Rigging a Spinnaker on a Catamaran

[Epicurean]

Originally Posted by fxykty

Pole is the bow pole. Do you have one?

With an asymmetric the guy can be called the tack line. With the Cat Impi setup you will have two, one to each bow (so that the tack can be moved to windward). It’s nice to lead these lines to the cockpit rather than handle them on the tramp, especially if the wind picks up a bit and you want to move the tack.

Don’t plan on never gybing - how else do you expect to go somewhere dead downwind if your sailing angle is 150*? Have two sheets, it’s really not a big deal. The sheets will need to be long to allow for gybing. Not allowing for this is penny-wise and pound-foolish.

I’m not in favour of ever separating the tack line from the tack on a cruising boat - not worth losing control of that corner. The alternative is to have longer tack line(s) that can be eased a long way out for drops.

Unfurling the genoa/jib partially is a good idea when hoisting in light and rolling conditions to help prevent a forestay wrap. It’s also a good way to depower the sail prior to dropping, especially if you haven’t hoisted the main.

You don’t need a fancy trigger release shackle - regular snap shackles are just fine. For size, what is the safe working load of the furler? The shackle should be the same or higher.

So, by bow pole I think you mean the bow sprit. There is a continuous screecher furler on that so I'd like to not attach to that; there are enough ropes going out there.

It's not that I would never gybe. But my experience on my mono was it was safer to pull the sock down, transfer the sheet to the other side, and then raise the sock then it was to gybe the spinnaker. But, I can change my mind later. This seems the simplest to get started.

I agree that separating the tack seems a little "risky".

The furler is on the screecher, which is 2.5 oz nylon. The spinnaker is 1.5 oz nylon. A sailmaker once told me the screecher should be light dacron, I think to keep an upwind shape. I guess I'll put off purchasing a Tylaska and go with a longer sheet and regular snap shackle at the tack, and longer tack lines.

I wonder if a symmetrical spinnaker would have been a better sail since I have a screecher and would have enabled me to better go dead downwind.

[Epicurean]

Originally Posted by fxykty

I would suggest snatch blocks with snap shackles, or with soft shackles for lighter weight and more strength. Snatch blocks are useful for a lot of things around the boat so three or four are not too many. With tack lines to both bows you will need four, or three if you want to move the sheet block from one side to the other along with the sheet.

If you only fly it from a bow pole, then you only need a single block on the end of the pole (or LFR).

I have never used soft shackles but I did read about their advantages, especially for cats. So I will look into using them. I have one snatch block but may get a couple more. What is LFR?

[Epicurean]

I want to thank everyone for their responses. I've really learned a lot! Even when I want to do it differently I appreciate your expressing your points of view.

[Palarran]

I don't know if they will help with all the advise you have been given and videos watched, but here are some I made. As an fyi, I think it's key to have a no load quick release snap shackle on the tack. I use the Wichard. https://marine.wichard.com/en/stainl...-snap-shackles

https://www.youtube.com/watch?v=7IaYnbYxjfg

https://www.youtube.com/watch?v=hBPF6-hIGPA

https://www.youtube.com/watch?v=6IW-WZb-sF0

[Epicurean]

Originally Posted by Palarran

I don't know if they will help with all the advise you have been given and videos watched, but here are some I made. As an fyi, I think it's key to have a no load quick release snap shackle on the tack. I use the Wichard. https://marine.wichard.com/en/stainl...-snap-shackles

Thank you. So why do you need the Wichard? Under what circumstances would you open it?
Also it looks like sometimes the tack goes between the windward hull and the bowsprit and othertimes between the bowsprit and leeward hull. I would think the former would enable it to be open more.
And, do you have a screecher/code 0? I have one on an endless furler on the bowsprit. I don't want the trouble of taking that off to attach the tack to the bowsprit.

[fxykty]

Originally Posted by Epicurean

I have never used soft shackles but I did read about their advantages, especially for cats. So I will look into using them. I have one snatch block but may get a couple more. What is LFR?

LFR is low friction ring.

[fxykty]

Originally Posted by Epicurean

So, by bow pole I think you mean the bow sprit. There is a continuous screecher furler on that so I'd like to not attach to that; there are enough ropes going out there.



It's not that I would never gybe. But my experience on my mono was it was safer to pull the sock down, transfer the sheet to the other side, and then raise the sock then it was to gybe the spinnaker. But, I can change my mind later. This seems the simplest to get started.



I agree that separating the tack seems a little "risky".



The furler is on the screecher, which is 2.5 oz nylon. The spinnaker is 1.5 oz nylon. A sailmaker once told me the screecher should be light dacron, I think to keep an upwind shape. I guess I'll put off purchasing a Tylaska and go with a longer sheet and regular snap shackle at the tack, and longer tack lines.



I wonder if a symmetrical spinnaker would have been a better sail since I have a screecher and would have enabled me to better go dead downwind.

