Wind damage to rolled jib

[sailingharry]

I just finished helping a friend sail from Key West to Cancun (actually, Isla Mujeres). Two questions came up -- one in this thread, one in another, so don't get confused!


We were anchored in the harbor. Somewhat open, but it passes as the "harbor." We had a front come through, winds to the upper 30's. Around 10PM, of course. Seems we anchored in eel grass, so we drug, adding to the fun. We pulled anchor and motored around, assessing options, when the upper part of the inside jib (Solent rig, 95% self tacking sail) started coming undone. We tried once to unroll and re-roll (in 35 knots while motoring in the harbor in driving rain on a moonless night with the dozen other boats that were motoring around -- fun!). Lasted about 10 minutes. So I drove slowly upwind while he unrolled and dropped it -- even more fun! Damage was mostly shredded stitching, so two days with the Sail Right and it is ready to go again.


Important to note -- on the way into the harbor after our crossing, we unrolled and carefully re-rolled both sails to have a nice neat "harbor furl" -- so while it might have been possible to stand up on the bow carefully pulling and making a tighter furl, we did have a furl that presented no white cloth, no big wrinkles, etc. Basically a decent furl. And the furling line was securely fastened -- the sail did not "unroll" and the clew was tight and not part of the problem. It is worth noting that while the sail is old (maybe original to the boat, so 20 years), it is in decent structural condition -- but maybe not as "tight" as a new sail.



Also, 35 is not "big wind." I have the same boat, and I have USED that sail in those winds. It's not like a hurricane or anything. In our home waters (Chesapeake Bay), this can happen weekly in thunderstorm season.



So, with that as background. What causes this? How can the upper third of the sail unroll and flog to death, with a decent furl and no unrolling?


And, most important, how does one prevent this? Taking the sail down and storing it every time you come into port is not viable, and defeats the purpose of a roller furler. In 45 years of sailing with roller furlers, it's the first time it's ever happened TO me, but I've seen it happen to others.

[deblen]

I don't know about various furling systems,but I noticed this feature in the Selden Furlex MK II Type B that came on my Danish boat.
The foil is allowed to turn a bit before the tack can turn. This allows for a flatter (more even?) furl.
Perhaps this is a standard feature of all furlers-I don't know-but it sounds like the upper part of sail may be un-furling/not furled as tightly as lower section-just a guess.
Cheers/

[Knotical]

Harry, what kind of sail and how old is it?

During storms, squalls, or a rare hurricane hitting our bay most jibs that unfurl start at the top, I guess the sheets prevent the bottom from unfurling. Also, I have noticed most jibs that unfurl are on the older side with loosely attached UV patches, and even though it can happen I have never seen a crisp dacron or a laminate sail unfurl in high winds.

During Isaias, a boat started sailing after her genoa unfurled, broke off its mooring and ended up on the shore, the UV patch was almost completely detached except at the top making it look like a long strip of flag, none of the other boats broke off in that storm.

[s/v Jedi]

Furl it tighter and let the sheets wrap around at least two times.

[SailingHarmonie]

It might just be geometry.

Sails with a very acute angle at the head do not get good over wraps at the top. Very hard to keep the wind from lifting the leech it the layers are far apart. The issue is typical of staysails.

[sailingharry]

Comments to above threads:
* The sail is a cross-cut dacron sail.
* The sail is a VERY high aspect sail. My notes for my boat say 15' on the foot, 58' on the hoist. So, as commented, "acute angle." I'll agree, it is hard to get good tight furl at the top.
* The sheet is two part, with a block at the clew. It's almost impossible to get more than about 360 degrees of wrap (one turn) as the sheet can't feet through.
* The Furlex tack swivel is very unusual. It also sounds very useful.

* The furl was good and neat. Getting tighter, especially on this high aspect sail, is quite challenging.
* The UV cover is very tired. Lots of fading, been re-stitched more than once. Kind of sloppy on the sail, due to age.
* The high aspect sail makes it very hard to trim off the wind (ease the sail 6" and the top is completely gone -- a Barber haul is critical beyond TWA of 60 or so). This same dynamic makes it doubly hard to get leach tension and tight furl at the top. Perhaps the answer is a man on the foredeck pulling down as it furls (a human Barber haul?).

[donradcliffe]

It sounds to me like the leech has stretched. Time for a new sail. It would help to pull down as you furl.

[Smokeys Kitchen]

Is it possible to get rid of the block at the clew and make it a one part sheet?

