french style sailing barge

Discussion in 'Boat Design' started by msaxton, Feb 1, 2014.

  1. Petros
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    Petros Senior Member

    That article is an interesting historic read, but I think little useful information can be drawn from the extensive research the author did. The configuration of the sail is only half of the equation, the hull is the other half. without a decent keel or dagger board/center board, no matter the sail efficiency there will not be much headway made.

    So the article only considers sail configuration, and near as I can tell, the hull shapes were almost the same. None of the hulls had any way to prevent the hull from sliding sideways, therefore one sail over the other will make little difference, both are only good for going down wind without an efficient deep keel.
     
  2. msaxton
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    msaxton Junior Member

    What I garnered from the article as it pertains to what im going to build is:
    since i will have a flat bottom shallow draft boat, i may need to make my keel a little more substantial then I drew up tonight, easy enough, will just lose a little shallow draft. I will also have some leeboards that will drop straight down on each side on a winch lower and raise system, they will be 5'6" total height with 3'6" down in the water when lowered (they are designed to handle the rearward forces), would that be deep enough for leeboards on a flat bottom sailer
     
  3. msaxton
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    msaxton Junior Member

    I also garnered a lot to think about as far as the type of sail, but am going to leave the jury out on that decision for awhile. all of the info you guys share is really helpful, thanks.
    on a side note, got alot of drawing and scheming done today :)
     
  4. Petros
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    Petros Senior Member

    that lee board should be deep enough. the rule of thumb is it should be about 5 percent of your sail area. since it will not be a fast boat, go for a simple rig that is easy to handle, you will use it more and enjoy it better if it is easy to use.
     
  5. SaugatuckWB
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    SaugatuckWB Junior Member

    The point that the article makes that pertains to this discussion is that even with an inefficient hull design, a simple, single square sail (like those pictured on the French barges) offers some windward capability. The addition of leeboards or a centerboard would improve on this, making it a practical consideration for the planned boat and would be in keeping with the vernacular design of these boats (whereas a modern junk rig, as previously suggested, would not).

    I'd like to see your drawings when you are ready to share them. This is a really interesting project that should result in a boat with a lot of character on a simple, easy and cheap to build platform while preserving a traditional type of craft.
     
  6. msaxton
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    msaxton Junior Member

    Saugatuck:
    Yeah, i got all of that from the article too, just didnt word it so well.
    as far as the drawings, i just started on them last night and will post a pic of them at some point. They are on 13" by 36" paper and i dont have the ability to scan that, but a pic should work ok. it's coming along pretty well considering i said im not a designer, but flat and square isnt too tough. will probably put up a pic of the first draft this weekend for critique.
     
  7. frank smith
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    frank smith Senior Member

    From just the practice point of view the square sail eliminates the the problem that the house imposes. Sheeting would be would be simple.
     
  8. rwatson
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    rwatson Senior Member


    Exactly what I said.

    To be brutal, without a proper keel - beating to windward is nearly impossible.

    If you can get some lift out of a sail plan ( maybe sometimes with a square rig) , that can ghost you to windward without a keel effect, but for all intents and purposes, you cannot beat effectively.


    While there is a good case for budget sails and a reliable engine, for true piece of mind, being able to efficiently beat your way out of a lee shore when the motor will not run is hard to beat.


    Its a frustrating experience to run out of fuel and realise that you will need to beach the boat, run up to the nearest fuel station with a fuel can, before you can get back up the narrow channel to the launching ramp.

    God bless the man who offered me a tow.
     
  9. SaugatuckWB
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    SaugatuckWB Junior Member

    In relation to the comments about square sails: It seems to me that many people on these forums just want to argue about things, or sell someone their plans or their buddy's, when what most people are looking for is ideas, information, and advice. But I guess I'm going to argue a little about this too because its too damn cold up here to do anything useful right now.

    The thread is about a sailing barge to be used on the ICW and rivers. Nelson and beating your way off a lee shore when the engine quits really have nothing to do with that. Yeah, beach it and go get gas (or anchor and wait); its a barge and designed for that.

    So, the article I referenced starts out by saying that there is an assumption that square rigged vessels can't sail to windward and that is why the rig was largely replaced by others. The purpose of his research was to see if this was actually the case. He chose vessels rigged with a single square sail as the basis for his research. This is why I referred to this article. That is what the original post was about. Comparisons to fully rigged ships on the open ocean serve no purpose in this thread.

    His findings were that ancient/replica square rigged vessels of various hull designs were indeed capable of sailing to windward, giving a figure of 60 to 65 degrees. Some were better than others depending on hull shape and keel size. He also noted that in calm waters square rigged vessels performed better to windward. Not better than some other type of vessel, but better amongst themselves.

    I can't vouch for the quality of his research or sources. But it was published in a prestigious, peer-reviewed international journal. I would say that it is therefore more authoritative than statements based on "its common knowledge" or some such thing.

