Jib halyard locks on dinghies

Discussion in 'Sailboats' started by NHRC, Jan 20, 2014.

  1. NHRC
    Joined: Jan 2014
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    NHRC Junior Member

    Hi is anyone aware of jib halyard locks on dinghies?
     
  2. gonzo
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    gonzo Senior Member

    Do you mean something that you need to open with a key?
     
  3. Stumble
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    Stumble Senior Member

    On small dinghys typically you just tie the halyard up, on slightly larger boats the weight of the lock is typically more than the weight of the halyard so it isn't worth it. For what it's worth Karver makes a small one for 25-30' boats that works very well, but it's pretty expensive.
     
  4. Richard Woods
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    Richard Woods Woods Designs

    I guess you want to reduce halyard stretch and the mast compression loads? Do you have a forestay or rely on the jib halyard?

    I would think you could use the same system as on a beach cat halyard. But I don't know anyone who has done it. I'd ask for John Claridge's or Pete Saunder's opinion, or someone else with similar experience (shows how long since I sailed at Lymington!)

    What boat do you sail?

    Richard Woods
     
  5. SukiSolo
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    SukiSolo Senior Member

    The OK dinghy uses a halyard lock, typically a ball and cage type. The newer RS 100 uses a Clamcleat high up on the leading edge of the carbon mast.
    Sometimes the biggest problem is getting the sail down! I have often thought of a little tiny slave line tripping a catch might be a more robust solution. Way back in the 30's one solution on the J class was to tie the main up, then raise it against a knife edge which cut through the lashing!.

    Note that the OK is unstayed and modern rigs are carbon (Aardvark is one manufacturer), and the RS 100 is stayed only with side shrouds (10.2 sq m asymetric) and two sizes of main 8.4 and 10.2 sq m. In both cases halving the compression seems to be beneficial.

    I have seen a couple of systems on Selden aluminium masts but believe the benefit of a halyard lock to be better on wooden and carbon spars. Both materials are generally a bit poorer in compression relative to stiffness. Wood is around a 4.5 to 1 ratio tension (Sitka spruce) to compression, carbon varies because of type of fabric and at the nano level. Whether they are hollow fibres, unidirectional, what diagonal angle etc all affect the compression properties.

    Agree with Richard, John Claridge is a helpful guy. I had reason to contact him over a repair to a Cadet he built about 20+ years ago, and he gave me bit of lowdown on the boat.
     
  6. NHRC
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    NHRC Junior Member

    Thanks for the replies guys.

    Good to see John Claridge is well respected and remembered on this forum. I talked to him about it a while ago, a long with many others lads of knowledge and reputation.

    I don't think anyone, even the French guys at Karver make anything small or lite enough to fit on my boat and be practical.

    Looks like I'll have to get cad out and start designing.

    I am thinking of combining a sheave block with a lock idea similar to the super spars design most top folk use on their main halyards.

    http://www.superspars.com/SSlatest/gallery3/Halyard-lock-fitting-pictures/
     
  7. FAST FRED
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    FAST FRED Senior Member

    IF the fore stay has a toggle in top , that might be the easiest to modify to hang a halyard lock.
     
  8. Baltic Bandit

    Baltic Bandit Previous Member

    Depends on the size of your dinghy but most use a ball and hook. Heck even the Star does.

    The lightest ones besides ball and hook are the constrictor clutches http://www.ronstan.com.au/marine5/range.asp?RnID=422 but they only go down to 6mm which seems big for a dinghy forestay or halyard
     
  9. gggGuest
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    gggGuest ...

    Assuming its a two hander I've always found it easier just to rig the boat on her side and lash the jib. On a singlehander I've come to believe the most practical option is just to have a halyard on the jib and accept the compression load.
     
  10. gonzo
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    gonzo Senior Member

    Do you mean something like the Selden 508482?
     
  11. Richard Woods
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    Richard Woods Woods Designs

    Some classes require you to be able to lower the jib at sea. And that is a problem with the OK/Europe/RS etc main halyard locks. You have to get well forward to be able to release it. Feasible on a Star jib but not really on most dinghies

    And you have the halyard tail on the outside of the mast, I don't think its possible to do it with an internal halyard. The design also depends on how close the jib head is to the mast

    Richard Woods
     
  12. NHRC
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    NHRC Junior Member

    Thanks for the input...
    The Ronstan rope clutches are an interesting thought that I had previously discarded but might work.

    The Selden/Superspars toothed version is still the preferable concept though.

    They work well on the mainsail. I have had plenty of experience of them with 470s.
     
  13. tom28571
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    tom28571 Senior Member

    I have made several ball and cage locks for both main and jib halyards. They work fine and lowering the sails is a non issue, just pull the ball through and it automatically disengages. A couple pieces of stainless and a bit of shaping will do it.
     
  14. NHRC
    Joined: Jan 2014
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    NHRC Junior Member

    Hi Tom

    Do you have any drawings or diagrams available to see a tried and tested method?
     

  15. Baltic Bandit

    Baltic Bandit Previous Member

    You might be able to fashion one smaller than 6mm on your own. Its not rocket science. In fact many skiffies (5ohs from a long time back) use a variant of that approach for adjustable trav bridles


    Essentially its just a Chinese finger trap. You couold make one out of some spare cover
     
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