Re: Mast Rake and Bend
Mon, 8 Feb 1999 18:02:07 EST

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West Wight Potter Website at URL
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In a message dated 2/8/99 2:34:50 PM Pacific Standard Time,

> Hi Judy, Thanks for checking that. I thought that the chain plates were aft
> of the mast step, but I wasn't in a position to check (Nightingale is under
> a tarp at our summer house). It seems like this arrangement would give even
> greater control of the mainsail shape, being able to rake the mast at 2
> points. It might make improper tuning of the shrouds more hazardous as
> masts not normally enjoying an S shape.

Hi Ted,

I think this whole shroud tuning topic could use more consideration. My ONLY
source for "how to" was Bruce, the Head Rigger at Svendson's BoatWorks in
Alameda, CA. He's considered topnotch around here and charges $70/hour just
to talk to you for more than a few minutes. But it was worth it for what I
learned, the busted stuff he found, and to get professional planning and
advice on re-rigging our P19. I'd rather pay to do it right the first time,
than pay to do it over again <grin>

As part of the whole inspection of my boat, he gave me a 10 minute
lecture/lesson about the design of the classic fractional rig (like the P19's
except that the P19 has no spreaders) and he tuned the shrouds for me and
demonstrated how it affected the mast rake and bend.

That's where I got my info on tuning the lower shrouds loosely to permit
forward flexion in the middle section of the mast and to prevent over bending
the top on my rig with the adjustable backstay. Even without the adjustable
backstay tensioner, it seems to me that *maybe* if you overtighten the lower
shroud on the P19, you could cause a weird S bend in the mast. But I gotta
mull that one over, I'm not at all sure that that's the right way to look at

If I can, I'll ask Bruce about tuning the shrouds on a P19 with a non-
adjustable backstay. Maybe somebody else out there has a professional naval
architect or rigger who can offer an expert opinion.

Judy B