Cunningham Tackle.

[DJE]

At the moment I tension the luff of the main with the halyard winch and I seem to get more tension at the top of the sail than at the bottom so I want to add an adjustable Cunningham system. I was thinking of a rope from a fixing on the mast through the eye in the sail and then down to a 6:1 tackle lead back to a cam cleat on the cabin top. But I also have a spare stopper on the cabin top and a 28:1 winch so could I do away with the tackle and just lead the rope through the sail eye and all the way back to the stopper?

 

[RJJ]

At the moment I tension the luff of the main with the halyard winch and I seem to get more tension at the top of the sail than at the bottom so I want to add an adjustable Cunningham system. I was thinking of a rope from a fixing on the mast through the eye in the sail and then down to a 6:1 tackle lead back to a cam cleat on the cabin top. But I also have a spare stopper on the cabin top and a 28:1 winch so could I do away with the tackle and just lead the rope through the sail eye and all the way back to the stopper?

In my experience, tension along the luff would shake itself even within a tack, or just pointing up a little with the mainsheet eased. What you've described isn't what the cunningham's typically used for - it's function is not only to tension the luff, but (unlike the halyard) to tension the luff relative to the leech, which drags the draft forwards and consequently helps the top of the sail twist off.

Either system sounds fine. The former is 12:1 of course. Either that or the winch is going to give you a good heave (more than enough??); easy to overdo it and knacker the sail.

The tackle system will have a lot of friction and probably won't relax itself unless you use very snazzy gear; a cascade type of 2:1 or 4:1 (multiplied by the 2:1 at the sail) might run more freely. The winch has the advantage of much less friction.

 

[Channel Sailor]

I prefer to have the mainsail Cunningham adjustment at the mast base. It gives the socially distant sat on the rail deck crew person something to do. Also less rope in the cockpit. The cockpit crew will be busy enough trimming the Genoa sheet and car adjuster. My top tackle block has a hook on it, so it is easy to clear it out the way if needs be.

Even when solo I am happy to walk to the mast and at the same time look up to check the Genoa to main slot trim. Bear in mine it will not get used when the sail is reefed in windy weather.

 

[dom]

Definitely adds a useful control dimension, but I'm not sure starting from the mast is a good idea as tension will be affected by gybing/tacking and there's a risk of introducing a load line at an angle to the sail which may damage the cringle/sail.

Possibly worth also checking/lubing the slides but a Cunningham is certainly better. I'd start it at the gooseneck end of the boom (reefing horn, hoop, etc.), then up through the cringle, back down to a turning block and back to the cockpit where it can be easily adjusted. A slightly better option would be to take a line up from the boom, through the cringle terminating at a pulley just below the boom. The Cunningham can now be safely led from lower down the mast, up the pulley, back down to the deck turning block and back to the cockpit.

A tackle or winch will both work well (tackle has more feel but more clunky) but if going the tackle route, be sure not to let it rub against your sail.

 

[flaming]

Previous boat had a cunningham that went from the gooseneck, through the sail and down to a 2:1 that then lead back to the base of the mast and aft to the clutches. So 4:1. Big tug from the cockpit seemed adequate. Never needed to winch it.

Current boat has the same up the gooseneck and down, but there has a 6:1 tackle. So exactly what you are proposing. It works. I can't see that it is significantly better or worse than the other system.

 

[DJE]

.......which drags the draft forwards and consequently helps the top of the sail twist off.

Yes I think that's what I'm after.

 

[dom]

Yes I think that's what I'm after.

I can't remember, is yours a masthead or fractional rig where one can more easily bend the mast to complement whatever you're doing with the Cunningham?

 

[DJE]

Masthead. It can be quite difficult to get much twist in the main.

 

[DJE]

Previous boat had a cunningham that went from the gooseneck, through the sail and down to a 2:1 that then lead back to the base of the mast and aft to the clutches. So 4:1. Big tug from the cockpit seemed adequate. Never needed to winch it.

Current boat has the same up the gooseneck and down, but there has a 6:1 tackle. So exactly what you are proposing. It works. I can't see that it is significantly better or worse than the other system.

First Mate suggests trying the stopper method before spending £100 on blocks!

 

[flaming]

First Mate suggests trying the stopper method before spending £100 on blocks!

That seems wise...

Just be a little cautious using the winch, I fear you could put a lot of load into your luff quite quickly.

