Rigging for Symmetrical Spinnaker

Gray Drohan · January 20, 2021, 03:18:50 PM

A few years ago there was talk about some boats doing the Delta Ditch Run (a 65nm drag race from a corner of the San Francisco Bay off of Richmond up the San Joaquin River to the Stockton Sailing Club). Being that I joined the SSC when I bought #223 last year, I am planning to "Do the Ditch" when it next is arranged. It is currently set for June 12, 2021. I've never done it before, but hear that this race is a blast. Usually into climbing temperatures in a building westerly. Usually fast. Always challenging. Big party. 100+ boats. It's a Bucket List race for many on the West coast.

But, as was noted in the earlier posts, running upriver can be a whole lotta work (and not necessarily fast) with an asymmetrical setup, as the course is often a.) dead downwind, and b.) 200 yards wide in places. A rough map of the course is attached.

So, for this particular purpose, I'm working on assembling the components to allow us to sail the race with a symmetrical chute. But I don't want to spend a lot of money on it until I know that it actually works well enough. I have a friend that has volunteered to fabricate a custom pole eye for the mast that can be temporarily affixed with Velco and straps. The spinnaker pole length on an Etchells is 8', which oughta be a good place to start, and there are lots of those around. I'll lash a topping lift block at the spreaders and rig some twings for downhaul. Someone suggested a Santana 20 kite would work, so I'll try that. Testing and adjustments will be necessary, I'm sure.

But I have a few questions:

1. Has anyone rigged a symmetrical spinnaker on a Viper before? I suspect so, but can't find any reference to it in the forum. If so, would you provide some comments as to your experiences?

2. What is the exact diameter (or circumference) of the mast section between the gooseneck and the mainsail track? I'd really like to be precise here, as the pole eye setup needs to work without fasteners.

3. Does anyone have any thoughts about approaches/techniques for sharing the spinnaker halyard (and, perhaps, the sheets) between the asymm in the launcher and the symmetrical? It may be best just to go with the symmetrical only, but the first half of the race tends to be a screaming reach and, so, am considering options.

4. And, of course, can anyone think of reasons why we should not be doing this? Other than the normal cautions regarding minding the rig when going downwind...

Thanks, All.

Peter Beardsley · January 21, 2021, 09:50:45 AM

Gray,

I am not aware of anyone having rigged up a symmetrical kite on a Viper before but I'm sure you'll get some people chiming in on this thread once they see it - it's the kind of whacky project that will get some people's imaginations flowing on things like optimum pole length and alternate rigging.

As you note, rigging twings will be "easy" - a temporary block secured to the chainplates that should be able to share the cleat with the windward jib sheet is a good starting point. Securing the topping lift dead end to a fairlead for the jib halyard cleat wouldn't be elegant but would work - a pole downhaul may be trickier - not sure if I would trust the eyestrap for the mast blocks for that.

I don't know if anyone will have the exact diameter of the mast at the location you'd like, but that seems like something you can measure on your own boat at the spot where you'd like to set it up.

I'm not sure if there's a good way to quickly toggle between sheets/halyard short of adding some temporary hardware that you'd never see on a Viper, like small snap shackles - and having someone bring all of that aft from the bow after you douse the asym. Sure wouldn't want to see anyone try a peel from the asym to the symmetrical, so it may be one of those things where you decide if it is worth losing two minutes of rigging time to make it happen. The other issue of course is where you'd secure the symmetrical kite when it is not in use - it'll likely be pretty wet by the time it needs to be hoisted.

Biggest question is # 4 as to whether there are any unintended consequences with new loads on the spreader bracket and rig. I'd definitely want the upper shroud tension to be pretty tight and keep a moderate amount of vang and cunningham on the entire time - not sure if the center of effort would be changed in a meaningful way with the symmetrical kite such that you'd risk losing the rig. Hopefully some engineers and creative thinkers can weigh in on that.

John Leyland · January 21, 2021, 05:22:21 PM

I've done it once on a Melges 24 and after a few painful light gybes in the ditch we decided to go wing on wing with the kite which worked quite nicely. I've never tried wing on wing on my Viper so don't know how it will be but might be worth a try before rigging up a pole, etc.

Jeff Grange has done it at least once when he had his Viper but not sure if he's still monitoring the forums or not.

Peter Beardsley · January 21, 2021, 06:40:41 PM

3 Vipers did it in 2016. https://www.viper640.org/usa-news/3312/

Steven Haywood · January 22, 2021, 04:01:01 PM

How about attaching the topping lift to the Keel hoist anchor on the mast? That's pretty strong, handles the 120kg keel with minimal sweat?

Gray Drohan · January 23, 2021, 03:00:55 PM

Quote from: Peter Beardsley on January 21, 2021, 06:40:41 PM
3 Vipers did it in 2016. https://www.viper640.org/usa-news/3312/

I can't believe that I missed this. Thanks to everyone for the input. I'll let you know what ends up happening.

Tim Carter · January 25, 2021, 04:33:41 PM

Hi Gray,

I hope you are enjoying my old boat... that boat has won lots of hardware.. =)

I first contemplated a sym kite for the Viper in 2008 when I did the 1st Sailing Anarchy regatta in #36. All of the things you mentioned were part of my game plan.. I was not going to put a pole ring on the mast, I was going to create just a single ended pole with a fork on the mast end like a Star wisker pole. I don't think you can have someone on the deck to end for end the pole, I was going to rig a Five-o launcher to shoot the pole out and retract.. To gybe, you twing down both sides and free fly the kite, pole comes in on stb, gybe boom and pole goes back out on port.

There will be issues with a sym kite in big breeze.. You can't ease main enough due to shroud sweep, no backstay to keep the rig in the boat unless you rig running backstays to the main bridle eyes in the back. (has been done)..

Jeff Grange did the DD and mostly ran or tried to run wing on wing for the shorter gybes across the river. Largest challenge is navigational and staying off the sandbars.

Some folks have rigged smaller asyo's that were easier to gybe when it's over 20 and you are crashing upriver.

Tim Carter · January 25, 2021, 05:54:18 PM

your 1st challenge is them letting you enter a Nor Cal PHRF race without a Nor Cal PH #.. They pulled the Viper ticket up there about 6yrs ago. Keel is "too light", there requirements is 400# minimum.. Called the "Wabbit Rule" because that's what a Wabbit Keel weighs.

The Vipers were allowed to sail in 2006 as a "Fleet", needed 5 entries and you are racing the other Vipers. The lead mines up there wont let you correct out over them...