Propellers are a complicated business. Pitch, torque, number of blades, fixed or folding… Not to mention the fact that they just get forgotten about when we are under sail. But when we fire up the motor, be it because you are becalmed, or at the entrance to a tricky port, we count on them working properly! But since they are a necessary evil on board our cruising multihulls, let’s try and get the best out of them. We’re going to try and take a look at the different factors which govern their workings, and at some different models on the market.
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Publié le
16/12/2016
Par
François Trégouët
Numéro :
141
Parution :
May.
/
Jun.
2015
First of all, to choose the right propeller, a few bits of information need to be collected. The boat’s displacement, hull shape, windage, all more important than on a monohull , are of course the first things to establish. Closely followed by the motor characteristics: graphs showing torque and power developed for a given level of rpm, type of gearbox and reduction ratio are all essential so that a real propeller specialist can work out your optimum prop, an appendage which is all too often overlooked. Be careful not to fall into bad habits inherited from years of monohull sailing. Twice the …
