Rigging a Spinnaker on a Catamaran

[fxykty]

Originally Posted by JustMurph

Another Mumby 48 owner here. In the year and a bit I've had the boat, I've made a few changes to make flying the Code D and asymmetric spin a bit easier. The previous owner had managed to bend and crack the tang on the top of the prodder that the furler or tack would attach to, so in repairing that we made a few more modifications. The prodder now has a clutch for the tack line at its base and two pad eyes at the end, so now the tack line now has 2:1 purchase and runs back to the clutch. This makes swapping between the Code D and asym a whole lot easier. Just open the clutch and haul the tack onto deck. Some other Mumby's I've seen just run the tack line through a block on the end of the prodder back to the cleat at the windlass. With the extra purchase I can adjust the tack by hand in light air, or just run the tack line back to one of the primary winches if it's loaded up.



I have no snap shackles anywhere in the system and it hasn't been a problem so far. I run a single extra long sheet, so that you can let it fly well forward when dousing....and provided you do let it go well forward, it comes down easily. If I did need to release the tack, then I could just pop the clutch.



Generally I fly the asym from the end of the prodder, but if I'm running DDW, then I'll either attach it to a bow, or let the prodder tack line go a bit at haul it across to the bow, or anywhere in between. Flying the asym DDW seems to work pretty well, but I'll usually run angles instead and make far better VMG. I don't think you'd ever bother with a symmetric spin on a Mumby. You don't need to crack off far before you start generating a lot of apparent wind.



I'm sure the setup could be improved upon, but it's proven easy to use and effective so far.

Looks great, we have a similar setup.

To haul the tack over to the windward hull do you just attach another line to the bottom of the furler and lead it through a block on the bow? Then haul in that line while easing the tack line?

We have a snap shackle on the bottom of our furler and simply release it from the tack line, then snap it to the pad eye on the bow. But we have to ease halyard tension and can’t do it when the sail is loaded. We’d have to lengthen our tack line to reach the bow.

We do have a symmetric spinnaker and use it when we’re being lazy, heading for DDW or near DDW destinations and can’t be bothered with large gybes. Especially effective without a mainsail. Also works when constrained by shallows and reefs. It works just fine up to about 90 degrees AWA (in lighter winds only!) if we want to heat it up by letting the guy go until the tack is at the centreline, but is more hassle than an asymmetric would be. Replacing it is not in the budget.

[JustMurph]

Originally Posted by fxykty

To haul the tack over to the windward hull do you just attach another line to the bottom of the furler and lead it through a block on the bow? Then haul in that line while easing the tack line?

Yes, either tied directly to the tack, or (in the shot below), tied to the bow shackle, fed through the tack eye, then back to the bow block for a 2:1 purchase.

Originally Posted by fxykty

We do have a symmetric spinnaker and use it when we’re being lazy, heading for DDW or near DDW destinations and can’t be bothered with large gybes. Especially effective without a mainsail. Also works when constrained by shallows and reefs. It works just fine up to about 90 degrees AWA (in lighter winds only!) if we want to heat it up by letting the guy go until the tack is at the centreline, but is more hassle than an asymmetric would be. Replacing it is not in the budget.

That sounds pretty good really. It seem either symmetric or asymmetric can do the job pretty well.

Here's a shot of it hauled across to the bow, running DDW in very light air with no main.

[fxykty]

Originally Posted by JustMurph

Yes, either tied directly to the tack, or (in the shot below), tied to the bow shackle, fed through the tack eye, then back to the bow block for a 2:1 purchase.


That sounds pretty good really. It seem either symmetric or asymmetric can do the job pretty well.

Here's a shot of it hauled across to the bow, running DDW in very light air with no main.

Lovely photo. The best I have is not so nice.

[JustMurph]

About 30 seconds after my photo the wind dropped under 3 knots and mine didn’t look so good either!

[dougweibel]

Originally Posted by JustMurph

Here's a shot of it hauled across to the bow, running DDW in very light air with no main.

Is there a concern with putting a lateral load on the bow sprit/prodder when moving the tack from center to near a bow when the breeze is up a bit? It seems you would have to maintain some tension on the regular (center) tack line while you haul the tack to the side and this would put a (temporary perhaps) lateral load on the pole that might be significantly more than is typical.

