Roller Reefing Main Sail Design

[capta]

We will soon be in need of a new main sail and I would like to hear some ideas on designing a roller furling main on a 53' ketch.
Our present sail is a radial design sail of some esoteric fabric called "tape drive" by HR in NY. Though it is a fantastic sail design wise, the material is failing after only a few hundred days of sailing. However, this seems this is a very labor intensive cut, probably much more expensive than we can afford.
It seems sail design for roller furling boomed sails has not quite caught up with the realities of the systems. With infinite reefing, stresses on the reefed sail are not along a reinforced seam as they are in slab reefing and with a loose footed sail the out haul pressure is not directly along the boom, but more like the pull of a high cut Yankee (the boom raises as we reef). Obviously, a high cut Yankee design would cost too much sail area, so I'm looking for ideas on a compromise. Perhaps a miter cut sail, giving more strength in the direction of pull on the outhaul, but probably more susceptible to stretching when reefed. At any rate, it may need many small panels rather than several larger ones.
This sail sets much more like a jib than a boomed sail, being loose footed, using the outhaul and the sheet to obtain a good sail shape. Since most of our sailing is in 20 to 30 knots of wind (usually hard to weather) we often have the sail rolled in to the second spreaders, a DEEP reef, way beyond the reinforced reef points presently on the sail, see the pic above.
I am not a sail designer and would really appreciate some input as to what might work or not. Looking at a sail and sailing with it leads to many ideas, most of which are probably unworkable in reality.
You couldn't give me a sail built of any of the esoteric cloths for cruising, roller furling or not. I like Dacron and it has held up well over many, many thousands miles of sailing on vessels from gaffers built before 1900 to the Maxi racers of the seventies, for me.

 

[shemandr]

I can only offer the observation that with my in mast main roller system, the first reef point didn't really depower the sail because it became more deep in draft as I rolled it in. It seemed like it needed some way to draw sail material from the middle area of the sail into the furl faster than the foot. It's possible the sail was just at the end of it's life but the early reef was just a big fat drag-monster. Performance upwind suffered mightily. The deeper reef positions worked better since there was so little sail out that it was less critical to flatten it.
I concluded I didn't like the system based on the inability to achieve a flat sail shape while reefed.
I didn't regard the system suitable for sailing in the conditions you've described.
Incidently, I had a tape drive jib that had a great shape. And it kept it's shape in puffs with minimal stretch. Unfortunately it became a sieve, with a really good shape, and had to be retired.

 

[capta]

Thanks for the reply.
I agree with your analysis which is why a miter cut came to mind.
Obviously, sailing inter-island in what seems to be the norm these days (rather than only at X-mas), high performance in 6 to 12 foot seas and 20 knots or more of wind, is not our prime concern.
She will do very well once in the calm water sailing up into the anchorages, even with the main, as you said, a sieve.
I am steadfastly a fan of the in-mast furling; infinite reefing has won me over, as well as the ability to roll in or out the main on almost any point of sail.
I believe with a properly designed sail, the system would be unbeatable for cruising.

 

[Barnacle Bill]

There are two manufacturers for in boom furling. One is Forespar and the other is Schaefer. Forespar does not make a unit for your size boat, but Schaefer does. The boom has to be pretty much at right angles to the mast to work properly, so if your boom rises to accommodate a dodger, for example, it might not work. Selden Spars have an in mast furling rig that works very well. Years ago they had a retrofit furling main apparatus that one could bolt onto the trailing edge of the mast, but the labor cost was so much that they discontinued it because it was actually cheaper to just order a new mast from Selden that furled the mainsail. The largest boat I have installed one on personally was a 47-footer and the boat owner, who had a behind mast ProFurl system was delighted because he hated the ProFurl. At any rate, that is what you are up against, but you will love the end result. As far as sails are concerned, I have sailed on many boats with Selden furling masts and I was quite pleased with how flat you could get the mainsail for decent cruising performance. One sailmaker that I thought did a particularly nice job was Doyle Sails out of Chicago.

 

[capta]

Barnacle Bill
I don't quite get you're point. Are you suggesting I get in-boom furling rather than a new main sail for my present system?
As I stated, I love the in-mast set-up and from my discussions with captains and crews aboard the mega-sailboats down here using in-boom furling, there are significant problems with those systems. Nothing about them appears to be viable on short handed (or single handed) cruising boats.
But to each his own, I guess.

 

[Gunni]

Great topic. I was also confused by your rig description. "roller furling boomed sails". So it took me a few re-reads to understand what your concerns were all about. Many, many rigs these days are built to fly a loose-footed mainsail, so it shouldn't be a challenge to a qualified sailmaker. There is no way that I would put a laminated sail on a boat headed to the windwards. The inevitable flogging of the sails in those consistent tradewinds would be guaranteed to eat up the laminate. They aren't built for that kind of "cycling".

I'm currently on the hunt for my next suit of sails so I can offer you my perspective: I'm interviewing sailmakers with a interest in their actual experience with my kind of sailing, on my size boat. I am clear about my kind of sailing, performance cruising, with a short crew. So my sail system has to be easy to manage, and accept the inevitable abuse of a sail left to flog a little too long. I will not allow myself to be talked into a performance sail by an inexperienced sailmaker salesman. I love my full battened sail, but understand that in the tradewinds, it hardly matters. And you have the roller-furler in mast, so you are all in. So, this isn't a mystery, plenty of boats like yours have been fit with durable, well built sails. It is just a matter of finding the right guy who knows how you sail, and what your clear expectations are. For regular sailors, every sail is a compromise. For cruisers there is no need to compromise on durability, and sacrifice power and windward ability. I assume you have a good vang, and a properly configured rig / spar geometry.