# reefing lines



## sailingtime (Jul 16, 2007)

I am looking to replace my older reefing lines with some new lighter lines. It is a simple system where the line runs through the boom and up to a grommet in the leech of the sail. Is there a rule of thumb or a guideline on what tensile strength a reefing line should be? With the vast array of line sizes, strengths and costs I would hate to be under severed or unnecessarily over spending.


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## sailingdog (Mar 19, 2006)

The line should run from the boom up to the reefing cringle and then BACK DOWN TO THE BOOM. This line has to act as both an outhaul (at least for the clew reefing cringle) and a downhaul. 

The lines should be the same size as your halyard roughly, since the loads are going to be pretty similar. If you want to go with a lighter line, you can use a spectra/dyneema cored line and go down a size in diameter generally. You don't want to use a single braid line for this, since a double braid will have a lot better chafe resistance. Also, the outer braid on most dyneema/spectra core lines is primarily there for chafe/UV protection with the core of the line providing most of the strength. 

BTW, a two-line reefing system is far better IMHO than a single-line reefing system, since it gives you far more control over the shape of the reefed sail.


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## sailingtime (Jul 16, 2007)

Thanks.

BTW, I do have a double reefing systam and they run through the sail and back to the otherside of the boom.


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## GeorgeB (Dec 30, 2004)

Below, is a photo depicting what SD wrote in his message. The object is for the boom to take the force on the line for the clew to lay next to the boom with the maximum tenstion. Getting the new clew to lay down flat can be a hassle in a single line system and easing off both the mainsheet and vang helps out a lot when setting a reef. You did not mention what size of boat/reefing line you have. The rigging specs for my boat (C34) call out for half inch dacron. I have gone down to 3/8 inch spectra on my reef #2 line to save weight. The strength/stretch properties exceed the original Sta-set that came from the factory. Make sure your line is properly sized for any clutch or cleat.

The second photo illustrates the problem with single line reefing. The reefing line suffers friction going through the new cringle, making for more tension on the tack than the clew. Unfortunately, most of the force is on the clew. I rigged a Harken Carbo Block to reduce that friction, but unfortunately, now have a point of chaffe in my system. The solution for that is to cut new exits on the bottom side of my boom, but the extra slots will weaken the boom just where you want it to be strong. One solution begets a new problem&#8230;

















<O


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## sailingdog (Mar 19, 2006)

George-

You might be interested in one of the solutions I found for reefing setups. Goiot makes a neat block that fits in the reefing cringle and effectively turns it into a block. It looks like this:










Using these would leave the line leading fair but reduce the friction in the system.



GeorgeB said:


> Below, is a photo depicting what SD wrote in his message. The object is for the boom to take the force on the line for the clew to lay next to the boom with the maximum tenstion. Getting the new clew to lay down flat can be a hassle in a single line system and easing off both the mainsheet and vang helps out a lot when setting a reef. You did not mention what size of boat/reefing line you have. The rigging specs for my boat (C34) call out for half inch dacron. I have gone down to 3/8 inch spectra on my reef #2 line to save weight. The strength/stretch properties exceed the original Sta-set that came from the factory. Make sure your line is properly sized for any clutch or cleat.
> 
> The second photo illustrates the problem with single line reefing. The reefing line suffers friction going through the new cringle, making for more tension on the tack than the clew. Unfortunately, most of the force is on the clew. I rigged a Harken Carbo Block to reduce that friction, but unfortunately, now have a point of chaffe in my system. The solution for that is to cut new exits on the bottom side of my boom, but the extra slots will weaken the boom just where you want it to be strong. One solution begets a new problem&#8230;
> 
> ...


