Storm jib

Moderator: GreenLake

Re: Storm jib

Postby talbot » Tue May 07, 2013 6:35 pm

Wow, that's a lot of discussion to keep up with.
1. I fiddled with block placement when I first got the sail. I finally installed them at the same geometry as the boat the sail came from, a JY 15. The angle aft is such that the line through the clew would intersect the forestay about 60% of the way above the tack. I may put them on a track for next year. Tack is fastened at the normal location. The sail clears the cabin with no adjustment. The main problem with block placement is that the JY15 is a narrow boat, and it's hard to get the sheets outboard on a run. The local Hyde Sails loft (Sailmaker's Art) suggests: run the barber haulers through the fixed blocks and pull them tight. On a run, release them and the sheets will pop out to let the sail fill.
2. The sail can be close hauled so that the tell tales (two sets) are parallel windward/leeward and upper/lower. The fabric is creaseless. All the tactile and visual cues say that the set is optimal. Only the compass reading spoils the parade.
3. The sail is probably too big to be a real "storm" jib. It almost overlaps. Over-trimmed, it can backwind the main.
4. My intended wind speed for the small jib and double-reef main was 18 knots (~21 mph). I have sailed it in those conditions a couple of times since my last post, and tack angle was about the same. (The test I reported was in moderate winds only because that's what happened to be blowing on the day my wind meter arrived and I had to, I mean had to, run out to the lake to try it.)
5. I had not thought of cutter rigging. It's an intriguing idea, but I will probably will do no more serious tweaking this season.
6. The sail drawing are great. Could I share them with my sail maker guy? Maybe we'll even get a production storm jib someday.

Which guy, by the way, says that the adopted sail probably does not fill the triangle properly and will never point as high as a sail designed with the specifics of the DS in mind. Of course, he wants to sell his own sails. So while I was there, I told the sail maker about the Doyle UPS craze. He said he would mention it to Hyde. He said that "code-zero" foresails came and went and are back in vogue again, and that Hyde is looking for new products.

Finally, I have to say that, aerodynamic inefficiencies and all, the small jib and reefing main are a total kick in the butt. My wife and I can sail the boat comfortably in conditions that used to scare us. The helm is balanced, and we can keep the clinometer to about 20 degrees. We normally put our foul weather gear away after April, because it gets too warm and we wouldn't sail the boat in conditions where we'd need it. Now I see some spray in our future, and we'll probably keep our bibs on the boat.
talbot
 
Posts: 781
Joined: Mon Sep 03, 2007 3:37 pm
Location: Eugene, Oregon

Re: Storm jib

Postby K.C. Walker » Tue May 07, 2013 8:49 pm

Talbot,

Just think of our discussion as comments to your personal blog. :-)

Good rundown on your experience so far.

I took some lessons from the racing coach at the University of Connecticut on a JY15. It's been a couple of years but there were some set up tips that he gave me that might help. For high leeway situations, such as heavy air, cranking the halyard tension so that the jib has very noticeable vertical wrinkles was appropriate to bring the draft forward and flattened the leech, he tied a slip knot up the halyard and looped the tail back through so that it was a 2:1 purchase. Then he said to set up the main out haul with a noticeable horizontal wrinkle along the boom, but of course that's with no reefing.

One thing you might try experimenting with to try to get a little higher pointing is to pull on the lazy sheet to bring the sheeting angle in closer, this is how they do it in the Flying Scott class. Dave Keran, I believe Barber hauls his jib sheets to 10 inches from midline. You would ease the jib sheet tension and get more twist out of the sail.
KC Walker, DS 1 #7002
K.C. Walker
 
Posts: 1326
Joined: Sun Jul 06, 2008 10:50 pm
Location: North Stonington, Connecticut

Re: Storm jib

Postby jdoorly » Wed May 08, 2013 2:01 am

I always thought that the storm sail clew was high to keep the sail from getting ripped by a boarding sea. Not that there aren't other good reasons!

But most importantly a storm sail has several attributes that are different than say a one-design racing sail. First, the sailcloth is heavier (2x) and there are more reinforcements. Second, the draft is much flatter. Third, the clew is high. Fourth, a storm sail is made to make VMG to weather, as that is usually the safest coarse (slow steady and no wild rides) and also the coarse you need to be on to heave to. Fifth, storm sails, especially storm trisails usually have dedicated pad eyes on deck for fairleads.

As some of you may remember I had an old jib that I didn't use when I got a new set from Intensity, and I cut it down to use as a "storm jib". As I recall I cut off 40% of the bottom, tried to flatten out the old baggy sail, and added new reinforcements and webbing at the corners. It was a fun project and I did all the sewing by hand. On my next sewing project, a mainsail cover, I did it all with a machine. I had only one opportunity to raise the storm sail so far and that wasn't in high or even median wind. But it set well and pulled OK using the standard fairleads. I think I used an 8" tack line to raise the tack a bit for the fairleads.

