[Sonar] Highlights about trim from a conversation with Steve Shepstone

[Martin Fossen]

Hello Fleet 5
I'd asked Steve for his perspective on the Mid winters.  Some of his response touched on light air trim which prompted me to ask more questions on that.  Steve, of course, was very generous in sharing his knowledge.  Here's some exerps from that correspondence:


Steve:  
In the last race of the first day, the race started in about 3-4 knots of breeze.  We loosened the uppers 4 turns, lengthened the headstay to just under 26’, and blocked the mast all the way to the front end of the partner.  We sailed away from the fleet for about 7/8 of the first beat.

The end of the boom was about 6” below the centerline, so we had close to no mainsheet tension.  Easing the uppers and blocking increased the headstay sag, but also flattened the main.  The main is designed for some mast bend.  With very little load on the rig and almost zero mainsheet tension, the mast is too straight.  The main looked too flat down low from the blocking, so we eased the outhaul about 1-1/2” or 2”.  We also moved the jib lead forward to power up the bottom of the jib.  The water was somewhat lumpy, but not really nasty.  We loosened the lowers and had about ¾” of sag to leeward at the spreaders.  With the jib really powered up, you end up with lee helm unless you have enough mast rake.  When you’re set up for the really light air and the breeze picks up, we found that you have to move quickly to change the blocks, so you can pull the headstay straighter without over flattening the main.

Marty:  
You mentioned easing the outhaul.  Does anything aid you in determining the right depth, or is it intuitive?

Steve:  
The depth choice is intuitive, but based on years of experience in a variety of boats, especially by my teammates, who are more into sail shapes than I am.


   Marty:  
Have you ever tried in-hauling the jib clew with the windward sheet? 


   Steve:  
We didn’t try in-hauling in Florida, but we did do it in the one race where it didn’t blow hard when we were in England.  When we tried it, it worked well, good pointing and speed.  Bill Lynn trims directly from the block on the jib track across the boat to a cleat.  In England, we put a small hook onto the jib sheet.  A loop of line with a clam cleat in it went through the hook and an eye on the cabin top.  I’m thinking of experimenting this year rigging the jib sheet like Bill Lynn does in the lighter air and rigging it the normal way when there’s more breeze.  That will give us two lead angles.  It may not be as good as the adjustable system we had in England, but I’m a fan of simplifying things.


Spring is getting closer.  See you soon.
MF





 
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