A system on a marine vessel or platform supports a load while allowing heave compensation. The load is supported via a hydraulic actuator. A transformer of the system includes a power source and at least one hydraulic pump/motor, for communicating energy between any two of: the hydraulic actuator; a hydraulic accumulator; and a power source. A valve associated with the pump/motor is switchable during at least one cycle of the pump/motor for selectively providing fluid communication between a drive chamber of the pump/motor and any of the hydraulic actuator, the hydraulic accumulator, and a hydraulic fluid reservoir, via at least one port of the drive chamber, so as to allow a desired displacement of hydraulic fluid from the pump/motor to be obtained.

A system and method of transporting and unloading a load from a floating container that includes placing a load on a floating container at a first location, wherein the load is a mixture of solid material and liquid; moving the floating container with the load on a body of water from the first location to a remote second location; positioning the floating container so that a crane at the second location is within reach of the load; positioning a dewatering unit at the second location proximate the crane; unloading a quantity of the mixture of solid material and liquid from the floating container with the crane; depositing the quantity of the mixture of solid material and liquid into the dewatering unit; and dewatering the quantity of the mixture of solid material and liquid with the dewatering unit.

A system and method of transporting and unloading a load from a floating container that includes placing a load on a floating container at a first location, wherein the load is a mixture of solid material and liquid; moving the floating container with the load on a body of water from the first location to a remote second location; positioning the floating container so that a crane at the second location is within reach of the load; positioning a dewatering unit at the second location proximate the crane; unloading a quantity of the mixture of solid material and liquid from the floating container with the crane; depositing the quantity of the mixture of solid material and liquid into the dewatering unit; and dewatering the quantity of the mixture of solid material and liquid with the dewatering unit.

A device for tensioning an elongated hoisting member, comprises: a first friction-generating member rotatably supported around a first support member; a second friction-generating member rotatably supported around a second support member, the first and second friction-generating members being adapted to provide friction to the elongated hoisting member when the friction-generating members are pressed against each other with a portion of the elongated hoisting member therebetween. A brake is provided for braking the rotation of the friction-generating members around the support members. There is also described a system that includes such a device, as well as a method for operating such a system.

A device for tensioning an elongated hoisting member, comprises: a first friction-generating member rotatably supported around a first support member; a second friction-generating member rotatably supported around a second support member, the first and second friction-generating members being adapted to provide friction to the elongated hoisting member when the friction-generating members are pressed against each other with a portion of the elongated hoisting member therebetween. A brake is provided for braking the rotation of the friction-generating members around the support members. There is also described a system that includes such a device, as well as a method for operating such a system.

A device is proposed for attaching a coupling device to a free-floating object, for example free-floating articles or free-floating persons. The device has: at least one first connection end, which can be connected to a load-receiving end of a lifting device; a coupling device for attachment to a free-floating object; a load-receiving connection between the first connection end and the coupling device; and a guiding device, which is separate from the load-receiving connection, connects the first connection end to the coupling device and is designed to guide the coupling device relative to the first connection end.

A device is proposed for attaching a coupling device to a free-floating object, for example free-floating articles or free-floating persons. The device has: at least one first connection end, which can be connected to a load-receiving end of a lifting device; a coupling device for attachment to a free-floating object; a load-receiving connection between the first connection end and the coupling device; and a guiding device, which is separate from the load-receiving connection, connects the first connection end to the coupling device and is designed to guide the coupling device relative to the first connection end.

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 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 catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames are spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames provides a space under the frame and in between the barges that enables a package to be lifted and/or a marine vessel to be positioned in between the barges and under the frames. In this fashion, an object that has been salvaged from the seabed can be placed upon the marine vessel that is positioned in between the barges and under the frames.