LNG fueled tug is first vessel with new Schottel thruster nozzle

Model test of Schottel’s innovative VarioDuct SDV45 nozzle

AUGUST 29, 2017 — LNG fueling is not the only innovation in the series of three dual-fuel escort tugs being delivered to Norway’s Østensjø Rederi A/S by Spanish shipbuilder Gondan.

The first of the trio, the 40.2 m x 16 m DUX, delivered in May, is the first vessel in the world to be fitted with Schottel rudder propellers featuring Schottel’s new SDV45 nozzle.

The vessel is equipped with a pair of Schottel Type SRP 630 CP rudder propellers powered by two Wärtsilä 6L34DF main engines with a power rating of 3,000 kW each. Additionally, a 250 kW Schottel Type STT 170 FP transverse thruster is fitted in the bow.

After extensive CFD analysis and trials, the new VarioDuct SDV45 nozzle used in the vessel’s rudder propeller has a modified shape to enable high-power applications along with reduced fuel consumption.

Schottel says that the SDV45 nozzle marks a substantial progress in terms of a vessel’s overall efficiency compared to other nozzle products. In combination with a compatible propulsion unit, fuel savings of up to 10% are possible at a certain speed, while maintaining a high rate of bollard pull. Furthermore, due to the nozzle’s relatively small diameter, it is well suited to operations in shallow waters.

DUX be the only vessel equipped with the new nozzle for very long time: a wind farm service operation vessel (SOF) being built for Louis Dreyfus Armateurs Group at the Cemre Shipyard in Turkey is to have three Schottel rudderpropellers featuring the new nozzle.