Use backstay to control forestay tension with furling mast?

Oct 26, 2008
6,051
Catalina 320 Barnegat, NJ
Its fractional. 15/16th, so barely.
Ah ... I have been looking at B 331 (with masthead rig) and just assumed it was a replacement for 323. Plus, Sailboat Data appears to erroneously call it masthead. Now I see that 323 actually replaces 331 and photos show the forestay not nearly to the masthead. Now that my eyes are open, this looks like a boat that might please both Sue and me! I looked at a 321 and was a little dismissive. The progression of numbers is just a bit odd!
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Ah ... I have been looking at B 331 (with masthead rig) and just assumed it was a replacement for 323. Plus, Sailboat Data appears to erroneously call it masthead. Now I see that 323 actually replaces 331 and photos show the forestay not nearly to the masthead. Now that my eyes are open, this looks like a boat that might please both Sue and me! I looked at a 321 and was a little dismissive. The progression of numbers is just a bit odd!
Its a very nice JM Finot design, based off of the original Figaro hull. Not a bad place to start! Plus how many cruisers do you know that have designer-provided polar charts?

http://www.finot.com/bateaux/batproduction/beneteau/oceanis323/polaires/polaires323.htm
 

Rick D

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Jun 14, 2008
7,132
Hunter Legend 40.5 Shoreline Marina Long Beach CA
All else being equal, the best fractional is rig is the one that is fractional enough to allow the benefits of the design (mast bending).. the higher it is, the bigger the headsail can be, and the higher the spin head is. But you lose leverage on the forestay to bend the rig. Fract boats started out at 3/4, then went to 7/8ths. For a long time now best is thought to be 9/10s for racy boats. We can bent the mast on BlueJ just fine, but we have a powerful backstay adjuster. You do see higher ratios for some models, most cruisers who are less likely to miss the the full range of trim adjustment.
Thanks. I have never sailed a 15/16th. I get a 3/4 or 7/8. It simply seems intuitive that a 15/16 doesn't accomplish much at all. But intuition isn't truth. What do you think?
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Thanks. I have never sailed a 15/16th. I get a 3/4 or 7/8. It simply seems intuitive that a 15/16 doesn't accomplish much at all. But intuition isn't truth. What do you think?
Well for sure as the ratio gets closer to 1:1 the backstay effort goes up, and the amount of actual bend goes down. That has to be factored into the overall design and sailcut. I've sailed on several very racy 15/16th (I think!) boats and we bang on the backstay all the time. For sure effects the rig and sail trim as expected. Not all boats will respond the same way, of course. For example, the SunFast 3600.

 
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Aug 2, 2010
502
J-Boat J/88 Cobourg
Scott, she is a fine ship and quite comfortable in most respects. The only criticism we have is the lack of galley storage for cruising. We love the aft cross berth, we love the rotating wheel at the dock, we love the cockpit (and the giant cockpit locker), and she is pretty fast for her size. I haven't done very well racing yet but we are carrying way too much weight and not at peak with our sail trim.....next year! The furling main is a problem in light wind racing but it sure makes day sailing easy both going out and coming in.
 
Aug 2, 2010
502
J-Boat J/88 Cobourg
If you have a furling mast and sail, then I'd assume the sail is cut very flat and with very little luff curve. So bending the mast might make your sail shape worse.
I get it now, the main is cut pretty flat to furl easily so the only real reason to mess with the backstay is to tension the forestay which we could do with the shrouds instead. Did I get that right?
Frankly, we cannot point as high as I would like but I think she sails pretty well. We have spent plenty of time over 20 knots of wind and I haven't really noticed any headstay sag, now I need to figure out how to look at that.
 
Oct 26, 2008
6,051
Catalina 320 Barnegat, NJ
Now that you've got me focused on this particular model, I think I'm there! Sue wants room both in the cabin and in the cockpit. She loves our neighbor's Hunter 310 but I'm not sold mainly because of the B&R rig. I've always been attracted to Beneteau's configuration in general and have been trying to identify which one I like the most. The interior of the 321 that I looked at did not compare well with the Hunter 310 (and my neighbor's boat is very clean/well maintained). Perhaps the 323 is the right one. They are newer (good thing!) so I'll have to think about higher price. I've always wanted polar charts for my boat! :cool:
 
Aug 2, 2010
502
J-Boat J/88 Cobourg
taken after a 4.5 hour sail this summer with an average from dock to dock of 6.5 knots. The speedo is perhaps a bit optimistic but certainly well within a half a knot. To be fair, a friend sent me an email saying they had just remarked that it wasn't fit to be out in that weather and then saw us glide by on our way into the marina after surfing into the entrance. I was dead set on a 40'er as I had owned a 375 Legend before but after owning this boat for a little over a year, I am perfectly happy with her for Lake Ontario.
 

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Aug 2, 2010
502
J-Boat J/88 Cobourg
Your boat is fractional with swept shrouds. While its a static setting while sailing, rig tension will greatly effect your forestay sag. We adjust ours every time we go out based on expected conditions. We use a fixed number of 1/2 turns from a baseline to simplify.

View attachment 141730
So Clay, do you return settings to medium after you return to the dock or do you keep a log so you will know where to go from where you are set? The tuning guide for my boat with the mid setting at 10-12 knots of true wind but the norm is quite a bit less than that so if I pick a spot to return to it will likely be more like the light setting though this guide has 6 increments.
Interestingly the guide also has settings for forestay tension (-7 full turns thru +10) and I am not sure that is very easy to do in my case as the furler is set flush to the deck!
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
So Clay, do you return settings to medium after you return to the dock or do you keep a log so you will know where to go from where you are set? The tuning guide for my boat with the mid setting at 10-12 knots of true wind but the norm is quite a bit less than that so if I pick a spot to return to it will likely be more like the light setting though this guide has 6 increments.
Interestingly the guide also has settings for forestay tension (-7 full turns thru +10) and I am not sure that is very easy to do in my case as the furler is set flush to the deck!
@danstanford ,

We used to dial to medium after sailing every time. Over time we developed a system where we leave the rigging and note where we left it. The only exception is if was set to max, then we turn it down unless we know for sure we will use that setting again within 24 hours. If we forget, we simply set the loos gauge on the rigging (V1) and the reading will tell us what setting we are in.

Normally a rig setting set with a forestay setting are for non-fuller boats, and you’ll have a different set that sets the forestay via shroud tension if you have a furler. Have a look around.
 
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