Installation of deep-sea crane in two Maersk A-type vessels
The vessels Maersk Achiever and Maersk Attender were transformed into deep-sea crane vessels with an operational depth reaching down to 2,500 meters.
The layout of the two 250 ton heavy lift marine cranes was divided into one upper deck with visible knuckle beam and slewing part and one lower deck installed with main winch and spooling device with 15 metres of the hull changed from the cargo tanks to the crane winch room.
The winch is effectively heave-compensated down to 2,500 meters with 200 tons payload in the hook where compensation takes place by means of a nitrogen oil cylinder accumulator that acts directly on the winch’s hydraulic motor.
A tank heeling system will be installed in order to keep narrow heeling tolerance during lifting operations.