PropacRudder Benefits Confirmed In Service
Wartsila NSD has completed shipboard trials with the new Wartsila NSD PropacRudder, and results are promising, according to the manufacturer. The innovative propulsion system was designed to reduce propulsive power requirement, with reduced hull vibration and noise, while providing for exceptional maneuverability.
The trials, undertaken last October and November aboard the 5,175-dwt paper carrier Lysbirs, reportedly confirm all of this. Norwegian owner Lys-Line AS of Oslo was the willing test partner and the vessel was equipped with a Propac propulsion package, which consisted of a 6,300 kW Wartsila 6L46C medium sped diesel engine, a 4.5 m diameter Wartsila CP propeller, gearbox and PropacRudder. The PropacRudder's signature is its streamlined torpedo shaped bulb on the rudder horn.
The bulb is designed to ensure a more homogeneous water flow both in front of the propeller and in the propeller slipstream. The bulb is designed to increase propulsion efficiency via a wake gain effect, meaning that it reduces the water speed into the propeller so that less power is needed to produce the same thrust. The bulb also has been shown to reduce propeller-induced hull noise and vibration by eliminating hub vortices and separation, and cavitation behind the propeller hub collapsing on the propeller. While model tests showed that solely by applying the PropacRudder, the presence of the bulb gives a large reduction in power of about 10 percent for the same ship speed compared to using conventional flap rudders, the full-scale trials actually demonstrated an even greater power savings. It was noticeable during the trial on Lysbris that propellerinduced noise level is very low right across the range of pitch settings with constant propeller revolutions, without any noisy face cavitation or local hull vibration problems.
Circle 57 on Reader Service Card
Read PropacRudder Benefits Confirmed In Service in Pdf, Flash or Html5 edition of December 2000 Maritime Reporter
Other stories from December 2000 issue
Content
- A Pointer to the Future page: 8
- Generator Replacement Proves Cascade General Capabilities page: 12
- ASRY Readies Facilities For Increased Demand page: 13
- Elliott Bay Design Applies FEA To Todd's Drydocks page: 14
- CSO Deep Blue Launched page: 16
- Enhanced Escort Tug Ajax Delivered to 0stensjo Rederi page: 18
- DH Tanker Launched page: 19
- Cammell Laird Secures Upgrading And Drydocking Of RFA Argus page: 20
- Bollinger To Build Two Liftboats For Cardinal Services page: 22
- New Deliveries, Consolidation Drive Cruise Industry page: 23
- GE Marine Engines' Gas Turbines To Be Used On Princess Newbuilds page: 27
- French Yard Tapped To Build $780M Queen Mary 2 page: 27
- Royal Caribbean Crew Honored For Rescue At Sea page: 28
- History Repeats Itself In the "City of Brotherly Love" page: 29
- Great Ships of 2000 page: 33
- New Crane Set To Revolutionize Salvage Work page: 38
- No Smoking Allowed page: 39
- STN Atlas Debuts PPB System page: 40
- PropacRudder Benefits Confirmed In Service page: 40
- A&R Introduces New SWATH Concept page: 40
- Is 3-D Product Modeling Practical For Small U.S. Shipyards? page: 47
