Requesting Small Sternwheeler hull design and analysis help

Discussion in 'Boat Design' started by phrogjlf@yahoo, Nov 18, 2014.

  1. phrogjlf@yahoo
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    phrogjlf@yahoo JL Frusha

    Design idea update

    Not much of a budget, I'm on VA disability. I had planned on 1/2" plywood and 2" X 3" members and plan to use Epoxy and either Hemp glassing fabric, or Bamboo glassing fabric. Both of which are weaker, but I really hate fiberglass. Everything will be glued and screwed, using Titebond II, waterproof glue. Not actually planning a houseboat, as such. No plumbing, very little electrical, but all-electric, with some 12 VDC outlets for accessories. I've tried to do extensive research and as much of the design concept as I can.
    Hull idea is to stretch the beam to ~7' 6", to maintain trailerability, stretch the length of the main hull to the original hull and deck outline, with the wheel-arms extending aft, from about where they end, now, but longer, to accommodate a larger wheel, or wheels.
    My idea is to split the wheel into halves, then use electric motors to drive them separately. Don't necessarily need a lot of power, but, as a backup and until the wheel drive is done, use a pair of electric trolling motors, on the transom. Modify them with wood, or sheet metal, to be the functioning rudders, as well. Also possible to use the trolling motors and put on a fake wheel, to have a current-driven trickle-charger/maintainer, and glue-down amorphous solar-electric-panel on a mollicroft.
    For the main hull (transom to bow), I was thinking a profile approximating the Selway 20' Sternwheel 'mould' design, using a simple, shallow 'v' jon-boat plan. For paddlewheel purposes, and to keep the trolling motors up, I think the transom should be angled at about 30 degrees, to allow the water to transition properly. Linked are 3 pics: one of the Selway lines, one of the Selway profile scaled closely to the Showboat top-view, and one of a jon-boat style hull plan with a low deadrise V (Email was taking too long to attach pics).

    http://i268.photobucket.com/albums/jj5/phrogjlf/ShowboatvsSelway-1.png?t=1416767970

    http://i268.photobucket.com/albums/jj5/phrogjlf/Stern20d1.jpg?t=1416768361

    http://i268.photobucket.com/albums/jj5/phrogjlf/modelvl35mw16ver2_Linesplan.jpg?t=1416768527

    For a trailer, I expect to get a 'tandem' axle low-boy style trailer, that uses torsion springs and trailing-arms.
    I'm trying to maintain the very-shallow water capability and keep her as light as I can. I plan to use flotation foam under the foredeck, in the sponsons/wheel arms, and in the bench-like section of the hull framing, along the gunwales, in the cabin. I want to keep her low and flat, but set the cabin over some combing, as if it were a hatch-cover. I would like to keep the deck at a level where swimmers can grab on and hoist themselves out of the water. Side deck sections will be either hinged, or removable, and about 16"-24" wide.
    Main cabin wall height should be about 5'3" above the cabin floor, roof sides curving up to another 9 inches, with a 12" mollicroft down the center, for standing height, and about 8' long, from the transom, forward. Kind of like the layout of a bus aisle, only with a roof instead of overhead storage. Forward of the cabin, at foredeck level, a raised pilot-house of about 4' depth, roughly styled after tugboat wheelhouses, with a view to stern, above the cabin roof, and outward angled glazing. I plan to put a queen size futon/sofa across the cabin, just forward of the transom, that unfolds forward. Should have enough space to carry camping supplies and sleep 2, or 2 and a child. Not intended as a live-aboard, but room to carry gear and go camping. Overall, the cabin and wheelhouse should evoke a cross between a wooden Pullman Coach, from a train, and a wooden tugboat.
    At the back of the wheelhouse, on both sides, at foredeck level, will be doors with raised sills, to clear the combing,, like a tugboat has, for more effective freeboard, to place the wheel and controls as far forward as possible, and to allow passage to and from the deck and cabin, without interfering with the operator, while underway. I figure 5 windows, around a semicircle, with the doors along the sides.
    Once she's built, and afloat, I can use the battery-bank as leveling ballast, then run wiring and finish filling spaces with foam. I figure 4-6 deep-cycle marine AGM batteries will give her a day-trip range, with a DC generator necessary for anything resembling an extended trip.
    We live along the Colorado River, East and downstream of Austin, at Pope Bend. Much of the riverbed is exposed and composed of a silt/clay mix that a flat-bottom would stick to, where a slight V would give me some ability to rock loose, when necessary. I've had a broad canoe stuck in it...
    Mostly, the boat will be anchored and my escape-hatch, from a crowded house, and a fishing pier. She may be used, from time to time, as an overnight spare-room, but I figure a port-a-potty and a jug of water is about all the plumbing she'll ever need, other than a bilge-pump. Side-walls will be paneled so that she can be opened up and mosquito-net placed, for most conditions, or sealed up for times she's untended, or the weather makes it necessary.
     