[Epicurean]

Originally Posted by Happ

You have asked great questions. Attaching the sheets can be done many ways. Trigger Shackles are the best IMHO as there is nothing to catch on. For size ask your sailmaker. He will know for sure.

Dyneema while pricey is again IMHO the way to go. However you will want to use a Poly cover on the areas going through blocks and around winches. It will make the line much thicker thus easier to to use going around a self tailing winch not to mention easier on your hands. This will also reduce the cost as you can use smaller diameter Dyneema.

I have seen all the system you have mentioned and the simple answer is what type of sailing are you going to do? Are you sailing port to port on weekends? Are you going to be making long passages? How precise are you in your trimming? If you are sailing port to port or anchoring every night then a sprit with a top down Furler should work just fine. Easy to deploy and furl at the end of the day. Easy to put up and down. If you go that way the Reflex system by Harken is the best IMHO. Their cable system is virtually flawlessly. It also has 3 different sets of attachments for the Head and tack. So you can use the Furler with many different types of sails. If you will be offshore for days at a time then having a system that you can move the tack from hull to hull is preferable. The reason being is you can have a flatter asymmetric for reaching and move the tack to weather when you want to go more downwind. One sail for many purposes. Of course you will need to have a sock on the chute which requires going to the bow to deploy and snuff it. If y9ou are really creative you could put a top down Furler on a track system but you will need to have the means to ease the furling line when moving the tack to weather. More stuff to deal with.

IMHO I would go with a Reflex with a Code sail (Code Zero) and if you feel later you want to add a mor downwind sail it’s easy to swap between the two sails as you desire. You could also add a Drifter and still use the same Reflex Furler.

I hope this helps.

Thanks for the comments. I have certain things that came with the boat: an asymmetric spinnaker and sock, bowsprit, and endless furler for the screecher. I'm not designing a spare-no-expense-dream boat but trying to live with what I already have. I don't have a sailmaker, What sailing do I do? Cruising from country to country if the borders open.

[Epicurean]

Originally Posted by JustMurph

Another Mumby 48 owner here. In the year and a bit I've had the boat, I've made a few changes to make flying the Code D and asymmetric spin a bit easier. The previous owner had managed to bend and crack the tang on the top of the prodder that the furler or tack would attach to, so in repairing that we made a few more modifications. The prodder now has a clutch for the tack line at its base and two pad eyes at the end, so now the tack line now has 2:1 purchase and runs back to the clutch. This makes swapping between the Code D and asym a whole lot easier. Just open the clutch and haul the tack onto deck. Some other Mumby's I've seen just run the tack line through a block on the end of the prodder back to the cleat at the windlass. With the extra purchase I can adjust the tack by hand in light air, or just run the tack line back to one of the primary winches if it's loaded up.

I have no snap shackles anywhere in the system and it hasn't been a problem so far. I run a single extra long sheet, so that you can let it fly well forward when dousing....and provided you do let it go well forward, it comes down easily. If I did need to release the tack, then I could just pop the clutch.

Generally I fly the asym from the end of the prodder, but if I'm running DDW, then I'll either attach it to a bow, or let the prodder tack line go a bit at haul it across to the bow, or anywhere in between. Flying the asym DDW seems to work pretty well, but I'll usually run angles instead and make far better VMG. I don't think you'd ever bother with a symmetric spin on a Mumby. You don't need to crack off far before you start generating a lot of apparent wind.

I'm sure the setup could be improved upon, but it's proven easy to use and effective so far.

It's good to see comments from another Mumby. I've had mine for almost 2 years but due to border closures have only stayed in coatal waters of Malaysia and Thailand where there usually aren't steady, good winds. So I don't have a lot of experience sailing it. I've never actually flown the spinnaker.
The screecher came with a sheet so long it goes through the cockpit and around to the other side of the sail. I've never seen that before, don't see the advantage, and don't like it. So I got a shorter sheet. To jibe I furl it and run the sheet around to the other side. I'm thinking this is the way to handle the spinnaker. So when you mention having an extra long sheet to allow to go forward, depowering the sail so you can sock it, I think of the hassle of working with a really long sheet. But maybe I'll find that's the way to go after trying it.

What happens to the Code's furling drum when you switch to the spinnaker?

