Junk rig on modern hulls

Discussion in 'Sailboats' started by BATAAN, Sep 2, 2011.

  1. pcfithian
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    pcfithian Junior Member

    Great points, I totally agree. I've not yet ventured into any specific design criteria, just a rough concept. Sail area on a conventional Didi 34 is 50 square meters (536 square feet), I wouldn't plan on much bigger than that in a final iteration of a junk rig for it.

    Arne Kverneland's Johanna is a reference I've seen with a fin keel and single sail.
     
  2. pdwiley
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    pdwiley Senior Member

    My Colvin design stretched 34' hull has 715 sq ft of sail area in its 3 lowers and another 125 sq ft in the fisherman between the masts for a total of 840 sq ft. Better to have more sail and reef as required than less is Tom's philosophy.

    PDW
     
  3. BATAAN
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    BATAAN Senior Member

    Yeah me too. Big is good in sails. The bowsprit on my particular boat is essential for adding sail in light air and also to make her steer easy downwind. I've seen several single junk sailed conversions of modern designs that suffered from lack of sail area in light airs downwind. In this condition your boatspeed is subtracted from what little windspeed there is, leaving you in very little apparent wind and the ability to set a light drifter of some sort is very helpful. This means shrouds usually and they have their limiting factors, quite severe, on sail shape, thus the very high peak seen on my boat and the junk photo a few posts back.
     
  4. pcfithian
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    pcfithian Junior Member

    OK, great input. But how many square feet should I have for a 34' hull with a single sail?
     
  5. BATAAN
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    BATAAN Senior Member

    The only answer I can give is 'as many square feet as practical' since so much sailing is done in light winds. A 34' hull could be anything from a one ton splinter of a design to a 20 ton barge, so I cannot give an answer since it depends so much on displacement, ballast and stability. Again, study the Hasler/McLeod book "Practical Junk Rig" since all the applicable design material (pretty much) is in it and your questions will be answered much better than I could do so. And for a light and high performing design that I like very much, with battened lugsail but not a Chinese one, is ROXANE, which you can see here: http://www.roxane-romilly.co.uk/ If I did not have BERTIE, I would build a ROXANE.
     
  6. pcfithian
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    pcfithian Junior Member

    Thanks Bataan, I do have the PJR book on order for study over the winter.

    Roxanne looks beautiful, but a bit shorter on the accomodations than what I was looking for.
     
  7. BATAAN
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    BATAAN Senior Member

    PJR is good. You'll enjoy the read as it is very well analyzed. My main complaint with the book is they concentrate on their own 'westernization' of the rig, which is fine and works well but tends to be moderately tall and narrow.
    Here is one of Jay Benford's old designs, BADGER (a boat with many many thousands of southern Atlantic miles and very proven) with a PJR type rig. A modified dory like this can be built and sailed away in six months.
    My boat with her huge displacement and ability to carry a massive rig far forward needed the low and wide Big Eye Chicken type 'ear shaped' sail used on heavy cargo junks with shrouds, and there is no research material on that so I did most of my design work from photos my brother-in-law would send me from China he would buy in second hand stores and such. There are many subtle nuances that have surfaced over the years between the pictures and lots of hard west coast sailing, including half a dozen gales and I have modified the rig to suit. It's gotten so I can find little to change now.
    Get Burnett or Irens to design a larger Rx or Ry type for you, then build that and you will have a Hot Rod boat that turns heads, wins races and makes new friends constantly. These two guys really come up with fast, innovative stuff. Irens' huge trimarans hold lots of records at sea, yet he came up with Rx for his own boat.
    http://www.nigelirens.com/nid_CRUISING3.htm
    http://www.burnettyachtdesign.co.uk/saildesign.html
    Really analyze your future use of the boat, as in 'what will this boat do for me?' and be brutal in your own mind about dreams, ages and such. What kind of sailing will you actually do? This designs a boat, really.
    The junk rig does work well within its limitations. After sailing and developing the same one since 1985 I have come to some conclusions. It's wonderful way to control a very large sail both on the wind and down wind. It's about equivalent to a similar gaff sail as far as 'windward' goes, but downwind Chinese is quite superior for equivalent area.
    For smaller sails its' aerodynamic drag should be compensated by excellent lightweight sailmaking and as small lines as practical. With modern cordage this is pretty small. Both these things tend to detract from its wonderful cheapness in larger sizes where perfection is less of a factor.
    Hoisted it is a lot of weight aloft. If a gust heels you suddenly all that weight is now hanging well off your lee side, making more heeling moment just from weight. Weight also translates into inertia. Say you have all sail up and are going pretty good and hit a big wake, or are running a breaking harbor entrance and get into some conditions that make your boat pitch wildly. This alone can break an unstayed mast. Enjoy PJR and remember, don't get racing confused with cruising because there are many fast cruising designs and designers out there who, unconfined by racing rules, can design something fast, easy to sail, and practical under a wide range of conditions, as well as cheap to build and long-lived.
     

