Dual Jib Furlers - Why Not?

[rgleason]

OP question was:
Why are there not sailboats with twin or side-by-side jib furlers

[fxykty]

Originally Posted by rgleason

OP question was:
Why are there not sailboats with twin or side-by-side jib furlers

Probably because they’re only useful for wing and wing dead down wind sailing - for all other points of sail, especially with different size sails, it is much simpler and better engineering to have in line furlers. And since most sailboats are sold for coastal sailing, why complicate that?

But if you’re crossing the Atlantic via the Canaries you’ll want them (or a wing/para sail) for that passage. I’m not sure how many other DDW passages there are - mostly in the S Pacific it’s reaching or deep reaching, but not DDW. So a wing/para sail is probably more versatile.

[rgleason]

Fxykty wrote:
"...it is much simpler and better engineering to have in line furlers. And since most sailboats are sold for coastal sailing, why complicate that?"

It's not entirely clear to me that in line furlers are better than dual bowsprit + boomed staysail. But I'd like to know why you think this and what you see as the advantages.

I have a bowsprit roller and solent rig, still working on a good wind range of sails (in particular the working jib at 78% or at 85% and trying to reconcile the resultant sails with light summer sailing (135%) and switching to a too small working jib on the rf. Would like to reduce massive sail handling changes in bad conditions.

[fxykty]

Originally Posted by rgleason

Fxykty wrote:
"...it is much simpler and better engineering to have in line furlers. And since most sailboats are sold for coastal sailing, why complicate that?"

It's not entirely clear to me that in line furlers are better than dual bowsprit + boomed staysail. But I'd like to know why you think this and what you see as the advantages.

I have a bowsprit roller and solent rig, still working on a good wind range of sails (in particular the working jib at 78% or at 85% and trying to reconcile the resultant sails with light summer sailing (135%) and switching to a too small working jib on the rf. Would like to reduce massive sail handling changes in bad conditions.

Simpler because you don’t have to deal with crossed sheets. Tacking or gybing the front sail generally requires furling it, but other than that no hassles nor drawbacks vs side by side. You can still sail wing and wing if you like, though the sails won’t be the same size, unless you partly furl the larger one to balance them.

But side by side is much more complicated from an engineering perspective. Bad enough solving the dual tacks problem on a skinny-bowed monohull, but imagine the masthead crane needed to support dual forestays that are at least 20 cm apart. What about the twisting when just one sail is deployed upwind?

Our boat has a 100% self tacking solent and a removable 270% furling gennaker on a soft luff. We use it upwind in light airs, and to moderate winds when reaching and running. Otherwise we use the solent - generally we can run the gennaker until there is enough wind for the solent. We haven’t had a DDW passage, but I can see dropping the main and going wing and wing (or use the symmetric spinnaker instead). No use case for us for dual furlers. YMMV

[billknny]

Originally Posted by Aaarrgh

When I bought my '84 Merit 25, it had a double luff groove extrusion on the forestay, and twin jib sheets. I was successful at learning to hoist and fly both my jib and my genoa. It was pretty brittle from age, and I recently replaced it with a furler. Those extrusions are still available, and if you want to fly two foresails, I assure you that this is much simpler than twin furlers, but no furling capability.

Is there such a thing as a furler with two grooves, where you could hoist a second jib?

Aarrrgh!

It can be done, but as several people have posted on most boats it is a hassle, not just to rig, but to reduce sail if the wind picks up.

For many years Amel sailboats featured a custom system that allowed two headsails for downwind work that set easily, AND easily furled if the wind picked up. We find sailing straight downwind gives a better VMG downwind than reaching off if the wind is over 8 knots. On our recent trip down from Annapolis to Florida we had twin jibs poled out for 3 days. Very easy and comfortable sailing. Here is how it works:

https://fetchinketch.net/2016/06/26/...d-sailing-rig/

We carry the full sails up to about 22 knots or so at which point we are pushing hull speed and then we start to roll them up to suit the wind speed. What's really amazing about the twin jibs for downwind work is there is NO ROLLING!

