Hull design-side paddlewheeler-need help

Discussion in 'Boat Design' started by russ@riverland., Jun 30, 2007.

  1. Guest625101138

    Guest625101138 Previous Member

    Russ
    The tractor might be a better match. You will probably find that big wheels with shallow immersion will do the best job. Not sure how you intend to set up the drive but you might consider some big chain drives from your toyota axle.

    6 knots is only 3m/s. Allowing for 25% slip the wheel will need a perpheral speed of 4m/s. If you make a 3m diameter wheel then it has a circumference of roughly 10m so will only be doing about 24rpm. Probably looking at overall gearing of 100:1 from a small diesel.

    I have read that sidewheelers are able to turn in their own length so if you set them up to work independently then you should not need a steering thruster providing you can get reverse with the wheels.

    Rick W.
     
  2. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    I listed some sites below. They tend toward sternwheelers but they all have links that will take you anywhere or if you google specifically for 'sidewheelers' you will find more. I used to belong to an Aussie paddlewheeler group, but I don't remember the name or where it was located. It was like the ASA (American Sternwheel Assoc.) and most of the boats were located on the Murray river and were sidewheelers.

    The big advantage to a sidewheeler is manueverability. If you can lock one side and put power to the other you can maybe turn fairly sharp, but if you can put one side in forward and the other in reverse you can spin around in place.

    The power requirements for displacement hulls of the size you mention aren't very much, 30-40 HP. Used farm equipment is chock full of various hydraulic pumps, motors, valves, etc. Although hydraulics aren't too effecient, paddlewheels are, so between the two you might end up as effecient as most other contraptions.

    Sam


    http://www.americansternwheel.org/

    http://users.wirefire.com/gemort/enter.htm

    http://www.usawaterways.com/cgi-bin/netforum/sternwheel/a/1

    http://www.hspsi.org/html/links.html
     
  3. SamSam
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    SamSam Senior Member

    Here's another guy that looks like he might be able to get some speed from a paddlewheel. The brown box (kitchen cabinets?) covers the engine and it looks like an automatic transmission (forward + reverse) behind that which runs to a differential, I would imagine, which would allow putting the brakes on one side or the other for turning. A fine use for a smaller old car or truck. Sam
     

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  4. alan white
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    alan white Senior Member

    Yes, brakes would work, though robbing some power, but simple (skid steer). Another way would be a generator/motor on one side only, which, with the addition of a small battery bank and controller, would either speed up or slow down that side. The advantage is that you could steer the boat by the controller, which could also be wired to many places on the boat
     
  5. russ@riverland.
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    russ@riverland. Junior Member

    Gents ,you have clarified so many grey areas, I have been negotiating a tractor diff with individual locking hubs today. Just need to squeeze the local farmer a bit harder. The power of the engine is more than adequate and my neighbour, (electronics Engineer) has volunteered to wire up the solenoids to operate the paddle brakes,gear change and clutch. I have finished the draft hull and station design and start building a scale model tomorrow. (hull only).I'll take a photo and post it when finished. Cheers Russ.
     
  6. alan white
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    alan white Senior Member

    Good to hear it, Russ. I look forward to your pictures and progress.

    Alan
     
  7. volkswagen50
    Joined: Aug 2007
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    volkswagen50 Junior Member

    Any updates on the boat project? I'm very interested in sidewheelers. I've been reading a book called Sidewheel Saga. It was written in the 1950's by a man who was very active in the saving of the Ticonderoga. The history of the book runs from 1790 -1954. In it, there was some data about wheel speeds/ and boat speeds. Some of the larger boats in the 280-320 foot range managed 25 mph with wheel speeds of 22.5-25 rpm. These were also massive wheels in the 40 foot range.
    While I am considering a smaller project of a steel hull, I would be using twin diesel motors to be able to reverse one or both wheels. Great idea you have of using tractor parts, nice and tough.
    The feathering wheels that came out around 1885 also served another purpose, the could take a better hit by debris. That's what was claimed by a few of the crew on some of the boats of the day.

    I recommend the book for the history alone, and the writting is fantastic.
    Update when you can, thnanks. greg
     
  8. Jan Lang
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    Jan Lang New Member

    Russ! Found your post and the following replys while sifting the net for info on a similar project. Great info. Exactly what i was after.

    As a thank you all for that. I have a few pearls to add, maybe, that I have been playing around with; My project is a twin stern wheel design, with a simple small cardiesel and a gearbox and a strong diff, much like yours. My hull is steamboat/wedgeshaped in the stem and has a flat stern with two independant paddlewheels. Simple and straightforward.

