Twistle Rig... 100% or 130%?

[rhumbunctious]

This is a question for those with direct, hands-on experience with twistle rigs. If you don't know what one is, or haven't used one, please just listen and don't post. Thanks.

I'm planning on having a twistle rig made, and am pondering whether I should go for 100% or 130% per side.

I'm also planning to use 4oz Dacron sailcloth, so that when spread out, it has reasonable light wind performance, but when folded double and used as a traditional jib, it has decent strength in higher winds.

Or should I go with 6-8 oz sailcloth and just deal with the extra weight?

Thanks.

[Adelie]

Try these sites if you haven't already:

The Twizzle Rig or Twistle Rig for Downwind Ocean Sailing
http://www.bethandevans.com/pdf/twizzle%20rig.pdf

[Adelie]

Have you considered the Britton system instead of the Twistle?

Both dampen rolling by placing the clews forward relative to the luffs so that there is sail area projected across the fore & aft plane.

The Twistle system moves the clews of the jibs forward by pushing the butts of the poles significantly forward of the mast.

The Britton system moves the luff aft to near the mast and leaves the pole butts on the mast.

As I see it the Britton would be safer because the poles are better controlled. The Twistle would have the advantage that the center of effort is somewhat farther forward and the boat is likely to steer itself better. Both should do equally well in dampening out rolling.

The Twistle's other advantage is going to be cost. If you use existing sails the only cost will be some line to create a universal joint for the pole butts.

If you have special made sails then the cost advantage narrows but doesn't close, you would want (but not really absolutely need) a free standing roller furler(Facnor) for the sails if you go with the Britton system.

On the plus side for the Britton system the normal headsail can be left in place when you fly the twins so the conversion back is much easier, roll the twins, get the leeward pole out of the way, then hoist or unroll the normal jib.

Overall I think the Britton system has the advantage of safety, and speed of changing back to a normal jib and the Twistle has the advantage of cost and somewhat better self-steering capabilities.

You can see a drawing of the Britton System in 'Singlehanded Sailing, 2nd ed.' by Richard Henderson, p 165.

[rhumbunctious]

Unfortunately, a Britton rig is not an option for me, as I have a baby stay where the furler would need to go (though possibly it could be moved and not critical when sailing downwind... not sure).

At least the same twin foresail used for a twistle rig would also work with a Britton rig. They are very similar as far as their components, so I could always later experiment with little additoinal investment -- particularly since I plan to have the luff rope of the twistle foresail made from Dyneema/Spectra and it could thus serve as part of a stand-alone stay (no need to add a further in front of the mast.

[Adelie]

What kind of boat do you have?
Could you convert to double lowers?
Could you set the Britton tack just in front of the baby stay?

[ice]

Originally Posted by rhumbunctious

This is a question for those with direct, hands-on experience with twistle rigs. If you don't know what one is, or haven't used one, please just listen and don't post. Thanks.

I'm planning on having a twistle rig made, and am pondering whether I should go for 100% or 130% per side.

I'm also planning to use 4oz Dacron sailcloth, so that when spread out, it has reasonable light wind performance, but when folded double and used as a traditional jib, it has decent strength in higher winds.

Or should I go with 6-8 oz sailcloth and just deal with the extra weight?

Thanks.

For twistle use, 4oz is more than heavy enough. You could in fact go for something like 2.2 oz 'storm spinnaker' cloth.

Its probably not going to be that good a jib when doubled on one side - ok for reaching I guess.

As to 100% vs 130% . . . depends on where you are sailing and the specific boat . . . . but I would lean toward 130%. You have a lot more light air than heavy air.

[Adelie]

Unless your are going to have custom poles made too it might be worth it to consider your current pole lengths when deciding sail size.

[rhumbunctious]

Originally Posted by Adelie

What kind of boat do you have?
Could you convert to double lowers?
Could you set the Britton tack just in front of the baby stay?

'79 Westerly Berwick ketch
Don't really want to start changing the rigging if I can find another solution.
Setting the Britton tack in front of the baby stay would force me to find another place to store my dinghy.

Thanks for the suggestions, though.