I'm interested in putting a backstay adjuster on my C315, but with the split backstays running all the way to the masthead, I don't see how I can do it. I'd like it for better control over the mainsail shape, and to reduce forestay sag. Anybody have a good idea about how to do that?
315 Backstay Adjuster
- Thread starter Bill Russell
- Start date
Dufour has an interesting solution for that. They have an adjuster inserted in the backstays with blocks to pull them together. Needs some modifications to existing stays though.
Would a backstay adjuster be advisable on an in mast mainsail furler like I believe your boat has ? Perhaps better to remove sag by tightening fore and/or backstays?
Bill: If you decide you need a backstay adjuster follow Stu J's advise and contact Garhauer. They gave me one of their nicest for my C30. I installed it but never used it. Folks would ask me about it and I told them that for my purpose it was like fancy hubcaps on a car - it looked great but didn't improve my performance.
I’d like to have a backstay adjuster to flatten and depower the main in heavy air.
That would make sense. The Selden spars can bend a bit. The adjuster would give you ability to impart mast bend, affecting trim to the upper 1/3rd of the mainsail. It is a control you need to apply with care. The force imparted puts a strong compression on the mast. It is possible to over stress the rig.
Bill: The easiest way to flatten the main is with the outhaul & boom vang. Trying to bend the Catalina mast is like trying to bend a telephone pole - it's not designed to be bent. No masthead rig is designed to be bent. Instead of bending it you're RAKING it and the boat thinks you picked up the mast and moved it aft and this causes other control problems. Raking the mast is not something you want to do because there's no sail trim control benefit to it, in my opinion. I'm sure someone will tell me how beneficial it is to rake the mast on a masthead rig but if I were to list the mainsail trim control in order of importance, to me, the back stay adjuster would be last. If you decide to rake the mast you'll still need to use the outhaul and boom vang to flatten the sail because raking does not effect the sail shape.
Also, as John indicates you're over stressing the rig.
If your front stay is loose you should tighten it and install a simple jib downhaul. You bring the jib to full hoist and back off a bit and use the downhaul to adjust draft depth instead of the halyard.
The engine of your boat is the jib. I don't know if you have a sliding fairlead adjuster (Garhauer sells them) but I'd invest in that control instead of the backstay adjuster.
Skip the backstay adjuster - instead, take your wife to her favorite restaurant. That might be more beneficial to you than you can imagine.
Also, as John indicates you're over stressing the rig.
If your front stay is loose you should tighten it and install a simple jib downhaul. You bring the jib to full hoist and back off a bit and use the downhaul to adjust draft depth instead of the halyard.
The engine of your boat is the jib. I don't know if you have a sliding fairlead adjuster (Garhauer sells them) but I'd invest in that control instead of the backstay adjuster.
Skip the backstay adjuster - instead, take your wife to her favorite restaurant. That might be more beneficial to you than you can imagine.
Don - thanks, as always, for your good guidance. The C315 has a (slightly) fractional rig, and if John is correct about Selden mast bend, a backstay adjuster might have some bending/flattening affect on the main. That's been my experience on every boat I've sailed rigged that way, especially the race boats (which this is not!). And I'd really appreciate the easy tensioning of the head stay with a simple adjustment from the cockpit. How would you rig the jib downhaul you describe on a furling genoa? I do have adjustable genoa lead cars, which I use all the time.
Any other suggestions about mainsail trim controls on this in-mast furling sail? I use the vang and the outhaul religiously, and appreciate the ability to furl it a bit as the wind builds. I miss having a cunningham - would it make sense to have my sailmaker install a cringle, and use a detachable cunningham after the sail is unfurled?
Any other suggestions about mainsail trim controls on this in-mast furling sail? I use the vang and the outhaul religiously, and appreciate the ability to furl it a bit as the wind builds. I miss having a cunningham - would it make sense to have my sailmaker install a cringle, and use a detachable cunningham after the sail is unfurled?
Hey Bill, just curious to know if you've had any feed back from Catalina Yachts? I would think someone in their shop might have some thoughts on your question. Wouldn't hurt to ask.
Anyway, to NOT discourage you to add a backstay adjuster.... I have an older Cat 27, a traditional masthead rig, the backstay adjuster is very powerful. A previous owner had added this for racing, mainly to enhance spinnaker work. I did try bending the mast when I first acquired the boat, having moved up from a series of bendy masted boats that could keep you quite busy. Very quickly, that wasn't gonna happen. I realized, after a bit of research that on a masthead rig the backstay is to control headstay sag.... and... DON.... to allow the mast to LEAN forward a bit for downwind sailing. It's an effective way of creating more fulness in the headsail,
My guess is that you'll evolve into that strategy with the forestay, in addition to whatever leverage you "mini" fracttional rig may allow. I just wouldn't be too enthusiastic about trying to bend a spar with all that sensitive roller gear stuffed inside.
