How to Use/Rig the Cunningham Cringle?

[rardiH36]

Although my sail slides move very freely (sailkote lubricated) and also that the halyard has been pulled up snug using its cabin top winch, scallops appear along my mainsail's lower luff when the wind picks up. This particularly after I've cranked in the mainsheet with the dedicated winch when sailing close-hauled. Then no further amount of tightening the main halyard with its winch will remove the scallops. Slacking off outhaul to relieve foot tension helps a bit, but the scallops are still very prominent.Probably contributing is that the mainsail isn't new and is likely to have stretched somewhat. But otherwise its in generally good condition and appearance with several seasons' life remaining.I gather the solution is to the use cunningham cringle (which on my sail is located about 8-10 inches above the tack grommet) to haul down and tension the lower part of the luff. Questions:- How is the cunningham down haul line usually rigged? Is it just as simple as a line tied somewhere near the gooseneck, then up through the cunningham cringle and back down to a cleat down lower on the mast. Or is a block system needed to provide higher purchase power? Or is the line routed down to a block on the mast base and then back to the cockpit through a clutch and to a winch?- Before down tension is applied to the cunningham, should the mainsail halyard be slacked bit and then re-tightened after the cunningham adjustment? Or can normal tension be left on the halyard?Thanks in advance for comments/suggestions.My boat is a Hunter 1980 Cherubini 36.regards,rardi

 

[Stu Jackson]

We have the same issue, and here's how

ours is rigged. Line from starboard side connected to eye strap on the mast, through the cringle. Line tied to top of three part purchase two block setup on port side of mast. Line from bottom of bottom block led back to a swiveling cam cleat under the dodger via the deck organizer. Usually some mechanical purchase is required, so we used the block arrangement. I'm tempted to say you could most likely get away without the blocks and just use a single line. You might try that before you go out and buy the blocks, but if you do, then get line long enough to add the blocks later. Don't adjust your main halyard at all. Most times it's not only the main luff that's stretching, it's also th halyard. When I need to redo our main halyard I'll use Stay Set X instead of regular Stay Set - I just don't know what i was thinking when I bought the new halyard.If you use a cam cleat you don't need a clutch, and a clutch is overkill and over cost $$. You won't need a winch either, so don't worry about the fairlead if you can locate the cam cleat somewhere easy to reach.Don't forget to pop the cunningham when you start back downwind.

 

[Warren Milberg]

My guess is that your

main, and main halyard, are getting tired and are adding some stretch to the set of your main. This is a common problem, particularly with roped luffs. It might be worthwhile to replace your halyard with a non-stretchy one and see what happens. If your main is permanently out of shape, you may want to take it to a sail loft and discuss whether a recut is practical. Most of the time it is not. A new and better fitting main may be in your future as your current problem with scallops may be that the main was just not cut correctly to begin with. When I use the cunningham on my boat, I can either pull down the cringle and slip it over the reefing hook or just tie is off. I prefer the latter as it chafes the main less. I usually do this at the dock before the main is raised. I simple run a line through the cringle and around the boom, tying it off with a slip knot. This works quite well and avoids the need for additional hardware.

 

[RickS]

Harken CompuSpec

A great source of information is the Harken CompuSpec site. It is boat specific and will provide you with an accurate load and equipment report.

 

[Ray T]

cunningham rigging

Your sail may be old but you really should have a 4-1 block and tackle for your cunningham. The proper way to use it is to raise the main first and then tighten the block untill the scallops disappear. Depending on the way your sail was built you may not be able to eliminate the scallops, I cant on my 216. I guess there is more than one way to rig a cunningham I have a hook going through the cringle and attached to a small boat vang with integral cleating. the bottom is attached to the existing vang bale. Ray T

 

[RichH]

Simplest is ....

