From: jeffh@nonsuch.EBay.Sun.COM (Jeff Huntington)
Newsgroups: rec.boats
Subject: Re: 5 sailing questions
Date: 14 Oct 1992 19:27:18 GMT
Organization: Sun Microsystems, Inc.
Distribution: world
Reply-To: jeffh@nonsuch.EBay.Sun.COM
NNTP-Posting-Host: nonsuch.ebay.sun.com

In article 92Oct13164044@lunch.austin.ibm.com, jamesm@lunch.austin.ibm.com (James Miller) writes:
> 
> Hello, all,
> 
> I've six questions related to sailing ranging from gritty technicalities to
> general curiousity and decided to economize by putting them all in one post.
> Any serious responses, either by email to jamesm@voyager.austin.ibm.com or as
> follow-ups on rec.boats, would be appreciated.  (Humorous responses -- if
> they're good -- might be appreciated, too.)  I'll try and get the nitty
> questions out of the way first and save the gee-whiz ones for the end.
> 
> sailing question 1
> 
> The fiberglass rudder is integral with the aluminum tube rudder shaft (1 5/16"
> O.D., 1 1/16" I.D.).  This shaft runs from beneath the transom up through a
> tube in the hull and projects several inches above the aft deck.  Two 1/4"
> holes are drilled laterally through this shaft near its top end to accept a
> stainless steel bolt which fixes the tiller to the shaft.  (They can be
> thought of as a single lateral hole if one thinks of the rudder shaft as solid
> rather than hollow.)  Since the tiller *swivels* on this stainless steel bolt,
> the bolt can sometimes swivel within the holes through the aluminum.  The
> result is that the stainless threads have over time wallowed out the holes in
> the aluminum so that there is considerable play (i.e. "slop" or "dead zone")
> between the tiller and rudder shaft.  Under sail the effect is like driving a
> car with a very worn steering pinion gear.  I'm thinking of drilling out the
> holes in the aluminum shaft to accept a brass tube (with 1/4" I.D., to accept
> the stainless bolt, and say 3/8" O.D.) of 1 5/16" length.  Then the aluminum
> need only contend with *smooth* brass and the easily replaceable brass can
> fight with the stainless bolt threads.  Does this sound OK?

I think it will work just fine.
> 
> sailing question 2
> 
> The main sheet is really a combination of 'center-mounted' and 'end-mounted.'
> It runs from the end of the boom, down to a turning block abaft the tiller,
> back up to a block on the end of the boom, along the boom to a second block at
> boom's center, and finally down to a swivelling block/cam cleat combination at
> the center of the cockpit.  I do not want to put a traveller across the middle
> of the cockpit, but one across the aft deck just forward of the transom
> wouldn't be so bad.  How much beneficial control of the main would be gained by
> replacing the block abaft the tiller with a travelling block while retaining
> the cockpit-centered block/cam cleat?

This should give you the traveler action you seek.  The Lido 14, which I sailed
for many years was rigged that way.  It worked fine, except that (due to the way
the traveler was made) it was hard to adjust.  In fact, I think if you were to 
put a traveler across the center of the cockpit, and still keep the fitting on 
the end of the boom, it would not work well at all.

> 
> sailing question 3
> 
> Being pretty new at this, I'm quite confused about how to tune a rig.  "In
> light wind and smooth water, adjust the sails for maximum flatness and a tight
> slot to reduce turbulence and therefore drag.  In light wind and chop, adjust
> the sails for greater fullness for increased drive..."  The only literature I
> have on this so far is skimpy and a bit inconsistent, and I don't think I'll
> have the opportunity to apprentice to a racer (=8^) any time soon.  What's a
> good book to peruse to learn the basics of tuning a marconi rig?
> 

Be careful about getting the sails too flat in light air.  In fact, it is usually
a good idea to bag the sail off in light air to get max. draft.  The old rule
"when in doubt, let it out" applies quite often.  As the air picks up, you will
want to make the sail flatter.  In chop, it is better to have a little more 
fullness forward for the extra drive.  Try a bunch of different adjustments and
see how the boat feels and moves.

> sailing question 4
> 
> There was some discussion here recently of preparing the hull surface to
> reduce its drag through the water and the 'legality' of such.  We heard about
> dripping detergent off the bow (yikes!), waxing or soaping the bottom,
> roughing up the middle third of the bottom, and finally of some kind of
> (longitudinally?) ribbed surface from 3M on the bottom of one of Dennis
> Conner's (sp?) 12 m Cup boats.  I read in a coffee table book on modern
> submarines that the Soviets stumbled upon a similar phenomenon.  When they
> sheathed a sub's hull in some kind of flexible, fabric-like material to
> minimize the hull's sonar 'fingerprint,' they found that the resulting
> rippling of the outside of this hull at speed reduced drag so much that it
> went much faster than anticipated.  (Imagine -- a squishy sailboat!)  Is there
> a good place (e.g., a particular issue of _Sailing_) to get a description of
> the prepared surface of that 12 m America's Cup boat?
> 
> sailing question 5
> 
> Another fairly recent fad in hull designs from our Cup racing guys is the
> winged keel.  (Weren't some people here talking about having their cruisers
> retrofitted with these?)  It seems that this might actually do some good when
> sailing *off* the wind (ddw to a broad reach), but wouldn't it merely increase
> drag when sailing into the wind (beam reach to close-hauled), when the boat is
> heeled over?  If this is the tradeoff, how close is it?  Is there a good
> writeup on it anywhere?
> 
> Okay, I'm talked out now (and need to get back to work, too!).  If there is
> sufficient direct response I'll summarize to rec.boats.
> --
> 
> _________________________________________________________________
> 
>   James Miller -- developing Unix software at (!) IBM -- Austin
> _________________________________________________________________
> 
>   Internet:  jamesm@voyager.austin.ibm.com   (129.35.131.245)
>   ibm?net:   jamesm@lunch.austin.ibm.com     (129.35.129.93)
>   VNET:      JAMESM at AUSVM6
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> _________________________________________________________________




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