Rigging an asymmetrical spinnaker

[jalmberg]

Our 40' ketch came with an asymmetrical spinnaker or cruising 'chute. (See my avatar for image.) I've never had one before, so am trying to figure out how to rig it.


The 'chute has a sock and I noticed that the previous owner had just one very long sheet rigged. This baffled me, so I've been reading and talking to people to figure out how this sail should be flown.


I found this here:


"Two sheets are attached to the clew of the sail. They should be led near the aft corner of the boat on each side. The “lazy” or windward sheet should be led all the way around the bow and aft to the other side. Each sheet needs to be about twice the length of the boat plus 10 feet.
...

To gybe – bear off to a broad reach, easing the sheet as you go to keep the sail flying. Turn the boat down to a run and when the spinnaker luffs, let the sheet all the way off. Gybe the boom and trim in the spinnaker on the other side. Head up to a reach to fill the sail, ease and trim the new sheet as needed."


I think I know what this means, but just to verify, I have a couple of questions:


1. "The “lazy” or windward sheet should be led all the way around the bow and aft to the other side."



Does this mean that the sheet should be lead in front of the sail? Rather than behind it, as usual with a jib, for example?


2. "Turn the boat down to a run and when the spinnaker luffs, let the sheet all the way off."


Does this mean that the sail will be blowing straight out in front of the boat? With the two sheets on either side of the boat?



If I am correct on both points, isn't there a potential for the boat to run over one or both sheets if the wind is really light? It seems really dicey to have all that line blowing out in front of the boat, particularly in light winds.



I guess that the sheets themselves also need to be lightweight. Anyone have a suggestion as to diameter, type, etc.?



TIA

[Tornadosailing]

I recently got an A sail for my cat, so I'm certainly not an expert, but I've learned a little.

If you only have one sheet, it's because you don't intend to gybe while flying the spin. Nothing wrong with that. You can just douse the sail, move the sheet, and re-launch. It's pretty easy with a sock.

If you do want to gybe the spin, you have to make the decision whether you want an inside or an outside gybe. If going inside, you're going to pass the spin leach between the luff and the forestay. If going outside, the leach goes around in front of the luff. You'll probably just need to experiment to see what works best for you.

One thing I've found invaluable is a Tylaska trigger shackle. I put a long-ish piece of dyneema on the clew with an eye in the end. It needs to be long enough that I can reach it when I sheet in the spin. It also makes it easier to launch because the tail sticks out of the sock and I can easily attach the sheet without pulling the spin half way out of the sock. When I'm ready to douse there's absolutely no drama. I simply sheet in until I can reach the Tylaska shackle, and release it. No whipping lines, and no load on the spin. Then I simply pull down the sock. It's crazy how easy it is. Thank you Catamaran Impi for the tip!!

[Tornadosailing]

Here, Impi drops the spin by releasing the tack. I have Tylaska shackles on the tack and clew. If I'm going deep, release the clew. If reaching, release the tack. One person drop, with no drama.

https://youtu.be/4XQoq9gOURw?t=2m27s

[cal40john]

Agree with above, but to add to it, if you're going to do an outside jibe you might want to add some sort of stick extending out past the prod. The lazy sheet in front of the spin luff can slide down the luff and under the prod then under the bow.

[Tornadosailing]

Originally Posted by cal40john

Agree with above, but to add to it, if you're going to do an outside jibe you might want to add some sort of stick extending out past the prod. The lazy sheet in front of the spin luff can slide down the luff and under the prod then under the bow.

Maybe that's why the previous owner only ran one sheet. It was probably more trouble than it was worth.

[Sardean]

Originally Posted by jalmberg

Our 40' ketch came with an asymmetrical spinnaker or cruising 'chute. (See my avatar for image.) I've never had one before, so am trying to figure out how to rig it.


The 'chute has a sock and I noticed that the previous owner had just one very long sheet rigged. This baffled me, so I've been reading and talking to people to figure out how this sail should be flown.


I found this here:


"Two sheets are attached to the clew of the sail. They should be led near the aft corner of the boat on each side. The “lazy” or windward sheet should be led all the way around the bow and aft to the other side. Each sheet needs to be about twice the length of the boat plus 10 feet.
...

To gybe – bear off to a broad reach, easing the sheet as you go to keep the sail flying. Turn the boat down to a run and when the spinnaker luffs, let the sheet all the way off. Gybe the boom and trim in the spinnaker on the other side. Head up to a reach to fill the sail, ease and trim the new sheet as needed."


I think I know what this means, but just to verify, I have a couple of questions:


1. "The “lazy” or windward sheet should be led all the way around the bow and aft to the other side."



Does this mean that the sheet should be lead in front of the sail? Rather than behind it, as usual with a jib, for example?


2. "Turn the boat down to a run and when the spinnaker luffs, let the sheet all the way off."


Does this mean that the sail will be blowing straight out in front of the boat? With the two sheets on either side of the boat?



If I am correct on both points, isn't there a potential for the boat to run over one or both sheets if the wind is really light? It seems really dicey to have all that line blowing out in front of the boat, particularly in light winds.



I guess that the sheets themselves also need to be lightweight. Anyone have a suggestion as to diameter, type, etc.?



TIA

1. Yes lead the lazy sheet in front of the sail.
2. Its easier than it sounds.
When cruising if main is up centre the main sail traveller and sheet it on hard. This slows the boat ( increases apparent wind and floats kite out better.) then head down wind ease the kite sheet so kite floats out front of yacht while taking up on lazy sheet(now name changes to kite sheet). The way the kite floats around the bow is controlled by the helm with assistance from the sheets. Unless you're racing or very experienced i would suggest dropping the kite before true wind gets to 15 knots.