Rigid "S" hook attached to a block; the S-hook fits into the cringle. Tie a line AT the gooseneck, through the block then 'back down' to a cleat .... or to a block then back to the cockpit. If thats too complicated forget the block and simply reeve the control line *through* the cringle instead ... but the cringle should have a pressed liner or you will quickly wear out the cringle attachment threads. This will give you a 2:1 mechanical advantage. If you need more mechanical advantage just keep adding blocks, etc. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Other ... and the following 'may' apply *IF and ONLY IF* your sail has a 'boltrope' at the luff....Scallops.For 'scallops' at the bottom panels and assuming you have a boltrope in a sleeve .... look carefully at the sleeve and see if it isnt 'bunched' along the lower section along the luff. Especially if you reef a lot the sleeve and boltrope can get 'bunched' - usually you can 'milk' the rope and sleeve by hand to get it back into correct (free sliding) position. Scallops are usually caused by sail slugs attached 'too tight' and too close to the 'rope' and prevent the rope from 'moving' freely in the sleeve. If there is no evidence of a the sleeve (or sail slug attachments) fouling on the the boltrope, check for a 'shrunken' boltrope. Shrunken boltrope.Raise the sail then additionally stretch the luff by applying additional halyard pressure: ....... raise the sail, and apply enough winch pressure to the halyard so that you stretch out the halyard by 1" for every 11 ft. of luff length. Your listed H38 luff is 46.7 ft. so once you get it 'just raised' you stretch out the luff by applying 4.25 inches of *additional* halyard stress. Then take a large 'square' of cardboard, etc. and hold it (over the sail) at the gooseneck ... one side of the cardboard along the boom and one side along the mast..... If the boltrope has shrunken, the aft end of the boom will be visually *lower* than the gooseneck ... and the cardboard when held along the mast will show an ever increasing 'gap' along its edge going towards the aft end of the boom. If so, consider to take the sail to a sailmaker and have the boltrope 'eased'. The actual angle of the luff to foot is 88 degrees for your H38 sail , but 90 degrees from a square is good enough for 'eye balls'. Every time a boltrope is loaded (raised or loaded by wind pressure) and then 'relaxed' it naturally gets 'shorter and FATTER' at 'each unloading'. If this is a real old sail thats seen a LOT of service you may have a shrunken rope and its now too FAT to fit in the sleeve .... hence the sleeve over the rope is not 'sliding' or 'relaxing' back into its normal position.Yes, a cunningham (or extra halyard tension) can 'compensate' for a shrunken boltrope ... but once it shrinks to the point that its 'binding' in its sleeve ... its time to get it 'eased'. For 'hard sailing', boltropes on my boats usually need to be 'adjusted' every 200-300+ hours of 'cruising' .... 75-100 hours when 'racing'. A sail with a severely shrunken boltrope will be 'draft-aft' (draft will be at 45-50% of cord length or 'further' back, too full draft / 'baggy', the luff section shape will be 'very curved'/'rounded' .... makes the boat heel excessively and will develop a LOT of 'weather helm' (sometimes the battens will be noticeably 'hooking to weather/windward') ..... and the boat will have a case of the 'congential slows' --- all power but no speed; light-wind sailing will be 'abysmal'. All the above is for a dacron cross-cut mainsail with a "boltrope in a sleeve". hope this helps

 

[Stu Jackson]

Good information here

I might add: I tried one of those gooseneck fittings and it kept falling out. This is because we often reef our mainsail, so I got tired of having the hook fall out when the sail was reefed, so I made the line permanent. Trying in a cunningham at the dock before you raise sail is counterproductive to the whole purpose of the cunningham, since you employ it when you want to tighten the luff. On our mainsail, the luff is just fine in light winds until it breezes up, or when (not IF ) the main halyard starts stretching, which I covered in my first post. Whether or not a single line, three part or full vang-sized four part block arrnagement is required for your boat and your use is up to you for trial and error and based on how much you want to spend.

 

[Scott]

Use a clutch ...