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## svHyLyte (Nov 13, 2008)

In the lower photo, the forward angle forced on the reefing line by the bull's eye block on the mast immediately below the boom pulls the turning block connected to the cringle strap at the luff forward, causing the line to run over the forward edge of the exit slot on the top of the boom. This arrangement introduces a lot of unnecessary friction to the system and will cause the line to fail at the slot in the boom due to chafe in any extended blow. Eliminating the bull's eye block below the boom will eliminate these problems and create a fairer lead to what I assume is a turning block at the mast base. Single line reefing sustems are great in theory, in practice, not so much.

FWIW...


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## sailingdog (Mar 19, 2006)

I'm not a big fan of single line reefing systems as a general rule, but if he wants to keep the single line system, the lead to the cringle would be much better if he ran the line through the cringle using the Goiot blocks. This would eliminate most of the chafe issue caused by that turning block on the dogbone going through the cringle, since the line would lead higher to where the cringle actually is,rather than three or four inches below it, as required by the dogbone and turning block. Also, it would be less weight aloft.

Finally, if the Goiot block fails, the line is still holding the cringle down. If the dogbone or turning block fail, the sail goes free.



svHyLyte said:


> In the lower photo, the forward angle forced on the reefing line by the bull's eye block on the mast immediately below the boom pulls the turning block connected to the cringle strap at the luff forward, causing the line to run over the forward edge of the exit slot on the top of the boom. This arrangement introduces a lot of unnecessary friction to the system and will cause the line to fail at the slot in the boom due to chafe in any extended blow. Eliminating the bull's eye block below the boom will eliminate these problems and create a fairer lead to what I assume is a turning block at the mast base. Single line reefing sustems are great in theory, in practice, not so much.
> 
> FWIW...


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## zz4gta (Aug 15, 2007)

George, lash the ti-lite block to the ring on the starboard side of the boat. Will raise the block up higher than the original design and hopefully change the lead angle enough to stop the chafe. 

I'm surprised you can use one of those blocks. Seems like a light piece of hardware for the task.


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## l_lym (Aug 15, 2004)

The Goiot block looks like a perfect solution. In a quick look I didn't see anyone distibuting it in the US. Where did you find them?


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## PeterSailer (Mar 20, 2010)

> Finally, if the Goiot block fails, the line is still holding the cringle down. If the dogbone or turning block fail, the sail goes free


Fail safe...I like it


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## sailingdog (Mar 19, 2006)

PeterSailer said:


> Fail safe...I like it


So do I... and they don't snag on the backstay in light winds.


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## MastUndSchotbruch (Nov 26, 2010)

PeterSailer said:


> Fail safe...I like it


Pretty nifty design.

Question: the Goiot site says it fits into "Rutgerson grommets" of 25mm or 35mm. How about just regular ole grommets that I have on my sail? What's a Rutgerson grommet anyway>


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## sailingdog (Mar 19, 2006)

MastUndSchotbruch said:


> Pretty nifty design.
> 
> Question: the Goiot site says it fits into "Rutgerson grommets" of 25mm or 35mm. How about just regular ole grommets that I have on my sail? What's a Rutgerson grommet anyway>


Rutgerson grommets are one of the most common brand of grommets used by sailmakers for reinforcing the reefing clew/tack cringles. If your sail doesn't have Rutgerson grommets, it is a relatively simple matter for a sailmaker to replace them. The loft I had install my third reef used them for the third reef and retrofit them for the other reefing points so that the blocks could be used on my sail.


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## MastUndSchotbruch (Nov 26, 2010)

sailingdog said:


> Rutgerson grommets are one of the most common brand of grommets used by sailmakers for reinforcing the reefing clew/tack cringles. If your sail doesn't have Rutgerson grommets, it is a relatively simple matter for a sailmaker to replace them. The loft I had install my third reef used them for the third reef and retrofit them for the other reefing points so that the blocks could be used on my sail.


Hm, in my case, I installed the grommets for the third reef myself. I don't think I paid attention to the brand of the grommets. Given that they size them in millimeters (25mm or 35mm), I wonder if they are metric.


