The Taming of the Screw

If I'm honest, the science behind the fine tuning of propellers has always been a bit beyond me. I remember on our last boat Silurian there was a lot of cursing and filing down, refitting and more cursing to do with the propeller. This time, I'm determined to get my head around it a bit better and it seems the hybrid engine might provide that opportunity. One of the main things which put us off the hybrid engine in the beginning was that we understood (wrongly) that in order to generate electricity the propeller would need to be in a permanently fixed position thus slowing the boat down. This was immediately dismissed as a no-no, just not something a Rogers would willingly sign up to! After Graeme Hawksley's visit from Hybrid Marine it became apparent that we could actually fit a feathering prop (one that slips into a streamlined position when the boat is sailing forward) which could be forced into a generating position (non streamlined) when we wanted to generate electricity from the prop - ie not during a race. After a little research it seems that the prop for the job is an 18" Featherstream propeller made by a local company called Darglow Marine. The exciting news is that Darglow Marine are keen to use Calypso as a test bed for props working with hybrid engines - I can feel a deal more cursing, filing and refitting ahead! At least we'll have the experts helping us.