Mainsheet doubling

[zoidberg]

I waited in vain for some discussion of the different mainsheet arrangements favoured by competitors in the recent GGR. Several had the conventional single multipart onto a cross-cockpit traveller setup. Others had a 'twin' multipart mainsheet , with the lower ends taken to strong points on the cockpit coamings. e.g.

Some of the 'differences' are evident - e.g walkthrough to transom, better control in crash-gybe circumstances - but I'd be most interested in others' perspectives.

 

[photodog]

Looks overly complex for no real advantage Imho... though I would be interested to hear what that might be...

 

[Poignard]

Looks overly complex for no real advantage Imho... though I would be interested to hear what that might be...

And very slow to sheet in. Looks more appropriate for the spanker of a barque or ship.

 

[photodog]

And very slow to sheet in. Looks more appropriate for the spanker of a barque or ship.

She doesn’t appear to have a very powerful vang... I suppose you could also get some control of the boom vertically with that Set up(?)

 

[zoidberg]

The owner of the boat in the pic 'knows his onions'. Both he and his boat survived a Round-The World Singlehanded Race, and some survival storms..... and he won it. He'd have had his reasons....

 

[Poignard]

She doesn’t appear to have a very powerful vang... I suppose you could also get some control of the boom vertically with that Set up(?)

Not when the boom is well out to one side, I wouldn't have thought. Perhaps her owner is disabled and needs an unusually powerful tackle.

 

[Poignard]

The owner of the boat in the pic 'knows his onions'. Both he and his boat survived a Round-The World Singlehanded Race, and some survival storms..... and he won it. He'd have had his reasons....

I'd like to know what they are because I'm always keen to learn better ways of doing things and if it's better than my set-up, which is that favoured by Eric Hiscock (see my avatar), I might adopt it.

 

[Kukri]

I noticed the same arrangement on ‘Nicola Deux’ at SIBS. I had the opportunity to ask Tony Curphey about it but I was preoccupied with some of his other arrangements. Anyway he is very much in favour of it.

The obvious point is that the main is triangulated, so to speak, so the boom is held rigid when reefing and stowing or and when hove to - indeed at all times when close hauled.

I get a similar effect with a handy billy and a pair of snap shackles braced against the main and traveller when stowing up. I can certainly see benefits to this.

 

[Poignard]

Here it is in use:



Looks like each tackle is double-ended so it wouldn't be slow if both ends are hauled in together.

And it doesn't need a traveller.

 

[Ohlin Karcher]

It looks great, with advantages of redundancy and triangulation, but..to move the boom, wouldn't you be having to ease out one sheet, under control, as you shortened the other sheet?
Unless I'm missing something, you'd need an extra arm!
Especially if you had to do the tiller or even swap over the runners, simultaneously :disgust:

 

[jimi]

One of the first boats I sailed had this arrangement. It made the boom very easy to tune precisely when beating or fine reaching

 

[dunedin]

There isn’t much in the GGR that is a pointer to new techniques. It is an exercise in enforced nostalgia for little apparent benefit

 

[Kukri]

Tony Curphey wasn’t in the GGR, but he has just done his fifth circumnavigation. I think he might know something.

 

[LadyInBed]

It looks great, with advantages of redundancy and triangulation, but..to move the boom, wouldn't you be having to ease out one sheet, under control, as you shortened the other sheet?
Unless I'm missing something, you'd need an extra arm!

Not if it's a continuous sheet, so no bitter ends.
I'm thinking of doing it on my main which is on a traveler on the coach roof. I have made the traveler sheets continuous which works well. I would like to remove the traveler block and anchor two main sheets at the ends of the traveler track. The only thing that's stopping me is the cost of the extra blocks.

 

[flaming]

Travellers are often a weak point, especially in accidental gybes. However if you just do away with it and go for a single mainsheet then you lose quite a bit of mainsail shape control.

This looks like a good offshore solution to having very strong mainsheet mounting point(s) whilst also being able to balance tension in the sheets to get the exact twist and boom angle that you desire.

Would be a pain in the backside for inshore work though, where a traveller is going to be king.

 

[lw395]

This kind of arrangement can give great control of boom angle and leach tension.
Having the sheet pulling to weather when you want it to, to allow more twist, is great, and the avoids the need to move the traveller in those conditions.
The leeward sheet works more like the kicker.
But unless there is some subtle thing out of sight which makes tacking easier, it's not what I'd choose for short tacking up a river or channel.
Horses (geddit?) for courses?

Many dinghies these days use a split tail mainsheet to provide a similar or flatter angle of pull on the sheet, leaving the leach tension to the kicker, or other windward sheeting contrivances.

 

[TLouth7]

A twin mainsheet like this gives you 2D control of the boom position (at least close to centreline), just like a traveller. I have looked into it fairly extensively (in the context of single-handed inshore sailing) and come up with the following list of pros and cons:
Pros:
- Theoretically step-through cockpit
- No need to adjust when tacking
- Cheaper to rig than a new traveller (my existing one is pretty knackered)
- Offshore it could be more robust (not relying on the wheels on the car)
Cons:
- More string in the cockpit/when pulling the boom in from a run
- Boom angle and sail twist are not independently controlled, so dumping the main when sailing close-hauled is different (though not necessarily worse)
- Harder to control boom position repeatably (vs bringing traveller back up to a given position after dumping)
- I'm not sure it would be acceptable structurally (or aesthetically) to remove my existing traveller, negating the step-through benefit.

Edit: some Open 60s have a double mainsheet arrangement, so I guess it is considered a competitive solution for short handed offshore use.

 

[Ohlin Karcher]

Not if it's a continuous sheet, so no bitter ends.
I'm thinking of doing it on my main which is on a traveler on the coach roof. I have made the traveler sheets continuous which works well. I would like to remove the traveler block and anchor two main sheets at the ends of the traveler track. The only thing that's stopping me is the cost of the extra blocks.

Aha thanks, my own mainsheet is continuous and works very well.

 

[Kukri]

For deep sea use, it seems much better, because you can stop the boom from moving.

Inshore, not so much.

 

[Ohlin Karcher]

On a long deep run, you could unclip one of those blocks and take it forward, to make a bombproof and easily adjustable preventer.