Damen works to cut scrubber retrofit times

Stena Scotia will be first vessel retrofitted with a scrubber using Damen's new Modular Approach

JUNE 1, 2017 — A new technique for retrofitting exhaust gas scrubbers is being trialed by Damen Green Solutions (DGS) in partnership with Damen Shiprepair & Conversion (DSC) and scrubber supplier AEC Maritime.

Designated the Modular Approach, the new process is designed to cut the time that a vessel typically needs to spend in dock from two or more weeks to just a few days. This dramatic reduction in downtime, in combination with a more cost-efficient, certified scrubber, will be welcomed by shipowners and operators. The first installation of this type is already underway for the RoRo cargo vessel Stena Scotia.

The key to achieving this sharp fall in downtime for the vessel is maximizing the amount of preparatory and manufacturing work that can be completed before the vessel arrives in the shipyard. This happens in two parallel processes. In one of these, the scrubbers and their supporting systems are fitted into two prefabricated modules while still in the workshop. The first module contains the scrubber plus all the necessary piping and electronics. The second houses all the auxiliary equipment including the pumps, heat exchanger and separators. These can then be tested and optimized in advance of the actual installation.

At the same time, preparatory works are undertaken on board the vessel at agreed times that do not interfere with the ship’s scheduled operations. In the case of the Stena Scotia, the preparations on board, including steelwork and pipe-fitting, will take place over a number of weekends during routine overnight stopovers.

The result of the prefabrication process plus preparation works means that when the ship does finally arrive at a Damen shipyard, the technical team can focus on the final stage of the retrofit process; attaching and linking up the two, fully operational modules to a ship that is ready and prepared to receive them. This last stage represents the third module of the operation.

Damen Green Solutions, the arm of the Damen Shipyards Group responsible for developing and implementing low-emissions and environmentally-friendly solutions, has oversight of the entire process including commissioning and training. It does this in close coordination with Damen Shiprepair & Conversion (DSC) and, in the case of Stena Scotia, Damen Shiprepair Rotterdam.

“With the need to access the vessel during its regular operations to undertake the preparations, it is vital to work very closely with the owner and crew to make the hours available as productive as possible,” says project manager Stef Loffeld. “Fortunately, DSC’s Harbor & Voyage teams are expert at working efficiently and unobtrusively when a ship is still in an operational mode. We also cooperate closely in the engineering phase with AEC, the suppliers of the scrubbing systems, to optimize the installation of the various components for maximum efficiency and operability. The result is a fast and effective installation with minimum downtime.”

Marcel Karsijns, Director of Damen Green Solutions, commented: “The combination of AEC’s simple yet effective scrubbers and Damen’s innovative installation approach significantly reduces up-front costs and reduces the payback period of the investment. We expect this solution to receive strong support in the market.”

Jurriën de Vries, sales director of AEC Maritime, said; “The close co-operation between Damen and AEC has resulted in this new modular approach for retrofitting SOx scrubbers. This is yet another example of the AEC philosophy; ‘SOx scrubbing made simple’.”