Using an Assy Spinnaker

[Dockhead]

Good advice on another thread has led me to decide to acquire an assy spinnaker for my boat. I have used conventional chutes, but never one of these, some I'm a complete virgin.


So, what advice can you give me on rigging, and using it?



From my reading, I gather:


1. Just like with a normal chute, you need a halyard with a fair lead ahead of the forestay. I've got a masthead truck crane and 2x blocks with 2x 12mm racing dyneema halyards with cam cleats at the base of the mast, so I'm good here!



2. Bowsprit is a really good thing, but you can make the tack line fast anywhere ahead of the forestay. Right? This is going to be tough on my boat because there is little room between the forestay and the teak step of my Swedish style split pulpit. Maybe I need to improvise some kind of sprit. I guess I could lash it down through the bow roller. Maybe get a piece of windsurfer mast or something. Anyone do something like this?



3. Tackline needs to be adjustable, so I think how to rig it. Maybe I'll use my staysail sheet for this. It's a single sheet since staysail is self-tacking. It's run to the cockpit through a jammer to an electric winch.



3. I'm going to need lighter sheets. Despite the miles of cordage I have on board, I don't think I have anything suitable. I guess I will need 12mm or maybe even 10mm double braid dyneema for this. Or maybe 12mm double braid polyester? But I think lightness will be really key -- probably 10mm dyneema is the right cordage for sheets. This ain't gonna be cheap.



4. I'll need turning blocks at the quarters for the sheets. I guess unlike a normal headsail, these sheets will never be led along the deck -- they will always be coming from across the rail, right? I guess I could just strop some snatch blocks to my aft mooring cleats.



5. How and when do you use the pole with an assy? What is the right size for the pole? Spin poles are normally limited to the length of the J dimension, by racing rules, but for an assy? Is longer desirable?


6. I guess turtle and snuffer are both highly desirable, right?


6. Sizing -- the luff of the assy should be less than the forestay length, I guess. Much less? What are the size constraints on either end?





Grateful for all advice!

[Gary Mc]

For spin sheets I use New England Flight line, it has a dyneema core with a light weight cover that does not absorb water so stays light.

I thought you were going with a symmetric spin, that would have been my choice.





Flight Line

Lightweight line

A lightweight line perfect for light air spinnaker sheets, as well as mainsheets and control lines in smaller boats.

Features:

• Cover: XLF
• Core: Dyneema®

[Dockhead]

Originally Posted by Gary Mc

For spin sheets I use New England Flight line, it has a dyneema core with a light weight cover that does not absorb water so stays light.

I thought you were going with a symmetric spin, that would have been my choice. . . .

I explained my choice in the other thread. A normal chute was my first thought, but after getting a bunch of good input, I changed my mind. One of the main reasons is that after the race, the assy will be more usable with small crews.

[sailah]

2. Bowsprit is a really good thing, but you can make the tack line fast anywhere ahead of the forestay. Right? This is going to be tough on my boat because there is little room between the forestay and the teak step of my Swedish style split pulpit. Maybe I need to improvise some kind of sprit. I guess I could lash it down through the bow roller. Maybe get a piece of windsurfer mast or something. Anyone do something like this?

It's nice but not necessary. I have a wooden sprit anyways with my bow roller but it wasn't designed for the upward vector of a spin tacked at the end so I made a bobstay. Was a fair amount of work designing it, laser cutting stainless. I'm well past my naval architecture days but I don't think a windsurfer mast has a chance to survive. You'd need something going down to cutwater to help with the loads and your boat is going to load it up. Also the loads are lateral as well and can be significant in reaches as the wind climbs.

I don't think it's worth the effort for you now. Just tack down with snatch block to something secure. If the luff is a bit short that's a good thing as you can get the sail up higher and away from grabby bits.



3. Tackline needs to be adjustable, so I think how to rig it. Maybe I'll use my staysail sheet for this. It's a single sheet since staysail is self-tacking. It's run to the cockpit through a jammer to an electric winch.