    Brakes are used to get the power onto the other wheel thru the differential, same as making a turn with a Caterpillar, not much power is lost that way. And you will get a good steering off the bat I suppose.

    I have designed cooling for the engine along the lines of fishing boats, two pipes on the outside of the hull, one on each side, acting as a cooler as well as swell stabilisers, as I have fitted many steelplates between the hull and the pipe along the side. Makes the whole thing much more stabile and stronger, and it probably even adds a little cooling effect.

    A fan on the engine (but no radiator) keeps the engine housing cool, and a wide "steamboat" funnel lets the hot air, as well as the diesel fumes, out. You will probably also see a small natural "hot air rising" effect in the funnel and as the diesel exhaust is set a few inches short of the funnels top inside the funnel it will help push the heat from the engine and the exhaust and silencer, out that way. Also all sound ideas based in the real world.

    I would consider toothed industrial rubberbelts (same as the rear and primary drive on a modern Harley, -only bigger) instead of chains and sprockets, no lubrication, quiet, lasts forever and they are non-rusting and waterresistant. And you can get them in any ratio. How wide is a Q sofar.

    By way of the gearbox I hope to use 1:st and 2:nd gear and the reverse. I believe that in higher cruising speeds you need fewer revs on the engine but some more revs on the very, very high ratio (even using the ratio of the "rear wheel" on the diff you needs serious high ratio on the belts and sprockets to make the slow turns you need) to the paddlewheels. I might be wrong here but then I just dont use the 2:nd gear, no problem.

    But to get even better steering: Here I added a cool twist.
    Angled pladdle leaves on the paddlewheels! Just a few degrees but that will make both wheels want to "walk off" at an angle to the boat. Each to its own side. Helping steering when you slow one wheel with the brake. (Indepedant brakes for Port and Starbord side naturally).

    I suppose they call the effect a "paddlewheel" effect in a ordinary prop, meaning that a prop is like a gyro and goes one way easier than the other when manouevering because its blades are angeled (how did I find out?) on my own sailing boat!
    Anyway, I believe this angleleaf effect will make steering to port and starbord more efficient and quicker than using straight paddle leafs, and even enhance stability going straight if you angle the paddle leaves so they are converging towards the middle of the boat.

    -Or the other way, the effect will actually be largely the same.

    Also I have a few ideas on the leaf design itself. Just a flat plank is traditional and proven, but you will get quite a lot of "cavitation" (prop-language) i.e. turbulence behind it creating unwanted drag on the leaf.
    Instead one could make a bigger paddleleaf with holes in it, almost the same power but less drag and turbulence as some part of the water pass straight through the leaf. -Actually less water the faster you go....the viscosity of the water adds a little goodness here. How large holes and how many needs to be figured out but the idea is basicly physically sound.

    Also when going faster with sternwheels of the angeled design you will get/make a stern wakewave (or whatshmacallit) that gets higher at higher speeds. So a smaller leaf on just a few of the paddlewheels spokes, but higher up will give you extra contact with the water when going faster.
    In the design above where the two wheels concentrate the wake hump in the middle you get even more effect with a extra higher smallish blade.

    So together these ideas might help us upgrade this technology to the current date. I will definitely try them out on a model to see what happens. I add my design and a rough linesketch for you to inspect. Please feel free to comment and critisize.

    Regards Jan
     

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  9. Guest625101138

    Guest625101138 Previous Member

    I made this little Excel file to estimate boat performance with a paddlewheel. The boat here is intended for human power so power levels are very low.

    It uses the output from Michlet to determine the hull drag and determines the required power at the wheel and efficiency. It is likely to be optimistic because there is no allowance for water lift.

    If anyone has a working paddlewheeler I would be interested in checking its accuracy. Would just need a rough idea of the hull shape such as WL length and beam and total displacement.

    Rick W.
     

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  10. Village_Idiot
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    Village_Idiot Senior Member

    I would submit a better paddle design would be that of a chevron pattern on the wheel, similar to an agricultural tractor tire of chevron lug design. The chevron, or V, would force water to the center of the paddle rather than letting it wash out the sides, thus providing better grip and thrust (perhaps allowing reduction in paddle size. Conversely, the following edge of the chevron would be more hydrodynamically efficient and not leaving such large vacuum pockets behind the paddles while they are under way. Of course, this does nothing for your steering - for that I would taper the beam of the boat at the stern and use rudders outboard of the gunwhales at the stern, sort of like outriggers. They can be made to breakaway (spring-loaded, etc.) to reduce/eliminate damage from hitting obstructions, and have little water interference from the hull itself.