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## sailingdog (Mar 19, 2006)

MastUndSchotbruch said:


> Hm, in my case, I installed the grommets for the third reef myself. I don't think I paid attention to the brand of the grommets. Given that they size them in millimeters (25mm or 35mm), I wonder if they are metric.


They look like this:


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## MastUndSchotbruch (Nov 26, 2010)

sailingdog said:


> They look like this:


thanks, that is very helpful. So they are the type that is pressed in by machine. I installed mine the old-fashioned way, straight out of the Sailmaker's Apprentice (sew in a cringle, then press in the interior fitting with a die set).

I guess I could measure my reef 1 and 2 (which are installed by machine) and see if by accident they are 35mm.

If I may ask, how much (roughly) is the Godiot gizmo?


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## sailingdog (Mar 19, 2006)

MastUndSchotbruch said:


> thanks, that is very helpful. So they are the type that is pressed in by machine. I installed mine the old-fashioned way, straight out of the Sailmaker's Apprentice (sew in a cringle, then press in the interior fitting with a die set).
> 
> I guess I could measure my reef 1 and 2 (which are installed by machine) and see if by accident they are 35mm.
> 
> If I may ask, how much (roughly) is the Godiot gizmo?


Hmm... I couldn't tell you, I don't remember how much I paid for them. I bought them off of a friend down at the marina, who bought them in France to complicate the issues, and they were priced in Euros, and I bought them in USD.


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## MastUndSchotbruch (Nov 26, 2010)

sailingdog said:


> Hmm... I couldn't tell you, I don't remember how much I paid for them. I bought them off of a friend down at the marina, who bought them in France to complicate the issues, and they were priced in Euros, and I bought them in USD.


Thanks anyway. It does seem like a good idea and may be worthwhile to explore.


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## catamount (Sep 8, 2002)

GeorgeB said:


> The ... photo illustrates the problem with single line reefing. The reefing line suffers friction going through the new cringle, making for more tension on the tack than the clew. Unfortunately, most of the force is on the clew. I rigged a Harken Carbo Block to reduce that friction, but unfortunately, now have a point of chaffe in my system. The solution for that is to cut new exits on the bottom side of my boom, but the extra slots will weaken the boom just where you want it to be strong. One solution begets a new problem&#8230;
> 
> .....
> 
> ...





svHyLyte said:


> In the ... photo, the forward angle forced on the reefing line by the bull's eye block on the mast immediately below the boom pulls the turning block connected to the cringle strap at the luff forward, causing the line to run over the forward edge of the exit slot on the top of the boom. This arrangement introduces a lot of unnecessary friction to the system and will cause the line to fail at the slot in the boom due to chafe in any extended blow. Eliminating the bull's eye block below the boom will eliminate these problems and create a fairer lead to what I assume is a turning block at the mast base. Single line reefing sustems are great in theory, in practice, not so much.


The Problem with svHyLyte's suggestion is that you need a forward pull on the tack line, otherwise all the pressure of the sail will come on the first luff slide above the reef.

Here's one possible solution -- add a small block on a strop to the top of the boom to help re-direct the reef line so as to avoid chafing against the edges of the sheave box:


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## svHyLyte (Nov 13, 2008)

catamount said:


> The Problem with svHyLyte's suggestion is that you need a forward pull on the tack line, otherwise all the pressure of the sail will come on the first luff slide above the reef.
> 
> Here's one possible solution -- add a small block on a strop to the top of the boom to help re-direct the reef line so as to avoid chafing against the edges of the sheave box:


This isn't a bad suggestion.

However, the simplest solution is to remove the bull'seye block from the mast.

Alternately, one could simply use a double sheave exit block on the boom such as the Harken H089:


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## sailingdog (Mar 19, 2006)

This doesn't really help much, since the exit slot is angled and the blocks would not line up fair with the line inside the boom, chafing the line, though probably to a lesser degree. Installing a spar slot exit plate would probably help a lot, since it would be less abrasive than the aluminum spar itself.



svHyLyte said:


> Alternately, one could simply use a double sheave exit block on the boom such as the Harken H089:


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## svHyLyte (Nov 13, 2008)

sailingdog said:


> This doesn't really help much, since the exit slot is angled and the blocks would not line up fair with the line inside the boom, chafing the line, though probably to a lesser degree. Installing a spar slot exit plate would probably help a lot, since it would be less abrasive than the aluminum spar itself.


