Preventer

[Witzend]

Any ideas on how to cobble up a preventer?
The 310 doesn't have an aluminum rail with holes like my Hunter 37 did so it seem we have limited attachment points.
-the base of the life line stanchion -not so good under load
-the movable ring on the headsail sheet traveler rail - doesn’t allow for proper boom angle for a broad reach.

The obvious point on the boom would be where the Main Sheet is attached.
T

 

[rpwillia]

I was thinking about this too

I have been thinking about this too, as well as a temporary downhaul for my spinnaker pole. Ideally, If I could make both sides the same, then no matter what side I have my boom and spinnaker on during a downwind leg I could rig them up. On my track for my genoa sheets, I have some movable cleats that I think I can use to attach some line and run that to a block similar to those on the mainsheet. I did read that the line should be the same size as your main sheet as the loads will be similar. I have an old fiddle block with a cam cleat that I may try and work out. Also I did read that the preventer should be attached to the end of the boom, although where the main sheet it attached should be fine.

 

[Witzend]

On a broad reach, when you would want to use a perventer to eliminate the chance of an un-intentional jibe, the end of the boom is well outside the beam of the boat, so attaching the preventer there would create a lot of slop in the system, and creates a problem to set it up after the fact. The only sensible way to utilize this important safety feature on a 310 seems to involve the installation of a mid-cleat on the rail. Actually a good thing to have for other reasons. A simple fixed line with two quick release shackles between the cleat and where the main sheet attaches to the boom should suffice. On my Hunter legend 37 this is how I had it rigged, with is stowed in a seat locker when not in use, was very effective.

 

[poliva]

Am I missing something? I just use a rolling hitch on the end of the boom, led forward to the bow cleat. I wouldn't think a preventer led to a mid-ship cleat would have enough forward angle to be effective, and due to the upward pulling angle from boom to mid-ship cleat would put a lot of stress on the cleat's fasteners and backing as opposed to the more lateral pull from the bow cleat.

 

[rpwillia]

You are not missing something

What Witzend and I are discussing are the merits of trying to rig a preventer in a couple of different ways. My desire is to have a setup that is easy to get set up and down and something that I could also use as a downhaul for my spinnaker pole. It would be nice to figure out a way to do something for port and starboard that could function as both.

 

[poliva]

Oh, I see -- we have different setups. I'll be curious to see if you get any other ideas.

My whisker pole is mounted on a track on the mast, with blocks to raise and lower a car on the track. For a spinnaker I don't use a pole since I fly an asymmetic. However, the arrangement may give you ideas. For the spinnaker tack downhaul, I have a block attached via snapshackle to the anchor bail and a tack line that runs aft from that block via a series of half-moon blocks on the starboard stanchions similar to the furling line and back to a ratchet block with cam cleat mounted on the forward starboard tube of the pushpit. This tack line has a snapshackle on the end where it attaches to my spinnaker tack.

I suppose you could use that very same setup for a preventer. You'd need a good 60 feet of line. At the end of the boom you could tie a stout line. If you tied a small bowline in one end of the line, I'd guess that you'd need three feet of standing part to use a round turn and two half hitches to attach the line to the boom. The snapshackle from the spinnaker tack/prevent could then be clipped to the bowline at the end of the boom. Then you could pull on the tack line at the ratchet block to tension the system. You'd need to ease the main far enough out before doing so that the preventer would run fair from the end of the boom to the block at the anchor bail. You'd want to check with a rigger to be sure the loads would be handled properly in case of an accidental jibe, or worse if you broached and buried the end of the boom in the water.

 

[rpwillia]

Interesting

Poliva, I am curious about you pole setup. I went with a fixed ring because it looked like a track went straight up the front of my mast (I have a 2002). With a fixed ring I could get around where it looked like the track was. I went with a spinnaker pole because I got a great deal on some ends and decided to go for it. I am also interesting in using an asymmetrical spinnaker off of the pole.

I realize the best place for a downhaul would be somewhere at the base of the mast, and I am thinking on that as all of my blocks and pass backs are full. Last fall during a race on a downwind run, I noticed puffs were lifting my pole (I was just flying my genoa) a little, and so my plans to add a downhaul were accelerated a little.

 

[poliva]

It might take awhile before I rememeber to take a picture of my track and the system for raising and lowering the car. Mine's a 2002 as well. Hull 179. Yes, the track runs up the front of the mast. The pole is a Forespar such as http://www.westmarine.com/webapp/wc...L=true&storeNum=2&subdeptNum=341&classNum=342 and the female end of the pole snaps into a male car such as http://www.westmarine.com/webapp/wc...true&storeNum=2&subdeptNum=341&classNum=10899. It's a reasonably common arrangement, though more expensive than the fixed-ring option.

You could use an asymmetric with the tack at the pole, but the hassle of the pole defeats the ease of use (and lack of pole issues) by using an asymmetric. An asymmetric doesn't require the more complex rigging of a pole-controlled symmetical spin (no spin topping lift, no foreguy, no afterguy).