True.  Particularly with a boltrope and round mast section -- you end up getting a semi-airfoil for at least half the angles of attack.

  However, that would make it tough to handle the sail if it's on the wrong side of the mast, either with the leeward hull to windward (very light wind), sailing wing-on-wing if there's a need to run straight downwind, or if caught aback.  I'd also worry about the sail track in such instances.

  I'd either go with a junk-rigged wing sail, which could go on either side of a non-rotating mast, or with sail track on the leeward edge of a rotating mast.  Mostly for the easy reefing and stowing of both systems.  I'm both lazy and safety-conscious, and that works for both qualities.  There's a lot to be said for being able to release a halyard and have a sail drop quickly into lazy jacks.

  Though if I listen to my own argument, I'd probably have to go with a rotating mast in either case;  there'd be some weird halyard twisting and wear going on if I tried to sail a junk-rigged wing sail on both sides of the mast.

        - Mike

 

Luff turbulence is less of a problem with a shunter. Boltrope/track goes on leeward side of the mast and gives a better flow than for a rotating mast in many cases.

Cheers,Peter

----- Original Message -----

From: Mike Crawford

To: harryproa@yahoogroups.com.au

Sent: Tuesday, August 06, 2013 3:42 PM

Subject: [harryproa] Re: 3 masts?

 

Ben,

  Thanks for the additional information.  I must have been mislead by the same articles that confused Chris Ream on that thread you found.  Perhaps it was the retrofit that I'd read about.

  So it's only the wishbone that rotates, eh?

  Well, at least there are no bearings to maintain, and since it's unidirectional, the only downside to a fixed mast is turbulence at the luff.

        - Mike