Jib Sheet Leads

[Bob Hunkins]

My day sailer I is a Spindrift, #11750. I have been told by a few folks in my sailing club that the jib lead placement is Terrible! Currently they are located on the after edge of the cuddy about 10-1/2" from the outboard edge of the cuddy. It seems the top of the jib is luffing way before the rest of the sail does. This implies to me that that the leads are too far aft(?) Or, perhaps having them so far inboard is what is doing it. Can anyone provide any tips on where's a good place to put these leads?
Thanks,
Bob

[Guest]

I haven't seen the jib sheet configuration you describe. My jib also lufts before the main sail, but I have viewed that as a beneifit and use it as an early warning system. I can see that it would be less efficient however. My sheets come in over the commings about 18 inches after the end of the cuddy. The blocks through which they lead are mounted on a small rails so that that can slide fore and aft about a foot which allows for adjustment of the problem that you are talking about. I have to confess that I have just left them where they were when I got the boat. The previous owner had it about 25 years and I figure that he must have known much more about it than I ever will. (It is a DS I.)

Best,

Steve

Steve Max (75264.153)

[Guest]

I recently purchased a used Spindrift Daysailer1. It too has the same block placement for the jib sheets that Bob Hunkins described in his posting. Will try it with the stock setup this Spring -- I'm anxious to see how it sails -- but may eventually be looking for advice for a more traditional jib sheet rigging.

Paul LaBrie (prl-at-cisunix.unh.edu)

[Guest]

There are two 'theories' to how to rig the jib sheets on a DS.

The 'Traditional' configuration derives from the original rigging for the DS I. Jib tracks are mounted on the face of cockpit coamings or, on the DS II, on the top of the cockpit perimeter. The jib sheets run from the jib clew [the corner of the jib that you attached the jib sheets to], back to a turning block on a car on the track and then across the cockpit to the other (windward) side for each sheet.

The 'Cabin Top' configuration has the tracks mounted along the back edge of the cuddy cabin. The jib sheets run from the jib clew to either a cleat on a car in the jib track or through a turning block on a car on the track (where it is lead somwhere else to be cleated off.

Each approach has its advantages and disadvantages. Before we get into them we need to discuss the 'dynamics' of jib trim.

Trimming your jib is a combination of doing three things. You can try them individually or in combination by holding a jib sheet in your hand before you run the sheets on your boat. Grab the sheet about 1 or 2 feet behind the jib clew. Pull until the jib is filled with wind.

First, as you raise your hand you will see the jib leech [the aft/trailing edge] get a rounder curve, the top half of the jib will swing out away from the wind (it will eventually start to luff), the jib foot [the bottom edge] will get very straight, and the bottom half of the sail will get very flat. In seeking the best trim for your jib at any time you want find the angle that allows your jib to be filled with wind along its entire length (no luffing) at all times.

The Traditional configuration works best at setting this angle because as you move the jib car forwards and backwards on the track it alters the angle relative to the jib clew in an up and down. One drawback to this rigging is that the jib tracks sometimes get in the way of where you want to sit and the jib sheets come into the cockpit, taking up space.

The second trim direction can be simulated by returning to your initial starting trim and moving your hand in and out, parallel with the aft edge of the cuddy cabin top. As you move your hand in towards the centerline of the boat the 'slot' between the jib leech and the mainsail's luff [leading edge/along the mast] gets smaller. Eventually the mainsail will get soft along its luff because the wind moving throught the slot is actually pushed into the leeward side of the mainsail. This results in the same lose of power in the mainsail as turning (and luffing) into the wind. But having too wide/open a slot can result in you not being able to trim your sails so you can sail as close to the wind.

The Cabin Top configuration is really good at allowing you to control this angle of trim. But it is weak in allowing you to maintain your first angle of trim, fore and aft. If you use this configuration you will need to have a clew board in your jib. The clew board will have several holes up and down it to allow you to vary the angle of the jib sheets relative to the jib.

By now it should be obvious that the Traditional configuration is weeak in this second angle of trim. To remedy this you might install a trim line on each jib sheet called a Barber Hauler. It consists of a 'thimble' (sort of an egg shaped loop) that the jib sheet is runs through attachhed to a 3/16' trim line. The end of the trim line runs through a bulls-eye and cleat mounted on the aft edge of the cuddy cabin, near the centerline, facing the opposite side of the boat that the sheet they control is on. By loosening and tightening this line you can open and close the slot untill you have it set so the mainsail barely does NOT luff when otherwise trimmed correctly.

This brings us to the third component of trim. Neither configuration has much impact on this component. But how you have set the previous two angles will play a part in how well your jib will draw and the whole (sail) rig is balanced. This third component is how hard you tighten the jib sheet, and thus how flat or full it is allowed to get. To tight and the jib loses power. Too loose and it may luff or, in heavy air, it may become to powerful.

I rigged my first Day Sailer (a Rebel/Spindrift DS I - #11100) in 1980 with a Cabin Top configuration. But I am maintaining the Traditional configuration my current O'Day DS I - #3231 came with. I prefer the control it gives me.

Keith Bay (kabay-at-execpc.com)