Twin mainsheets

[oldbilbo]

I'm doing a 'refurb' and planning to relocate the existing mainsheet track, which is close to the companion-hatch, to a position about 20" further aft.
However, I am reminded that Jean-Jacques Van Den Heede used a 'twin mainsheet' arrangement, and that it worked Right Round for him.


I like to ask for others views, for usually I learn something I hadn't sussed out for myself, so I invite opinion on the relative merits of retro-fitting a twin mainsheet system on a 27' sailboat of similar shape to J-J's boat.

[tkeithlu]

You don't have much to lose in giving it a try. If you go to two sheets first without moving the track, you can sail it and see if you like it better than one. Then consider moving the track to get it out of the way of the companion-hatch, which I infer is your original concern.

I'd really like to hear how this goes. I've never sailed such a rig, and am out of sailing due to age, but wow, that could be really neat.

There are riggers on the forum who may be able to point out problems. I hope you'll hear from them.

[sailormed]

If you look up “Adventures of an old Seadog” on Youtube you will find that this is exactly what he did to get rid of the traveller in the cockpit. Apparently he is totally satisfied with this solution for his circumnavigation.

[slug]

Originally Posted by oldbilbo

I'm doing a 'refurb' and planning to relocate the existing mainsheet track, which is close to the companion-hatch, to a position about 20" further aft.
However, I am reminded that Jean-Jacques Van Den Heede used a 'twin mainsheet' arrangement, and that it worked Right Round for him.


I like to ask for others views, for usually I learn something I hadn't sussed out for myself, so I invite opinion on the relative merits of retro-fitting a twin mainsheet system on a 27' sailboat of similar shape to J-J's boat.

What are you attempting to accomplish ?

[pcmm]

I fitted a twin mainsheet arrangement on a 34' boat that I had 20 years ago. I loved it. You get a lot of control and some vang like benefits as the leeward mainsheet can pull down a bit as well. You end up with twice the rope in the cockpit but loose all those bolt holes going through the deck! When at Anchor you also can stop the boom from slatting around completely. Its a good setup just a bit cumbersome to use at first.

[AiniA]

Have a look at a Niagara 35. It has two mainsheets just forward of the cockpit. Works well.

[rbk]

I’ll second what everyone else has said above and add that it gives you may more control gybing.

[tomfl]

Eliminates the need for a preventer.

[LoudMusic]

This responses in this thread are much more positive than I've seen in the past.

To pcmm's point about more rope in the cockpit, two main sheets replacing a main sheet traveler, theoretically you'd be eliminating two traveler lines, a preventer, and a vang, but adding only one additional main sheet?

I think potentially you could come out WAY ahead. I very much want to make the conversion on my 44' catamaran.

[Pete7]

Originally Posted by tomfl

Eliminates the need for a preventer.

Are you sure? if you were sailing down wind and suffered a gybe the mast can still move along way across the boat.

Pete

[hlev00]

Jboats that I am familiar with have a traveler track in front of the wheel pedestal. On the track there is one set of blocks. Centering it is managed by control lines. The mainsheet comes out of the blocks with one end going to a starboard winch and the other to a port winch. See 2:1 with Dedicated Winch here https://www.harken.com/content.aspx?id=3901



It can help keep the bulk of the mainsheet out of the middle of the boat and the helmsman can also adjust the mainsheet without having to go all the way around the pedestal and over the track if there were a single cleat on the blocks riding on the track.


I've sailed cruising boats with the traveler (I think just a single fixed point) behind the helmsman. You have to be sure to bring the boom near center line during a gybe or you will likely snag the helmsman. But that is good practice anyway. The biggest risk being during an accidental gybe.


harry

[rbk]

Originally Posted by Pete7

Are you sure? if you were sailing down wind and suffered a gybe the mast can still move along way across the boat.

Pete

I wouldn’t say it completely eliminates the need but it does act to some degree as a preventer. The boom won’t swing completely across but does still have a few feet of play but not enough to sustain damage.

[thinwater]

I'm planning to look into this as soon as I can get back on the water (Maryland is shut down right now). There are a few statements I don't fully understand.


