The Top 50 Advantages of Junk Rig

Discussion in 'Boat Design' started by David Tyler, Jan 16, 2014.

  1. Rurudyne
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    Rurudyne Senior Member

    This made me think about the "build the dinghy first" advise for those wanting to build their own boats ... and also about the dress makers pattern kits that fabrics stores still sell.

    Sure, some proverbial paper sewing pattern in a kit wouldn't be tailor made for the boat to get the best performance, but ... hey, that might not be a bad idea for a product: dinghy cambered junk sail pattern sewing kits.
  2. rwatson
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    rwatson Senior Member

    Lets not forget the problem of having a "wrong" side for effective tacking, when the mast shape ruins the leading edge.
  3. gdavis
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    gdavis Junior Member

    hey, this is a great thread. Many moons ago I junk rigged a 17' old town canoe and sailed it all over moose head lake here in maine. It didn't climb to windward as well as I hoped but other than that it did okay. I know I didn't have enough sail area but it was on a canoe and that's approaching insanity to start with. I also junk rigged an oday widgeon, this performed much better maybe due to a better built sail and more than enough area. You guys mention sail panels with camber built in.Are the battens still stiff or do they need to be adjustable or is the better shape only between them? I know this may be a low tech question but I'm curios. And with all the pros and cons flying around here the biggest pro that's been missed is the fact that junk sails are so beautiful. Just saying! Any how, I recently built a scale working model of a 46' two masted junk rigged catamaran. Now I know its just a model but this bad girl really sailed and definitely went to windward pointing quite well. I figure a cat is pretty easy to get moving so why not junk rig it, she'll still go by a lot of mono hulls Okay, I blabbed away enough..................may fair winds escort you(and your junk rigs)...g
  4. ImaginaryNumber
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    ImaginaryNumber Imaginary Member

    Avoid Rocks, welcome to

    As best I can tell, for the simplest style of cambered junk sails, it's only a small increase in complexity to add camber to a junk rig, and with virtually no added cost.
  5. ImaginaryNumber
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    ImaginaryNumber Imaginary Member

    The simplest variant has stiff battens with the sails cambered between them.
    Arne Kverneland has put together a number of pdf documents detailing how to build this style of cambered junk sail.

    There are two groups you can join to ask questions: (small membership fee, but forums are free to browse) (free)

    Dragon Wings, Gary Lepak

    China Moon, Pete Hill

    Oryx, Pete Hill

    PHA, Bertrand Fercot
  6. pdwiley
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    pdwiley Senior Member

    I'm pretty sure, from those photos, that the sails are sewn up in panels corresponding to the batten spacing which is also how you can get some camber in them.

    This isn't how the sails for Colvin hulls are specified. They're done in vertical panels sewn with a seam every 500mm or so. That way no rip can propagate very far and the vertical seams help carry the weight of the entire sail better as they extend to the attachment points on the yard. How those sails in the above pictures are made, all the weight is on the top panel attachments to the yard alone.

    They may set better, I don't know, and maybe you'll get another 5 degrees or so better pointing ability, but they're structurally weaker and the sailcloth is lighter. The cloth in my sails is about 2X the weight of that in my friend's BADGER design for example.

    As I said, TANSTAAFL. In my case if I really really wanted to point higher, I'd have put a ketch rig on the hull.

  7. tom28571
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    tom28571 Senior Member

    I generally ignore threads about the perfect anything or such but eventually read the OP's claims and am still unimpressed about any boat or rig being the "best". Most favorite rig I ever owned was a cat-ketch with freestanding aluminum masts and unbattened sails with sprit booms. Simplest imaginable and easiest to rig-unrig as well as very satisfying in all respects. Whether its the "best" or not, I have no clue but it was the best for me. Don't know how many advantages this rig has over a junk rig but there are enough to suit me.
  8. ImaginaryNumber
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    ImaginaryNumber Imaginary Member

    I posted these four photos to demonstrate how junk sails (or junk-like wing sail) were being used on catamarans. I don't think that any of them are using cambered panels such as those that Arne Kverneland has developed.

    Dragon Wings has traditional flat panels.

    China Moon may have flexible battens to allow camber, but if so it is not a good system as the camber is least when wind speed is least (and you then want the most camber), and the camber is greatest when the wind speed is greatest (and you then want the least camber).

    Oryx has an experimental split junk rig ('jiblets' and mainsail) with half-wishbone battens. It didn't work so well, and Pete has replaced them with something closer to the junk-wing sail like on PHA.

    PHA, (Paix Harmonie Amour --> Peace Harmony Love) is a junk-soft wing sail with wishbone batten foresail and articulated straight batten aftsail. Bertrand now has a 46' Wharram, called Grand PHA, also with soft wing sails. He is sailing it west-bound around the world from France, and now is in Australia.

    This is an example of one of Arne's cambered panel junk sails, maybe on Johanna?


    Junk sails typically have very little stress on the sail cloth as the weight is carried by the bolt ropes (or bolt webbing) at the luff and leech. Because the weight is carried by the bolt ropes camber can be built into the sail panels and the panels will 'billow' into shape with relatively little wind. Also, because there is little stress on the sail cloth compared to a Bermuda-style sail, lighter-weight cloth can be used, and if a sail is torn the sail will often still be quite functional.