    For a drive system, I still like the idea of each wheel being independently driven by an electric motor. I would consider a direct gear drive with a small gear on the motor shaft driving a large ring gear on the circumference of the wheel - gear teeth can either be on the inside or outside of the ring. This would enable a large ring gear to allow a possible 100:1 reduction, so if the electric motor turns 1750rpm, then the paddlewheel itself would turn on the order of 17.5rpm. Main advantage of electric propulsion is max torque at 0rpm, main disadvantage is constant wheel speed. By raising and lowering the wheels in relation to the water's surface, forward thrust could be modulated. Motors would be reversible, but would also need protection in the event that a wheel might get jammed. Electricity would be provided via onboard diesel generator.

    For the engine room, I would design a funneling system into the roof of the engine room so that ambient heat would naturally be drawn up around the smokestack, thus naturally sucking in fresh cooling air from vents around the lower edge of the engine room. I like the idea of placing cooling pipes in the hull itself, similar to heated floors. The conductive cooling provided by ambient river water and a metal hull should be sufficient for cooling a small diesel without having to utilize too much piping, but that is for a heat exchanger engineer to figure out...
     
  11. Guest625101138

    Guest625101138 Previous Member

    I got some actual data for a paddlewheel canoe and upgraded the Excel model to include water lift with radial blades. It now has a goal seek macro to balance thrust and drag.

    I think if you were going to use fixed blades then the best result would be achieved with blades that are curved radially with a forward facing scoop.

    Unless the blades articulate, energy is loss in pushing water down when the immersed blade is forward of the axis and lifting water as the blade moves behind the axis. With curved blades you do more work in pushing water down but you can reduce the work in lifting water substantially. The net result is uplift on the wheel.

    The uplift would counter some of the boat weight so would reduce hull drag.

    Rick W.
     

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  12. Jan Lang
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    Jan Lang New Member

    Rick! Hmmmm good idea, how about a blade that is not rigid all the way (peripherally) but bends a little at the tip or say halfway down the blade. i e a thinner or tapered blade/leaf or a thick halfblade of wood with a thinner metal lip or edge, that would make a slight curveshape after the immidiate immersing? This would still make lift initially but no aftereffekt at the other end, no puchdown. In the water for the main stroke the leaf would have basicly the same effect. no? Pushing down and up all the way.

    Cool idea!

    Jan
     
  13. Jan Lang
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    Jan Lang New Member

    Obviously you are NOT a village idiot!! Great input! Thanks.

    Maybe we should change the subject to Paddlewheeler Design instead :)

    [/QUOTE]I would submit a better paddle design would be that of a chevron pattern on the wheel, similar to an agricultural tractor tire of chevron lug design. The chevron, or V, would force water to the center of the paddle rather than letting it wash out the sides, thus providing better grip and thrust (perhaps allowing reduction in paddle size. Conversely, the following edge of the chevron would be more hydrodynamically efficient and not leaving such large vacuum pockets behind the paddles while they are under way. Of course, this does nothing for your steering.... [/QUOTE]

    Ahhh but that was the whole purpouse with the idea, The chevron IS actually there, only half of it on each wheel! See my pix. Together they makes for a better steering (I hope) than two straight paddlebladed ones. Two wheels with chevrons would (I think) pretty much revert to the old straight paddles design i practicallity, but be more efficient and definitely look nicer!

    "No rudders" is a thing I'd really like to have as they often are non-efficient on paddlewheelers, and always in the way on a shallow draft boat. I like the "Caterpillar steering" with braking on one side, simple and straightforward, but wheels on the sides of the boat will be unpractical in my application.

    This design is specially intended for the Mekong (and rivers Asia) so a totally flat bottom is neccesary to be able to beach it along the way if needed. And there are lots of snags and stuff in the water to foul a rudder, let alone the 6-8 they had in the "day" this seems to me like a late-added-on no brainer -but probably the only available solution at the time. Bow props are a much better solution, even if only addad as abackup or added turning help. You could just "saw" off the lower portion of a scrapped (but still turning prop) outboard, fit it in a tunnel in the hull, weld it solid with a supportstrut downward, and add an electric engine to the shaft, -simple.