  2. gonzo
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    gonzo Senior Member

    If you don't have much of a budget, a sternwheeler is a bad choice. Everything will have to be custom designed and fabricated. You can buy a new outboard for less that what you will invest in all that. Things like pull-out futons are fine for a house, but really heavy. On a boat you need to really watch the weight of every item, or the draft will increase too much. Everything you describe is heavy. Before drawing a hull, add all the weight of the stuff you intend to carry, the crew/passengers and the doors, sternwheel, batteries, motors, decking, etc. Divide that total weight, plus at least 50% safety factor by the weight of one cubic feet of water: 62.4 lb. That will be the submerged volume. If you can live with the draft, then it's OK. Otherwise, either you build a larger hull or get rid of stuff.
     
  3. phrogjlf@yahoo
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    phrogjlf@yahoo JL Frusha

    light futon frame

    [​IMG]

    Futon frame will probably use White-wood, screws and a few bolts. It'll be resting on boxed-out, bench sides, mostly filled with flotation foam and battery-boxes, once battery placement for ballasting is done. Flotation foam will also be filling the majority of the bow, under the deck, as well as the wheel-arms/sponsons, aft of the transom.

    I'm putting a larger, more efficient hull under what was a 2-bicycle powered, paddlewheel boat. If she needs more than 7 hp, it'll be strange.

    Adding about 24 sq ft to the hull, but keeping weight as low as possible. Cabin structure will be framed with 1" X 3"s, with epoxy-&-hemp-fabric over foam panels, hull framework of 2" X 3"s, bumping the plywood hull skin to 1/2" ply, with epoxy and hemp-fabric in place of fiberglass.

    Original design called for about 5" of displacement. I hope to keep her close to that mark.
     
  4. gonzo
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    gonzo Senior Member

    Hemp will soak a huge amount of epoxy resin for very little strength. If cost is not an option, I guess it is OK. However, there are more economical solutions. For example, plywood with good veneers.
     
  5. phrogjlf@yahoo
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    phrogjlf@yahoo JL Frusha

    Bamboo is the other alternative to fiberglass. Hemp is just the one that's most common, commercially, for the fiberglass substitution.

    May go with this technique. Use several layers... I like the idea of the low-voc, low toxicity epoxy resin, too...

    https://www.silverfishlongboarding....821-eco-green-epoxy-bamboo-fabric-review.html

    One thing I never see ref to, anymore, is the old-school technique of using a rubber roller to work most of the excess resin out, then using a shop-vac to get even more out, before it sets-up... I guess we all hear about different tips and tricks, as we come across them... Follow those up with vacuum-bagging and I should have it as thin, light, and evenly laminated as I can have, short of fiberglass...
     
  6. gonzo
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    gonzo Senior Member

    Hemp or cotton can be used. However, it will cost you several times what using fiberglass or painted plywood will. Run the cost numbers and see if your limited budget can cover the extra expenses.
     
  7. phrogjlf@yahoo
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    phrogjlf@yahoo JL Frusha

    Avoiding the fiberglass is more expensive than fiberglass, but epoxy and which ever fabric is cheaper than a 2nd, handmade hull. I may be on a tight-to-nearly-nonexistent budget, but spending it twice is worse than doing it well, the first time. Fiberglass would last longer, but it will still be cheaper to re-skin as-needed, than to build another hull. I figure this boat might even outlive me. Then again, I've also already had a number of strokes, so I'm building one of my dreams, my very own boat. In and amongst, I will be gathering the tools and skills to build and fulfill other dreams. I need the escape-hatch of doing it, and I need the escape-hatch, once she's built and in the water.

    Paint, other than the final surface treatment, hasn't been one of my real options, for the hull. It may not last long enough, and I don't have easy access to a ramp. Once she's in the water, she'll be there for quite a while. With all the flotation foam going in, I'm going to make certain the hull is sealed quite well. Epoxy and fabric will handle that chore far better than paint. Not that she won't HAVE paint, just that it's not as permanent a solution, and, it doesn't do much more than hide a multitude of sins.
     
  8. gonzo
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    gonzo Senior Member

    I think you need to check prices of used boats and compare them to a new build. Used boats are quite cheap in the US. If you are pursuing a dream, make sure it doesn't become a nightmare. Boatyards and back lots are full of half-built dream boats. Add up the costs before making claims. We are trying to help you. However, reality often forces people to either adjust or give up their dreams. From your description of the intended use, a pontoon fulfills it.
     
  9. phrogjlf@yahoo
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    phrogjlf@yahoo JL Frusha

    I can't reliably get anything that large, into and out of this area. One reason for enlarging the hull, on this, is the draft. Original draft was about 6 inches.Even accounting for added wood and several batteries, I think I'll be able to match that. Another reason for a decent hull is the fluctuation of the river. I've seen the space I'll have her in without water. Not dry, just plain mud, as far as 20 feet out from the bank. Nice thing about a fairly large, almost flat hull is that it distributes weight, not merely displacing water.