You can pretty much use anything. I have a piece of 5mm Dyneema with a trigger shackle. I also have an aluminum marlin spike I machined stationed at the pulpit with a lanyard to blow the trigger if needed but I've never had to do this. Having it to a winch would be great because you can easily adjust tension by luffing it.


3. I'm going to need lighter sheets. Despite the miles of cordage I have on board, I don't think I have anything suitable. I guess I will need 12mm or maybe even 10mm double braid dyneema for this. Or maybe 12mm double braid polyester? But I think lightness will be really key -- probably 10mm dyneema is the right cordage for sheets. This ain't gonna be cheap.

It can be cheap. I use 3/16" dyneema (5mm) but my boat is 11.3m. I have approx 25-30 dyneema with a spliced loop at the end of each sheet. These attach to a Y bridle at the clew with a snap shackle, although I'm thinking about getting rid of shackle.

Then I spliced the Dyneema to regular StaSet yacht braid where it comes through the blocks and winch. During normal conditions, the dyneema and and maybe a bit of braid are the only things hanging overboard. In light airs it makes a big difference in not collapsing the sail. Have flown to 20+ kts on a beam reach and never had an issue. Clearly you'd probably want to step up the sizes. But that was really cheap to make and took a couple hours max.

Some people will take Dyneema core line and strip off the sheath. I bought 35m hank of dyneema on ebay for $50.



4. I'll need turning blocks at the quarters for the sheets. I guess unlike a normal headsail, these sheets will never be led along the deck -- they will always be coming from across the rail, right? I guess I could just strop some snatch blocks to my aft mooring cleats.

Yeah I have padeyes I installed with backing places on the very aft quarters. My cleats weren't in ideal location for leads so I had to fit them. But if your cleats are, perfect. Just dyneema loops and you're done. I added some shock cord up to the lifelines so they didn't bang around on my varnish.

5. How and when do you use the pole with an assy? What is the right size for the pole? Spin poles are normally limited to the length of the J dimension, by racing rules, but for an assy? Is longer desirable?

I don't so no comment.


6. I guess turtle and snuffer are both highly desirable, right?

For sure. Turtle bags are really nice for deploying. Mine came with spin. Snuffer socks are also excellent esp for short hands or future cruising. They really allow you to get control of the sail if things get out of hand. Blow the trigger shackle, let it flag out and then snuff it. They do add a bit to your hoist height so make sure you've accounted for this in your luff length. They also bunch up a bit at the top but it's not really a big deal. When I take down, I'll blow the tack, let it flag, snuff it and then lower the tube down to turtle bag. I also will do this on gybes as it's safer and I'm usually shorthanded.

I've flown mine solo but it's a lot of work and it burned me once offshore at night which was my own fault.


6. Sizing -- the luff of the assy should be less than the forestay length, I guess. Much less? What are the size constraints on either end?

The snuffer will add to the length. Guessing mine adds 2 feet? If I max out hoist, the tack on mine is about 1-2' off the sprit. In reality I never have luff that tight so the tack line is longer.

Give yourself some margin, it's better to have it too short than too long.

[Breaking Waves]

Usually, there is some sort of relatively simple way to get the asym tack line out in front of the furler using the anchor rollers. I can't say what would be best without seeing the geometry. Just lashing your pole along deck and to the rollers and sticking out a ways would likily work.


but hmmm . . . . you do realize have the option to fly the tack of an asym from the end of your pole - in exactly the same way you fly a sym? So the pole is your 'bow sprit'. And with a bit of extra rigging complexity (which you and your crew probably already know how to do) you can then square back the pole if you want.

you apparently already have a significant pole - I would use it, either just as the sprit or if you end up in a very deep running situation as an actual spin pole.

Usually, there is some sort of relatively simple way to get the asym tack line out in front of the furler using the anchor rollers. I can't say what would be best without seeing the geometry.

