Flatiron

Discussion in 'Boat Design' started by coopscraft, Mar 29, 2018.

  1. coopscraft
    Joined: Dec 2013
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    Location: oregon

    coopscraft Junior Member

    i am curious about rowing flatirons of a size for 1-3 passengers on a mountain reservoir about 10 miles long. Intended use would be Kokanee, bass, or trout fishing under oars or electric troll. What are some easy design mistakes to make with this form. Please understand, I have zero desire to plane.
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    There's many difficulties you can run into if you self design, though there's so many low costs designs available for these types of boats, that just buying a set of plans is the intelligent way to go. Send $50 to someone and get plans. The math is done, so it'll float upright on launch day, it'll track straight and carry what you'd like, no guessing. You can also consider a kit, too, which for some is a good way to go, especially if materials are hard to find in your area.
     
  3. coopscraft
    Joined: Dec 2013
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    Location: oregon

    coopscraft Junior Member

    Stability I can figure. Capacity for rowing craft in sheltered water is very straight forward. It’s just .5(the weight of the water needed to cause swamping) according to the coast gaurd. Even if I buy a plan or kit I wouldn’t know if it’s the right one unless I have some idea of what makes a good flatiron and what is a mistake for my use. Suitable wood grows like a weed in my neighborhood and I am a better than average amateur craftsman. I’ve built two boats before. One I designed and it works great. I can do the math.
     
  4. messabout
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    Location: Lakeland Fl USA

    messabout Senior Member

    The Coast guard rule only tells you what the presumed safe total weight capacity might be. That does little to describe the design of the boat that fits your particular needs.

    If you can get your hands on John Gardners wonderful book titled: Building Classic Small Craft, you are in business. Page 337 has plans for a 15 foot Flattie that is built the old fashioned way with solid planks. All the needed building details are there. Gardner says that even though this is an ancient boat type, his plans will satisfy the CG rule. You have said that Oregon has plenty of wood so it is presumed that you will build from solid wood not plywood.

    I have spent many a pleasant hour in such a boat. Here in Florida, way back in time, we had lots of Flatties. The most popular ones were called Port Ritchie Skiffs. They were made of cypress, with cross planked bottoms. Left in the water they would soak up and become very heavy but that did not seem to affect rowing performance.. Actually a heavier boat is better in some respects than lighter ones. The heavy one will carry its way between strokes better than a light one and also punch through a chop a little better. They are just a little harder to get moving.

    A sweet little flattie graces my yard even as I type this. It is a 16 footer that is deliberately built light. 130 pounds of pretty Ocumee ply. It rows well enough but its primary design is for sailing. If I were to design a purpose built boat for rowing, it could be a simple design but not a flattie. Flat bottomed boats have excessive wetted surface which is not the best for rowing any distance or for use with the trolling motor. Check out some of the Bolger designs that have a narrow flat bottom with wide and high beveled chines. One of his designs that come to mind is called Gypsy. It is nominal 16 feet, can carry sail if desired. That one does a good job of minimizing wetted surface.
     
  5. coopscraft
    Joined: Dec 2013
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    Location: oregon

    coopscraft Junior Member

    Thanks messabout, so when comparing plans, minimizing wetted surface is a plus for saving energy. Being on the heavier side is not necessarily a minus if I might encounter some afternoon mountain breeze. I presume level float when swamped too.
     
  6. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Designing a good pulling boat isn't an easy task, assuming you'd like a nice, comfortable, easy to pull, good tracking, appropriate capacity, with the ability to punch through a chop occasionally and not have any finicky quirks about her. Designing a boat that can be rowed, though with more effort than you'd like, that dances around in a contrary wind or chop, can't track well, etc., etc., etc., is a surprisingly easy thing to do.

    It's clear you have some experience, but you don't at least in my observation seem to have a grasp on many of the subtleties, necessary to design a "good" pulling boat, though you may be capable of designing a bit of a dud. It takes many years of design experience, working though what works and what doesn't so much, to truly refine something seemingly as simple as a pulling boat.

    Why is it that you can skip over the years of learning curve, the professionals have had to bear for generations, just to pen up a 14' skiff like structure, hopefully somewhat doing what you'd hoped? It can't be the money, as plans are cheap. You'll spend more on band-aids and paint. Find John Gardner's books and pick one of the several well evolved designs, if anything just for inspiration.
     
  7. coopscraft
    Joined: Dec 2013
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    Location: oregon

    coopscraft Junior Member

    I don’t like to buy things I don’t understand. There are lots of examples of crude boats optimized for production in grp or aluminum that neither row nor motor especially well. Typically the design criteria seems to be whether a chubby American can fidget and not feel like he has left terra firma. But gardeners boats are different. I built one. Specifically the Lowell dory skiff in the last chapter of the dory book. It rows really nice as long as lightly loaded. Designs are cheap. Gardner’s are free at some libraries and his designs are good. That doesn’t stop me from being curious what makes a good rowing flattie as opposed to a dud. I suppose it could be even a matter of the market—landlubber or merman.
     

  8. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A typical flatiron hull isn't a very good pulling boat, though if lightly loaded and seating will permit it's stern from being immersed underway, not too bad.
     
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