Rolls-Royce has been assigned by the Brazilian ship owning company CBO, to equip an existing offshore platform supply vessel (PSV) with a new patented dual draglink (DDC) subsea crane. This will be the first installation of a subsea crane designed to be able to use either fibre or steel wire rope.
The hybrid DDC subsea crane is designed for continuous operation in a tough and corrosive offshore environment and will be installed on the vessel CBO Manoella, which is currently being retrofitted from PSV into a ROV Support Vessel (RSV).
Marcelo Martins, CBO, Technical Director said: “This is one of two vessels CBO is now retrofitting from PSVs to RSVs, and we are very satisfied about the flexibility of the crane from Rolls-Royce. A hybrid solution, with use of either fibre or wire, makes the vessel better prepared to take on a larger variety of future subsea tasks.”
The hybrid dual draglink crane has a lifting capacity of up to 50 tonnes and an operating depth of up to 3,000 metres. It will be equipped with wire rope, when it embarks on its first subsea assignment off the coast of Brazil, but there is also the possibility of changing to fibre rope, that can increase the vessel’s deck load capacity to approximately 100 tonnes and its lifting capacity at large depths.
The cable tractions control unit (CTCU) forms the crane winch and is located at the crane’s main boom. This solution saves space compared to a solution where the CTCU unit is mounted below deck, and also makes it a better choice for retrofits. The horizontal elbow derrick movements provide Active Heave Compensation (AHC), reducing wear and build-up of heat in the lifting line compared to when the AHC is part of the winch.
Gary Nutter, Rolls-Royce, Director, Products – Marine said: “We are very happy to be able to continue our close cooperation with CBO by retrofitting one of our previous designs. This project is a great example of how offshore ship owners are adapting to a new reality with the use of new technology.”
The delivery from Rolls-Royce, comprising a complete DDC crane system including the CTCU, cabin and control system, will take place in Q3 this year.