[dougweibel]

You may want to check out the ATN Tacker as a temporary or permanent solution for the tack point. I had one on my last boat, but no spinnaker, so only used it to hang a hammock on deck. Seemed like it could be used effectively for its intended purpose.

[FabioC]

For the sheets (and halyard and tack line), dyneema core makes it easier and achieves better performance because it reduces the stretch, but it is not an absolute must.

You'll need dedicated blocks as aft as possible for the sheets. THe jib leads are way too forward.

For the luff length, it is typically around 107% of the distance between the halyard point and the tack point, but shorter luff lengths can work as well.

For the tack line, if possible, bring it back to the cockpit or at least to the mast. That way, when you take the asymmetric down, you simply release the tack and the sail deflates (it also works by easing the sheet, but easing the tack is more common, so you can bring the sail behind the main and drop it while staying in control).

Certainly get a sock for the asymmetric, especially if you are short-handed, it makes it much, much easier to handle the sail.

[rhpike]

I attach my tack to the bow roller guard with a snap shackle, which is about 1.5' forward of my jib roller furling drum. I don't mess with an adjustable tack line. It's an Island Packet 440.

[Dockhead]

Originally Posted by Breaking Waves

Usually, there is some sort of relatively simple way to get the asym tack line out in front of the furler using the anchor rollers. I can't say what would be best without seeing the geometry. Just lashing your pole along deck and to the rollers and sticking out a ways would likily work.


but hmmm . . . . you do realize have the option to fly the tack of an asym from the end of your pole - in exactly the same way you fly a sym? So the pole is your 'bow sprit'. And with a bit of extra rigging complexity (which you and your crew probably already know how to do) you can then square back the pole if you want.

you apparently already have a significant pole - I would use it, either just as the sprit or if you end up in a very deep running situation as an actual spin pole.

Usually, there is some sort of relatively simple way to get the asym tack line out in front of the furler using the anchor rollers. I can't say what would be best without seeing the geometry.

Well it looks like this:





It's a crappy stock photo, but you can see how the stemhead fixtures are arranged.


I rather like the idea of the ATN Tacker mentioned in the post above:





The sling around the forestay just keeps the tackline from running forward and interfering with the pulpit. Very clever. I guess I could make a sling like that.

[Dockhead]

And what about the sheets? Maybe a couple of long leaders -- nearly a boat length -- of light dyneema or Acera -- maybe 8mm? Or 6mm? With eye splices on both ends, and hitch on a regular sheet at the end. Then the sheets will be super light and won't hurt the shape in light wind.

[dougweibel]

The ATN Tacker has s rigid and gives you the ability (supposedly) to adjust the tack up and down. I don’t think a sling would allow that

[Pelagic]

Hi Dockhead,
Following this as I am just starting to look at a better down wind solution.
Can you post the link to the other thread you mentioned.

As to bow spirit extension, this Uma project might give you some ideas.

https://youtu.be/hs9xnaKvNOU

[Silverfox]

Originally Posted by Dockhead

Well it looks like this:


Attachment 216216


It's a crappy stock photo, but you can see how the stemhead fixtures are arranged.


I rather like the idea of the ATN Tacker mentioned in the post above:


Attachment 216217


The sling around the forestay just keeps the tackline from running forward and interfering with the pulpit. Very clever. I guess I could make a sling like that.

I used an ATN Tacker for many seasons and can recommend them wholeheartedly.

I had a friend who made a successful equivalent by cutting up a fender for use as the " cuff" around the furled sail and that worked well too.

I have a spinny pole but never had to use it.

[georgeg305]

Re: your comment about using an electric winch. In my PHRF area, use of power ( electric winch ) is not allowed.

[Dockhead]

Originally Posted by georgeg305

Re: your comment about using an electric winch. In my PHRF area, use of power ( electric winch ) is not allowed.

No such restrictions in this race.