Olds Mechanical Engineers and Founders - Innovative Engineering Excellence

OLDS ENGINEERING     Marine Division

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Published in "Vi Båtägare no. 1-2 1999"


Information for boaters


A propeller with variable pitch and replaceable blades is this spring’s big innovation - and not only in Sweden.


Once again, Sweden is at the leading edge in propeller technology. A recent Swedish invention patented all over the world is a composite propeller with replaceable blades, which can be adjusted to five different pitches. It will facilitate the handling of propellers throughout the distribution chain, all the way to the consumer. Let’s examine the new propeller from the boat-owner’s perspective.

The boat-owner is five times more likely to find the right propeller, i.e. one with the correct pitch, than when buying a conventional propeller. One of the five pitches will undoubtedly be the right one. The propeller has a range of five inches and 200 rotations/inch.

Being able to adjust the pitch according to the boat’s load is a useful attribute, although not one necessarily required on a daily basis.

An indisputable advantage, however, is that retailers can now keep a constant stock of propellers in the correct size. The new propeller comes in four different sizes, covering the entire spectrum from 30-140 hp. This means saying goodbye to those long, sunny days of waiting. 

A further advantage is that even the smallest retailers in the tiniest locations can afford to keep a full range of propellers in stock. The propeller is available from Olds Engineering

Replacing the blades couldn’t be easier. Undo the bolts, remove the damaged blade and attach the new one - you can’t go wrong. Adjusting the pitch is equally foolproof. Loosen the bolts by 3-4 turns, then raise or lower them. All the blades move simultaneously - that’s the patented feature.

Going aground inevitably damages a propeller blade or two. The blades on the new propeller are easily replaceable, their cost varying according to the model size. The new propeller, christened ProPulse, costs the same as a standard propeller, approximately 2,000 SEK. This makes the cost of each blade around 350 SEK.

Many people are doubtful about composite as a choice of material. But composite, like steel, comes in both high and low quality varieties. The composite used for ProPulse was developed by Sicomp of Piteå, owned by the Swedish government and the Luleå University of Technology, and considered a European leader in this field. The propeller is manufactured by Formelprodukter of Boden. Tests have proved ProPulse to be stronger than standard aluminium propellers in every respect, although the overall winner was stainless steel.
Creating a variable pitch propeller is no mean challenge. Experts insisted that this feature would cause the propeller to lose too much in efficiency.
Anders Samuelsson of Piteå, the son of Erik Samuelsson, designer and constructor of the Orrskär motorboats, chose to swim against the tide, and succeeded in making the pitch adjustable by five inches, while getting all the blades to move in co-ordination, at exactly the same pitch. Following two years of tests, patent applications, market surveys and pursuing manufacturers and distributors, ProPulse will be ready for the market this spring.

Order Your ProPulse Propeller Now

Wm. Olds & Sons Pty. Ltd. trading as OLDS ENGINEERING
78-80 North Street, Maryborough Q, 4650 Australia
P.O. Box 3030, Pallas St. Post Office, Maryborough Q, 4650
Phone: 07 4121 3649 Fax: 07 4123 3590 International Phone +61 7 4121 3649 Fax: +61 7 4123 3590

Innovative Engineering Excellence ~ serving over 100 years