Ljungström Sail

Discussion in 'Multihulls' started by Newickspark, Jun 16, 2019.

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  1. Newickspark

    Newickspark Previous Member

    I’m buying plans for a Newick Spark

    It has a Ljungström sail that opens like butterfly wings.

    I’m seeking suggestions on how to get the same twin sail use, as planned, with better performance and ease of use while cruising.

    Newick mentioned yrs ago how he likes the
    Whisker poles for this rig. The original builder went from the boomless rig to a boom.

    I’m thinking something in between.

    One very amateur idea I have is:

    Could you use a stiffer batten on the bottom edge of both sails?

    These battens one inside each sail, would connect
    And become a boom, so to speak.

    When your going down wind, the two battens
    release from each other, and become whisker poles.

    I have the idea for the way they Attach, and release. I also have a idea about how the other battens connect the two sails together.

    Also, with this type of rig, is a jib beneficial in any way? This boat has none

    Top photo is not the spark, just shows how the sails open.
    Bottom Photo is the Spark

    Thanks
     

    Attached Files:

  2. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    Old school mate, like a mono running square with a symmetrical spinnaker. Wind speed is your max speed.
    Look for a boat with an asymmetrical.
    Given your other thread I have to ask
    How much trimaran sailing have you done ?
     
  3. bjn
    Joined: Jul 2014
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    Location: Stockholm

    bjn Senior Member

    I have seen a Ljungström boat sail here in Sweden. The boat was beautifully Restored to perfect conditions. A real classic, but the sail tech is oldschool, although has some interesting benefits.

    If you use a boom or horizontal battens, you loose the ability to reef by rolling the sail around the mast.

    I think this rig isn't very suitable to a trimaran if you want performance. Maybe it could be easy to use if you cruise and do a lot of sailing dead downwind.
     
  4. Newickspark

    Newickspark Previous Member


    One idea I have. And I’m not the right one to be having sail and rigging ideas!!

    Maybe use a pair of whisker poles, as a kinda’ boom. When it’s not needed, swing out of the way.

    I’m not focused on racing, I just want to make the rig the best it can be, as designed. Always room for improvement.

    I’ll get the right people to look into it. Just need to find them!

    Thanks
     
  5. Corley
    Joined: Oct 2009
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    Location: Melbourne, Australia

    Corley epoxy coated

  6. bjn
    Joined: Jul 2014
    Posts: 135
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    Location: Stockholm

    bjn Senior Member

    I don't think it would be impossible to get the sheeting point of the reefed sail right, like the owner says. The sheeting must be similar to the sheeting of a foresail. I've seen sheeting arrangements with one or two normally loose/unused pulleys, to get the sheeting point right in different conditions, by pulling the sheet down or in/towards centre for example.
     
  7. Newickspark

    Newickspark Previous Member


    We can shoot a rover through space, land it on mars.

    I agree, I will find Someone to fix / improve the reefing and use of this rig.

    I don’t wont to scrap the whole plan, over 1 issue.

    Allot of people look at the rig and see the negative.

    It won’t point as well
    It’s not the shiny new tri tech
    Ect.....

    I see with a little TLC and refreshing to the design...

    Boom less

    FreeStanding

    Less Complicated rig

    Very easy down wind sailing

    Self steer system with the mizzen!

    Use of a mizzen stay sail for added umph,
    I haven’t read one person that hasent raves about having a mizzen staysail, people who fly them love them...

    Now, if the boat was a total slug, then none of the above would matter...
    On its maiden voyage, with Johnstone
    (Jboats/Gunboats) onboard the boat was reported as :
    Sailed 100% wind speed 2-12 knots
    Max speed that day was 18 knots

    Johnstone “on a reach the boat was
    Just Magical”

    I think that once I look at the sail plan closer, and have an expert slightly improve its function, build the boat even lighter then the first, I’ll be very happy with it.

    Thanks for begin positive, I feel the rig as designed
    Is very close to begin exceptional....

    And last but not least, the sailplan in use is just
    Beautiful.

    Should I paint the insides of the sails like a
    Monarch butterfly???

    So when I split the sails open, I look like
    I’m sailing off the set of Avatar?
     
  8. Rumars
    Joined: Mar 2013
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    Location: Germany

    Rumars Senior Member

    Just a few toughts about improving the rig.
    1. Big roach square head to be supported by vertical battens.
    2. Double boom with (rigid) vang or separate deck atachement.
    3. Curved traveller without booms.

    Now the downsides to the above:
    1. Watch the sailmakers face while you drop the hints about your new mainsail: unstayed mast, continuous around mast furling, vertical battens, double sided sail. Yes it can be done just not cheap or by anyone.
    2. You have just gone from two line sailing (2sheets&furl) to outhaul, downhaul, vang, traveller lines, etc. depending on how exactly you rig the booms. Remember everything is doubled as there are two booms. Same cockpit spaghetti as with conventional slab reefing if not more.
    3. Sacrifice of cockpit space, esthetics and weight in order to avoid the booms and their lines.

    IMHO the Ljungström is best like it was designed, no booms, no battens, central sheeting. One gains simplicity and comfort and looses top end performance. That's the deal, take it or leave it, there is no improvement or underway tuning. You make your choices of mast bending and sail chamber for the expected prevalent winds and live with it in all other conditions.
     
  9. magwas
    Joined: Oct 2009
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    Location: Hungary

    magwas Senior Member

    Given the freestanding mast, you might consider a soft wing sail. It is beautiful in a different way than the Ljungstöm, but you can have more sail area upwind, less force sideways, and also easy to handle. You might need additional deck hardware for all those ropes though.
     
  10. Newickspark

    Newickspark Previous Member


    Ahh! Mr Wharram
    Love his designs for the last 15 years, and yes I’ve thought about that option to.

    Matter of fact, I’ve thought about a softsail
    Wing that can split open like the luj.

    And I bet with a little work from a respected sail designer, the shape could be made more performance focused then his standard gaff type shape (top gaff)

    How about a Wharram softsail with a modified square top with a top carbon batten, that would work like the gaff top made of wood?

    I think you achieve the benefits of the softsail (around the mast sail, smoother air flow)
    A better shape with battens
    And the Benefits of a boomless system.
    Plus the ability to open her up and sail downwind.
    You are adding a jib, and like you said more clutter on deck. But would the added performance be worth
    It?

    Would love to hear some opinions on that.
     

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    Last edited: Jun 18, 2019
  11. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    How about a snuffer that sits at the top of the mast, possibly with built in rings to give it more shape, or just rings that can concertina down the mast , the first one would need to be padded perhaps to stop chafe on the sail. (or I have missed some thing), It keeps the system simple and deals with the reefing issue. A little mizzen does tick a lot of boxes.
     
    Last edited: Jun 18, 2019
  12. Newickspark

    Newickspark Previous Member

    I like the little rings, made of carbon fiber.
    Padded as you said for protection
    Of the Cloth.

    Then a strong seam where the two sail cloths meet, the split location, Closest to the mast.

    That’s the part that bothers me, can that seam be strong enough to withstand the force of trying to be ripped apart when in butterfly mode. As I call it !
     
  13. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    Re deploying the cocoon then..ha .. the first few rings may have some stretch/give..
     
  14. Corley
    Joined: Oct 2009
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    Location: Melbourne, Australia

    Corley epoxy coated

    I don't think I was being negative pointing out the original builder's concerns. In my view the more trimarans in the world the better, good luck with your project.
     

  15. Newickspark

    Newickspark Previous Member

    Neve thought it was negative, I’m trying to improve on the sail design.
     
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