Single line reefing

Discussion in 'Sailboats' started by dnmeid, Aug 8, 2012.

  1. dnmeid
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    dnmeid Junior Member

    Hi folks,
    I have a question concerning single line reefing systems for mainsails. So far I used a few different systems on smaller boats and mainly furling mainsails on larger boats. I've found three different systems so far:
    [​IMG]

    System A uses two blocks in the sail and can be used for reefs higher than the boom is long.
    Systems B and C are very similar, they use a moving block attachment inside the boom and can only be used for reefs which are not higher than the boom is long. If I got it right the purpose of those systems is to first pull in the tack and then the clew. C is the system which Selden uses now since years.
    All systems use a block or cringle to build a pulley for the clew line.
    I understand that two line reefing has the advantage that one can adjust tack and clew tension independently. At least the solutions with the moving car inside the boom have the possibility to limit the end position of one line (B: clew, C: tack)

    My questions are:
    • Is single line reefing suitable for smaller mainsails only or is there no problems with larger sails, say more than 60sqm?
    • Why is always a pulley built for the clew?
    • Are there more working options than the three I've found?
    • How do the options compare? What are the benefits for the different solutions?

    Thank you for your help
     

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  2. sean9c
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    sean9c Senior Member

    B and C are interesting.
    A is 2 to 1 on both luff and leech
    B is 1 to 1 on both luff and leech
    C is 2 to1 on the leech and 1 to 1 on the luff
    Always seemed to me that with A (since the leech takeup is longer) that you grind the luff tight first and still have more leech to take up so you're grinding the line thru the already tight luff which adds a bunch of friction.
    B has the most line load since it's 1 to 1.
    I sort of like C but there is a lot of stuff in the boom.
    It'll be interesting to read what some of the smart people think
     
  3. dnmeid
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    dnmeid Junior Member

    I'd say B is 1:1 on luff and 2:1 on leech and C is 2:1 on both, luff and leech.
     
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  4. sean9c
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    sean9c Senior Member

    Aw, you're right.
     
  5. philSweet
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    philSweet Senior Member

    I've seen A flipped fore/aft with a turning block aft. The lines exited under the boom to a quad jammer near enough the mast to allow you to use a halyard winch to crank them in and still reach the jammer. Fifty foot cat. 74' mast. Four permanent rigged reefs.

    I don't particularly like them on bigger boats because once underway again, the sheeting load gets transferred to the luff tension via the reefline. That is not always desirable. That is probably a good argument against the 1:1 setups.
     
  6. Luc Vernet
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    Luc Vernet Senior N.A.

    You are wrong, and also is Sean: all three systems are giving the same pull to both leech(+ foot) and luff (+foot).

    A gives 2:1 on both
    B gives 1:1 on both
    C gives 2:1 on both

    Your mistake: you forgot that the pull on the traveler in "B" is 2:1 by the reefing line, but this traveler then pulls 1:2 on the "captive" line, which in turn pulls 2:1 on the leech = back to 1:1!

    Anyway, and to answer to some of the questions:
    - single reefing line can be used for any sail size....but some prefer double line (or one line + one hook for better control.
    - sometimes you will find a single line going up to the clew (if that is what your second question is asking...?)
    - there are many more options. Those with a traveler inside the boom are favored by harken.
    - K.I.S.S.
     
  7. dnmeid
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    dnmeid Junior Member

    Do you know if they wish they had a different solution or where they fine with it?
    Often I've seen that reefing in is not as a big deal as shaking the reef out.

    At least version C works around this problem. When the reef is in the traveller sits at the boom peak. More tension on the leech can't pull the traveller further aft. The tack position is limited.


    2:1 x 1:2 x 2:1 = 4:2 = 2:1

    Exactly. I just wonder why. I think this is a two part problem.
    1st the load distribution to luff and leech. As we can see with some effort it is possible to give more load to the leech line even with one line.
    2nd I can think of a very practical reason. If you have that pulley like configuration the reefed sail is kept between the two lines. On the other hand think of a very deep reef where you have to flake 50% of a large main. What is better here, pushing the stack to one side with a single clew line or squeezing it between two clew lines?
     
  8. Chuck Losness
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    Chuck Losness Senior Member

    In my experience I have never been able to get a reefed main to set properly with any single line reefing system that I have used. And I have never seen a proper set on any boats that I have seen with the reef tucked in with a single line reefing. Maybe that's just me. But the main always has too much draft. It just looks like a bag. The problem is that you can't get the tack to stay close to the mast. The tack always gets pulled aft causing excess draft in the main. If you really think about it single line reefing is the same as trying raise your jib and sheet it with the same line. Who would ever do that?
    Regular jiffy reefing is so simple and works so well that I can't understand why anyone even wants to bother with the complications of single line reefing.
    When I reef my main, I let off the halyard, hook the tack on the tack eye on the gooseneck and then tension the halyard. Then I pull in the reef line and set the clew. Lastly I tie in the reef points. This results in a nice flat reefed mainsail. Just what you want in a reefed mainsail.
     
  9. Landlubber
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    Landlubber Senior Member

    simple really isn't it Chuck....
     
  10. dnmeid
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    dnmeid Junior Member

    I think I understand the disadvantages of single line reefing (maybe I'm wrong though). But I have additional factors to consider:
    • Offshore: makes you reef regularly, so there are two kinds of easy, simple in terms of non complex construction and simple in terms of simple operation.
    • Singlehanded: makes you want to have one single point of boat operation. If it were a mid cockpit boat this would surely be at the mast, but it is not, so all lines to the cockpit.
    • Rotating mast: makes it a little trickier to lead the lines to the cockpit and almost every line changes in length with rotation and every line under load is pulling the mast back to centerline, thus restraining free rotation.
    My thoughts are to reduce the number of lines and to minimize the loads on them as possible.
    Another option I'm thinking about are remotely operated jammers at the mast. This would give cockpit operation, pertain mast operation and minimize loads, but it also gives you all the additional jammer control lines in the cockpit and they also need to be guided there with some blocks...