It sounds like your cunningham will get a lot of use, as all of ours should .You've got the right idea. Stu is right about increasing the purchase to at least 4:1. That means either multiple passes through the cringle or rigging a hook of some sort with blocks both at the cringle and at the base of the mast. Having greater purchase will give you much more control and will aid with achieving he right set.(Stu, you lost me when you said "line tied to top of three part purchase ...". I thought you had one end of the line tied to a strap on the starboard side and the other end leads to a cleat under the dodger. Assuming you are using a single line passed through a set of blocks, where are you finding another end to tie off at a block? *o) Actually, if you are using a set of blocks, why wouldn't you just use a pair of fiddle blocks with one having a becket to tie one end of the line off at?I assume you have deck organizers and clutches already for control lines leading back to the cockpit. The cunningham would qualify as a control line that you will want to use frequently so why mess around? Rig it for control at the cockpit. I use Spinlock XAS clutches and am very pleased. They work flawlessly and look great on the coach roof. It makes my boat look like a well organized racing machine .Actually, I have not rigged my cunningham yet either and am going to make that addition this spring, too. I saved a position on the deck organizer and a clutch just for this purpose. Like you, I have sail slugs for the main sail, but my sail is only a few seasons old and our use is not heavy, so the sail still has a good shape. I am with Stu on getting the right halyard I think I made the same mistake when I purchased mine. But, I have not experienced the scalloping that you describe so I have not felt the urgency to add the cunningham. While reading about sail trim, though, I want to use it to begin adjusting the draft position properly. So I appreciate the thread.Rich, that was interesting about bolt ropes ... I thought rardi said he had sail slugs?

 

[RichH]

You can have it 'both ways' on an boltroped sail

Either the boltrope fits into the track .... common only with race boats.ORThe slugs are attached to pressed grommets located just 'behind' the boltrope. Full batten end pockets or slug grommets that are too close to the bolt rope can often cause the sleeve and boltrope to 'bind' (the sleeve and boltrope stretchout at different 'rates' ... causing 'scallops' below the 'jam' and 'overcorrected' above the jam/bind if there 'is' any binding. Would be the same as if one used the first reef cringle for the cunningham cringle. Tape luff sails dont have this problem; but are not nearly as 'adjustable'. Bolt-roped sails have a greater 'range of adjustability' through wider wind ranges. 

 

[rardiH36]

Just to Let You All Know, I am Following the Thread ...

Just to Let You All Know, I am Following the Thread with great appreciation. Based upon what I have read so far my thought is:I have on hand a Harken both a triple block and a double block. One (I'm not sure which) has a becket. So a 5:1 purchase at least will be available. Looking at the Harken link provided by Rick, the blocks I have exceed the working and breaking strength specified by Harken for a Hunter 36. Leading the cunningham control line back to the cockpit probably will be the desired outcome. But first I will cobble together an experimental cunningham control with the above mentioned blocks: - One end of the line will be tied to the bail at the bottom of the mast (say port side), then; - Up through the cunningham cringle, then: - Back down an through the block system, then;- I'll attach a snatch block I have to the mast bail (say starboard side) through which I can lead the line to a convenient cleat somewhere. Cost of the experimental rig will be next to zilch.Again thanks all.regards,rardi

 

[Stu Jackson]

That's a good idea and the price is right

One thought: try using the 5:1 as a 3:1 first, because using 5:1 you're gonna have a LOT of spaghetti in the cockpit for just a short change in distance at the cringle.Another idea: put snap shackles at both ends of the tackle and use it for a preventer, too, if your line is long enogh. Yet another reason to go 3:1.

 

[Roger (Ninette Manitoba)]

one item not mentioned yet

I found this on my boat just last week. The cleat under the boom was set a bit high but the screws had loosened over time. I did not know that until I stepped on the boom to get at a halyard that got loose on me and went part way up the mast. As I stepped on the boom (all 200# of me), it slipped down about 2" which both surprised me and made me realize why my luff was scalloping between slugs last year!!! I have since adjusted that lower stop so that the boom sits a bit lower on the mast. You may want to check that on your boat as well.