Propeller drag

A pertinent question, oldbilbo.

The Scouse Mouse is going without any engine power at all as I'm currently in the process of cutting out her glassed-in outboard motor.

It just didn't seem right to drag an outboard leg all the way across an ocean.

On the other hand, a built-in engine has served me well, and getting from Liverpool to Plymouth is, for me, quite a daunting task on its own, especially doing so by an early May deadline. I took a short cut for the Baltimore run this year.

It would be nice to think it will make half a knot difference, but somehow I don't think so.

So, Alan ashore, fixed blades and with a leg, on a 22 footer. What do you reckon?

My guess: a quarter of a knot.

Robin.
 
Jester I believe is engineless and had a long passage for JAC 2012. I don't know how Trevor's passage went (let us know if you are out there), but whatever happened it was other factors other than the prop that caused it. No idea what the leaders were swinging.

Having said that, I am going 'feathering' for the next one, and will hopefully knock a day off the trip.
 
Extra speed. Even better, remove the shaft and fair in the deadwood and fill in any cut out in the rudder. I believe Trevor Leek did this when he completed an OSTAR in a Twister and he made a very quick passage. But are you brave enough to sail engineless? I did for two seasons in my old 30ft racing boat and found it very uplifting - lots of fun (adrenaline!) sailing into marina berths. The best was sailing into the lock at Eastbourne marina one foggy night! Doesn't half hone your sailing skills. And it's not the same as sailing with an engine but not using it, because at the back of your mind you know that you can always start it up to get you out of tricky situation. I've also sailed a Jeanneau Sun 2500 with an inboard diesel and another with an outboard - the outboard version is significantly quicker. My present boat has an outboard and there is a lot of drag with it left down at 5 knots and a huge amount with it down at 10 knots. Above 10 knots and I don't think I could even get it down into the water.
 
That's what I call positive thinking, jesterchallenger. :)

And another thing. My engine locker is the ideal place to store the Jordan drogue.
 
PacketRat said:
That's what I call positive thinking, jesterchallenger. :)

And another thing. My engine locker is the ideal place to store the Jordan drogue.
Click to expand...

I'm looking for an 'ideal place to store' my medicinal brandy container. Needs to be accessible in an emergency.... :cool:


IMG_3744.jpg
 
I changed Scallywag's 12" 3 bladed prop for a 2 bladed feathering autoprop. It improved speed by 1/2 to 3/4 knot. It should also have reduced leeway a bit, but I did not try to assess how much. Performance under power was also improved, though I usually motor only to get head to wind while raising the main. Otherwise the battens snag on the lazy jacks.
 
Pulled Meteors' diesel inboard out and sold it last month. Gained cash. I got shot of fuel tanks (more cash) Exhaust (cash) and controls and wiring and seacocks etc etc etc. Now glassing up the holes and enjoying the extra space (for stores) and lightness. I have taken the view that the engine is if no real use at sea (battery charging is by solar and wind) so have invested a small amount in a small lightweight o/b and transom mount for harbour manouveres when needed. o/b easily stowed in the locker for sea and very little petrol needed. On a windless day I had to go 50nm in 10hours on this little engine on 20l of fuel. Needed earplugs though!
Also picked up a pair or 15ft sweeps today and a sculling oar so in event of engine failure or threat of lynching due to early startup of the banshee engine I still have a chance of not hitting everyone else in the marina. Roger Taylor and Larry Pardy show the way and I am comfortable with my setup.
Not bad as a "gains" list and if the reduced drag without prop, shaft and P give any increase in speed it will be a bonus gain.
Nick Meteor
 
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