    In addition, the French barges pictured have this rig and they wouldn't if it was useless or problematic. And as someone else noted, it reduces interference problems with the house and could be quite simply rigged.

    So, my conclusion is that a single square sail on a river barge is a viable option, among many.
     
  10. rwatson
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    rwatson Senior Member

    Is 'arguing' by presenting alternative information not ideas and information ?


    The problem with poor performing sails is even more moot on embayed waters. Those who have actually tried to sail in restricted waters are well aware of the desirability of well performing sails. I remember sitting in the bow while sailing on a narrow channel to advise the helmsman of the impending channel bank and other obstacles. if the sails and hull shape in the light airs had not been efficient, then motor power would have been the only option.
    Often, unexpected traffic on often busy internal waters makes the motor option a time problem, if not a reliability one.

    The 'assumption', as the info I have provided clearly shows, is correct in general - if you apply it to 'typical' square rigged boats. As Petros agreed with me, the hull shape is more a factor in windward performance than sail design - and this is the real key.

    Of course they do ! Trying to assess sail/hull performance on sheltered waters is more difficult due to the vagaries of inland conditions.


    Just stating the obvious. Windward performance has had nearly a 100 years of scientific research applied to it. The problem is that the exception does not disprove the overall truth, that square riggers in general didnt do windward very well.


    I cant make out the meaning of this. If its trying to say that traditional hullforms would beat better with a square rig than say lateen or gaff - I would stick my neck out and disagree, based on sound scientific principles.

    how about 100's of journals on the performance of hull/sail combinations and the detailed physics involved ?

    The reason for the 'traditional' rig on the French barges is driven by the fact that sails in enclosed waters on commercial craft are largely redundant, and in the rare exception that the wind direction and strength co-incides with the direction they are motoring, you wouldnt want to spend a lot of money on putting cloth in the air.


    Sure it is - and you may want to consider that putting sails on a sheltered water barge is less useful than spending the money on a good fuel conditioning system and larger motor.

    Like the French barges - the sails are just an aesthetic throwback to a difficult historical reality, and for all intents and purposes are just an artistic folly.
     
  11. msaxton
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    msaxton Junior Member

    my drawings thus far

    I have attached pics of my drawing thus far, i also have done a down view of the hull with cabin layout but will save that for further refinement.
    was hard to get it real good in one pic, so there are several.
    -On the profile you can see where I originally drew the keel, then decided to make it deeper and longer. I extended it up the bow slant for additional bow strengthening and also thought that it would helpas far as cutting the waves and sideward stability???
    -the sides have about a 6 degree flare
    -in trying to maximize material the sides are 2 feet tall, would that be high enough freeboard?
    -the drop down leeboards are 5'6" tall with 3'6" in the water when down, with a winch lift system. deep enough? (just have them basically drawn not detailed, will have a detailed drawing of the leeboard system later.
    - the craft will be 31'6" long and 8'6" wide at the top of flared sides, 8' wide at the bottom of hull. was going to originally go longer and wider, but in the interest of building space and legal trailering, decided to make it smaller.
    -as you can see with a 20' cabin, it ends up being more cabin then open decking. but the roof will be built solid enough for additional useable deck space
    -obviously you cant see it in this view, but the bow will be 7'6" wide, flared in from 8'6" at the front of the cabin.
    - One thing i am concerned with is if the mast would be too far forward being at the front of the cabin and right where the bow starts going upward, would that have an effect on handling??
    Well, this is just the first rough draft, so fire away, any critique is welcome!
     

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    Last edited: Feb 5, 2014
  12. SaugatuckWB
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    SaugatuckWB Junior Member

    RWatson,
    I glad you agree with my conclusion that a square sail is a viable option. I'll ignore the rest as the photos posted are more interesting.

    Chris
     
  13. msaxton
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    msaxton Junior Member

    One thing i forgot to ask is:
    is it better to have the bottom of the rudder even with the keel as drawn, or would it be more beneficial for the rudder to be deeper and/or a swing up rudder for the draft issue?
     
  14. frank smith
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    frank smith Senior Member

    The amount of flair you have will add basically nothing but complexity to the build. Just go square section and put the work into making the the bottom rounded. It looks to be more of a motor barge than a sail barge. The sail look to be to far forward for the rig chosen, and the location of the boards.
    I would want the rudder a hair less draft than the keel, and forgo the complexity of a kick up rudder. do you any idea of the the final draft at the keel.
     

  15. msaxton
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    msaxton Junior Member

    So, in these pics I did away with the flair on the sides, ( which will also make the leeboards fit within the trailering width) But, instead of rounding the bottom, i just gave it a slight vee (does it make much difference between round or vee?)

    what is the reasoning behind making the rudder a hair less draft then the keel? protection?
     

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