[alberg30] Tacking Angles

John Birch sunstone at idirect.com
Mon Nov 8 14:05:11 PST 1999


Well Bob, now that you ask ... the boat was reefed Q: How tight was the foot, was
the new clew bladed all the way back to reduce power and improve pointing?  Where
was the traveller?   What was the leach tension, was the leach standing up or
badly sagged?  Was the boat on her ear?  The main is tired, how tired?  Draft too
far aft?  Halyard tension? What were the leach ticklers doing, top one stalling
50%?

Jib was rolled, some times Sunstone points slightly better with one roll in the
Genoa? What was the wave action?  Head stay tension? Shrouds tension? Jib
ticklers drawing well? Track car at 45 - 60% sheet angle? How open was the leach?
Ticklers stalling evenly up the sail?  How old is the sail, draft too far back?
Halyard tension? Is the sail a deck sweeper or high cut and is the cloth any
good?

The cloth you say, well people don't realize it but bias stretch in cloth will
undo the best cut sail - THE CLOTH HAS TO BE STABLE that's why some sails cost
more than others ALL DACRON IS NOT THE SAME!!!!   There is $3.50 per yard Dacron
and there is $15.00 a yard Dacron AND IT 'AIN'T THE SAME THING, the expensive
stuff is far more stable and will have a much longer usable performance retaining
it's shape.

So the next time you hear of someone giving a great quote on a new sail, realize
it is likely a lower quality cloth.

Wind instruments won't make your boat point better, good sails properly set
will.    Unless you have a neck problem I wouldn't bother with them.   Wool on
the shrouds, a compass and a knot meter is all you need.

You have identified some of the problems you had, in flat water I've had maybe 35
- 40o but most times it is more like 40 - 45o  it depends on the conditions.

Cheers,

John
Robert Kirk wrote:

> From: Robert Kirk <kirk at neptune.gsfc.nasa.gov>
>
> >Tom Forhan wrote;
> >Beating down Delaware Bay one night last August into a vaguely 20 knot wind,
> >I was disappointed with tacking angles of about 120 degrees- i.e., one one
> >tack we would be heading 180 degrees on the compass, after tacking the new
> >course would be about 60 degrees.
> >
> >I think we had one reef and the genoa furled to about 90%, so surely that
> >was not optimal. Also I'm sure there is lots of room for improvement on my
> >boat: needs a new main, rigging could be tighter, needs wind instruments,
> >etc.
> >
> >Still I would like to hear from you all about what your experiences are- how
> >close winded are our boats, both in moderate conditions (full main and
> >genoa) and reefed down.
>
> Tom... I'm not sure your tacking angles are all that bad given the slightly
> shortened sail configuration.  Last year I took my trusty GPS out and did
> some close hauled  tack legs out in the Chesapeake Bay under controlled
> conditions: Steady course and evenly spaced half-mile tacks both upwind and
> downwind.  The resulting GPS tracks that I plotted later were regular and
> averaged ~90-100 degrees if I remember. Might have done better with tighter
> rig, closer sheeting, traveller adjusting, etc, but my conclusion: the
> Alberg 30 can't point much better than 45 degrees to the wind.
>
> Do the racers have any comment?
>
> Bob Kirk
>
> 
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