    You can also make cambered panel junk sails with vertical seams, using a different technique from that promoted by Arne.

    Note torn, holey sails and diagonal seams.

    Just had to add another photo demonstrating that seams can be put wherever/however you please. :)

    A "modern junk". :rolleyes: <LOL>
  9. rwatson
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    rwatson Senior Member

    Got any pictures of this rig on the opposite tack ?

    Attached Files:

  10. sharpii2
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    sharpii2 Senior Member

    There's a lot of trickiness here.

    True, the junk rig is heavier and has more top hamper, when fully set.

    Also true, that that weight comes down the mast, as the rig is reefed, reducing the top hamper (but not the weight) substantially.

    The Bermuda rig, with its tall mast and wire rigging, most of which reaches to the top of the mast, keeps most of its top hamper, even after all the sail is furled.

    The moral here is that the junk rig has most of its top hamper at a time when it does the least harm, in light winds.

    True, the unstayed mast, of the junk rig, is more likely than not going to be heavier than that of a Bermudan rig, made from the same material, supporting the same SA.

    Also true, the junk mast will be somewhat shorter, meaning the added top hamper will actually be less than the added weight might suggest. Remember, a mast twice as tall must weigh half as much, as the mast it replaces, to have the same top hamper.

    True, the junk rig is better off the wind than the Bermuda rig.

    Also true, the modern Bermuda rig has evolved into a primary upwind rig, with special added sails for downwind sailing. It is possible to design a low aspect ratio Bermuda rig which can sail quite well off the wind, and be much cheaper to make.

    True, the Bermuda rig can be a bear to reef and furl.

    Also true, that that is because it is designed to ape an airplane wing, and either has cussed short battens, splaying every which way, or expensive full length battens, which need expensive 'cars' to help them slide down the mast. Much of the reputed extra cost of the Bermuda rig is due to performance enhancing design refinements and equipment.
    It can be made easier to reef and less expensive, if that were ever the design goal.

    So really, IMHO, the junk rig has just one real advantage. It is easier to reef. Just lower the sail until you have the desired reduction. The boomlets placidly stack in the lazy jacks.

    Its many 'battens' (really boomlets) are spars in themselves, They too cost money. Phil Bolger used to classify it as an expensive rig.

    I consider the junk rig to be what I call a 'stack sail', meaning a sail made of individual cells which stack on top of one another. Considering it as such, I have thought about having fewer boomlets and larger sail panels.

    This would reduce the reefing options, but would cut the weight down somewhat.

    Imagine if there were a class of racing junk rigged boats.

    Then it would be thought as efficient, but expensive and inconvenient.
  11. ImaginaryNumber
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    ImaginaryNumber Imaginary Member


    Interestingly enough, some 'junkies' have fitted wind measuring instruments to their boats and claim that on their 'bad tack' (with the mast to leeward) they actually point a few degrees higher than on their 'good tack'!
  12. ImaginaryNumber
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    ImaginaryNumber Imaginary Member

    The Junk Rig Association has a forum dedicated to racing junk-rigged boats.

    In particular, Ketil Grieve of Norway, sailing a junk-rigged X-99, has been actively racing against Bermuda-rigged boats and been doing quite respectable.

    MARIE G (cambered panels) - Ketil Grieve - Norway
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    FAST FRED Senior Member

    or expensive full length battens, which need expensive 'cars' to help them slide down the mast.

    These are required only id the sail is being reefed under load.

    Since a fully battened sail does not flog itself to death when luffing , no car or anything else special is required hoisting or lowering sails into the wind.

    Fully battened (no cars) since 1975 ..
  14. bpw
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    bpw Senior Member

    Agreed, my full battens cost a few hundred dollars extra and run on regular sail slides. Works fine and is a huge improvement in sail shape. I actually get more chafe and wear on the slides that don't have battens.

  15. David Tyler
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    David Tyler J. R. A. Committee Member

    I have it on good authority that three of this year's awards by the long established and most prestigious Royal Cruising Club have gone to junk rig sailors in junk rigged vessels :
    The RCC Claymore Cup - Annie Hill, for a delivery trip in much less than ideal sailing weather.
    The RCC Medal for Seamanship "for an act or acts of outstanding seamanship" - Roger Taylor, in Mingming.
    In announcing the Medal for Seamanship, the Vice Commodore quoted from the winner’s writings: “I have been driven [in my writing] to show that ocean sailing which is simple, harmonious, unaggressive and patient can bring the richest of rewards. The modern sailor is too often drowned in a technological morass. Overload obscures vision. Digital excess veils the real world. Constant hurry induces blindness.” and went on to remark how such a sentiment was very close to the traditional heart of the RCC. Roger Taylor’s achievements as a singlehanded sailor are of legendary proportions. He has voyaged to Spitzbergen, Jan Meyen, Bear Island, Greenland and Iceland in a 21ft boat, Mingming, which many would consider more at home in a sheltered bay. His voyage to the Labrador Sea was an epic example of small boat ocean sailing. If you are not familiar with his books or YouTube videos, then will provide you with a great deal of entertainment, and possibly inspiration.
    The RCC Challenge Cup, which is the top members' only award - Charlotte Watters and Dan Johnson in Hestur.

    Not bad, eh, for a rig that struggles to find acceptance on account of it's not really such a good rig, certainly not fit to go cruising with?! :p
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