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Reply to: Help needed in Prindle 18-2 mainsheet downhaul system and 4 way jib system.

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[quote=Doug-p182-590][quote=Ucfsailor19]Doug,

I have a prindle 19 and was a little confused on the downhaul setup.  I'm not sure if its the same between the two boats or not but I have two little blocks on the mast, one block right where the boom attaches and then two on the sail.  So from what you are saying I would go through the one on the mast up through the one on the sail then through the one near the boom then through the other little one on the mast then through the sail then put a knot in it?

thanks,
pete[/quote]

The stock setup on the 19 is the exact same as on the 18.2  Yes - two blocks on the tack of the main, two blocks on each side of the mast and a clutch on the port side of the mast.  You tie the line to the center ring in the main with a bowline and bring it down, through the wishbone and through the block on the mast on the starboard side.  Back up through the starboard-side mainsail block, back down to the block on the port side of the mast.  Up again (always through the wishbone) through the block on the main on the port side and down through the clutch.  You haul DOWN through the clutch where it locks off.  It's a 4:1 purchase

It works on the beach or when your crew can adjust it in calm water, but adjustments on the fly, from the hulls and ESPECIALLY out from the wire can be difficult, if not impossible.  Your crew has to be at the mast base to adjust it.  If you use the stock system you would set it as:

Pull in on the mainsheet until the boom is near horizontal - fairly tight.

Light wind (0-10):  Downhaul just enough to get the diagonal wrinkles out of the sail.  Look up when you do it.  If you see the pocket (curve in the main) begin to decrease at all, that's too much.  You won't be able to sail to wheather too well because a large pocket in very light air will stall.

Medium wind (10-20):  Downhaul until the wrinkles are gone and you just begin to flatten the pocket.  One more pull down and that's it.

Heavy wind (20+):  Downhaul until you see the sail flatten and there's a much smaller pocket.  A flat sail produces little power.

The mechanics behind this are simple:  The luff of the mainsail (the part that attaches to the mast) is curved, not straight.  If you were to lay your sail out flat on the ground, you'll see this.  But your mast IS straight.  So when you put a curved sail on a straight mast, that extra sail creates the pocket which, like an airplane wing, produces lift.  That power NOT the wind pushing sideways against the sail is what causes you to fly a hull.  When it's too much power, you need to decrease the lifting force.  When you crank down on the downhaul and the mainsheet, what you're doing is BENDING THE MAST!  So when the mast is bent (as it's meant to) it begins to match the shape of the mainsail as it were lying flat on the ground.  And so, exactly that - the sail flattens out.

THAT'S where the downhaul and mainsheet come into play to control the speed/power/control of the boat.  Any side-force wind on the sail (even at 20+ knots) isn't nearly enough to knock your Prindle over with the crew out on a hull and especially out on the wire.  All that happens is the boat slows down and wants to move sideways.  Your weight as ballast is too much.

There in lies the problem with the stock downhaul system - It can't be adjusted from the hulls.  It's designed as a "fix-it-and-leave-it" system and that's not good when you want to adjust it while sailing when a strong puff comes or the winds change.  In all honesty, the four main controls on the boat should be:  skipper; mainsheet & tiller, and the crew; jibsheet & downhaul.  The two of you work together.  Big puff comes and you call out to the crew, "more downhaul!"  They crank down, you crank down on the mainsheet and let out on the traveler.  The main flattens and the angle of attack spills out and you won't get over-powered.

Something like this though is meant to do just that:  [url]http://www.murrays.com/mm5/merchant.mvc?Screen=PROD&Product_Code=07-2088&Category_Code=C-MO-D&Store_Code=MS[/url]

I hope this helps.
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