    [/QUOTE]For a drive system, I still like the idea of each wheel being independently driven by an electric motor. [/QUOTE]


    Ahhhh I was there too, definitely independant motion on the paddlewheels. But not necceserily reversing at one side while powering at the other. I believe (and hope) that braking on one side will allow the power to go to the other wheel thru the diff (as when turning a car, the outer wheel in the curve travels a longer distance) and the slowing (braked) wheel with its angeled blades will make less turbulence on one side. i e Steering the boat well even if not reversing, just reducing.

    But electric engines??? hmmm Electricity and water mix badly in my oppinion (and experience) and there will be a lot of paddling, wet splashing and watermist close to the paddlewheels. High maintainence I suspect...

    [/QUOTE]I would consider a direct gear drive with a small gear on the motor shaft driving a large ring gear on the circumference of the wheel - gear teeth can either be on the inside or outside of the ring. This would enable a large ring gear to allow a possible 100:1 reduction, so if the electric motor turns 1750rpm, then the paddlewheel itself would turn on the order of 17.5rpm. Main advantage of electric propulsion is max torque at 0rpm, main disadvantage is constant wheel speed. By raising and lowering the wheels in relation to the water's surface, forward thrust could be modulated. Motors would be reversible, but would also need protection in the event that a wheel might get jammed. Electricity would be provided via onboard diesel generator.[/QUOTE]


    OK so no greener drive solution... I think it's easier to use readily available cheap junk from the nearby junkyard. Lots of rear axles, gearboxes and dieselengines there....in Asia it's easy to get 8 year old Japanese technology as they scrap all cars and trucks before or at that date. (Or go through a horror of an expensive to-new-specs refit and fitness exam)

    All the good bits ends up in containers and go to China, and all the poorer Asian countries. Cheap as hell too. 100-150 US bucks for a good 7-8 year old truck engine.

    A simple sollution to gearing is to pair two gearboxes. locked to 1:st on the one and then use 1:st or reverse on the other, that would take care of the revs, possibly more gearing can be added as needed on the "bicycle" design of the drive to the two paddlewheels with toothbelts. To get the desired range of revs on the aft wheels. 1 full turn every 4 seconds or so, cruising?

    [/QUOTE]For the engine room, I would design a funneling system into the roof of the engine room so that ambient heat would naturally be drawn up around the smokestack, thus naturally sucking in fresh cooling air from vents around the lower edge of the engine room. I like the idea of placing cooling pipes in the hull itself, similar to heated floors. The conductive cooling provided by ambient river water and a metal hull should be sufficient for cooling a small diesel without having to utilize too much piping, but that is for a heat exchanger engineer to figure out...[/QUOTE]

    Yup! All sound ideas! I thought of sucking the air from under the decks to keep it dry down there, no moisture.

    Keep them good ideas coming!

    Regards Jan
     
  14. Guest625101138

    Guest625101138 Previous Member

    Jan
    You posted earlier that you intended to make a model. Do you have a boat size in mind?

    I could make performance predictions of the model and the full scale boat if you want.

    I have very reliable models for propeller driven displacement craft and I would like to do something similar for paddle wheels as I often get asked how wheels will perform in certain applications.

    Most peolpe underestimate the size of the wheel required and end up with poor efficiency. There is design data around but the problem does not seem particularly complex.

    Rick W.
     

  15. Jan Lang
    Joined: Oct 2007
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    Jan Lang New Member

    Rick!

    OK nice, thanks, can't pay you thou, exept in help and gartitude...

    Boat size, well it's all pretty much to scale on the pix, estemating width and height after my own length 1,9 meters (6'2")

    I guesstimate the final fullsize boat will be aprox 9 meters long /30 feet by 2,5 meters /8 feet wide and the paddle wheels all behind that (added to the hull length with say 1,5-2 meters /5-6 feet) I hope for a draft of only about a foot or so and a completely flat bottom over 2/3 of the hull with a "steamer sloop" frontend with a straight-up stem, tapered in both directions to the flat part and rather narrow.

    It would be highly interesting to see what size paddlewheels would be needed for that size boat and what turns per second will get what speeds.

    A model is likely to be in the easy to calculate 1:10 scale. So 0,9 meters/ shy of 3 feet long.

    Needed speed would be about a maximum of 10 knots /18,5 km/hour to beat the current upsteram but more is always good.

    All help and ideas/input will be greatly appreciated.

    Regards Jan
     
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