Preventer. How is it more useful as a preventer than a traveler fully eased and locked down? I seems geometrically identical (sheet to rail), since this is only a concern with the sheet is WAY out (if it is in tighter, you are reaching at a hot angle).



Vang. How is it different from a traveler in the same relative possession and the sheet tensioned appropriately? The boom can be constrained more than a traveler/vang system because a triangle is formed. But is this better or worse? In moderate winds, the ability of the boom to move and twist off in gusts is reduced, which can be better or worse. In light sloppy conditions banging can be reduced, but many sailors run a line from the boom to the stern cleat in those conditions anyway... but it is handy. On the other hand, if the sail leach is loose (which it probably is) when it fills the "bang" on the sail can be stressful to the cloth. Pluses and minuses and I am interested to listen.



Jibing is different, but either can be controlled. In the case of a traveler system, you sheet in first, then travel up, and so forth. With twin sheets the process is similar (sheet in leeward tackle part way, then sheet in windward tackle, then ease new leeward tackle (old windward now)) and slightly more controlled. Either requires active sheeting in fresh conditions (quick easing to avoid round-up).


My summary (probably wrong) is:

• Preventer. Same.
• Jibing. Different, possibly more controlled, but slower to manage. Won't see this on a race boat for that reason.
• Tacking. Little difference.
• Complexity. A lot more line. Cheaper gear, unless two winches are needed. More weight on the boom.
• Redundancy. Maybe.
• Safety. No traveler, but a lot more line to tangle in.

These can change if the sheeting base is wider than the traveler, but that is not a direct comparison. But a wide traveler can be difficult to install. Many travelers are too narrow to provide full function off the wind.


I am anxious to hear more.

[thinwater]

Originally Posted by rbk

I wouldn’t say it completely eliminates the need but it does act to some degree as a preventer. The boom won’t swing completely across but does still have a few feet of play but not enough to sustain damage.

How is this different from a traveler that is locked down (which it should be in this circumstance)?

[slug]

Originally Posted by thinwater

I'm planning to look into this as soon as I can get back on the water (Maryland is shut down right now). There are a few statements I don't fully understand.


Preventer. How is it more useful as a preventer than a traveler fully eased and locked down? I seems geometrically identical (sheet to rail), since this is only a concern with the sheet is WAY out (if it is in tighter, you are reaching at a hot angle).



Vang. How is it different from a traveler in the same relative possession and the sheet tensioned appropriately? The boom can be constrained more than a traveler/vang system because a triangle is formed. But is this better or worse? In moderate winds, the ability of the boom to move and twist off in gusts is reduced, which can be better or worse. In light sloppy conditions banging can be reduced, but many sailors run a line from the boom to the stern cleat in those conditions anyway... but it is handy. On the other hand, if the sail leach is loose (which it probably is) when it fills the "bang" on the sail can be stressful to the cloth. Pluses and minuses and I am interested to listen.



Jibing is different, but either can be controlled. In the case of a traveler system, you sheet in first, then travel up, and so forth. With twin sheets the process is similar (sheet in leeward tackle part way, then sheet in windward tackle, then ease new leeward tackle (old windward now)) and slightly more controlled. Either requires active sheeting in fresh conditions (quick easing to avoid round-up).


My summary (probably wrong) is:

• Preventer. Same.
• Jibing. Different, possibly more controlled, but slower to manage. Won't see this on a race boat for that reason.
• Tacking. Little difference.
• Complexity. A lot more line. Cheaper gear, unless two winches are needed. More weight on the boom.
• Redundancy. Maybe.
• Safety. No traveler, but a lot more line to tangle in.

These can change if the sheeting base is wider than the traveler, but that is not a direct comparison. But a wide traveler can be difficult to install. Many travelers are too narrow to provide full function off the wind.


I am anxious to hear more.

Many Ocean racers use a gunnel to gunnel mainsheet traveler

This is done to reduce load on the boom vang
And gooseneck

Many of These boats carry no boom vang

A leeward mainsheet will accomplish the same engineering task