Catana Mainsail Sheeting System ?

[cvondo]

Hello, i noticed that the catanas have an atypical main sail sheeting system . From what I can tell there is no traveler and there are 2 separate sheets which triangulate to the boom. I was curious how it works a d if the catana owners like the system. I have a st Francis 44 and was considering installing this versus the standard traveler system. Thanks chris

[Southern Star]

Cvondo, my boat also has a bridle system for the mainsheet rather than a traveler and I quite like it. The windward sheet functions as the mainsheet/traveler while the leeward one is used to flatten the sail. The only disadvantage is that the main is not strictly self-tacking: on each tack, one needs to release the leeward sheet( as it will become the windward one on the new tack) and then flatten the sail by tightening the new leeward one.

Brad

[Abaco]

Having sailed on a Catana 58 with this system quite a bit, I have to say any future cat I own will use this system. You have perfect leach control and jibes are much quiter. Overall the system has less hardware, requires fewer lines on the deck, and is a works quite well. It also stabilizes the boom when you are not sailing, where a traditional mainsheet system requires an extra line tied off to the rail in order to keep the boom from swaying.

[JayH]

I have been curious about this as well. Do you use winches for each sheet? How much purchase? Don't the sheets have to be very long for when the boom is eased way out, and the lazy/windward sheet has to reach all the way across the boat?

I do often have another line from the end of the boom through a block on the rail and back to a winch to keep the boom from swaying. It's essentially a preventer, and I think it would still be needed with the dual-sheet system anytime the boom is eased past the leeward sheeting point.

I'd like it if someone who has used this setup could explain a tack and jibe step-by-step. I'm usually running the boat by myself and I'm sure I have enough hands.

Before I tack, I haul my traveler to windward so it is low on the new tack. Then after the tack and the boat gets moving again I move it up to where I want it. Otherwise it is self-tacking. I don't need to jibe much, and even when I do will often tack instead.

[Abaco]

The Catana uses two winches. Assuming you are on a starboard tack, as you go head to wind you don't have to worry about the starboard sheet until you complete the tack. The new weather sheet or port sheet will control the position of the boom. Once you ease it to centerline the boom, you trim the starboard sheet to control your leach tension.

[Glenn C]

The lightwave 45 i inspected a couple of weeks ago used the system and i was currious as well, so this thread has been quite helpful.

[ejlindahl]

I sailed a 47' catana for a long weekend. I've chartered Lagoons with travelers several times. The Catana was more fiddily; ease one side a few inches, tighten up the other side, oh too much, bring it back in and now ease the other side....... If it were my own and sailed it regularly and knew where to set or pre set it for each tack then maybe I learn to set it right the first time and wouldn't need to fiddle with it so much. I do agree that you have better control of the leach. But I am cruising and would rather have more convenience of the standard traveler and don't really care so much about a bit better sail trim.

Though I raced dingys for years and like getting the most out of sails I did not really like the Catana for cruising. We were near shore, island cruising so there was alot of tacking with winds up and down. If you were in steady winds or on passages then triming the main after each tack would not be an issue. I think it boils down to how much you want, (or need to) to mess with the sails. If I didn't mind the outboard helms of the catana I might have bought it. In other words, though I found it a little less convenient, this sheeting wouldn't be a deal breaker.

[paulrack]

I have the bridle system on my cat that works very well. It is a bit different to that described in the previous threads in that it is a continuous sheet with the one end coming out out to the starboard side of the cockpit and one to port. That means you can control the mainsheet from either side of the cockpit. My cat also has a boom vang for additional control of the twist of the sail. Tacking is simple you do not need to touch the mainsheets. The system also holds the boom securely in the centre when anchored or when flaking the mainsail into the stackpack. I have attached some pics showing the system.

[Southern Star]

The earlier comments about being able to firmly center the boom (or firmly have it at any position) are quite accurate. While mine does require some sheet adjustment on tacks, as Ejlindahl suggested once you are accustomed to your boat, prior to tacking you can automatically determine the amount that the leeward sheet should be backed off for the next tack and then, after the tack, it is a simple matter of tensioning the new leeward sheet until you have a proper leech shape. Mine does not require winches, although admittedly my mainsail is a bit smaller than on many other cats since it is a cutter rig. My arrangement has multiple sheave blocks with two lines per sheet, tied together at the tail, so that there are 2 speeds for fine and coarse adjustments on each side of the bridle. If designed with sufficient mechanical advantage, I see no reason that larger mainsails (say on boats up to about 40 feet with 'conventional' big roach mains) couldn't be handled without winches.

I love paulracks continuous line design, although I suspect that one disadvantage would be the lack of independent adjustment of leech tension with the leeward sheet; hence the need to resort to a boom vang, something which is surplusage on a twin sheet bridle.

