If I can't figure out how to use two horn cleats, my backup would be to use a fiddle block and camcleats like this:
http://l-36.com/3161fiddle.gif

If I use a double block like in Harken 401 or 402, then the lines would cross as the block swivels as the boom block is a fiddle block.

This would keep everything in line although it would require that I fabricate the base for the camcleats. One of the posters suggested always using fiddle blocks and not doubles or tripples. As I already have enough fiddle blocks to do this, that is an added advantage. I do think, however, that two doubles and a single mounted below the boom double runs true with the single mounted crosswise.

I have not figured out how to eliminate the turning blocks and use just horn cleats in a way that seems like it would be workable in race or emergency conditions. This is still my goal.

Allen

I tried out the system today and it really didn't work that well. When doing a gybe with the 3:1 configuration, all the lines got tangled up and it was basically a mess. The 6:1 was nice though. I am thinking of abandoning this setup and trying something different. Basically, taking one line to the gooseneck and then back through a block to a cleat on the cabin top or to a free winch. I have two free winches on the cabin top. One end aft and one forward. It would take two crew to do a fast gybe but at least all the lines would not get tangled. Also, this would allow the mainsheet trimmer to sit on the rail and trim from there at the aft of the cabin top. There would still be the option to trim from the stern using the swivel block cam cleat when crushing, or from a winch on the cabin top for that matter. I need to work out the blocks so it is fair.

Allen

Option
 

Hi again,
Sorry to have been so long in getting back to this; we have had a lot of fascinating work going on here.
First, I can see why your version of 3:1/6:1 would produce a tangle. I'd be amazed if it didn't. But let's not condemn the idea because of, um, alternate takes. Stacking a Harken 2138 on top of a 2139, and anchoring the latter to your cockpit sole fitting, would give you leads coming out one above the other, with both or either available for hauling or slacking, tangle-free. You might experiment with cam angle, and orientation, for best ergonomics for your situation.
The boom block for this setup would be a double with a crossblock on it (the upper part of Harken 400), and the lower block would be a double.
Alternatively you could have a double block on the sole, with side-by-side cams on a swivel arm (Harken 402). In your case, I think this would only work if the arm could be bent wa-a-y up, to get a usable angle on the cams; check with Harken on the feasibility of this.
Two-speed purchases only work if it is easy to handle either or both lines. That precludes having them exit anywhere but right next to each other.
There are other ways to do this, of course. On a fairly large cutter we are working on now, for instance, we have one lead going to a self-tailing winch, and another going to a rope clutch. The clutch is positioned just outboard of the (port-mounted) winch, so it is easy to grab both it and the line coming off the winch. Most often in a boat this size, though, the crew will take up on the clutch line for low loads, and use the winch for taking up high loads as well as for slacking for either low or high loads. And so on.
Fair leads,
Brion Toss

Brion,

Thanks for getting back to me. Good for you that you are busy. I understand what you are saying about my implementation of the 3:1/6:1. Perhaps I gave up on it too quickly but I did and have tried several different systems and rejected most of them for one reason or another. Most were versions of what is called the German or Admiral's Cup system. I tried aft winches and cabin top winches. Problems with both. The next thing, and one I think I am going to really like, is a double ended system but with the leads way apart. It will be basically 5:1 with one lead going to my sole mounted swivel block cam cleat or the horn cleat and the other along the boom to a cabin top mounted winch. This will allow 2.5:1 although it will take two people to do it. But that is OK as I have a big enough crew when racing. It will also allow for considerably more leverage with the winch but still have the advantage of the 5:1 on the line aft for our general line control.

The issue I have is trying to figure out the blocks to make it work. Tomorrow I am going to try a single with a fiddle hung from it with the intersection pulled forward so the lines clear each other. Fiddle on the traveler. That was the best I could come up with without having multiple attachment points on the boom. I have never seen such a system on a boat so I may be in new ground.

PS. In terms of my "alternate take", I really never could figure out a good way to have the 3:1/6:1 come off the boom and what I did was the best I could come up with. I certainly understand your assessment of it and what it takes to make such a system work. I still can't see a way to have it come off the boom though. In terms of the use of fiddle blocks instead of duals that didn't seem to contribute to the problem. The tangle was in the piles of line on the cockpit sole. I am off to the boat to try the latest system.

What would be the best way to rig a 5:1 dual ended mainsheet system with one end aft forward of the traveler and the other end going along the boom to the cabin top? I can tell you many ways that don't work and one that does work but looks like something Rube Goldberg invented.

Allen

Added 7/28 -- I tried several more systems that didn't work. What does work is a single with a fiddle block hung from it on the boom and a fiddle on the traveler. The line along the boom goes to the single and the line to the aft cleat comes from the top of the boom mounted fiddle block. To make it work I pulled the junction forward with a line that has to split around the line going forward. Several ways to do that so they don't rub. Looks a little complicated so I am still wondering if there isn't a better way. I tried a triple on the boom and everything got crossed up as the lead to the aft cleat is at a different angle than the line along the boom so everything rubbed. --

Added 7/29 -- NOTE: This doesn't work. The single block capsizes.

AE

After many trials I think (emphasize think) I have something that works. It is a fiddle on the boom to a fiddle on the traveler but the line that would normally be tied off on a 5:1 system goes back to a single block aft of the boom fiddle and forward to the cabin top. The trick is that the line going forward has to go under the fiddle block (between it and the boom) so some kind of trap door is necessary. I hung the fiddle block from a couple of lines one of which was attached to a ring that was attached to a padeye already on my boom 1.5 ft forward of the end of the boom (under the clew). The sheet going forward then goes through the ring.
http://l-36.com/mainsheet/boom2.jpg

Can you see something I can do better than this or anything that is wrong with it?

As I have said before, this allows 5:1 control of the main from an aft position yet effectively 2.5:1 when needed for a gybe although it will take two crew, one working the cabin top terminated end, one the aft end. There is a winch cabintop for extra power if needed.

As to the question I started with, I am using 7/16 Samson XLS.

Allen