The sheets are normally kept under light tension to controll the gybe.

One way you can run over the kite is if you go faster than the wind, this is not as hard as it sounds. Or if you dip the kite in the water.
In very light winds use thin sheets(and if on a long run untie the lazy sheet). I normally use 8mm spectra and under 5knots i use vb chord. I always tie my sheets on to save weight at clew.

Have fun and practice in light winds. I wouldn't gybe the kite on inside like a jib as its too easy to damage kite like that.

[RaymondR]

I use a single sheet and pass it around the front of the genaker to the other side to jibe. Trying to pull the tack between the genaker and the rolled genoa to jibe tends to end up a bit disastrous. Also I use a double line with one end tide to the prod, up through the ring on the clew, back through the ring on the prod and bought back to a cleat so that I can release it under load.

[Sailmon]

OP mentioned that sheet was very long. Wondering if the PO hitched the sheet to the clew of the sail midway on the line - with half to port and half to starboard.

[jalmberg]

Originally Posted by Sailmon

OP mentioned that sheet was very long. Wondering if the PO hitched the sheet to the clew of the sail midway on the line - with half to port and half to starboard.

No it was tied on at one end.

What is a ‘prod’? That’s a new term for me.

[jalmberg]

Originally Posted by Sardean

1. Yes lead the lazy sheet in front of the sail.
2. Its easier than it sounds.
When cruising if main is up centre the main sail traveller and sheet it on hard. This slows the boat ( increases apparent wind and floats kite out better.) then head down wind ease the kite sheet so kite floats out front of yacht while taking up on lazy sheet(now name changes to kite sheet). The way the kite floats around the bow is controlled by the helm with assistance from the sheets. Unless you're racing or very experienced i would suggest dropping the kite before true wind gets to 15 knots.

The sheets are normally kept under light tension to controll the gybe.

One way you can run over the kite is if you go faster than the wind, this is not as hard as it sounds. Or if you dip the kite in the water.
In very light winds use thin sheets(and if on a long run untie the lazy sheet). I normally use 8mm spectra and under 5knots i use vb chord. I always tie my sheets on to save weight at clew.

Have fun and practice in light winds. I wouldn't gybe the kite on inside like a jib as its too easy to damage kite like that.

Excellent. Can’t wait to give it a try. Thanks.

[Sailmon]

PO is previous owner. Still seems strange to me that he would only use one sheet. Sails & snuffers are not not inexpensive. Can’t understand scrimping on the line. Wondering if there were originally 2 sheets & one got repurposed. Did the boat come with turning blocks for both port & starboard. At any rate, if you plan to use the chute with any regularity, it would probably be a good idea to invest in a second sheet.

[jalmberg]

Originally Posted by Sailmon

PO is previous owner. Still seems strange to me that he would only use one sheet. Sails & snuffers are not not inexpensive. Can’t understand scrimping on the line. Wondering if there were originally 2 sheets & one got repurposed. Did the boat come with turning blocks for both port & starboard. At any rate, if you plan to use the chute with any regularity, it would probably be a good idea to invest in a second sheet.

It stumped me too. We were just playing around with it on the Chesapeake a couple of weeks ago and I didn't have the nerve to put it up with just one sheet, so I untied it and tied it back on in the center so I had two sheets.



I didn't know any better, so I rigged it behind the roller furler, but then the normal jib sheets were in the way... it was a real mess and I realized there was more to it than just hoisting it up the mast and pulling up the sock!


There were no turning blocks rigged, but I have a whole box of extra blocks, in various conditions.



I also have twin spinnaker poles -- one for each side of the boat for flying twin head sails. Besides the jib on the furler, I have a hank-on version that goes on the extra headstay. The original owner crossed the Atlantic nine times using twin head sails poled out to either side, running down the Trades.



I also have a huge mizzen staysail, much bigger than the yellow one shown on my avatar. I haven't had the nerve to put that up yet! One of these days I would love to put up all those sails and see how she moves in light air.

[svHyLyte]

Originally Posted by Sailmon

PO is previous owner. Still seems strange to me that he would only use one sheet. Sails & snuffers are not not inexpensive. Can’t understand scrimping on the line. Wondering if there were originally 2 sheets & one got repurposed. Did the boat come with turning blocks for both port & starboard. At any rate, if you plan to use the chute with any regularity, it would probably be a good idea to invest in a second sheet.

If the sheet is unusually long, it may be that both ends are connected to the clue, passing through the turning blocks across the cockpit ahead of the binnacle. We use that arrangement, a single continuous sheet to good advantage, especially eliminating to a large extent an unruly lazy sheet. The sheet is led forward of the headsail but aft of the tack line (in our case) as we have found inside gibes preferable.


FWIW...

[AiniA]

We started with two sheets and realized after a couple of years of full-time cruising that we basically never gybed the A-symm so we took off the second sheet. It was just something else to get in the way and it added weight to the sail in light air.

Did you get a strap that goes around the furled genoa from the tack. These are useful. Any sailmaker can make one easily.

[jalmberg]

Originally Posted by AiniA

We started with two sheets and realized after a couple of years of full-time cruising that we basically never gybed the A-symm so we took off the second sheet. It was just something else to get in the way and it added weight to the sail in light air.

Did you get a strap that goes around the furled genoa from the tack. These are useful. Any sailmaker can make one easily.

That is probably what happened in this case. The POs crossed the Atlantic on the Milk Run, so they probably always used it on the same tack. I'm guessing they never even used it in the Caribbean. We certainly didn't. The four working sails were more than enough.