Requesting Small Sternwheeler hull design and analysis help

Cool! I love old designs. They offer simplicity that modern crap doesn't. Granted, there are many improvements, but the complex regulating systems are a PITA.

If I thought I could make it work right, and was efficient enough, I would be tempted to used a solenoid drive. Maybe an electric radial, similar to the Brotherhood steam engine. Right now, I'm trying to emulate the look and feel of steam engines, to drive separate paddle wheels, like the "Major" sternwheeler had. With twin wheels, I can still turn circles within the overall length, if necessary.

 

You may want to consider that you could possibly spend more money emulating the look and feel of a low HP steam engine than you would actually using a low HP steam engine.

Two examples. Rappahannock sells some pretty units ready to run. Those by Tiny Tech, ready to run as a rule rather than option, are more utilitarian in appearance but are less expensive.

These engines will top out at around the rpm at which modern IC engines idle at, and far slower than electric. That means less of a hassle for reduction gearing to reach wheel speeds not plagued by cavitation.

 

Unfortunately, weight and room for a boiler, as well as the need for fuel for the boiler, makes that less practical. Costs of the castings is also a factor, much less access to a machine-shop. If I thought I could scale up the solenoid piston drive from this article, I'd still be electric, but I also have no idea on the efficiency...

https://books.google.com/books?id=X...onepage&q=birdbath and backyard train&f=false

 

That why I mentioned ready to run. Engines that aren't just castings you have to finish. As for the size and weight, Fredrosse hereabouts can probably help.

Here's a thread about his paddle steamer.

http://www.boatdesign.net/forums/propulsion/steam-paddlewheel-boat-6304.html

 

There are any number of possibilities. Even something like a drive crank on the shaft, pulling and pushing a swing-arm, to drive a Pitman, to another crank on the wheel. I'm looking at the possibilities, just that the wiggle-drive has one input and 2 opposed output shafts.

 

Thanks! Had seen her, elsewhere. Didn't realize that was on here, too. Nice sidewheeler he built! For my next trick... Actually hope to do a logginf alligator sternwheeler, sometime, later on.

If you look at those yard-train plans, you can see how simple disguising a linkage conversion can be. At 3 HP, per wheel, she'll be over-powered, following his thread, but linkages for that can be far lighter than a set of engines...

 

If you look at some of the 2-cylinder steam engines, such as the Emerson-Walker steam capstan and the Worthington-Simpson feedwater pump, you can see how easy it will be to mock up something worthy, to hide whatever drive mechanism.

 

Can Do

Have been away from the forum for several weeks (surgery), and now have a lifting limit of only 8 pounds for several more weeks. I have almost never seen such a large amount of discussion about how impossible and impractical it is to build what Jeff F. wants, although in my mind it is not such a daunting task as many of the "nay sayers" indicate.

Building a small plywood hull sternwheeler is no big challenge, has been done many times.

As to paddlewheel propulsion, it works OK, although not as efficient as modern propellers. What Jeff F. wants would be a boat of about 1 ton displacement, 16-20 ft long x 7-8 ft beam, with independent electric driven stern paddlewheels, running at about 5 MPH. The attached photo shows the 19ft-3inch sidewheeler Margaret S., underway at about 4 MPH, displacement just over one long ton, and total shaft power a little less than 0.6 horsepower. In my view this is entirely satisfactory performance for the boat’s intended purpose. The Margaret S. hull is much stronger than what Jeff might want, and the build process is documented on Thesteamboatingforum.net under “plywood sidewheeler building”.

While the Margaret S. is a steamer, I have also built an all-electric inboard boat at very low cost. Yes, amateur designers (as well as professionals) can work up a propulsion system with costs far beyond what might otherwise be found, but that problem is solvable by getting the proper engineering background to design the machine properly.

For Jeff’s application, simple belt and chain drive from a 1 horsepower electric motor for each stern wheel will work just fine. The main drive shaft can also be fitted with a lawn-mower type gasoline engine, which can drive the setup without electric use. The same setup will allow the gasoline engine to charge the batteries, with or without the paddlewheels operating. The proper drive motors will also be acting as generators to charge the batteries when the gasoline engine is running.

As far as costs go, again one can hire a high-end yacht designer and pay thousands just for preliminary design sketches, and hire Eaton Transmissions to design the power transmission system that costs $20,000 just for the design effort. But just because these choices exist, they are not the best choices.

I put together the 3/ 4 horsepower electric propulsion system for a 14 foot skiff at a cost of a few hundred dollars, including the deep cycle batteries, switchgear, electric motor, belt/chain reduction system (1750 RPM Motor, 400 RPM prop shaft), drive shaft and 14 inch bronze propeller. Yes, this required a lot of DIY work, but nothing more complicated than what any lawnmower repair mechanic would be capable of, and no tooling beyond what many homeowner’s basement shop has. In a pinch, an electric drill and hacksaw can do the whole job. A full description of this build can be found on the Yahoo ElectricBoats Group. This electric inboard ran without problems for 5 years, and I am now converting it to a fast steamer.

 

I found out a simplified electric motor, to horizontal push-pull, for each side of the wheel... MUCH easier than I dared hope!

Do the reduction with roto-tiller drive unit, turning a crank on both sides, to get a shaft on each side of each wheel. reduction and cranks under the rear deck, hidden under a fake steam engine. Sliding cranks operate Pitman Arms to the wheels... Here's the basic mechanism...

 

Thanks for the vote of confidence! Hope you are healing well. I've had this idea on hold, after several strokes, so she's going to be a project, therapy, and an escape-hatch from an overcrowded house.

I've got her figured at about 30 ft. LOA (24 ft hull, plus wheel arms and wheels), with dual sternwheels, like the Wild Goose, but with Pitman and crank on both sides of each wheel. Anything shorter starts looking stunted and cuts out on space for something, or other. I expect to use pancake motors from scooters, a heavy-duty roto-tiller reduction drive, and a simple sliding crank mechanism with that setup. I also plan to run a temporary, freewheeling wheel, and a lower unit converted to electric, mounted through the hull. Gives me power, while I gather the rest, also gives me a backup system, should there be a problem.

 

Here's another option to consider if what you want is the look: conceal a drive shaft, or whatever, and drive fake running gear as if for a horizontal steam engine from the wheel. The fake gear should be built of light weight materials and have good low friction bearings to minimize parasitic losses.

Your fake steam engine might help conceal your real motor ... most people today have no clue how big or small one should be. You could use a "vertical boiler" as a cleverly disguised cooler for your sandwiches and suds.

 

This is very close to what the actual drive will be. Driving the lower crank will pull the rods downward, which pulls the aft Pitman forward, turning the crank on the wheel. The forward end is a fixed station, as is the bed with the yokes that guide the rods. I may cap it with a sliding cover/fake beam, attached to the aft portion, to help protect and hide the working mechanism. The fake steam engine will be for looks and an access cover. It may have some additional function, if I can get that figured in.

May have room for a half-shell fake boiler, with the top over the roof line, and a fake stack. I'll try to figure that out, once everything else is done.

 

BTW, phrogjlf, here's an outline of what I'm leaning towards in a paddlewheel boat.

http://www.boatdesign.net/gallery/showphoto.php/photo/24218/ppuser/54771

 

Looks good! Funny thing...? I saw a mouse-trap sternweeler design that was similar in outline. I like the way he did his wheel arms... Just a grab-cad design, but...

http://grabcad.com/library/mousetrap-paddle-boat

 

For catching Mississippi River rodents.