Hybrid electrical service for stern trawler

Ocean Choice International, of St. Johns, Newfoundland, Canada has ordered a new 74- by 16-metre freezer trawler to be built at Tersan Shipyard in Turkey. For the design work, both hull and equipment, they went to Skipsteknisk. Given the vessel size and freezing capacity, electrical generation is an important consideration in the design.

In addition to a 4,868kW MAN main engine the naval architects designed in a Cummins QSK 60-powered generator with an output of 2,155 kVA/1,724 kWe. An additional Cummins QSK19-powered generator has an output of 700 kVA/560 kWe.

These will meet the extensive electrical needs of the vessel’s 39-crew accommodation block, extensive navigation suite, and processing factory. Most importantly the large freezer capacity will have a significant draw.

It is to partially meet electrical demands of the trawler that Ibercisa electric winches have been selected. These trawl winches have a remarkable quality: when the net is being payed out, the force of the turning winch generates electricity. It is similar to a hybrid car going down hill, but the new energy is not stored in a battery.

“By the use of active front end (AFE) technology, we are able to utilise regenerative power from the winches when paying out the trawl gear. Thus the winches work as a ‘power plant’,” explains Inge Bertil Straume of Skipsteknisk.

“This free power will normally be utilised through the other major consumers on-board, like fish-factory, freezing machinery and the hotel load. In the case of low demand on-board, this free power will be put on the propeller through the gearbox shaft alternator/motor (in PTI mode).”

Delivery of the, as yet unnamed, vessel is scheduled for the fourth quarter of 2019.