Downwind rig

[Guest]

I'm being talked into a downwind rig for long distance cruising (short handed) as follows: two 100% jibs on a twin groove roller (presumably sharing a halyard) and two carbon poles. Poles are set port and starboard and you roll up or out from the cockpit (once it's set up) as desired. Single watch keeper can take off all sail at night if he wants to. Have you liveaboard guys got any informed prejudice on this subject? Anyone know how much you expect it to roll? Last Atlantic crossing was flying a spinnaker all the way - I think I'd like to sleep more this time.

 

[ccscott49]

I thought of exactly the same rig, but was informed by those ion the know, (including my bruv, who has vast downwind experience) that it would induce roll, which when you study the dynamics, it would. But!! I have had a sail made which is identical to my roller yankee, with the luff tape and just a 1/2" in from that, a kevlar luff line. This allows me to either run it in my twin grooves, or set it on another halyard, allowing a gap, I've yet to try this sytem, it needs a few crew to set it up prperly on my boat, with my heavy wooden poles, I intend to try the twissle rig thing at the same time, I made up a bracket to link my poles together and allow them to be slightly controlled by the boom of my staysail. I'll post about all this when the tests start/end.

 

[summerwind]

I have heard about the Twistle rig several times but have never managed to discover exactly what it is.

Apparently it allows you to use twin headsails in the grooves on the roller rig but because the inboard end of the poles are not fixed to the mast, rolling does ot result. Is this right?

If the poles are not fixed to the mast, what are they fixed to? I see that you say that you made a bracket to fix them together - what is the bracket fixed to?

I am really keen to try this so any help would be greatly appreciated.

 

[ccscott49]

The "twissle" rig, can be used with seperate headsails, noit just in twin grooves. The inboard ends of the poles, with a bracket or somesuch,(hood or somebody make one I think) are fixed together, in such a way as to allow them to swivel in relation to each other. the outboard ends are fixed the same way. An uphaul is used to support the poles and a downhaul both at the bracket to control them. This allows the poles to swing in front of the mast, keeping the sails with the wind in their centre, if the boat is on course and the wind shifts off exactly down wind to even a broad reach, the poles swing, keeping the sails pointing at the wind, difficult to explain, sorry. This allows the sails to behave like a square rig of old, when the yard pivoted around the mast, keeping the sails, flat would be a better word, to the wind. this is said to improve the performance of twin sails and has been proved, but I have still never seen a difinitive report on this. One aspect of course of this rig with twin grooves, is the sails can be furled/reefed together as and when required. With snatch blocks on the ends of the poles and a uphaul on the ends of the poles, the poles acn be left in position, this is the way mine are rigged, with pole downhauls aswell. My inboard ends are fixed to the boom of my staysail, which supplies the uphaul and down haul and makes it more controllable when I reef the sails and the poles all stay together and safe from decapitating somebody, Me! I hop this is not too complicated, I know what I mean, but I'm not very good at explaining this without sketches and hands!

 

[Guest]

I guess you can mitigate the roll a little by having a trisail on the main boom sheeted in hard - it will bang a bit but might damp out some roll. I'm told the reason the twin foresail works is that the centre of effort is forward and only a small component gets transmitted to the mast in the roll axis. Also not having too wide a foot to the sails should help. But it's all theory - someone must have tried it!

 

[peterk]

hi,
I have used various downwind rigs
including a fullsized spinnaker.
My record sailed solo on the way to Japan:
5 days and 13 hours non-stop,
but it was a paranoid scene!

For a while I used my own variation of the gunmount.
Short tube swivelling on the pulpit,
boom inside that - like a squareyard at the bottom of the sail.
This keeps the boat amazingly steady,
but in tradewind-waves the shock load is very hard on the connection
between the boom and my icebreaker- pulpit.
Twice I busted 5/8" stainless bolts!

I heard about the twistle,
never seen one in action.

If you don't HAVE to go
exactly downwind :
I found that my triple-reefed main
or the stormtrysail let out to leeward about 45 degrees
and cinched down
will cut down considerably on the roll
as well as the lurch

...peter, www.juprowa.com/kittel

 

[ccscott49]

Due to the roll directly downwind, some people crossing the atlantic and not in a hurry, unlike the ARC, tend to do 12 hours on one broad reach and 12 hours on the other, apparently it's a lot less wearing on sails/equipment and crew.

 

[alex_rogers]

I found this report about the Twissel Rig which is quite interesting.

www.bitwrangler.com/ug/twissel.html

I was wondering how it would work on a cutter. Would the inner stay foul the poles or would they stay between the stay and the mast?

 

[ccscott49]

Mine stay inside the inner stay, but my inner stay is well forward. Just about 4' from my outer, which makes tacking an interesting procedure, you have to furl the yankee and re-set it on the other tack, not really a problem in a motor sailer, or a cutter sailing yacht actually.

 

[peterk]

hi CC,

They have tables that explain the angles and extra distances involved
in downwind tacking - and prove that you are actually FFFaster
that way than sailing straight before it!
- though wave action-influence was not considered.

peter, www.juprowa.com/kittel

 

[ccscott49]

Yo! Bruv!
It's certainly more comfortable! You can do it with your "twissle" "twistle" rig aswell!

 

[LadyInBed]

No one has mentioned using a Genica.
I have no experience of really long runs, but have used a Genoa and Genica goose winged comfortably on a 22ft boat on a 12 hour run.
I now have a Ketch and use the same Genica set from the Mizzen, goose winged with the Genoa (no Main) which works very well.

 

[Gunfleet]

Is a genica a cruising chute?

 

[LadyInBed]

Re: Genica

No. Its a fat bellied light weight Genoa with a non-stayed luff. GENoa-spinICA.

 

[Gunfleet]

Re: Genica

I thought that's what the term might mean, and I've seen it spelt gennaker, but I've never knowingly seen let alone used one. I have a spi,a cruising chute, a couple of jibs and a roller reefing genoa. I'm definitely not adding a genica!

 

[LadyInBed]

Re: Genica wouldn\'t guarantee my spelling! nm

 

[chippie]

Re Downwind sailing

Some years ago in the American magazine Wooden Boat there was an article about twin forestays being fitted for downwind sailing, the interesting thing was that the port sail was on the starboard stay and vice versa for the starboard sail so they overlapped. Has anybody tried this? I found myself wondering if the hanks would cause chafe.

Re gennaker, they seem quite good as they can be sailed in circumstances where a spinnaker would drop out as the wind moved forward a bit.

 

[ccscott49]

Re: Re Downwind sailing

I would have thought, when the wind filled them, the stays would take up and lie over one another anyway, opening the gap. Never heard of it before, chafe would almost certainly be a problem. Why would you want to do it anyway?

 

[charles_reed]

Usual spelling genniker

Assymetric spinnaker carried on a bowsprit for reaching.

A very effective sail, but does result in terrific apparent wind-shifts.

Should not be confused with the "cruising chute".

 

[charles_reed]

Quite a few dedicated tradewind sailors swear by twin headsails.

Much depends on the boat - with a fine-entry, broad-bottomed boat the resultant harmonic oscillations make it a terrifying rig, on a long-keeler it's great.

I think you'll find, even with a snubbing winch, the weight on the roller reefing drum makes it well-nigh impossible to roll both up.

I've tried it on my boat and gone back to using main and spinnaker - it's actually easier to handle.