 

[TernVI]

The advantage of a tackle is that it gives you finer control. Let off inches of string to adjust the luff half an inch.
It should not cost much to sort out, most of the blocks are not under much load so can be 'dinghy sized'.
You could even experiment with a couple of turns of slippery dyneema.
Our old boat's cunningham was a 2:1 bit of dyneema through the sail, with a (vintage) 4:1 dinghy kicker purchase with v-cleat block on the end. It worked fine. I think its good to have the control near the mast so you can look up the luff while you adjust it.

 

[ashtead]

When you have worked out a solution be interested to see a photo as interested in what’s required in a yacht compared to this type of control in a dinghy.

 

[DJE]

When you have worked out a solution be interested to see a photo as interested in what’s required in a yacht compared to this type of control in a dinghy.

Well I found some dinghy blocks in a box in the garage, last used to haul a train set up to the ceiling in a nine-year-old's bedroom. (Said nine-year-old is just about to turn 30!) Set it up today - on a beam reach with 10 to 12 knots of wind so I didn't really need it. But tightening it has a pronounced effect on sail shape. Cost so far is zero!

Pictures aren't great but the black rope is in a 6:1 tackle anchored on the rod kicker swivel, this pulls down on a short rope from the other side of the kicker swivel after this rope has been up, through the eye in the sail and down again. The working end of the black rope goes through a couple of turning blocks and back to a cam cleat on the cabin top. The cam cleat was used for a boom brake when we bought the boat but we took it off. The small diameter plain bearing blocks aren't great but they will do for now I'll have to see how they stand up to a bit of a blow.

 

[flaming]

That'll do the job... In general plain blocks are fine for applications like this which are set and leave. Ball bearing blocks are best used for constant trimming applications.
If you're only pulling them by hand then I can't see that you'll ever put too much load on them. But if you're worried you could put a fuse in the system, say by anchoring your 2:1 purchase using a much smaller line.

 

[ashtead]

Thanks for that -blocks are quite small but maybe that's helpful to avoid bulk and things catching . Might give it a try as cheaper than replacing our 10m halyiard with 12 m dynema.

 

[dom]

Thanks for that -blocks are quite small but maybe that's helpful to avoid bulk and things catching . Might give it a try as cheaper than replacing our 10m halyiard with 12 m dynema.

See if that works, but spongy braid halyards allow unwelcome creep into a sail, although some braids seem moderately ok in that if one wellies up the tension they kind of reach a point of diminishing elasticity.

Dynema (or suchlike) is of course the go-to choice for halyards, whereas with control lines it doesn't matter so much.

 

[DJE]

Thanks for that -blocks are quite small but maybe that's helpful to avoid bulk and things catching . Might give it a try as cheaper than replacing our 10m halyiard with 12 m dynema.

Our main halyard is good old-fashioned wire spliced to rope. But the effect of tightening the Cunningham seems to be quite different to that of tightening the halyard. The Cunningham is much more effective in pulling the flow forward in the sail for a lot less effort.

 

[ashtead]

Yes we used to have wire on braid halyard on our Bavaria which was standard spec and worked fine. Now in current boat have 10m Lyros in a spin lock clutch and useless in terms of retaining tension. Apparently I’m told it’s a common problem with Lyros 10m to slip in clutches but I don’t know if others have found this. Anyway a Cunningham looks a useful idea to try.

 

[dunedin]

Yes we used to have wire on braid halyard on our Bavaria which was standard spec and worked fine. Now in current boat have 10m Lyros in a spin lock clutch and useless in terms of retaining tension. Apparently I’m told it’s a common problem with Lyros 10m to slip in clutches but I don’t know if others have found this. Anyway a Cunningham looks a useful idea to try.

Lyros make a variety of different rope types, but we have Dynamic Plus cruising dyneema) which holds fine in Spunlick clutches - but as noted in another thread, spinlock cams can wear and need replacement on heavily used items.

We also have a cunningham - 12:1 with a triple set of mini Harken blocks (disposed if by dinghy racer son), doubled up on 2:1 dyneema through cringle and back to gooseneck. Helps a lot upwind prior to more backstay then reef 1.

 

[ashtead]

Thanks Dunedin -it would certainly be cheap to replace a spx cam than a 5 year old Lyros 10m halliard . I thinking Lyros isn’t great quality maybe compared to othe makes like kingfisher and Marlowe but I’m no expert -is Lyros the rope equivalent of elvstrom maybe . I feel I might have a few dinghy blocks lurking for a Cunningham .