> - - - - - - - - - - - - - - - - - - - - - - - - - -
> Curiosity finally got the better of me and I went out into the boat to
> measure my headsail. Why?
>
> When I bought the boat used, I think Bob (who sold it to me) told me it
came
> with the standard jib. But things I read like "the puny jib" and how people
> reef the main with the jib don't quite add up with this thing, and I usually
> hit hull speed in about 12 kts wind.
>
> The foot is 8.5 feet, the luff 16.5 feet (I didn't measure the leach).
> What sail is this?
>
> Thanks in advance,
>
> J.J. Falkanger
> Cary, NC
> P-19 #792 "Fozzguppy"
>
Hi JJ,
The standard IM lapper has a luff of 17.5', foot of 8.42' (8'5"), Leach of
14.68' (14'8-1/4"), LP of approx 6'10-1/4", and area of approx 60 sf.
The standard IM "working or storm" jib (aka 70% jib) has a luff of 14', foot
of 6.68 (6'8-1/4"), leach of 10.725' (10'7-1/3"), LP of approx 4'7", and area
of approx 32 square feet.
These measurements were taken off a two year old sail, so they probably
reflect a 2-3% shrinkage.
What you've probably got is a custom sail. One of the things that happens
when you order a custom sail is that sailmakers use "rules of thumb". For
example, a 115% jib usually has a luff equal to 85% of the headstay length.
If you just give then the measurements of your boat and don't tell them you
want a high aspect sail for a fractional rig, you typically get which
something with a luff of 85% of the headstay -- in your case is about 16.5
feet. The sailmakers "data sourcebook" is what he used to get the headstay
deck to mast length, at about 19' 5". The data source doesn't match the
measurements on my boat, however.
You didn't tell us what the LP (length perpendicular across the sail) is. but
I'd guess its about 6'10" to 7'. You've probably got a "110% lapper". Am I
close?
The P19's fractional rig was designed for "high aspect" sails -- that means
very long luffs and short LPs for any biven sail area. Also, they have very
high clews so you can see easily underneath them for cruising. High aspect
sails go very well to weather, but are a little slower on a broad reach or off
the wind. The high aspect sails on the P19 offset her broad beam and flat
bottom, which doesn't point as well as a deep, needle-nosed hull.
What you've got, most likely, is a custom 110% lapper, which probably works
just fine, is a touch faster off the wind than the factory sail, and points
just a touch lower and sails a touch slower into the wind than the factory
sail.
Regards,
Judy B