Adding second reef to main sail?

jviss

.
Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
it looks like the luff of the main is a little slack. This is the functional equivalent of tightening the cunningham, as it creates more curve in the sail near the intersection of the mast and boom, increasing power.
Use a Cunningham to bring the draft forward.
The Cunnigham is an invention of Briggs Cunningham, skipper of Columbia and winner of the 1956 America's Cup, as a way of tensioning the luff of the main without violating the class rules regarding maximum luff length, which could be exceeded by stretching the luff. So, if your sail is properl sized for your boat you should be able to tighten the luff with the main halyard. No need for a Cunningham, unless you are racing in a class with that rule.
Nit: heel.
 

Ward H

.
Nov 7, 2011
3,655
Catalina 30 Mk II Barnegat, NJ
Trying to use the blocks to reduce friction. And I only have 1 set of blocks, so I used the ‘biners to attach the blocks, but want to try soft shackles instead…those locking carabiners are heavy!
Ditto with reducing friction on the reef line. I lashed my blocks to the dog bones.
 

jviss

.
Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
Ditto with reducing friction on the reef line. I lashed my blocks to the dog bones.
I haven't detected a friction problem with mine. Maybe it's related to line size?
 
Jul 27, 2011
5,009
Bavaria 38E Alamitos Bay
The Cunnigham is an invention of Briggs Cunningham, skipper of Columbia and winner of the 1956 America's Cup, as a way of tensioning the luff of the main without violating the class rules regarding maximum luff length, which could be exceeded by stretching the luff. So, if your sail is properl sized for your boat you should be able to tighten the luff with the main halyard. No need for a Cunningham, unless you are racing in a class with that rule.
That’s not such good advice IMO. You can use a Cunningham to bring the mainsail draft forward racing or not as I said.. Easy to rig. If the mainsail slips some in high wind, quicker to use the Cunningham to tighten the luff than “winching up" to try to get more halyard hoist. Ever use one?:doh:
 
Last edited:

jviss

.
Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
Ever use one?:doh:
Duh! Uh, have used since maybe about 1976 with Stephen Colgate on City Island, NY.

I know very well what it is, and how to use it. I can't fathom how it's easier than just applying more main halyard tension.

Quicker? How's that? My main halyard comes to the cockpit, and there's a winch right there.

I'm not concerned about breaking class rules.
 

jviss

.
Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
And I am probably past due to replace my reefing line…I noticed it is a bit crusty when reefed this weekend…

Greg
Mine's relatively new, but I know a lot of guys put blocks on there. Then, the blocks need maintenance, and can add to wear on the sail. So maybe six one, half dozen of the other. Whatever works!
 
  • Like
Likes: Ward H
Jan 7, 2011
4,839
Oday 322 East Chicago, IN
Mine's relatively new, but I know a lot of guys put blocks on there. Then, the blocks need maintenance, and can add to wear on the sail. So maybe six one, half dozen of the other. Whatever works!
It is always something, and always a compromise:)

I have thought about using one line for the tack and a separate one for the clew, as I think I could tension it correctly that way…but I really want to get the single line reef to work halfway decently.

I do not really expect to need a second reef (I will drop the sail, sail under jib only, or motor in if necessary). So I don’t intend to rig the second reef point (all the time)…I can move my blocks fair.y easily if I REALLY needed to Using the carabiners….But haven’t needed it yet.

Greg
 
  • Like
Likes: Ward H

jviss

.
Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
It is always something, and always a compromise:)

I have thought about using one line for the tack and a separate one for the clew, as I think I could tension it correctly that way…but I really want to get the single line reef to work halfway decently.

I do not really expect to need a second reef (I will drop the sail, sail under jib only, or motor in if necessary). So I don’t intend to rig the second reef point (all the time)…I can move my blocks fair.y easily if I REALLY needed to Using the carabiners….But haven’t needed it yet.

Greg
Where I sail I think a second reef is necessary. I really like the single line reefing system. It had been abandoned on my boat when I acquired it, and I resurrected it. It required new line, and also two new "shuttle blocks," which were hard to find. It works really well. I can reef once, and then a second time, while single handing. That second reef is often necessary, it seems always when rounding East Chop off Martha's Vineyard, heading West into Vineyard Sound. :)
 

Ward H

.
Nov 7, 2011
3,655
Catalina 30 Mk II Barnegat, NJ
Back to the use of a Cunningham for a minute.

I thought the Cunningham was used to add luff tension after the main was fully raised because it was pulling on the luff only, requiring less force.
The main halyard would need more force to tension the luff because it would also be pulling on the leach which was already tensioned by downward pull from the boom to set the leach trim.
While both could be used to tension the luff the Cunningham would get there with first with less force.?

Another tool designed for racing being adopted by non racers?
 
Jul 27, 2011
5,009
Bavaria 38E Alamitos Bay
I can't fathom how it's easier than just applying more main halyard tension.

Quicker? How's that? My main halyard comes to the cockpit, and there's a winch right there.
See Ward's post #31 above.
 
Jul 27, 2011
5,009
Bavaria 38E Alamitos Bay
Back to the use of a Cunningham for a minute.