My reason for wanting a 'storm sail' was to balance the boat when there was 2 reefs in the main. I singlehand and use a Tiller Pilot to steer but this requires keeping the boat flat. Auto pilots don't like weatherhelm and tend to go off in random directions with an unbalanced helm. Auto pilots also don't like it when you move about on a small boat as the weight changes also imbalance the helm. I made a nice tiller tender out of oak and a spring, now days I use that more than the auto helm.

So, anyway, there's a lot more to storm sails than profile and square feet! Not that I didn't enjoy and learn stuff from John's graphics
DS2 #6408 "Desperado"
jdoorly
 
Posts: 379
Joined: Mon May 17, 2010 2:24 pm
Location: CT

Re: Storm jib

Postby K.C. Walker » Wed May 08, 2013 7:19 am

jdoorly brings up some good points about storm jibs. In particular he mentions that they are cut flatter which made me wonder how much tension you are running on your rig. It's possible you're getting too much jib stay sag which adds to draft. With the double reefed main you're probably not getting much help pulling back on the mast. I usually put a couple of extra turns on the shroud turnbuckles in heavy weather. I do this for several reasons but one of them is to keep the jib stay from sagging too much.
KC Walker, DS 1 #7002
K.C. Walker
 
Posts: 1326
Joined: Sun Jul 06, 2008 10:50 pm
Location: North Stonington, Connecticut

Re: Storm jib

Postby talbot » Wed May 08, 2013 2:33 pm

Great advice. It does look to me like the small jib has too much draft, too far forward. I was thinking of taking in my shrouds a few turns anyway, and I will try that slip-knot trick on the halyard (maybe with a carabiner so I can get the thing undone quickly if I have to drop the main).

I agree that balance is a big part of the mix. In fact, a pillow case on the bow would probably increase speed because it would help compensate for excessive weather helm and let you keep the tiller amidship.

My using the term "storm" jib was a mistake out of the gate. It's a small jib, that's all. The idea isn't survival in a near-gale >30kts, but rather enjoyable sailing in a fresh breeze < 25kts.
talbot
 
Posts: 781
Joined: Mon Sep 03, 2007 3:37 pm
Location: Eugene, Oregon

Re: Storm jib

Postby talbot » Sat May 25, 2013 12:58 am

I think the advice on a tighter headstay and luff was correct. I took my shrouds in a bit (about 1/4 increment on a Johnson adjuster) and tightened the halyard.
The wind was a shifting a bit, so my data is messy. But I think I got as close as around 50-55 degrees to the wind with my odd jib and a single reefed main. Not great, but better than before. I forget my wind gauge, but there were scattered whitecaps.
talbot
 
Posts: 781
Joined: Mon Sep 03, 2007 3:37 pm
Location: Eugene, Oregon

Re: Storm jib

Postby talbot » Mon May 27, 2013 4:07 pm

Gave the double-reef-plus-small jib a good workout yesterday in 14kt winds. Here's my final evaluation: Don't get the JY15 jib as a heavy-weather jib for the DS. I think I've done all the tuning I can do, and the sail simply does not work smoothly with the main.

That said, I will continue to use it any time the only other option is to lower the jib. The boat goes much faster, and can beat to about 50 degrees of the wind with the double-reef main. That's only about 5 degrees off the tack angle of the standard sail configuration, and way, way better than sailing without the jib.

But you can do better. You want a smaller sail, with a shorter luff length. (See the diagrams shared on this thread.) With that you might be able to "cutter-rig" the sail aft of the working jib on its own Spectra halyard/boltrope. (Another suggestion in this thread.) It would have to be high enough off the deck to clear the furled working jib (or the roller-furled working jib's sheets). The JY15 jib runs out of forestay at its peak. Anyway, it's already too much sail area too high. The last thing you want to do is lift it farther up in the rig.

Thanks for all the help. I think I'll sign off this thread for a while. (It finally rained. Lake is filling. Less talk, more sailing.) I look forward to any other discoveries people make in extending the range/conditions of our amazing little boats.
talbot
 
Posts: 781
Joined: Mon Sep 03, 2007 3:37 pm
Location: Eugene, Oregon

Re: Storm jib

Postby K.C. Walker » Mon May 27, 2013 9:11 pm

Talbot,

Thanks for the research, experimentation, and the report!

Winnipesaukee had 4 foot waves down at the Southwest end yesterday… yikes! Not even with a storm jib!!! Also, a bunch of the ski slopes opened for free skiing over the weekend!
KC Walker, DS 1 #7002
K.C. Walker
 
Posts: 1326
Joined: Sun Jul 06, 2008 10:50 pm
Location: North Stonington, Connecticut

Previous

Return to Sails

Who is online

Users browsing this forum: No registered users and 1 guest