    Given all that circumstances single line reefing seems to me most appealing and I'd like to hear your opinions and if going that road which system gives me the best possible overall value.
     
  11. Chuck Losness
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    Chuck Losness Senior Member

    Dnmeid
    I have a fair amount of miles offshore, both on crewed boats and as a singlehander. Leading lines back to the cockpit works well on a crewed boat because you have people in the cockpit to handle lines and you have people on deck to deal with the invariable snafu's that arise.
    But as a singlehander leading all your lines to the cockpit does not eliminate the need to go on deck. You end up doing what my friends and I call the reefing shuffle. You first deal with the lines in the cockpit, then you have to shuffle up on deck to clear something or another, then you have to shuffle back to the cockpit for more line handling, then back on deck. Back and forth, back and forth until your are done with tying in the reef points and you still don't have a sail that is set properly. Note that even if you don't have any snafu's requiring you to go on deck you still have to go deck to tie in the reef points. So single line reefing does not eliminate the need to go on deck.
    IMHO the most dangerous time in heavy weather is the transition zone between being in the cockpit and being on deck. With lines lead aft you spend more time in the transition zone.
    On the other hand, reefing at the mast has all your lines coming to one place and puts you in the position to deal with the snafu's. No shuffling back and forth. The job gets done quicker and easier and you end up with a properly set sail.
    BTW, a boat with couple on board is not a crewed boat. It is a boat with two singlehanders on board because you only have one person on deck at a time.
    Reefing at the mast works best for me. You will have to make your own decision on what works best for you.
    Good luck
    Chuck
     
  12. dnmeid
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    dnmeid Junior Member

    Thanks Chuck, your experiences with the reefing shuffle (nice term) are exactly the same as mine with luff rope sails. You just can't handle them from the cockpit. But for a full battened main with batcar-system and working lazyjacks I think it could work. Depends much on the flaking system.
    And there will be no reefing points to tie in anyway. I have a loose foot for more then ten years now and no reefing lanyards. I consider outhaul and mastbend to be the better option for controlling sailshape.
     
  13. Chuck Losness
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    Chuck Losness Senior Member

    I have had loose footed mains for over 30 years and have always had reef points because it keeps the reefed portion of the sail from flogging around and IMHO looks neater and more shipeshape. I have tied them in both ways, i.e. around the boom and sail or just around the sail. Doesn't seem to make much difference which way you tie in the reef point that I can tell.
    Full batten mains don't guaranty a properly set sail when reefed. Several years ago I helped a friend sail his boat from to San Diego, California to Cabo San Lucas, Mexico. Most of the trip was made with a reef in the main, sometimes double reefed. Even with full battens, we were not able to take the bag out of the main with a single line reefing system. Two years ago I helped bring the same boat north from Mexico. Same problem. Could not get the bag out of the sail even with the full battens. My friend was adamant that his sail was just blown out and he needed a new mainsail. I convinced him that the problem wasn't the sail but the single line reefing system. He finally got rid of the single line reefing system and this past June I helped him again bring his boat north. The same sail now sets properly with just the 1st reef in or with both the 1st and 2nd reef in.
    The above is just an example of my experience and not necessarily representative of how your boat would work.
    There are of course more factors to consider than just the type of reefing system to get a reefed main to set properly. The attachment at the tack has to keep the tack fixed in place and close to the mast and the reefing blocks have to be placed right to be able to outhaul the sail. Even how you run the reefing line at the clew effects sail shape. What I think works best is to have the reefing lines run on one side of the sail so the reefed portion of the sail doesn't interfere with the reefing line. Kind of hard to explain in words but easy in a picture or drawing. I'll see what I can come up with and put it in another post.
    Chuck
     
  14. Chuck Losness
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    Chuck Losness Senior Member

    Here goes with my attempt to show how I like to run reefing lines. So give me a break. I am not an artist and drawing is not my forte. The pictures are probably laughable.
    The way most people run their reefing line is shown in B in my crude drawing. The line is attached on one side of the boom, goes up through the reefing cringle and then back down to the boom and then led forward. When run this way the reefed portion of the sail is sandwiched between the boom and the reefing line and you cannot get the reefing line tight. It is even worse with a second reef.
    I like to tie a bowline in the end of the reefing line, run the line around the boom and have the line pass thru the bowline, then up to the reefing cringle and then back down to the boom and finally led forward. While this causes the reefing line to pass over the leach of the sail which does cause minor chafe, it allows the reefing line to be pulled tight so that you can get a good set to the sail when reefed. To keep the reefing line in place I put a pad eye on the boom or run the reefing line behind the block. Either way keeps the reefing line in place. I have tried to show this in A below and in the picture.
     

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  15. dnmeid
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    dnmeid Junior Member

    Ok, this answers one of my questions from message #7 and is the same I was thinking. Additionally many sailors like to use a small block in the sail to reduce friction, this would also prevent the chafe of the leech. Nowadays I would prefer a low friction ring over a block here.
    Has anybody ever tried to use a dutchman flake for reefing? On one hand I like the general idea but on the other hand I dislike all the holes in the sail.

    The more I think about it the more reasons I find for system C from my first message. Still it all depends on a good LJ system.
     
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