[fxykty]

Originally Posted by dougweibel

Is there a concern with putting a lateral load on the bow sprit/prodder when moving the tack from center to near a bow when the breeze is up a bit? It seems you would have to maintain some tension on the regular (center) tack line while you haul the tack to the side and this would put a (temporary perhaps) lateral load on the pole that might be significantly more than is typical.

Imagine how much lateral force there is on a prodder when a gennaker or screecher is installed and used close hauled or close reaching - the windward whisker stay will be taking the majority of the load, and lots of compression on the prodder as well. This would be way more load than created by a spinnaker that is being moved to windward.

Nothing to worry about.

[JustMurph]

Originally Posted by dougweibel

Is there a concern with putting a lateral load on the bow sprit/prodder when moving the tack from center to near a bow when the breeze is up a bit?

Originally Posted by fxykty

Imagine how much lateral force there is on a prodder when a gennaker or screecher is installed and used close hauled or close reaching ...

This. The loads are relatively light.

Originally Posted by Epicurean

It's good to see comments from another Mumby. I've had mine for almost 2 years but due to border closures have only stayed in coatal waters of Malaysia and Thailand where there usually aren't steady, good winds. So I don't have a lot of experience sailing it. I've never actually flown the spinnaker.
The screecher came with a sheet so long it goes through the cockpit and around to the other side of the sail. I've never seen that before, don't see the advantage, and don't like it. So I got a shorter sheet. To jibe I furl it and run the sheet around to the other side. I'm thinking this is the way to handle the spinnaker. So when you mention having an extra long sheet to allow to go forward, depowering the sail so you can sock it, I think of the hassle of working with a really long sheet. But maybe I'll find that's the way to go after trying it.

What happens to the Code's furling drum when you switch to the spinnaker?

That must be so frustrating being stuck with Covid!
I've had mine a bit over a year now, but have been lucky that with the fairly consistent present winds in Moreton Bay, I've been able to sail it a fair bit. I'm very much still learning though!

My Code D is setup with two sheets, but I always furl it, at least partially before gybing. The first time I tried an inside gybe it ended up wineglassed around the genoa. I think if I had a consistent and experienced crew we'd be able to get the timing right......but I don't and it's pretty quick and easy to furl it.

When I swap the sails, the continuous line furler stay with the Code D and the spin is shackled to the tack line fitting, which is a Wichard MXEvo halyard shackle.


The really long sheet is a bit of pain when swapping sides on a gybe, but necessary for easy dousing. I learned the lesson there quickly. If the wind is up and you have any pressure on that sheet, the sock won't come down easily!

Off the top of my head, I think we made it about 25m.

[Epicurean]

Originally Posted by JustMurph

This. The loads are relatively light.


That must be so frustrating being stuck with Covid!
I've had mine a bit over a year now, but have been lucky that with the fairly consistent present winds in Moreton Bay, I've been able to sail it a fair bit. I'm very much still learning though!

My Code D is setup with two sheets, but I always furl it, at least partially before gybing. The first time I tried an inside gybe it ended up wineglassed around the genoa. I think if I had a consistent and experienced crew we'd be able to get the timing right......but I don't and it's pretty quick and easy to furl it.

When I swap the sails, the continuous line furler stay with the Code D and the spin is shackled to the tack line fitting, which is a Wichard MXEvo halyard shackle.


The really long sheet is a bit of pain when swapping sides on a gybe, but necessary for easy dousing. I learned the lesson there quickly. If the wind is up and you have any pressure on that sheet, the sock won't come down easily!

Off the top of my head, I think we made it about 25m.

So, does the red arrow point to the place you separate the furler from the tack? I'm trying to picture where the furler is after you switch to the spinnaker; just on the trampoline with the code D, coiled up? Or maybe your setup is different.

[JustMurph]

Yes, that is where you would separate it, though my setup is a little different. Here's the best shot I could get at night.



In my case I have a D shackle between the furler and the MXEvo. I undo the MXEvo, then the furler and D shackle go with the Code D. The MXEvo gets attached directly to the tack of the spinnaker. The code D will usually be put in its sailing bag (along with the furler and put away).

I see your prodder has also been modified to make it a 2:1 setup for the tack.

Edit: God damn birds sh*tting on my prodder!