Re: Shrouds
Thu, 20 May 1999 20:08:50 EDT

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West Wight Potter Website at URL
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In a message dated 5/20/99 12:00:06 PM Pacific Daylight Time, writes:

> Just to stir things up a little, mast bend is better than no mast bend.
> My Capri manual advises the following (details deleted). There is no
> backstay. Once you have the mast up straight, tighten the upper shrouds
> so that there is a 3" forward bend in the mast section at the spreaders,
> then tighten the lower shrouds so that the forward mast bend at the
> spreaders is reduced to 1-1.5". This dynamic tension reduces "pumping"
> of the mast resulting in overall less stress on the rig. The Capri has
> similar loads to the P-19. 1350 lbs displacement, 138 sq ft sail area,
> 22' mast, 1/8 1x19 wire shrouds, etc.

Hi Webgang,

Steve's instructions from the Capri manual sound pretty consistent with how
my rigger tuned my shrouds and with the instructions he gave me for using the
backstay on my P19.

I raise the mast with the forestay length preset so it's just tight enough to
barely get the pin in without excessive effort. Then I tighten the backstay
enough to put about 1" of bend in it. The upper shroud is pretty snug at
that point. My lower shroud is looser than my upper and it's set to stop the
mast if I try to go past 2". If I try to tighten the backstay further, the
lower shroud starts to fight me and I can tell it's time to stop. That's as
far as I ever go.

For light to moderate winds, I sail with about 1" of bend in the mast. In
general, I do the same for most points of sail below a reach (slow apparent

For high winds, I sail with about 2" of bend in the mast. That flattens the
draft considerably and loosens the top part of the leach so it can twist off
and spill wind in a gust. In general I do the same thing for pointing (fast
apparent wind speed).

Judy B