Shifting Through The Sail Trim Gears

[Gudenuph]

RichH
Thanks for your summary of gear shifting but then I'm a fan of Bethwait and Gentry also. While not permitted by Racing Rules, but no less proper tools in my opinion, your acceleration tips probably should be practiced more often if for no other reason than to be available when really needed. I wonder, however, how you would equate "sculling" with "fanning" for light air acceleration. Could they be used simultaneously with synergistic effect?
Thanks, Geohan

 

[RichH]

Could they be used simultaneously with synergistic effect?
Thanks, Geohan

Yup, thats exactly how one gets a big ILYA scow or most other 'sport boats' up on a plane to windward in 'light' air .... heel the boat to leeward, 'fan' the main a few times .... and 'end' with ONE BIG 'scull' on the tiller(s) to the centerline AND simultaneously pull in on the main real hard (to 'cup' or 'hook up' (power up) the main leech - and you can then 'break free' and onto a plane much 'earlier'. Even if you dont break into a plane, your apparent wind increases .... so youll be going faster (building apparent wind across the sails) so you may 'break free' on the next .... 'oooch'.

Of course, on a race course, you can only 'legally' hard-trim-in/scull 'once'. Ditto when 'roll-tacking'. The 'mighty' hooking-up the leech also sends MASSIVE turbulence 'behind' you to any competitor who is 'sneaking through' a start line ... stops them 'cold'. ;-p

But lets keep this simple as Don's topic is 'shifting gears' by sails and not 'boat handling'.
;-)

 

[jimmyb]

RichH,
I feel bad telling you after you took all the time explaining for me. My rig is a simple 3 stay rig. I use a hank on jib with very cheap hanks that have a slot and are twisted on. If we have to sail this boat again this year Im going to replace with snap piston style hanks the others are a PITA. The can pop off when dousing the jib.

The other mistake I made was (im a bit dislexic) that the 1/8" line running threw the edge of the sail is actually running through the leech and ties off at the clew. :bang: Going by memory was a big mistake. After reading your post I grabed the sail to refresh my memory. Still wondering what its purpose is if you have time for a quick post. Very sorry, man I dont like wasting folks time especially when there trying to help me.

jimmyb

 

[RichH]

Not a problem at all.

Your 1/8" line is the leech line and is used to tension the leech to prevent fluttering of the very end of the leech (fluttering leech = leech line too loose), etc.
If too tight, will cause the leech/aft to be no longer flat to the very aft end of the sail ... (leech that is 'puckered up' near the far aft end = leech line too tight).

Constant 'fluttering' of the leech will quickly 'fatigue' the fibers of the cloth and quickly break down any 'filler' that wss pressed into the sail cloth to make the cloth 'stiffer' .... leach then quickly loses it 'strength'. Such 'fluttering' can also lead to premature stitching failure/breakage.
The opposite condition - A too tight leech line, and the air flow 'exiting' the sail is 'disturbed' by the 'little crease' that usually forms along that 'edge'; thus, the sail isnt as efficient as when the leech shape is 'flat-ish'.

;-)

 

[jimmyb]

RichH,
Thank your sir, will observe on first launch as soon as the water turns to a liquid again around here and adjust accordingly.

take care, jimmyb

 

[Joe]

Don't over tighten the leech line to the point where it "cups" the trailing edge. It will negatively affect air flow. ONLY use it for reducing the flutter.. it has no other function.

 

[jimmyb]

Thanksk Joe.

 

[Stu Jackson]

In addition to all the great technical advice here in these replies, one of the things I learned is: If it LOOKS GOOD then it's probably right.

Here's a few examples of why:

1. leech flutter - looks crappy, right? Tighten the leech cord.

2. Main backwinded by jib: luff of main keeps blowing around (like a fisherman's reef). Readjust angle of attack or draft of main, readjust jib sheet tension or car position.

3. Jib telltales are uneven going upwind: readjust fairlead car position.

The lis goes on and on and on...