[rgleason]

Thanks for the posts. The fetchinketch rig looks good.
And fxykty appears to have a fast modern boat with few headsails. I am envious of the 100% self tacking.
On my boat 85 or 78% might work with self tacking. I have a 95% north 3dl that is a great sail, but it is sheeted to the rail at about 16 degrees upwind, and at 13 years old it is showing signs of delamination. I am having trouble deciding/resolving to get a 78% LP replacement which will sheet closer, provide an appropriate reduction in sail area, and be easier to wrestle up on deck in heavier winds clipped to the solent.

But during spring and fall when we normally fit the 95% on the RF, would the 78% provide enough power and versatility?
Or am I going to be disappointed in the lower wind ranges?

[fxykty]

Originally Posted by billknny

It can be done, but as several people have posted on most boats it is a hassle, not just to rig, but to reduce sail if the wind picks up.



For many years Amel sailboats featured a custom system that allowed two headsails for downwind work that set easily, AND easily furled if the wind picked up. We find sailing straight downwind gives a better VMG downwind than reaching off if the wind is over 8 knots. On our recent trip down from Annapolis to Florida we had twin jibs poled out for 3 days. Very easy and comfortable sailing. Here is how it works:



https://fetchinketch.net/2016/06/26/...d-sailing-rig/



We carry the full sails up to about 22 knots or so at which point we are pushing hull speed and then we start to roll them up to suit the wind speed. What's really amazing about the twin jibs for downwind work is there is NO ROLLING!

I’ve seen the sv Delos videos where they’ve highlighted the Amel twin headsail twin pole setup. This is an excellent solution and much simpler than dual forestays. Thanks for the link to your explanation.

A way to implement this setup without a triple track furler is either (if you have a head foil with twin tracks) two light sails each in their own track but on a single halyard and furled together, or a special sail that also can be done for hanked forestays that consists of a single luff tape but has two layers that split for downwind. In both cases you have the balanced downwind rig and for the occasional reach or upwind you have a double layer and heavier sail. To reduce sail you simply furl both together. A bit more hassle as you have to decide to go double at the outset of a passage.

The Amel twin pole setup is another lovely innovation, but one they seem to have done away with on the new models (or is it just less visible?). As long as you have a topping lift, you can split it in two to support two poles as their vertical range is not too much. The mast fitting for two poles is trickier, but a large bail could work. Otherwise, terminate the inboard ends at a deck fitting - then your poles can be shorter.

For multihulls we don’t have to worry about rolling and having two identical balanced sails is not a requirement, so using a furling gennaker off a bowsprit and a smaller jib or genoa off the forestay will work fine. Poles could be useful for further projection in this case. What we’ve done with our gennaker when we can’t be bothered to use the spinnaker is to move the tack from the centreline bowsprit to the windward bow - this allows us to sail with the main to about 160 true wind angle and DDW with no main. This latter rig provides the quick furling that is one of the benefits of sailing downwind without a main.

Haven’t tried this on any passage yet but have used it coastal sailing.

[fxykty]

Originally Posted by rgleason

Thanks for the posts. The fetchinketch rig looks good.
And fxykty appears to have a fast modern boat with few headsails. I am envious of the 100% self tacking.
On my boat 85 or 78% might work with self tacking. I have a 95% north 3dl that is a great sail, but it is sheeted to the rail at about 16 degrees upwind, and at 13 years old it is showing signs of delamination. I am having trouble deciding/resolving to get a 78% LP replacement which will sheet closer, provide an appropriate reduction in sail area, and be easier to wrestle up on deck in heavier winds clipped to the solent.

But during spring and fall when we normally fit the 95% on the RF, would the 78% provide enough power and versatility?
Or am I going to be disappointed in the lower wind ranges?

We have a performance oriented catamaran, but the white sails rig applies to any boat. I guess our solent is 95% as it is full hoist but short on the J measurement so that it can tack on a track just in front of the mast. The clew is relatively high to allow for constant sheet angles (fore and aft), as there is no adjustment for that.