By the way, that pic of the Dufour systems for the twin backstays looks interesting. I think you could cobble together something to at least test it out, for a pretty small investment. My thought was to treat it like running backstays... where there is an adjuster on each stay.. you might research that..."rigging running backstays.
good luck.......... have fun
Bill: Where the flattening effect comes from on a fractional rig is in the middle 3rd of the main when the mast is bowed out. Personally, I don't think you can bend your rig to make enough of a difference.
I had a furling jib and I attached one end of the downhaul (Cunningham was the word I was searching for and forget - it's hard getting old) to the bottom jib cringle and I put a pad eye on the deck for the other end. I made a simple block and tackle and led the line to the cockpit.
I had the same set up for the main because I was tired of having line all over the deck every time I tried to get a few inches with the halyard. Folks will do what is easy and not what's hard and as a result I never adjusted the main halyard. 95% of the time I single handed (my wife was with me but she didn't care about sail trim and didn't adjust anything) and I would have to leave the cockpit and then I came upon the idea of a main cunningham. Unfortunately, I can't answer your question because I never had the luxury of a in mast furling system and I don't know how it's attached or what the effect would be yanking on the bottom of the sail.
The adjustable lead cars are the first mod I added. What a lot of folks don't realize is that the various controls for the main adjusts certain sail trim elements and not others but the jib faileads adjust EVERY element (there are only 4 elements).
I lived in Syracuse (small town of Marcellus) for 7 years before being transferred to So Ca - hated the winters. Where do you sail your boat?
I had a furling jib and I attached one end of the downhaul (Cunningham was the word I was searching for and forget - it's hard getting old) to the bottom jib cringle and I put a pad eye on the deck for the other end. I made a simple block and tackle and led the line to the cockpit.
I had the same set up for the main because I was tired of having line all over the deck every time I tried to get a few inches with the halyard. Folks will do what is easy and not what's hard and as a result I never adjusted the main halyard. 95% of the time I single handed (my wife was with me but she didn't care about sail trim and didn't adjust anything) and I would have to leave the cockpit and then I came upon the idea of a main cunningham. Unfortunately, I can't answer your question because I never had the luxury of a in mast furling system and I don't know how it's attached or what the effect would be yanking on the bottom of the sail.
The adjustable lead cars are the first mod I added. What a lot of folks don't realize is that the various controls for the main adjusts certain sail trim elements and not others but the jib faileads adjust EVERY element (there are only 4 elements).
I lived in Syracuse (small town of Marcellus) for 7 years before being transferred to So Ca - hated the winters. Where do you sail your boat?
Not to hijack this thread but I think that is an overgeneralization. We used a backstay adjuster to flatten and depower the main on an Express 37 (masthead rig) all the time. It was very effective. Of course it was a fairly bendy mast. Not like a Catalina 315.
Bill, I don't understand what you are thinking?!? Can you do that with an in mast furling main? If it's furled, wouldn't whatever is in the cunningham cringle have to be removed?
It appears that with in mast furling you have the vang, the outhaul and the halyard, but not so much the halyard.
Catalina masts are what Don & Joe described, not like Richard's Express model. They do not bend and no backstay adjuster is going to do much more than help on the forestay on a Catalina. I've owned one since 1983, and my backstay on my C34 has been in use for only that for 23 years.
Stu - what I’m thinking, is to attach a small reefing hook to a block and tackle arrangement leading back to the cockpit. When the mainsail is unfurled all the way, I would slip the hook through a Cunningham grommet and use it as a Cunningham to control luff tension and draft position. when I wanted to furl the sail, I would just remove the hook from the grommet. The mainsail furler is essentially the same as a Genoa Furler, just inside the mast. A luff tape on the sail fits into a slot in a foil, and is hoisted up the foil with a swivel at the top. So I think I could tension it with the Cunningham arrangement that I’m describing and gain some benefit from it.
I am not to sure.
- You are hauling the sail to the top of the furler, is there still need for additional sail tension on the luff?
- Furler design is usually not supportive of high tension on the luff. The luff is mostly contained in the mast. Tension on the luff (beyond that provided by the secured tack and the halyard hoist) could disrupt the attachment of the sail in the furler extrusion. Care would be needed in designing the Cunningham, the attachment points, and the angles of force, so as not to damage or strain the furling system.
You may be right, John. But I can adjust the tension of the luff with the halyard, so I'd think a cunningham could accomplish the same thing. I'd remove it before furling, so there shouldn't be a problem with excessive luff tension affecting the furling mechanism. The sails are middle-aged, so they stretch some. I'm trying to figure out sail controls that will help provide a better shape, especially as the wind builds. Of course, I could always buy a new sail . . . 
Yes you can, as long as you get financial approval and it doesn’t impact the expected Christmas Shopping plans.Of course, I could always buy a new sail . . .
I am not sure what Middle Age is for a sail.
I knew my sails were aged when I bought my boat. One day I looked up at the sail with the sun shining on the back of the sail and I saw thousands of tiny holes with sun rays sparkling through. The sail went immediately from “maybe it can go another season” to “Damn… That sail has been living on borrowed time”. Good luck with the CFO in your house.