of the paravane by when the deployed length of the tow rope is adjusted by the winch, thereby balancing tension between the tow rope and the spur line.

A compact and simplified heave compensation system for reducing the effect of waves or wavelike movements on a lifting device. The system can have active and passive heave compensation components. An overload protection to protect lifting equipment can also be implemented. The system enables accurate load and displacement calculations, as well as simplifying the control schemes utilized for lifting devices.

A compact and simplified heave compensation system for reducing the effect of waves or wavelike movements on a lifting device. The system can have active and passive heave compensation components. An overload protection to protect lifting equipment can also be implemented. The system enables accurate load and displacement calculations, as well as simplifying the control schemes utilized for lifting devices.

A deepwater hoisting system includes a synthetic fibre rope winch assembly including a motor driven first winch and a length of synthetic fibre rope driven by said first winch. The synthetic fibre rope has an end remote from the first winch. The system further includes a steel wire winch assembly including a motor driven second winch and a length of steel wire driven by said second winch. The steel wire has an end remote from the second winch. At least the second winch is an active heave compensation motor driven winch. The system further includes a lifting block having a lifting block sheave, through which the synthetic fibre rope is run. The end of the synthetic fibre rope is connected to the end of the steel wire, so that the lifting block is suspended in a double-fall arrangement.

A compensator device includes a hydraulic cylinder with a first end, a second end and an inner cylinder rod extending axially from the second end; and a piston rod with a piston movable axially within the cylinder. The inner cylinder rod has an end with a blocking diameter. The piston rod is generally hollow and includes a cavity to receive the blocking diameter of the inner cylinder rod.

A compensator device includes a hydraulic cylinder with a first end, a second end and an inner cylinder rod extending axially from the second end; and a piston rod with a piston movable axially within the cylinder. The inner cylinder rod has an end with a blocking diameter. The piston rod is generally hollow and includes a cavity to receive the blocking diameter of the inner cylinder rod.

A method of upgrading a knuckle-boom crane to a heave-compensating crane includes: removing a knuckle-boom from a main boom; mounting a main boom extension to the main boom for increasing the length of the main boom; and mounting a heave-compensating boom at a far end of the main boom extension such that the heave-compensating boom extends in a downward vertical direction (Z) in operational use of the heave-compensating crane. The heave-compensating boom is configured to be pivotable with respect to the main boom extension in both horizontal directions (X, Y). A heave-compensation system is provided to the knuckle-boom crane, wherein the heave-compensation system compensates for horizontal variations by controlling the orientation of the heave-compensating boom relative to the main boom extension, and compensates for vertical variations by means of a further vertical heave-compensation system, such as a winch-based heave-compensation system.