Folding propeller now available in four-blade version18/11/2002
It is well known that folding propellers provide substantially less drag and consequently greater speed under sail than fixed propellers.
Volvo Penta’s highly effective three-blade propeller has been available for several years for boats with engines up to 60 horsepower. However, for larger sailboats with more powerful engines, the alternatives have been a fixed propeller, or one of the more complicated and more expensive variable-pitch versions.
With its new four-blade folding propeller, Volvo Penta is now offering a highly attractive propeller alternative for engines up to 120 horsepower. “The new folding propeller provides owners of sailboats from about 40 feet and longer the possibility to select a propeller that offers minimal drag under sail combined with effective propulsion when the boat is cruising on the engine. Compared with a fixed propeller, the four-blade model can offer up to 1.5 knots higher speed under sail, according to Bror Gustavsson, Product Manager at Volvo Penta.
Volvo Penta’s three-blade folding propeller quickly set the standard when it was launched six years ago. As a result of the efficient blades, propulsion fully matches the power delivered by a fixed propeller and is about 50 percent better in reverse than a two-blade folding propeller. Tests conducted with the four-blade propeller indicate that the results will be at least as good.
The propeller blades have a unique, elliptical (high skew) shape and the propeller is patented by Volvo Penta. The design originated with submarines, which of course seek the smoothest, quietest and most vibration-free operation possible. The water slides along the propeller blades and is released smoothly from the tip, which ensures effective operation with minimal vibrations.
The four-blade folding propeller is available for S-drives and traditional shaft installation. The hub and the blades are sold separately, which offers a great number of various combinations and helps ensure that each boat is equipped with exactly the right propeller. The hub fits 25-40 mm shaft diameters and corresponding sizes in inches. The blades are available in several sizes and with different pitches as well as for left and right hand rotation.
The material is a specially developed bronze alloy that is highly corrosion resistant. Volvo Penta’s four-blade folding propeller is being launched in November 2002 and will be available for delivery in the spring of 2003.
For further information please contact
AB Volvo Penta,
phone number +46 31 3221606.