[sailingharry]

Originally Posted by Smokeys Kitchen

Is it possible to get rid of the block at the clew and make it a one part sheet?

That's a long standing wish of mine. The current arrangement has a lot of friction in the tacking action, and it doesn't like to go all the way to the end of the track.



The current arrangement is from one end of the traveler to a block on the car, then to a block on the clew, then to a block on the car, then to the other end of the traveler. This allows the sail to tack.


All the modern boats go up the mast 20-30 feet, then down to the car, then up to the jib. This allows the car to easily move left/right, but fails if you have anything on the mast front (like, say, my whisker pole).


It could also be done by running the sheet all the way to the stem, then back to the car. But this leaves a trip hazard across the foredeck and tangles with hatches.


In reality, the wraps around the jib wouldn't have solved this problem, as the area where it would have had wraps never unrolled or flogged. It was all at the upper half.

[5BTM]

" Taking the sail down and storing it every time you come into port is not viable, and defeats the purpose of a roller furler. "

It is and it does not.

[sailingharry]

Originally Posted by 5BTM

" Taking the sail down and storing it every time you come into port is not viable, and defeats the purpose of a roller furler. "

It is and it does not.

I'm sorry, but that's just a completely useless comment. I see your boat is somewhat small -- have you ever folded and stored a 150% on a 40+ foot boat? Remembering that in trade wind latitudes, the odds are that you will have 15+ knots over the deck while doing this.



Taking it down and folding it -- better than 1/2 hour job. Longer if you are at anchor and not alongside a pier. And it's a struggle with only 2 people.

Storing it -- on a cruising boat, really?
Putting it back up the next day -- another 1/2 hour. And again, this is a 2 person job with a furler.

Why roll it when the day is over, just drop it and fold it and stow it -- and why have a roller anyway?
Oh -- these boats have two jibs, so double all the above.


Note, I have actively raced for years. Taking a jib off a boat and folding it after each day of racing is not new to me. With a crew of 5, it goes pretty fast. Doing it as a cruiser with two is a different story.


Approximately what percentage of active, competent cruisers with furlers do you see that take their jibs down each night? Or even when in port for a few weeks? From my experience, it's well under 1%. In 50 years of cruising with a furler, this is the VERY FIRST time I've ever personally experienced an issue, so the return on investment for taking it down daily over those last 50 years would be... poor.

[Jim Cate]

Originally Posted by 5BTM

" Taking the sail down and storing it every time you come into port is not viable, and defeats the purpose of a roller furler. "

It is and it does not.

Even if this was true (and I don't agree with your statement) the situation can also develop at sea when sailing on main or trysail alone in high winds. Thus, some remediation of the problem is needed IMO, for striking the sail under such conditions is dangerous and difficult and would indeed defeat the purpose of the furling sail.

Jim

[JPA Cate]

I just spoke with Jim about this, because I wasn't sure. It happened to us once, a long time ago, during a thunderstorm in a marina. Also with a Solent stay sail. Our guess is that the top coming loose and flogging like that is due to two factors: the leech has stretched over the life of the sail, and cannot get "tight" any more (though it might look okay). So it is really easy for the tearing fingers of the wind to get it started undoing And there is also the issue of the stretched UV cover. The cover could actually help pull out the not-really-tight sail underneath. If there's a way to tighten the leech by pulling down, as donradcliffe suggested, that MIGHT have helped, but it isn't a real-life, long term solution.

I am wondering if, when you sewed it back together, you tightened the leech a bit, and the cover? If you did, you may have helped the problem, but I'm thinking the boat is due for a new sail. Especially if it is a dacron sail. The loss of sail shape is so gradual it is hard to see, but I'd be concerned. It wasn't so bad on the 36 footer we had, but by the time we got to 46, even the stay sail was fairly large, and stretchable after 4 yrs.

Ann

[5BTM]

Originally Posted by Jim Cate

Even if this was true (and I don't agree with your statement) the situation can also develop at sea when sailing on main or trysail alone in high winds. Thus, some remediation of the problem is needed IMO, for striking the sail under such conditions is dangerous and difficult and would indeed defeat the purpose of the furling sail.

Jim

I will bow to your experience but my plan for this upcoming sailing season, which will hopefully include a partial Down East Circle Route, is a removable Solent stay with hank-on sails with rigged downhauls.

[sandy stone]

Would it have been possible to take a spare halyard and wrap it around the furled sail, in the opposite direction of the rolled-up leech? Obviously a last resort.