River Roller! Pontoon Boat that Rolls Across the Water!

Discussion in 'Boat Design' started by Matthew Lee Towne, May 10, 2017.

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Do you think the River Roller will work?

  1. Yes

    1 vote(s)
    2.9%
  2. No

    27 vote(s)
    79.4%
  3. Maybe

    6 vote(s)
    17.6%
  1. Matthew Lee Towne
    Joined: May 2017
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    Matthew Lee Towne Senior Member

    Very interesting feedback. A mixed bag for sure. In the end displacement is my concern. Conical trantoons would present about 25% less buoyancy than conical trantoons.
    Not to mention a more complicated implementation. A deck on top of cylindrical buoyant bodies seems to be a mature science. All Im suggesting is a 90 degree rotation. There are many applications here. Lets consider an extremely inefficient, well armored application. The capabilities of an amphibious tank without the vulnerability of a track come to mind. Shoot out one of the trantoons, and the rest will continue to move the vehicle forward. What about hunting? The ability to easily transition up onto land and park is clearly appealing to hunters. There are many applications beyond my initial thoughts. In the end the River Roller may not be efficient, but it will be useful.
     
  2. Poida
    Joined: Apr 2006
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    Poida Senior Member

    Another thought, although I don't like doing it too much.
    Would there be any benefit in having electrically driven conical rollers attached to the front of a conventional hull to increase hull speed?
    Some members have pointed out that Matthews design creates aeration of the water and if a conventional hull had a mass of bubbles in front of the hull, it would reduce drag.
    Poida
     
  3. latestarter
    Joined: Jul 2010
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    latestarter Senior Member

    Could aeration of the water reduce its density resulting in the hull sitting lower in the water?
     
  4. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Yes, that's why in some of the linked videos it shows the craft digging a hole in the water and dropping into it.
     
  5. Matthew Lee Towne
    Joined: May 2017
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    Location: Oviedo

    Matthew Lee Towne Senior Member

    Well aeration and paddle depth is the motivation behind having a variety of diameters. The idea being that deeper paddles aft would always grab fresh water and get better traction. Ultimately I've done away with this as I figure the acceleration and weight distribution will control paddle depth and adress aeration and paddle depth. Keep in mind that the aeration of the water behind the forward paddles will increase efficiency of the aft paddles.
     
  6. DCockey
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    DCockey Senior Member

    How does that work?
     
    SamSam likes this.
  7. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Uniquely?
     
  8. Matthew Lee Towne
    Joined: May 2017
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    Location: Oviedo

    Matthew Lee Towne Senior Member

    Yes. The craft will sit lower until it "Grabs", at which point it will move forward and upward. Simple dynamics my friend.
     
  9. Matthew Lee Towne
    Joined: May 2017
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    Location: Oviedo

    Matthew Lee Towne Senior Member

    Well the forward paddles will lose efficiency as they will also be lifting as they move the craft forward. The aft paddles will be operating in an increasing vacuum ( as speed increases) and hense less upward force. Ie more forward velocity and efficiency.
     
  10. Matthew Lee Towne
    Joined: May 2017
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    Location: Oviedo

    Matthew Lee Towne Senior Member

    Why don't you like doing it?
     
  11. Matthew Lee Towne
    Joined: May 2017
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    Location: Oviedo

    Matthew Lee Towne Senior Member

    Hello All,
    After much consideration, and all of your input, I have decided this project is worth pursuing. If nothing else a solar charged pontoon boat is far superior to an ICE version. I really like the idea of my boat being fueled and ready for me every Saturday morning. Let me know if anyone here can really poke holes in that! All else is just icing on the cake!
     
  12. Matthew Lee Towne
    Joined: May 2017
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    Location: Oviedo

    Matthew Lee Towne Senior Member

    So your are saying that pontoon boats have no application? They sit high and are largely top heavy. My concept is an alternative pontoon boat at this point. That being said, why wouldn't the river roller work?
     
  13. Matthew Lee Towne
    Joined: May 2017
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    Location: Oviedo

    Matthew Lee Towne Senior Member

    Maybe. What about tapered lengths?
     
  14. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Does this mean that after 20 pages of vaporous theory, you're just going to make a solar powered pontoon boat?
     
    PAR likes this.

  15. Yellowjacket
    Joined: May 2009
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    Yellowjacket Senior Member

    No it won't, because it won't ever "grab" and go because there is no real surface to create lift at low speed. At low speed you have a rotating "sleeve" of water around each cylinder. This "sleeve" of water between each paddle element has velocity relative to the still water and creates a lower pressure around the wheel. It isn't the "bubbles" that cause the wheel to dig down it's the effect of a cylinder rotating in a fluid that causes negative lift when the speed of the paddling cylinder is greater than the surrounding water. This is why you need a hull to create lift and keep the paddle wheels very lightly loaded and mostly out of the water for them to create enough forward speed that you plane the hull and have a boat that is now propelled by a paddle wheel.

    The only vehicle that is even remotely feasible that is using the concept of a paddle wheel is the "Fast Track" amphibian. Here is s short clip of it running, there are a bunch of other videos of it on youtube. I picked this one because it shows this craft pulling two water skiers out of the water which shows it has the capability to pull some weight out of the water. This boat has done over 40 knots on the water and over 65 on land, so it is the real deal.... At really high speeds this runs on just the tracks, the hull is totally out of the water and it's pretty impressive...



    The folks that designed this did a good bit of analysis and scale model work and found that the immersed aft portion of the tracks were responsible for "digging down" the transom, preventing the hull from getting up on a plane. These folks patented a vane behind the track to partially negate the digging down effect. The problem with the proposed multiple rollers is that you have this "digging down" effect from the aft part of each wheel, so with four rollers, you have 4 times more digging down momentum compared to the Fast Track. You aren't going to generate lift without using their patent, or getting a hull to get your "wheels" dry...

    Bottom line is that you need a hull to support and provide a surface to plane on and if you do that you don't need as many rollers so the whole concept falls apart. As Par noted in one of his earlier posts, if you're thinking of some kind of paddle wheel approach a track actually works and it's been done, but you'd have to buy the patent rights to have a viable craft.
     
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