Adding a spin to a SC 17

[whalerman]

Anyone out there added a spin to an older 17? It does not look like an insurmountable job as I have a front beam with a track in it and the beam is in really good shape with the double sleeve in the middle of the tube. I was thinking it might be necessary to put a piece of aluminium angle on the inside of the tube for more strength. Where should the blocks go? It seems like a tramp bag would make more sense than a turtle, at least in the beginning. How long should the pole be? I'm thinking about 10 feet. I would add a tang to the mast about 3' down from the top. I'm not sure how large the spin should be, but I would imagine not huge.

Any thoughts?

[ultrarunner]

Anyone out there added a spin to an older 17? It does not look like an insurmountable job as I have a front beam with a track in it and the beam is in really good shape with the double sleeve in the middle of the tube. I was thinking it might be necessary to put a piece of aluminium angle on the inside of the tube for more strength. Where should the blocks go? It seems like a tramp bag would make more sense than a turtle, at least in the beginning. How long should the pole be? I'm thinking about 10 feet. I would add a tang to the mast about 3' down from the top. I'm not sure how large the spin should be, but I would imagine not huge.

Any thoughts?

The track in your front beam is for the self-tacking jib, right? You're not using that setup? I'd want to hear from the factory on what areas are going to be stressed with the spin....

[havliii]

The newer front beams have a bolt rope track integrated into the extrusion for the tramp. I'm guessing this is what 'whalerman' is referring to.

[Matt Haberman]

The main beam on the SC17 should be up to the task as that beam extrusion is the same one that is used on the ARC-22.

To me a tramp bag and a turtle are the same thing but I would agree that launching from the tramp is probably the simplest way to go before investing in any other spinnaker retrieval system.

You would have to talk to Tom about spinnaker pole length and size of the spinnaker, but we do offer this as an option on the ARC-17 so I am sure he could point you in the right direction. However I can tell you that the spinnaker hounds should be NO higher then 30% of the distance between the main hounds and the top of the mast. I don't know that measurement off the top of my head but I can tell you that if you only put it 3' from the top of the mast you will probably have a 2 piece mast in a relatively short time

[whalerman]

Just so we are all on the same page this is how my boat is currently equipped.

SC 17 mid 80's vintage
Traveler on rear beam
Bolt rope rear beam
Bolt rope track added to front beam
Aquarius Sail mesh tramp (very nice)
Pin top main
Overlapping jib with roller furling

I do not race this boat, I just want more speed down wind. I was thinking of adding a hooter, but I now understand why this really does not do much downwind.

I do really like this boat.

[whalerman]

Here is what I have accumulated so far in data and parts so far

Length of bows from front of beam to tip 81.5 inches 6’ 8.5”

Length from tip of mast to bottom of hounds 106 inches

30% from tip of mast to bottom of hounds = 31.8 inches
25% from tip of mast to bottom of hounds = 26.5 inches

Length of my spin pole 123.5 inches 10’ 2” +- (this piece of aluminum tube is a remnant from a spin project on a Tornado)
2 H2625 57mm Carbo Ratchamatic blocks.

I've also looked at a bunch of spinnaker setups. Most on boats with roller furling jibs, but the serious race folks tend to use the self tacking setups.

[Matt Haberman]

Remember the hounds should go no higher then 30% above the hounds, NOT 30% down from the top of the mast.

[whalerman]

Thanks for the reminder Matt. I appreciate your input and support. This project is interesting to me on a whole lot of levels. I don't want to break the boat in the process. I'm thinking about adding a spin of around 250 sq feet, 40 sq ft smaller than on the ARC 17 as a safety factor.

Most of the cats I see with home brew spinnakers have roller furling jibs, but very few of the factory boats are built that way. Is this because smaller, self tacking jibs have taken over?