    COULD I put the cabin on something else? Yes. I could probably build a PVC pipe Sampan and put a paddlewheel and this cabin on it. I haven't checked, but I'm fairly certain that would be prohibitively expensive, given the amount of pipe I think it would take (not to mention ugly).

    I looked at building a floating dock, with a cabin on it, but I'd need all sorts of ecological impact studies, engineering for waste disposal and access for emergency personnel. Believe me, I checked.

    WOULD a pontoon DO what I want? Possibly, but it would also be larger, for the same displacement. How much pontoon to replace the equivalent of two 16' plywood jon-boats? How much to build those pontoons, vs building a plywood hull? Build plywood pontoons...?

    I am asking for help with my hull design, and simulation if possible, to be relatively sure she'll behave. I could, like countless others, think how easy it should be, and start on another one of those countless incomplete nightmares you mentioned.

    I've included flotation foam that many, if not most DIYers leave out. I've taken the time to SAY I was increasing the skin to 1/2". rather than the standard DIY 1/4" of days gone by. If you look at the Showboat, you'll see the spec for 3/4" X 2" frame members, which I've also increased. If you look, you'll see that the Showboat cabin walls are not raised above the hull and over combing, but I've included that, to reduce the potential ingress of water. Rather, it relies on flashing, caulk and 1/4-round molding.

    I have gone to great lengths to fill out a rather complete idea of the whole thing. Sure, it was overzealous to think of using the end-pieces of an antique piano would make a cool console, within the wheelhouse. Yes, I can lighten that up, considerably, and will.

    The 2 things I am being ragged on are:
    1) not building (or not building ON) a pontoon boat
    2) personal hatred of fiberglass

    If there's a 3rd, it generally boils down to using the body off of a travel-trailer, rather than building the cabin I want.

    I haven't made extravagant proclamations for luxury, no head, no galley, no air-conditioning, no chandeliers, no monster stereo, no water-slide, not even a refrigerator. Now, maybe we have a completely different idea of what camping is, but, if I recall correctly, I said generally 2 adults and one child, a DC genset, a porta-potty, a bit of gear, and a cooler, for any extended trip. So far, I have 1 piece of furniture. A light-weight, wood-framed futon sofa/bed. Add 2 trolling motors and, what would you say, 4 batteries? 6? 2-banks at 24 VDC, and a spare, since she's all electric?

    Here's a fairly complete camp kitchen (minus cooler and water) that would fit a general description and a chest that could lock into place, as a galley...
    [​IMG]

    Decent cooler...? I have a 70 qt Coleman Xtreme 2 frozen 2-liter bottles of salty water keep it cold for about a week.

    Port-a-potty...

    Do you really think I couldn't fit that stuff into ONE 16' jon-boat and get in and out of here with 2 adults and a child? Why not the equivalent of two...?

    Buying a pontoon boat, or buying almost any boat worth having, is beyond my means. Buying materials and building, spreads that out, which makes it fit within my means.
     
  10. phrogjlf@yahoo
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    phrogjlf@yahoo JL Frusha

    You know, I COULD cheap out and go with something really 'old-school'. Canvas/cotton-duck cloth and oil-based enamel paint. Some of the old Chris Craft still have their original sheathing, from the '50s...The cotton would shrink, as it and the paint dries, lending some level of pre-stress to the hull...

    What would you think of using truck bed liner for the hull interior? Waterproof, damage resistant, fills small crevices, available in a multitude of colors, too...
     
  11. PAR
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    PAR Yacht Designer/Builder

    I don't want to insult you or burst your bubble, but you have a lot of research to do, before even thinking about this project. I've haven't fully read this whole thread, but the quick overview I have, I see repeated misunderstandings, misnomers, etc.

    TiteBond II isn't even close to water proof for example. TiteBond III is close, but not a structural adhesive and will not tolerate being submersed for very long, plus it costs more than epoxy per ounce.

    There's no 50's era Chris Craft with cotton duck deck and lead paint treatments that have survived, unless parked in a hermetically sealed warehouse since 1961.

    The idea of a stern or side wheeler is cute, but if you're interested in cheap and efficient, toss this idea out the window quickly. There's a reason 99.8% of powerboats kissed this contrivance goodbye, once a prop was invented.

    As to self designing this puppy, you're no where close to this level of understanding, even if it is a small boat. Designing an easy to build, efficient, low cost build and inexpensive operation boat, requires some real skills, especially as a home built.