Passing the reefing line through the center of the two sheaves would eliminate chafe at the exit slot from the boom. The aft box-sheave keeps the line fair within the boom. (The line doesn't care whether the block is vertical or horizontal or anything in between.) The forward box-sheave provides a low friction lead to the turning block on the luff. That, coupled with the Goiot cringles you described would pretty much eliminate friction/chafe at the boom end.

FWIW...


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## Omatako (Sep 14, 2003)

It has to be said that as single-line reefing systems go, the George's system is a compromise on the real thing. The turn block that looks so incongruous on the outside of the boom in picture 2 is almost certainly an after-market solution and hence it doesn't work very well. These add-on systems are touted by Harken others as a solution for vessels that were never set up with single line reefing originally.

On a properly set-up single-line reefing system, the boom will have a set of sheaves in the upper front end of the boom to feed lines up to the tack cringles without any chafe and another set of sheaves in the lower front end of the boom to feed the reefing lines coming from the clew end down to the winch. This system will have a balance block in the boom that creates the interaction between the tack line and the clew line.

The positioning of the sheaves at the very end of the boom also ensures that the tack cringle is pulled as far forward as is practically possible.

It is however true to say that most smaller boats will have a boom section too small for dual sheaves to be installed without weakening the boom or to accommodate the balance blocks (one for each reef).

There are also those amongst us who will say that a single line reefing system results in excessive line length which clutters the cockpit. I wonder how this differs from having two different lines for each reef coming into the cockpit (if this is even possible, most double line systems operate from the mast) each having to have it's own tackle (rope clutch, cleat, whatever). 

You will glean from the above that I am a full-on supporter of single line reefing.


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## Outrageous (Aug 18, 2010)

Thanks to Saildog, I'm going to pursue these on my mainsail. Here is the site: Goiot products

here is the PDF for the grommet/block:
Goiot Quick Reef System

I'm not leading lines aft to cockpit just yet, but this should make it faster/easier to get the main tight to boom. Later, I can explore cockpit reefing.

We've ripped the main reefing in 30kt+ winds 2 of the last 3 races on SF Bay. Of course the sail is 13 yrs old, so time to replace. Also, I'm putting in one reef minimum before we leave the slip from now on. Safer to shake out than put in.


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## knuterikt (Aug 7, 2006)

svHyLyte said:


> In the lower photo, the forward angle forced on the reefing line by the bull's eye block on the mast immediately below the boom pulls the turning block connected to the cringle strap at the luff forward, causing the line to run over the forward edge of the exit slot on the top of the boom. This arrangement introduces a lot of unnecessary friction to the system and will cause the line to fail at the slot in the boom due to chafe in any extended blow. Eliminating the bull's eye block below the boom will eliminate these problems and create a fairer lead to what I assume is a turning block at the mast base. Single line reefing sustems are great in theory, in practice, not so much.
> 
> FWIW...


Removing the bull's eye will create a new problem...
The reefing line will pull the sail away from the mast casing wrong load pattern on the sail.
So if you remove the bull's eye you must move the reef cringle furter aft in the sail.


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## MedSailor (Mar 30, 2008)

Outrageous said:


> Thanks to Saildog, I'm going to pursue these on my mainsail. Here is the site: Goiot products
> 
> here is the PDF for the grommet/block:
> Goiot Quick Reef System


Are you contacting them directly to buy them or did you find a source? How much do they cost?

MedSailor


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## Outrageous (Aug 18, 2010)

I'm asking my sailmaker, who is building me a new main next month, to get them. Will advise.


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