Re: [Amel Yacht Owners] Re: Mizzen Staysail setup, aka foc d'artimon, aka "Little Artie"
Bill,toggle quoted messageShow quoted text
I agree with your comments here. When Olin Stephens was testing the weatherliness of the infamous yawl “Stormy Weather” he was using his earlier smaller yawl Dorade as a trial horse. The winds were quite strong and Dorade was consistently faster to weather. So a decision was made to hoist the mizzen on Stormy and she slowly pulled ahead. I think that story is contained in Olin’s book “All this and Sailing too” but I am reaching back more than a few years… Those older very deep and narrow boats develop very little weather helm from heel so I think that it is quite possible that the difference in this case was just as you stated, a change from Lee to Weather helm. As I am sure that you already understand, Lee helm creates an underwater coupling between the keel and rudder that is in effect camber in the wrong direction (increasing lee way) and weather helm as you state reduces leeway by creating camber in the correct direction making the coupling between the rudder and the keel a lifting shape.
While on the subject of balance, I wanted to say that my Amel ketch has the best course keeping ability of any boat that I have owned to date. I attribute this to the pretty well balanced hull and the Ketch rig but I would like to understand all of this better. On a sloop the CE of the two sails are both fairly close to the point that the boat wants to turn about so any coupling between the sails is not very meaningful or stable from my experiences. On a Ketch there is a significant spread between the Genoa and the Mizzen so a large turning moment can be developed when there is an imbalance and fortunately when the sails are trimmed correctly the imbalances that occur tend to be favourable for holding the boat at a particular wind angle. The stability I find is most noticeable with the wind forward of the beam and the mizzen eased to the verge of luffing and the Genoa just slightly over trimmed. As the boat deviates towards the eye of the wind, the Genoa creates a stronger force to leeward as the apparent wind increases and the Mizzen being already close to luffing (Which also happens naturally when hard on the wind since the Mizzen is flying in wind that has been altered by the Genoa and Main so that the Mizzen is seeing an apparent wind much closer to the bow) unloads removing some of it’s force to leeward creating a turning moment to leeward which is in the direction to restore the trimmed course.
It would be interesting to hear more about what you have learned about sailing your Amel if you have more to add.
I would like to add one thing that helps explains just one of the reasons that I have become a convert to having either a yawl or a ketch for a cruising rig. In addition to providing a tool to balance the boat, the mizzen can also be used as an “air rudder” to steer the boat when there is little or no way on. ( I have not tried this on any other boats besides my Loki yawl and my Maramu so maybe this will not work on all yawls/ketches. ) This technique can be useful if you find yourself needing to sail off of a mooring or anchor and do not have the engine available. It also often happens that the tack that you depart on can be quite important due to hazards on a particular side of the boat. In my experience, departing such a situation in a sloop is risky because there is not much control of which tack you might end up on. One brief wind shift and the backed jib can become full and drawing which isn’t good. With either my yawl or the Maramu on anchor (with no current), if I put up the mizzen and the main, then draw the mizzen boom to windward on the side that I wish to turn to, the boat will rotate in that direction. As the boat rotates, the main fills and the boat begins to move forward. By alternating sides it is even possible to tack the boat slowly to windward. I have so far only tried this in lightish air but in theory it should work in higher winds too. Maybe some food for thought.
SV Sueno, Maramu #220