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  8. pdwiley
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    pdwiley Senior Member

    Somewhere I've got the rigging plan for the 34' Colvin hull. I'll see if I can find it.

    However, it still has 3 sails not 1. Also as Bataan points out, it's going to be dependent on the hull how much sail you can carry. In Tom Colvin's book on making junk sails he suggests a figure of between 10 and 20% more area than the original rig due to the ease of reefing when needed.

    There was a 25' Colvin Witch design - GINGER - with a single junk sail but most of his in this sort of size are 3 sail schooners. The Benford dory is a 2 sail rig; I've seen one of these sailing and it was a very pretty sight. If you haven't bought Annie Hill's books, I recommend that you do.

    So I'd consider why you want a single sail on a 34' hull when others with a lot more design and sailing experience use multiple sails.

    PDW
     
  9. pcfithian
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    pcfithian Junior Member

    Many thanks for your experienced input.

    The Benford 34, aka "Badger", is growing on me. The construction looks far easier than the Tolman Jumbo skiff I built and have used for the past few years. I think I'll order the study plans.
     

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  10. SpiritWolf15x
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    SpiritWolf15x Senior Member

    There is a 40 or 50 foot schooner'ish type hull sailing around with a Junk looking style rig around the islands here. Really quite a beautiful boat. I'll try to get pictures of it the next time I see it.
     
  11. BATAAN
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    BATAAN Senior Member

    Nice Tolman!
     
  12. BATAAN
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    BATAAN Senior Member

  13. BATAAN
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    BATAAN Senior Member

    I'm going to throw these 3 fifteen minute videos out there to show some junk rig boats, and to encourage you to think low-tech first and see if that works before you go expensive and difficult.
    In 1999 BERTIE went North from SF to BC to find legendary boatbuilder and artist Allen Farrell on the verdant "Sunshine Coast" and interview him as a film project.
    He was 86, living on his junk rigged CHINA CLOUD, and his wife of 50 years had recently died.
    I was in night class film school at the time and this seemed a good subject for a final project.
    Allen's CHINA CLOUD is well known, but most people don't realize it was built on the beach with hand tools in about 2 1/2 years, or that it was the end of a long line of boats he had built starting with fishing boats in the 30s.
    On a couple of his sailboats he and Sharrie had cruised to the So. Pacific several times.
    The paintings in the videos are all Allen's and of the local area, Lasqueti Island, Bargain Bay and the coast.
    The last chapter has some good footage of BERTIE self steering under junk rig in a following force 6-7 with a fairly gnarly sea running.
    http://www.youtube.com/watch?v=Zw6mdrcDL1o
    http://www.youtube.com/watch?v=tFb3AfxxgO0
    http://www.youtube.com/watch?v=XIBDOUSd-Ag
    Scattered throughout in there, is some footage of various junk rigged modern hulls we encountered in BC.
    Due to Allen, many people have experimented with the rig in that area so I hope this gives you some ideas.
     
  14. Tad
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    Tad Boat Designer

    Bataan,

    Thanks for those films, I've enjoyed them a few times.

    To be a bit picky (as is my nature :p ) I'll take some issue with your statement above. Certainly some use of the Chinese Lug in BC is due to Allan's influence, but it goes back much further and Allan himself was influenced by what came before.

    In 1922 the big (69' by 19') three masted junk Amoy arrived in Victoria after 124 days at sea from Amoy, China. Amoy's design was typical of the fishing and coastal trading junks of the Fujian Province port city now called Xiamen. Looking at pictures it's easy to see the connection with China Cloud. I don't doubt Allan found pictures of Amoy to base China Cloud on.

    In 1939 the Chinese junk Tai Ping sailed into Ocean Falls from Japan after 113 days at sea. She was smaller than Amoy, about 50' on deck, also carrying the 3 masted rig and her design originated in the Shanghai region on the Yangtze.

    40 years ago (around 1972) I sailed on one of the earliest "modern" junk rigged boats in BC, a 40' Wharram cat. About the same time the McAlister family launched a Colvin designed 3 masted junk pinky schooner. This was 10 years before the creation of China Cloud.

    In the 1970'-80's a Vancouver yard, Greenwich Yachts (sp?) built a series of aluminum Colvin designs which greatly influenced local thinking. The work of Hasler and McLeod was not unknown either and contributed to our fleet.

    While one person can have considerable effect on thinking, when confronted with a whole group working on similar concepts it becomes much easier to accept.

    By the way, I've just come into possession of the original hull lines drawing for China Cloud, done on the back of an old Victoria Harbour chart.
     

  15. pdwiley
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    pdwiley Senior Member

    Yeah and you should hear Tom's opinion of both the boats and the company, who altered the design just enough (and had few available assets) to avoid both licensing fees and being sued.

    Unfortunately, according to Tom, they also destroyed some of the sailing ability of the hulls at the same time.

    I have no personal knowledge, but I'd be inclined to take the designer's opinion at face value on this.

    PDW
     
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