From: tarkkone@klaava.Helsinki.FI (Lauri Tarkkonen)
Newsgroups: rec.boats
Subject: Re: "Jiffy" reefing
Date: 10 Sep 92 00:34:47 GMT
Organization: University of Helsinki

In <1992Sep9.215730.24186@morrow.stanford.edu> francis@oas.stanford.edu (Francis Muir) writes:

>My Freedom 21 has built-in one-lead jiffy reefing on each of two
>reef points, and its not as practical as it should be. One problem
>is that all the sheaves have worn, and i'm taking care of this with
>a bunch of new small parts from Kenyon. But the other thing that disturbs
>me is that the reefing line -- both at the luff and the leech -- goes
>up to an eye and through and down again. In a perfect world this would
>give me a 2:1 advantage, but it seems to me that the frictional losses
>as the line bends sharply through the sail will more than offset this
>mathematical advantage. Questions. Would I do better using reef hooks
>and no mechanical advantage? Could i use blocks at the reef hooks to
>return me the 2:1 advantage? Is it OK to use blocks like this or is it an
>aerodynamic disaster? maybe blocks are OK forward at the mast end but not
>at the leech?

>Francis Muir
>FELIX
>Redwood City
>California

IMHO the jiffy reefing with one line is in most cases useles. Why to make
a simple thing more complicated than necessary and why do someone want to
loose the advantage of separately controlling the leach and luff tension.

If you by some reason escaping my imagination want to use a one line jiffy
reefing think that you usually want the leach more taut than the luff. To
achieve this you could do it the following way:
 
1 Tie the reefing line to the luff cringle.
2 get to the goosenec in a seave or pulley.
3 pull it to the end of the boom
4 get it through the leach cringle
5 get it back to the end of the boom
6 lead it to the gooseneck
7 lead it to the mastfoot
8 lead it back to the cockpit

Now you have double advantage (minus the friction) at the leach and 
single (minus some more friction) at the luff. 

Mark your hallyard, let it go and pull the reefing line until the reef is
set.

This is not the way I set my reef, if you want to know a faster and
more efficient system read on:

1 get two selftatiling winches on the front end of your cocpit or lead 
  your reefing lines to any two selftailing winches.
2 get one reefing line from the gooseneck to the luff cringle and back
  and further down to the foot of the mast and trhrough the locking
  device to your winch
3 get the other reefing line from the boom fitting to the leach cringle,
  back to the end of the boom and to the gooseneck and to the foot of
  the mast and to the other locking device and the other winch.
4 mark your hallyard so that you can let it go precicely to the reef.

Then the reefing:
 When you think it is coming time to reef, you but bot of the reefing
 lines to their respective winches, let he hallyard to the mark and
 pull the slack of both reefing lines (usually you get about 70 per
 cent of the luff and about 50 oer cent of the leach. Then you winch
 and you can get the luff as tight you want to controll the draft and
 you can pull the leach and foot as you please by controlling the posi-
 tion of the end of the reefing line on the boom and how tight you pull
 the rope.

The result is pa perfectly setting sail reefed faster than with the
single line, because you pull les rope by winch, because there is less
friction. 

The only case where I would recommend you the first prosedure with one
line is when you have a electric winch for the reefing (and enough 
electricity to use it),  because the electric winch has the speed and
power to pull the single rope with the extra friction, and then you 
can get the reef by slackking the hallyard and pushing the button.
But if you use manual power and you are particular of the set and shape
of the sail, use to lines.

If you have any crew helpping you, let the one first slack the hallyard
and let the other start with the luff reefing line, and when the halluard
is set let the first one winch the leach reefing line home. The reefing
will take less than ten seconds. 

I have done it single handedly several times, even without an autopilot.
Even with some high quality hardware the friction of the single line
system is going to slow you down. 

- Lauri Tarkkonen