    Your best advised to simply get a set of stock plans and put the lipstick and mascara on it as you like, leaving the structure, hull form and build details intact. You can have a boat that looks like what you want, has some predictable level of efficiency, reasonable operation costs and ownership, while having the styling you desire. You assumptions about the design, propulsion, hull forms, beam/length ratios, etc. aren't taking into consideration your requirements (some obvious and huge conflicts from what I see) and you'll just end up with an overly heavy, pig of a boat, that costs way more than you wanted and performs way less than you'd hoped.

    Stock plans for a boat of this general size and arrangement, count in the many hundreds and don't cost much, some less than a hundred bucks, which is cheap. Avoid free plans or those that seem like a real good deal, as you'll get what you pay for generally. Make a prioritized list of all the various things you absolutely need to have on this boat, in terms of costs, build type, material choices, physical dimensions and performance attributes. Not what you'd like, but what you have to have for the boat to work, the essential minimums so to speak. This means bye bye the stern wheel, in favor of a good used outboard and learn to live with your aversion to 'glass work, as this will be the cheap way to get her done. You could build in a traditional style (plank over frame), but the boat will have many more parts, will be much heavier, which you pay for in the build and underway and it'll leak. Yeah, you'll be 'glass work free, but you quickly see why these methods aren't used any more, compared to taped seam (and other types) builds. With any luck, the list making will force some reality into the project, especially once you start to calculate materials costs and you can move past, some of the preconceived notions you have about certain things, that plainly aren't based in the same reality most others have of these types of projects.
     
  12. johnhazel
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    johnhazel Senior Member

  13. phrogjlf@yahoo
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    phrogjlf@yahoo JL Frusha

    Jon-Boat Hull Design

    It's not about what anyone wants, but me. It gets me to DOING something creative, instead of dreaming at the computer. I'm 52 and unemployable... Let that sink in... UNEMPLOYABLE. If I had a job, I wouldn't have the time to build. If I could GET a job, I wouldn't have time to build. Jobs have legal restrictions on what I'm ALLOWED to do. Doesn't mean I can't do it, just not the way others do. LEGALLY, I'm not ALLOWED to lift over 20 pounds. No standing for long periods, no sitting for long periods, no running, jumping, stretching, bending, twisting, or stooping... LEGALLY. Those are FEDERAL regulations for JUST my back. I've had strokes, too. No job in sight... EVER.

    Why am I doing this? Because I CAN. This is about what I CAN do. NOT about what I CAN'T do.

    If catamaran and pontoon hulls could get to this stretch of water, they'd be here. There are a number of reasons the only boats that even cross this stretch are jon-boats, kayaks, canoes and inflatables.

    If I had several thousand to throw at a used boat, I could. What I have is time, some tools, some carpentry skill, and a trickle of cash, not a bank-roll.

    The Chris Craft canvas and paint method works, and, yes I can find where some has even lasted since the '50s, or I wouldn't have brought it up. As a surface treatment, it's better than just paint, and, as I said, it even creates some strength.

    TiteBond II is water resistant. I never said water-proof. Once everything is screwed-and-glued, then cured, it gets a coating, usually paint.

    Most props extend well below the hull, while a sternwheel drive does not. If you'd bother to look into them, you'll find that their primary shortcomings are size and speed. I'm not even planning on building a particularly large sternwheeler. Sternwheelers navigated shallow waters before props became the norm. Why? How?

    Despite the ragging, I've been rather thorough in detailing, point-by-point, how to do the very things I'm being told I can't do, how and why they should work, even finding other alternatives to the objections. I've described the restructuring, added hull dimension to account for added weight, added descriptions of building methods that work, to overcome the shortcomings of the original design, even shown that, rationally, I could load everything into a smaller boat, with the same type hull, and be expected to be able to navigate shallow waters, reasonably well.

    All I'm asking for is a little help with design and analysis of a large jon-boat hull. A hull that resembles one posted to this forum, years ago. It took me time to narrow it down, but I did. It's not a particularly difficult hull design, either to do, or to build. Post # 13, in this thread...

    http://www.boatdesign.net/forums/wooden-boat-building-restoration/dive-fish-jon-boat-31590.html

    [​IMG]

    The best profile I've found, so far, is for a sternwheeler :)!:), on the Selway site...

    [​IMG]

    The main problem to overcome is the lack of transition to the transom, that is shown in the profile of the Selway.

    Let me reiterate: Max Beam- 7'6", hull length (bow to transom)- 16'6"
    The length to beam ratio is only slightly above the recommended minimum of 2:1, but this is not a high-speed design, it's a shallow-water, muddy-bank design.
    The wheel arms will be structurally integral and extend behind the transom, just as sponsons do, on many commercial jon-boats.
     
    Last edited: Nov 24, 2014
  14. phrogjlf@yahoo
    Joined: May 2006
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    phrogjlf@yahoo JL Frusha


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

    PAR Yacht Designer/Builder

    You're right I haven't a clue about these things, you have fun with it . . .
     
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