Sternwheeler Design and Propulsion

Discussion in 'Boat Design' started by ecodevoman, Feb 1, 2010.

  1. ecodevoman
    Joined: Jan 2010
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    ecodevoman Junior Member

    I have a 24-foot kayot fiberglass houseboat hull that has been gutted. There's going to be a paddle hung off the back. Seeking early expert advice on the best way to configure this. The objective is to use it for some short tours in a relatively calm bay on a lake. I want to install back to back seating for 10 people, an awning up top with a pilot house.

    1) I have a 12 hp Deutz diesel from a generator that could be mated to a hydraulic pump. Diesel is important because we want to be able to do ecotours and run biodiesel in the future.

    a) Would it be realistic to use hydraulic as the propulsion? (I've read that direct drive is much better, but this doesn't need to go fast).
    b) Or would it be better to make this an electric hybrid, set up the diesel as a generator for extra punch in transit with solar panels over the awning for continuous charging?
    c) Should I forget about this motor and go with something like a 3 liter isuzu with direct drive from a hurth marine transmission (already have the tranny)? Problem with this option is a full size engine takes up too much space where the other options would allow for us to hide the drive aparatus or batteries under the seats.

    2) What is the best way to set up the axle and drive for the paddle? Source for parts?

    a) Would prefer to avoid chain drive due to safety and maintenance issues.
    b) Right angle gear?

    3) Advice on setting up and sourcing the paddle itself.

    a) Thinking of stainless steel paddle structure, perfectly round hoops. I have stainless mig and tig welding equipment and knowledge. I'm assuming any machine shop can handle fabricating the hoops, but am I being realistic about such an assumption?
    b) Would like to use fiberglass paddles for resiliance, strength and lowering maintenance, but where on earth would I source those? Ideally a honeycomb substrate covered with fiberglass would be best to reduce the weight on the back. Any ideas on this?
     
  2. DianneB
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    DianneB Junior Member

    Do an Internet search - there is a large group of stern- and side-wheeler enthusiasts who have build paddle boats from small to huge! There is a lot of experience there. (I just don't remember what the groups called.)
     
  3. ecodevoman
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    ecodevoman Junior Member

    I've been doing that for three weeks. What's out there doesn't answer most of my specific questions, but thanks for your suggestion.
     
  4. Guest625101138

    Guest625101138 Previous Member

    On the technical side I expect you will not need much power but you have not stated what speed you are after. A wheel or wheels of suitable size will get efficiency around 80% but it depends on blade size relative to the hull drag.

    Hydraulics should be a good solution. You can get swash plate pumps for full speed control including reversing:
    http://www.boschrexroth.com/industr...anguage=EN&VHist=g54572,g54573&PageID=g144067
    You can get high torque motors that would not need gearing:
    http://www.hagglunds.com/Upload/20060809110728A_En396.pdf

    Hydraulics need to be well designed and installed to get good performance. If you are in an environmentally sensitive are you might need to give special consideration to avoiding leaks and broken lines. They can also be noisy. If you use a variable displacement pump you should get a quieter system than one using valve for flow control.

    An alternative could be electric. There is some good EV stuff around like the motors here:
    http://www.electricmotorsport.com/store/ems_ev_parts_motors_ac-induction.php
    Of course the motor would need a gearbox.

    These electrical systems work with batteries so you have the ability to run at low noise level if required. You could charge with a small generator running continuously to a heavy duty charger and could be quite compact. These are off-the-shelf.

    I expect the hydraulic system, done to an industrial standard, will be more expensive than an electrical system but the electrical system will not be as robust and bullet proof. On the other hand from batteries to drive you have a very simple system. The batteries will be a significant cost for the electrical system and will add some weight if you use lead/acid but probably not prohibitive for a slow moving boat.

    Another consideration is steering. If you are draft constrained water than dual wheels will give you better steering at low speed than a shallow rudder.

    Rick W
     
  5. SamSam
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    SamSam Senior Member

  6. Village_Idiot
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    Village_Idiot Senior Member

    With all of this extra weight, your boat might be riding low once you get a bunch of passengers on board. This may be a benefit if you are in calm waters (no big waves or barge traffic) because you will have less effect from wind trying to blow you sideways. OTOH, if you need more freeboard, you might consider adding floatation pods to the transom or even the paddlewheel assembly itself to help offset the extra weight. With enough extra buoyancy, you could even use steel for your paddles. If you just need more level floatation, then you might put the fuel tank or even the engine up toward the front of the boat.

