Jib & Spinnaker Sheeting

[Ian Bamsey]

I've never been totally happy with the jib sheeting on my Tiki 21. It's currently on a 2:1 which runs through a block on a lanyard much as per the design except that it is cleated off on a cam cleat fixed to the cockpit side. It's visible in the shot below.

This is ok, but you can't easily pull hard on the sheet. Also it's not good single handed as you can't control the head sail from the windward side. It has the advantage of keeping the decks clear which keeps my kids from tripping. 

The next issue is sheeting my planned asymmetric. Where is the best place to fix this? In the model below you I've marked out some possible points.

My thoughts include:

1. Some kind of block at C, a cleat at E

2. Similarly a block at D, cleat at E.

3. Perhaps E also be used to cleat the jib sheets.

4. Might D interfere with the tillers.

5. It might be inconvenient to thread blocks at D.

6. I might need to release sheets in a hurry.

I would hope to perhaps come up with an arrangement that would work for both sails. I've already checked out Roger's blog and many online pictures of other arrangements, but I'm still working through the possibilities.

I've little rigging experience and am not sure of the best solution or hardware choices.

Suggestions and comments would be welcome.

Ian

Gratitude

[Big tane]

G'day Ian.
Gerry on big tane.
I owen an tanenui 28 which i am going to do an refit including the rig and sails. The setup i am aiming for is self tacking and that will be putting the jibb out on an spar as the jibb will be in front of the mast with an furler to roll up the jibb on an traveler and an sheet through an pully as an outhull. The spinneka will have an self taker placed over the furl up jibb at the clew and be able handle like an jibb. As well as an sleeve to snuff and set the spinnika. The main sail will have an whisbone boom and an double up v sheet system with two trim lines to trim the sail for and aft. There is on ytube an tiki 30 called katamaran with an whis bone boom.I am an solo sailor, so i have make everything as simple as possible. Type on ytube atn self tacker for spinnaker. Anyway, i will be posting photos when i start my rebuild in around end of next march.
Gerry on big tane.
Toora.
ps. I have allready posted some photos and one of an deck tent on an freinds catamaran. Please take an look.

[Ian Bamsey]

Thanks Gerry, I'll check out those youtube videos and I look forward to your photos. 

Ian

[Brad Ingram]

Roger has some good input on his Little Cat blog under "Boat Setup and Maintenance" tab

[Ian Bamsey]

Thanks Brad, you're right about Roger's blog. It has really good information. You can see his spinnaker sheet set up in this shot. (I hope Roger doesn't mind)

I think this is quite good, but it's difficult me. First, my hatches slide forward and the sheets and cleats would get in the way. Second, as my design progresses, the sheeting angle is best served if attached further back. I am moving toward a set up not dissimilar to the above, but running along the rear beam.

I'd like Roger's views on this and also how much an advantage the ratchet block is for the spinnaker sheet. 

[Roger]

Hi Guys,

Surprised to see my kitchen on WB&Fs this morning :-)

This pic shows my spin sheet going to the 40mm block on the beam and then back to the auto ratchet. Note that I use the cam cleats on the windward hull which are close at hand (not the one you can see in the kitchen pic). I have a cleat on the deck and on the top of the cabin that I can use.

Once the wind gets up you need the ratchet. With the ~250 sq ft tiki 21 spin I can hold the sheet on the ratchet quite comfortably up to 15 knots or so. I have flown both my spins in over 20 knots true and can still hold the sheets on the ratchet for short moments to change cleats etc. 

The block position on the shroud actually works really well as it is about a foot above the cabin top and keeps the sheet clear of the cabins. When I'm reaching, I take the sheet to the rear turning block, but when deep running, I take the sheet straight through the ratchet as the sheets are running way out front.

One other thing. I now use the sprit mainly for light air (up to 10 knots). Once there is some breeze, even the 22' luff assym will fly out in front of the boat, and I can tack it to the guys off the bow blocks.

[Ian Bamsey]

Thanks for the clarifications Roger. Useful comments and food for thought.

Ian

P.S. Here are the latest views on my A2 spin geometry. What do you think?

[Roger]

Love it - impressive computer skills!

[Dan Hammond]

I've been sailing my Hitia 17 with a 2nd hand asymmetric - not made for the boat and maybe a bit on the small side but it's fine for cruising. I have the tack on on the middle of a line run to each bow where the forestay bridle is attached and then back to the middle beam near the mast, so that I can adjust the tack's position across the width of the boat, but do away with any need for a pole. The sheets run through blocks at the outside ends of the aft beam. Might not work for a sail the size it looks like you are planning, but it keeps things simple and seems to work. Sorry I've not got any fancy computer imagery to explain it more clearly! - nice work on that. 

[Ian Bamsey]

Thanks for the reply Dan. It sounds like your set up is similar to my plan. I think I'm beginning to get this straight.
Contributions still welcome.

[Andy Best-Dunkley]

Hi Ian - You might like to check out this earlier discussion I started regarding asymmetrics on larger Wharrams http://wharrambuilders.ning.com/forum/topics/asymmetric-spinnaker-g...

Particularly Ann Clement had some very useful advice! We now have our new asymmetric which we've used quite a lot last summer so can give some comments:

You don't need a pole out front, you can use two adjustable tack lines, this gives you much more flexibility with positioning the tack of the sail. I tried to fix this using one continuous line, but it didn't give enough position flexibility, so use two independent ones lead back to somewhere convenient.

The sheets need to be lead back to blocks pretty far towards the stern imo, but this of course is dependent on the size of your sail. Good to have a few attachment points for the blocks so you can experiment.

I would suggest that you cannot work everything out on paper/computer beforehand, install a system that you can test, then when you are sure, fix in place!

We have a sock for the sail, a top down furler would be nice but not in my budget. Maybe for a smaller boat this is affordable....

Good luck!

[Ian Bamsey]

Hi Andy, thanks for the useful comments and that link. I've learnt loads for these really helpful discussions.

Ian

[Ian Bamsey]

A few more thoughts on designing and making an asymmetric spinnaker. Some progress I think.

See here http://tiki21gratitude.blogspot.co.uk/2016/12/spinning-spinnaker.html