Double Mainsheet System

[Al Oliva]

Dear Friends,

I have recently purchased a 2022 Hanse 348 which has a double mainsheet system and no traveler.
I have sailed a double mainsheet system recently and was unable to move the boom directly over the cabin top to improve sailing performance in light wind.

Do you have any advice on how to move the boom to windward with a double mainsheet (German) system?

Thank you,
Al

[thinwater]

I'm guessing from pics.


There is only one sheet, possibly with two ends, but the line is continuous, correct? It is split in a V, but they all connect with blocks? Sometimes the sheet is endless. This is a V main sheet. A twin or double main sheet has sheets and sheet ends, and is a different thing.


I think the answer is that you cannot pull the boom above the CL. How could you, with one adjustment? You need something pulling from windward, like a second sheet or a traveler. It simplifies operation, but limits adjustments.



In fact, only very weatherly boats really benefit from hauling the boom above the CL. For most boats, most of the time, all it does is increase leeway.



With two sheets (twin or double mainsheet) you can move the boom above the CL by tightening the windward sheet more. However, the system is a bit more fiddly than a sheet/traveler system. Some people love it. I have used both on the same boat and don't love it.

[Cowpoos]

It should if the lee mainsheet is fully loose, then it should come over. Or do you have a hydraulic vang that is interfering? Do you have some pictures?

[Al Oliva]

Originally Posted by thinwater

I'm guessing from pics.


There is only one sheet, possibly with two ends, but the line is continuous, correct? It is split in a V, but they all connect with blocks? Sometimes the sheet is endless. This is a V main sheet. A twin or double main sheet has sheets and sheet ends, and is a different thing.


I think the answer is that you cannot pull the boom above the CL. How could you, with one adjustment? You need something pulling from windward, like a second sheet or a traveler. It simplifies operation, but limits adjustments.



In fact, only very weatherly boats really benefit from hauling the boom above the CL. For most boats, most of the time, all it does is increase leeway.



With two sheets (twin or double mainsheet) you can move the boom above the CL by tightening the windward sheet more. However, the system is a bit more fiddly than a sheet/traveler system. Some people love it. I have used both on the same boat and don't love it.

Thank you for your answer. The photo you posted is not quite what is on the Hanse 348. I've attached a photo from the Hanse 348 brochure.
The question I have regards sailing in light air when there is a clear advantage to a fuller main sail by bringing the boom to windward and releasing the mainsheet a bit to provide more "belly" to the mainsail.
With the double mainsheet system, releasing the main will drop the boom to leeward and defeat the objective. I am hoping that someone can instruct me on how to achieve this objective, namely to be able to move the boom to windward while at the same time releasing the main. It may not be possible without a traveler. Thank you, Al

[ggray]

I'd say what you have pictured is a double ended mainsheet, not a double mainsheet.
Don't thnk you can do what you want to do with this system

[wingssail]

Oh! I see the problem. They put the traveller on the jib instead of the main. Warranty issue!

[thinwater]

Originally Posted by ggray

I'd say what you have pictured is a double ended mainsheet, not a double mainsheet.
Don't think you can do what you want to do with this system

Yup. Honestly, this is something you should have noticed. I always look at the rigging before the interior.


It could be converted, of course. Easier than adding a traveler.

[Sailmonkey]

Originally Posted by Al Oliva

Thank you for your answer. The photo you posted is not quite what is on the Hanse 348. I've attached a photo from the Hanse 348 brochure.

The question I have regards sailing in light air when there is a clear advantage to a fuller main sail by bringing the boom to windward and releasing the mainsheet a bit to provide more "belly" to the mainsail.

With the double mainsheet system, releasing the main will drop the boom to leeward and defeat the objective. I am hoping that someone can instruct me on how to achieve this objective, namely to be able to move the boom to windward while at the same time releasing the main. It may not be possible without a traveler. Thank you, Al

What thinwater posted is what you’ll need to modify your mainsheet to to accomplish what you desire.

You currently have a double ended mainsheet, what you need is a double mainsheet.

[Snore]

There are two options. Either modify the boom to handle the blocks, or add a traveler.

Contact the manufacturer- if the coach roof is reinforced to accept a traveler (perhaps as an option?), adding a traveler is likely the safer bet and will provide better sail shape.

[thinwater]

I suggest trying a double mainsheet first. Sail shape with traveler or double mainsheet are exactly the same, as they both offer exactly the same range of adjustments (as I said, I have used both on the same boat as a test).


You will need to:

• Add an additional block to the boom next to the existing farthest aft sheet block) to get the purchase you need. Because you are fixing the bitter ends to the deck now, the purchase is somewhat reduced in some positions.
• Reverse the sheet and tie the ends to the deck on either side (where the aft blocks are). This results in a continuous sheet, which is good, because that slightly reduces the amount of rope required, compensation for the purchase you added.