    Speaking of the engine, IIRC the Deutz engines are air-cooled. You will need proper ventilation to keep it cool.

    You can also find/run bio-friendly hydraulic fluids.

    You might consider discrete trolling motors for use as bow thrusters to assist in turning.
     
  7. gonzo
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    gonzo Senior Member

    Hydraulics are very inefficient. 35-40% losses are common unless you go to a very expensive high efficiency system. Even then it will be at least 20%. Also the weight of hydraulics makes it undesirable.
    Eco-tours is something that grates my nerves, specially when referred to a motor vessel. But that is my personal belief.
    Using a generator engine for propulsion is a very bad idea. They are set up to run at a fix RPM. You can modify it by changing the governor and maybe the injection pump and injectors
     
  8. Easy Rider
    Joined: Oct 2009
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    Easy Rider Senior Member

    Chain drive

    Easy Rider
     
  9. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    The only paddlewheel drive I have experience with is chain drive and I agree with your thoughts. Broken links are common and when one breaks, it has to be fixed then, no matter where you are or what the weather is. Delay is not an option or the chain will be on the bottom. On such a small boat, chains might be more practical but I was on a 100 footer with dual wheels and it was a messy and often difficult job, especially if the water was rough.

    Rudder steering with paddllewheels is only useful going forward with the rudders behind the wheels. In reverse they are less so but still work. Dual wheels work in all directions and at slow speed.
     
  10. Village_Idiot
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    Village_Idiot Senior Member

    You may also consider belt drive...

    Both chain and belt drive are more efficient than shaft drive. Chain is obviously messier than belt, but you have more chance of slippage with the belt, unless you go with a toothed belt. Slippage isn't all bad - better to break or burn an easily-replaceable belt than other parts of the driveline - think of the belt as a clutch.

    I personally like the idea of electric motors with direct gear drive. Consider you have a 10-foot diameter wheel. If you could fit a large ring gear on that wheel with, say, 2500 teeth, then direct drive it off of an electric motor(s) with sprocket of, say, 8 teeth, then your motor turns at 1750rpm which would drive your wheel at 5.6rpm. Good thing about it is simplicity and you have maximum torque starting out. Bad thing is that you have constant speed (unless you use variable-speed motor), and you have to be careful with electricity around water (proper grounding, etc.).
     
  11. SamSam
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    SamSam Senior Member

    This would seem ideal. Do you have any experience with these? if so, did they each have separate forward and reverse capabilities, and how was power divided and applied to the wheels?
     
  12. rambat
    Joined: May 2002
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    rambat Member at large

    Small Paddlewheel

    We have a few down here in Bayou country, the preponderance use chain drives off a reduction geared diesel. The key being a small generator diesel like you suggest and a oafish chain drive like found on some older tractor cranes. The best I have seen is a turn-buckle suspended fantail that holds the paddle wheels to be able to adjust paddle depth for speed, hp, tow or cruise. He really never adjust it once it was set. For paddles you could look for old Fiberglass arena bench seats. Personally, I am a purist and would rather it be wooden looking planks driven with an articulated rocker arm. Our local "Cotton Blossom" Steam Paddle wheeler I think is turned that way. That's a 120' Steam paddle wheeler also owned by the guy that built his own 60' houseboat as I described above.
     
  13. narwhal
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    narwhal Junior Member

    Many sternwheel towboats in the early part of the 20th century, and some of the sternwheelers operating today, had/have flanking, or backing, rudders. These are placed ahead of the paddlewheel, and provide side thrust for turning and maneuvering when the paddlewheel is operated in reverse. Here's a link to a sternwheel pontoon boat with both a flanking rudder and a 'monkey' rudder behind the wheel: http://users.wirefire.com/gemort/vern p1.htm .

    Flanking rudders ae also used on propeller driven towboats today: http://website.lineone.net/~alanann/towruddr.htm .
     
  14. SamSam
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    SamSam Senior Member

    I had a real small sternwheeler with wood buckets, easily made and replaceable anywhere and anytime. One disadvantage was sitting at the dock for long periods without the wheel turning two or three paddles absorbed water and upset the balance of the wheel.
     

  15. Easy Rider
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    Easy Rider Senior Member

    Motorcycles go tens of thousands of miles w/o broken links. The more expensive chain has rubber O ring seals that keeps the water out and the lube in. You could design it w smaller sprockets, higher loads and slower speeds. HTD belts are great but if something got between the sprocket and the belt it could be big trouble. With chain it would be cheap and easy to vary the drive ratio and optimize the system.
    Easy Rider
     
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