Brad

[seashine]

Southern Star - do you have any photos? OUr Hitchhiker has a dual mainsheet system but as we tack the whole conglomeration of blocks tends to get snarled around the line, and as we're also dealing with up to 3 headies it's a cumbersome procedure! Basically each mainsheet (P &S) has 4:1 purchases, then is led through a standing block back through a fairlead to the cleat. NO winches!! Because of the curve of the cabin roof the lower blocks in the purchase clunk down onto the roof, then the sheets get snarled :-(( Would love to see some pics!
OUr main is sheeted a bit over half way along the boom thanks to whoever designed the cockpit roof (which supports massive solar, so I'm reluctant to do away with it). We do have a rope vang but have really never bothered to tweak it. Having whinged about the system, I must say that the control of the main is perfect with this system and we can really get some power out of what is quite a small (and non-roachy) sail.

[Barra]

Originally Posted by JayH

I have been curious about this as well. Do you use winches for each sheet? How much purchase? Don't the sheets have to be very long for when the boom is eased way out, and the lazy/windward sheet has to reach all the way across the boat?

I do often have another line from the end of the boom through a block on the rail and back to a winch to keep the boom from swaying. It's essentially a preventer, and I think it would still be needed with the dual-sheet system anytime the boom is eased past the leeward sheeting point.

.

THE Bridle system also has a second fixing point for each main sheet on the edge of the hull (on my boat at least) so once you ease the sheets past the first fixing point you can then shidt to the second one which then acts as a prevent as well as keeping good sail shape control deep downwind.

I was a little dubious of the system initially being used to traveller arrangements but I would really miss it now if i was to go back to a more standard set up I think

[Southern Star]

Seashine, sadly my boat was hauled last week and is currently on the hard for the winter. I may have some shots of the bridle arrangment somewhere, however, and will attempt to locate one. My bridle is fixed and the mainsheet/s exit the main fiddle block to a double cam cleat. I purchased the main fiddle and swivel blocks from Garhauer Marine and lines do not twist, or tangle. I'm not sure if I am entitled to post a link, but if you go to the Garhauer site they are listed under 'two-speed vangs' and are model 40-2-SP. They provide either a 3 to 1, or 6 to 1 purchase. I have end-boom sheeting which does provide some additional torque, but they work perfectly!

Brad

[mikereed100]

Originally Posted by JayH

I have been curious about this as well. Do you use winches for each sheet? How much purchase? Don't the sheets have to be very long for when the boom is eased way out, and the lazy/windward sheet has to reach all the way across the boat?

I've got a double mainsheet arrangement on my main and find that it works very well. One unexpected benefit is that when the boom is roughly amidships the loads are shared by the separate sheets. With a 4:1 purchase this means that I rarely have to use the winches to trim. Short tacking is not a problem as it usually involves just a quick release of one sheet and tug on the other. I know of one fellow who attaches a line from the end of the boom to a central point on the boat and uses this for self tacking. I may try this some day but as yet have not felt the need.

As you point out the sheets do have to be very long to reach across the boat when bearing off. I use a single, continuous sheet to keep the length to a minimum. I also set up the lower blocks with snap shackles so that they can be moved to the leeward side when running, but find that I rarely do this.

When I added a boom to the jib I rigged it with the same system and find that it works even better with the jib. No more flogging, and I have precise control without resorting to tracks and barber haulers, plus the boom is always "locked" in place by the sheets, eliminating most of the danger of a self tacking boom. With the jib I do often move the attachment points for the sheets to leeward when running. This allows for precise trimming and the boom becomes, in effect, a whisker pole. It is not self tacking, but I can tack it more quickly and safely than when I was using a traditional setup.

[simons]

Mike,

I would be interested in how you fitted the anchor points for the mainsheet blocks to the aft beam? Did you have to reinforce the structure? What kind of loads do you expect?

Could you give us more details on the layout with the continuous sheet and where you have put the winch(s)?

Thanks

Simon

[mikereed100]

Simon,

The attachments are simple u-bolts. I reinforced the glass inside the crossbeam a bit where the bolts pass through. I can't remember what the mainsheet loads are, but I used the Harken calculator Harken Mainsheet Loading Calculator and sized the blocks accordingly. When the loads are highest, on a close reach, the loads are split between the 2 sheets. As I fall off most of the load is transferred onto the leeward sheet but the loads are less so I can still trim by hand.

This arrangement is particularly well suited to my boat since I have a forward "workpit" much like a Gunboat. The mainsheets come back forward along the boom where I have line stoppers at the front of the boom, just overhead in the cockpit. From the stoppers they pass through blocks on the boom and down to winches on the mast, but as I mentioned, I rarely use the winches. The continuous sheet forms a loop in the cockpit that I flake into a bin.