Brian alludes to what are called around here "Lazy Ians" but are better called "Lazy Lifts". They are not exactly new or my creation, but are an evolution and combination of some traditional practices, starting with my observation that most lazy jack systems were rigged backwards, putting the parts of the system that acted under the least strain further out on the boom and thus causing the boom to sag if the lazy jacks were used to hold the boom up. The other observation was my annoyance with the weather jacks slapping about and the lee jacks cutting into the sail.
My catboat Marmalade has a very heavy boom and uses a LazyLift system that's 4:1 per side or 8:1 theoretical pull, minus friction which is considerable and minus the extent to which the angle of the rig and where the lines intercept the boom considerably reduce the effective leverage.
For a normal sloop have pulleys under the spreaders. One line passes under the boom about 3/4 out from the tack, up through the pulleys on each side, and down ending in a thimbled eye. A second line passes under the boom about half way back and up, through the respective thimbles, and back down to a belay point on the boom about a quarter back.
Were this rig run through blocks, oriented vertically, and to the end of the boom, it would give a 6:1 lift on whichever side you pull on. Even with the inefficiencies it's powerful enough to pick up the boom and furled sail.
I adjust it so that when the sail is up and full in a moderate breeze (Force 4) the lee side lays against the sail's belly and the weather side is without slack and without load. When we tack, the system shifts under the boom taking the slack out of the old lee side.
The order of the lines ensures that the major weight falls on the line 3/4 out.
No leech mess, no hassle.
For Marmalade with her heavy painted wooden boom I have pulleys rather than thimbled eyes, four parts per side rather than three, chafe guard under the boom, and cleats at each place the lifts pass under the boom. The latter are to have the guide you need to keep the rig in place on the side rather than under the boom and to provide a way to freeze the side to side movement when sailing in light airs and I want to belly the sail by putting some strain on the weather lifts. Very adaptable.
For pix and explanation, check on the WoodenBoat Forum -
http://forum.woodenboat.com/showthre...22#post3172222
G'luck