What I'm suggesting is a little different from the image, but it is the way I tested it and liked it. With the addition of one block, you can convert to double main sheet in 15 minutes. Easy. Then swap back if you don't like it, because this requires no hole-drilling.


https://www.practical-sailor.com/sai...l-the-mainsail

This is different from the OP's rig, in that there are two completely independent mainsheets. With snap shackles, I could switch from this rig to the traveller rig in seconds, testing them side-by-side.

[Joh.Ghurt]

Originally Posted by Snore

There are two options. Either modify the boom to handle the blocks, or add a traveler.

Maybe I'm a little stupid rigth now, but why not simply tie a knot (eg a double 8-knot) where the double line leaves the aftermost block and goes down to the blocks on the coach roof? Then the two sides will be isolated from each other and you have a double main sheet. Tie it very closely to the block.

If that works satisfactory, you can get rid of the aftermost block on the boom with a shackle, cut the sheet in half and and tie / splice both new sheet-ends onto it.

To me this construction looks a little as if it was offered in the "stupid cruiser" mode and with a simple modification make it a regular 2-sheet main control which is just as good as a traveller.

[Dockhead]

A cheaper and much simpler way to deal with this is just rig a handy billy to the rail whenever you need to haul the boom up a bit to windward. If you don't need to do this very often, then this will be very practical and far cheaper and simpler.

That was what the crew on one Swan 60 racing boat, which I sailed on once, was doing. That boat had a weird single powered mainsheet with no traveller and a powerful hydraulic vang. Same problem as yours exactly.


The geometry will not be perfect, but you can't get perfect geometry -- proper separation of controls for leech tension and boom angle -- without a traveler. So the handy billy will be no worse than any other traveler-less mainsheet arrangement.


I once had a boat with a German mainsheet, and will never again have a boat without a proper traveller. Life is too short.

[citlab]

Originally Posted by Al Oliva

Dear Friends,

I have recently purchased a 2022 Hanse 348 which has a double mainsheet system and no traveler.
I have sailed a double mainsheet system recently and was unable to move the boom directly over the cabin top to improve sailing performance in light wind.

Do you have any advice on how to move the boom to windward with a double mainsheet (German) system?

Thank you,
Al

Hi!


On our Grand Soleil 37 we have a continuous mainsheet with one end at the traveler and the other looping via the mast to halyard winches (for heavy weather gybes).



We often disable the front section by tying a knot at the block aft end of the boom.



For light winds you could simply loosen the leeward section of you sheet by tying a knot at each of the leeward blocks. This will remove all the tension from the leeward section and all tension will be to windward.


We often forget our arrangement but he knot has never come loose even under severe tension.


This will be a zero cost - zero equipment solution, but if you plan on tacking a lot , it won't be practical.

[Al Oliva]

Originally Posted by citlab

Hi!


On our Grand Soleil 37 we have a continuous mainsheet with one end at the traveler and the other looping via the mast to halyard winches (for heavy weather gybes).



We often disable the front section by tying a knot at the block aft end of the boom.



For light winds you could simply loosen the leeward section of you sheet by tying a knot at each of the leeward blocks. This will remove all the tension from the leeward section and all tension will be to windward.


We often forget our arrangement but he knot has never come loose even under severe tension.


This will be a zero cost - zero equipment solution, but if you plan on tacking a lot , it won't be practical.

Thank you,
I understand the point you are making and I think it is an easy way to put all the work on the windward sheet. However, what I don't understand is how to move the boom to windward in light air. The windward sheet would need to be overtightened to move the boom and would defeat the mainsail shape. The main would be overtightened for the light air conditions.
Ak

[thinwater]

Originally Posted by Joh.Ghurt

Maybe I'm a little stupid rigth now, but why not simply tie a knot (eg a double 8-knot) where the double line leaves the aftermost block and goes down to the blocks on the coach roof? Then the two sides will be isolated from each other and you have a double main sheet. Tie it very closely to the block.

If that works satisfactory, you can get rid of the aftermost block on the boom with a shackle, cut the sheet in half and and tie / splice both new sheet-ends onto it.

To me this construction looks a little as if it was offered in the "stupid cruiser" mode and with a simple modification make it a regular 2-sheet main control which is just as good as a traveller.

Two small problems. You will need more purchase, since when only one leg is loaded you have only half the blocks. in practice, the loss is smaller than that.


The sheet may be short. Reversing the sheet reduces the problem, since the tail is shared. But it is in the way a bit. On the other hand, continuous tails never tangle.