If you don’t want to use your bow pole (sprit) for the spinnaker then you need to take it to the windward bow. Follow the Cat Impi set up with two tack lines and you can move and raise the tack at will to any point between the bows. Remove the screecher though when flying the spinnaker.

If your screecher is 2.5oz nylon it will only be good for reaching. If you want an upwind screecher then dacron tri radial or laminate exotics are the materials that can handle the loads.

A cat foredeck is fundamentally different from a monohull - you now have tons of room and a steady, flat platform. Working up there even in rough conditions is relatively easy and safe, albeit wet.

[Epicurean]

Thanks. Actually I have to take the screecher down because I only have the one halyard for that or the spinnaker. But I want to leave the furler attached.
I haven't done any real ocean sailing on this because of Covid border closures. So when I leave here I'll see which of these things work as I imagine.

[Palarran]

Originally Posted by Epicurean

Thank you. So why do you need the Wichard? Under what circumstances would you open it?
Also it looks like sometimes the tack goes between the windward hull and the bowsprit and othertimes between the bowsprit and leeward hull. I would think the former would enable it to be open more.
And, do you have a screecher/code 0? I have one on an endless furler on the bowsprit. I don't want the trouble of taking that off to attach the tack to the bowsprit.

With the Wichard it is super easy to douse the sail in the sock either with or without crew. All you need to do is head downwind, take your down hauling line in hand, walk up and pull the shackle release, and pull it down. If your in a fair amount of wind, you really want it to be easy. But we release it every single time we douse the sail, it's just what we do.

Maybe I missed it, but you have a screecher and a downwind asym in a sock? It really doesn't matter, every boat is a little different and you will have to figure it out in the end. But to answer the question of tack placement, in general the further downwind you sail the more you want the tack to be on the windward hull. The further upwind, the closer to centerline or leeward and tighter for the tack. With my North A4 we have sailed it from 70 degrees apparent to (this is the odd one) 170 degrees IN THE LEE. The more downwind I go, the more the spin sheet needs to be controlled, which is why I use the barberhauler.

[chris mac]

Ours is an asymmetrical in a sock, on a 42' cat. Central attachment off the cross bar(no sprit) and I have a sheet running up each side with snatch blocks close to the shrouds. I attach leeward sheet with a shackle so if i need to jibe we can sock it and change to the other side easily.
If we are running ddw I move the snatch blocks to the bow eyes and use both sheets, kinda like a symmetrical.
Low tech, but works well. We dont use it above 15 knots.

[belizesailor]

Originally Posted by Epicurean

... I don't think a pole is called for since the beam is 24'. Therefore no guys. ...

Re spinnaker pole. Correct, you dont typically use a spinnaker pole on a cat because the wide beam makes it unecessary.

However, guy lines can still be useful for more control over the sail position & shape. Example: I run 2 sheets and 2 guys on my boat, but thats with a big light air symetrical spin. It gives me quite a lot of control over the sail.

But, for an asym used for cruising, guys are certainly not necessary. I suggest just going with sheets and a tack line and see how it works for you. Then you can add more rigging if you want to tweek more, but I think you will find it unecessary.

I think there has also been some confusion over the term "pole" in the thread. It appears to me your intended use was "spinnaker pole" (very uncommon on a cat) and others may have thought you were referring to a "bow sprit pole" (way more common on a cat).

Re jibing, it is not an uncommon technique, on a cruising boat, to first dowse an asym then jibe and reset...to avoid fouling the asym, sock, etc.

[Factor]

I have been running bridled tack lines for years and years, what is referred to as the Impi approach but obviously predates them.

see MPS 1 photo - A bridled tack line leading from tack of MPS (Asymmetric Spinnaker) to blocks on each bow that come back to clutches and cheek blocks near winches. This means that the tack position can be anywhere between the two bows of the boat and indeed can be to the leeward of the leeward bow. That means that from the cockpit I can adjust the tack position easily as direction changes.

MPS 2 Photo - a sheet from clew to standing block aft, onto winch and cam cleat. If racing two sheets from clew with the lazy one led outside absolutely everything on the boatto similar position on the other side, most of the time, particularly if i am on my own, I just sock the MPS then Gybe, then relaunch.

[belizesailor]

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[belizesailor]

Jibing considerations...for the OP.

Asymetrical. Jibing an asym is much like jibing a genoa...it has to cross the foredeck. This is why you read here, and see in practice, of some dousing their asym, jibing, and then reseting the asym. This avoids the potential problems of hauling the sail across the foredeck.

Symetrical. Since on cat a spin pole is not normally used, and a symetrical does not need to transit the foredeck, jibing is simple...just a matter of shifting sheets and guys and jibing the main (if flying).

[theDangerz]

Following!

Getting ready to rig our cat for a parasailor... so this has already proven VERY helpful!!