Wärtsilä has retrofitted an inline shaft generator system on the Berge Toubkal, a cape-size bulk carrier of Singapore-based Berge Bulk. This is the marine industry’s first-ever shaft generator retrofit.
Shaft generator systems on board ships are driven by the main engine to supply power to the mains, thus saving fuel and emissions. They are sized to eliminate the need to operate auxiliary engines while at sea. While such systems, also referred to as Power Take-Off (PTO) systems, are today’s standard installations on newbuild vessels, large inline versions with the generator sitting directly on the propeller shaft and turning at 50 to 100 rpm have never before been retrofitted.
The retrofit on the Berge Toubkal will improve the vessel’s Energy Efficiency Existing Ship Index (EEXI) while reducing its overall carbon footprint.
‘Berge Bulk made an industry commitment to go carbon neutral well before the IMO’s plan, and we are installing now the latest fuel-saving technologies, like shaft generators, air lubrication, or wind propulsion on our vessels,’ says Paolo Tonon, Berge Bulk’s Technical Director.
Torsten Büssow, Director for Ship Electrification at Wärtsilä, adds: ‘Wärtsilä is actively working on the development of new technologies that can be integrated into existing vessel systems to make their operations cleaner and more economical.’
Air lubrication system
The retrofitted shaft generator will also provide power to an air lubrication system installed at the same time. The system includes a Wärtsilä control system, as well as a converter to allow the generator to operate over a broad span of rpm. The existing intermediate shaft and bearings were replaced to accommodate the increased weight.
The Berge Toubkal retrofit was completed in Q4 2022, following ten months of preparation time.
Picture: Shaft generator entering Berge Toubkal in dry dock (by Wärtsilä Corporation).