I thought the Cunningham was used to add luff tension after the main was fully raised because it was pulling on the luff only, requiring less force.
The main halyard would need more force to tension the luff because it would also be pulling on the leach which was already tensioned by downward pull from the boom to set the leach trim.
While both could be used to tension the luff the Cunningham would get there with first with less force.?

Another tool designed for racing being adopted by non racers?
Yes. But when it adds luff tension, some small amount of cloth gathers below the mainsail tack. It must. That displaced material is "replaced" by the draft of the mainsail moving forward some small amount. Also, FYI, the line to the Cunningham can be led aft to the cockpit via a turning block at the mast step plate, and through a rope clutch; etc.
 
  • Helpful
Likes: Ward H
Jun 11, 2004
1,646
Oday 31 Redondo Beach
I thought the Cunningham was used to add luff tension after the main was fully raised because it was pulling on the luff only, requiring less force.
The main halyard would need more force to tension the luff because it would also be pulling on the leach which was already tensioned by downward pull from the boom to set the leach trim.
While both could be used to tension the luff the Cunningham would get there with first with less force.?

Another tool designed for racing being adopted by non racers?
We are adding to thread drift here so maybe this should be a new topic in the sail trim forum, but:

My understanding of the Cunningham is that it came about as a result of racing rules where the top and bottom of the main sail were limited to certain points on the mast. To maximize area the sail would be cut to use this maximum dimension without the luff being very tight. The obvious problem with that was when you needed a tight luff you couldn't raise the halyard because it would be above the allowed height (the "black band"). So, Cunningham developed a system that could tighten the luff without extending the sail beyond the allowed limits.

Obviously, the halyard and cunningham can both be used to tighten the luff. Your choice as to which is easier for you to use.
In my experience, all the various racing boats I have been on (all under 40 feet) have used a cunningham to adjust luff tension. They have usually been set up with a multiple purchase system so the effort required to tighten them is much less than using the halyard. Tightening the halyard in a blow can be very difficult without luffing the sail, even with a winch. A properly set up cunningham can make it a lot easier. I don't think it has anything to do with leach tension. Anecdotally, I do think that the upper section of the halyard often seems tighter than the lower section (because of the friction in the track?) and that's another reason to use the cunningham over the halyard. Others' observations on that could certainly be different than mine.
 
Last edited:
  • Helpful
Likes: Ward H
Jan 1, 2006
7,099
Slickcraft 26 Sailfish
Because of friction it is hard to tension the luff of the main with the halyard alone. I've posted here before that that ultra low stretch halyards are the best practice. But even so sometmes a snug on the Cuningham is necessary and welcome. It is not about removing wrinkles. It is about moving the draft forward in the main which is necessary in less than ideal upwind conditions (Or if you are sailing with a worn out Dacron main). When I say less the ideal conditions I mean when sailing in waves where you need more power, with a less able helmsman, or shifty conditions. The draft forward position is more forgiving to the helm.
Having said this, with modern molded and shaped sails the ability to adjust the shape is more limited. They are pretty much what they are.
I will say if the sailmaker nails it you've got a great sail. If not, there's not much you can do from the trim prospective to fix it. So watch out for those hardly used second hand sails. Some of them were hardly used because they weren't good. .
 

jviss

.
Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
Well, mine are mylar-on-mylar film, Pentax-reinforced (like Kevlar) sails, so like blades, airplane wings, and the shape is the shape, pretty much. But it's near perfect. I have no prob tensioning the luff with the low-stretch halyard I have. I only wish the outhaul came back to the cockpit - I don't understand why it doesn't, everything else does!
 
Jul 27, 2011
5,009
Bavaria 38E Alamitos Bay
We are adding to thread drift here so maybe this should be a new topic in the sail trim forum,…
This thread may have drifted from the “discussion” of how to install a second reef point in an old sail to prevent rounding up hard in strong gusts, to one that discusses the actual.need for a second reef point when other options of gust control might be viable. But yes, those options depend on understanding sail trim, but do not justify a separate thread on sail trim b/c there is no issue there except, evidently, how one would use a Cunningham if on a racing boat by citing its origins, etc. (thread drift), rather than focusing on how its use might apply to the OP’s root issue of gust control. I commented that one can use the Cunningham to adjust the draft position of an old sail (#19), then in response we get a lesson on Cunningham history (#21) and halyard tension lacking useful testimonial on having used it (Cunningham) to adjust draft position, or some discussion of that, until much later (#35).
 
Last edited:
  • Like
Likes: Ward H
Apr 19, 2020
64
Catalina 310 Kenosha, WI
I assume you apply the regular remedies to rounding up in gusts. Drop the mainsheet traveler, temporarily ease or lug the mainsail, feather up (pinch slightly) to flatten the boat in strong gusts. Shorten headsail. I would not put in a new reef point before attempting (mastering) these other gust-control measures.
Yes I've done those things except for maybe "shorten headsail"? You mean furl it partially?
 
Apr 19, 2020
64
Catalina 310 Kenosha, WI
So I did look into some options to add the second teef to my existing 23 year old main sail. Sailrite did a nice quote with all the items for around $290 but then I found a local sail loft that will do it for less in a day.