For your boat I would replace your beloved 95% sail and design the new one for self tacking. I think your smaller sails (I assume shorter on the luff) will leave you under powered in lighter air. Explain what you want to a few sail makers and see what they suggest. Do you have room in front of your mast for a track? And do you really need self tacking? If not, a 120 or 130% genoa, built heavier in the clew for use partly furled in heavier winds, make get be more versatile.

[hellosailor]

One furler, two tracks. Plenty of boats routinely have the foredeck send up the jib inside the genoa, or vice versa, so the sails can be changed on the one foil, no clumsy set of second gear needed.

But hey, if you think it would work, it is easy enough to bring a sketch to a machine shop and make one up. Maybe in another ten years everyone will just have a "double johnny" on the front of their boat.

[Jim Cate]

One furler, two tracks. Plenty of boats routinely have the foredeck send up the jib inside the genoa, or vice versa, so the sails can be changed on the one foil, no clumsy set of second gear needed.

Racers are not using a furler foil for inside out sail changes, they are using a "Tuff Luff" or other NON-furling foil. With a furler, the first (furling) sail is hoisted with the upper swivel at the head. With a second halyard, you could hoist a second sail in the second slot, but you then can not lower the first sail because the swivel can not descend past the second sail.

You could do the second sail for downwind twins, but you could not then furl them together since there is no swivel on the second halyard... need to lower the second sail before furling the first. Pretty awkward...

Jim

[fxykty]

Originally Posted by Jim Cate

Racers are not using a furler foil for inside out sail changes, they are using a "Tuff Luff" or other NON-furling foil. With a furler, the first (furling) sail is hoisted with the upper swivel at the head. With a second halyard, you could hoist a second sail in the second slot, but you then can not lower the first sail because the swivel can not descend past the second sail.

You could do the second sail for downwind twins, but you could not then furl them together since there is no swivel on the second halyard... need to lower the second sail before furling the first. Pretty awkward...

Jim

I haven’t tried this, but couldn’t you hoist both sails in separate slots but both heads attached to the one swivel and one halyard? Then both sails would furl, wouldn’t they?

[Jim Cate]

Originally Posted by fxykty

I haven’t tried this, but couldn’t you hoist both sails in separate slots but both heads attached to the one swivel and one halyard? Then both sails would furl, wouldn’t they?

Yes, you could hoist both attached to the swivel, but then when you wanted to revert to a single sail you would have to drop both at the same time, and the ensuing mess would be daunting at sea. Further, I don't think using two sails partly furled would work to windward very well, and two Dacron genoas would make a kinda big bundle when rolled up... if your plan had been to switch to a Solent or stays'l in stronger winds or upwind. Theoretically possible, I guess, but doesn't fit with my ideas for use offshore.

There was a Dutch sailmaker who used to flog a double genoa sewn to a single luff tape. The claim was that you could simply flop one inside the other and have a useful upwind sail. Sounded good when he said it fast, but I've not seen the adds for a few decades, so perhaps it didn't work out so well.

Jim

[fxykty]

It would be fine to have two sails like that for a predominately downwind passage, such as the Atlantic east to west trade wind route or the US West Coast to Hawaii passage. But agreed not useful for a mixed passage such as between AUS or NZ and the islands. All depends on where you are sailing.

[Jman]

It is funny how off topic this has become. OP was just asking if anyone had done it as an alternate to solent rig. Where you might have a large Genoa on the forward stay, and a small jib on the aft stay. Often the forward Genoa is more optimized for off the wind sailing.

The problem he was hoping to fix is that when you tack or gybe the forward sail you have to roll it up and back out again. This would be resolved with side by side head stays.

Unfortunately reality is that it is not really practical to do that.

[rgleason]

Fxykty Thanks for the suggestions.

Hellosailor
"One furler, two tracks. Plenty of boats routinely have the foredeck send up the jib inside the genoa, or vice versa, so the sails can be changed on the one foil, no clumsy set of second gear needed."
One time I tried this and felt really silly because the top RF head fitting gets stuck at the top.
To do it you need to just use the foils and not the RF, and you need double halyards of course.

This is unless you make a special release and a capture at the head fitting similar to the amel.