paddlewheeler recuction drive

Discussion in 'Propulsion' started by xxdroom, Oct 30, 2014.

  1. gonzo
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    gonzo Senior Member

    There is no ease on engineering on a paddle wheel. They have more moving parts and more things to break. As far as having a radiator, it makes no sense when a heat exchange does a better job. However, if you do want a radiator, the engine can run a shaft and propeller anyway. The only thing a paddle wheel can do better than a propeller is attract tourists to a floating casino.
     
  2. slow fred
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    slow fred Junior Member

    You could hook the prop to the pto shaft on the tractor.
     
  3. parkland
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    parkland Senior Member


    When I said ease of engineering, I meant for someone putting together one of these boats like this guy is. A paddle wheel boat can easily be build using some welding skills and old truck or farm powertrain. A prop boat is going to need some marine parts and a little more expertise.

    The radiator, the main drawback I see is needing to waste power on the fan to blow through it, other than that, it seems like a way simpler system than using a heat exchanger and fresh water pump. Personally I love the idea of keel cooling.

    I understand your hate of the paddle wheel, it is an out dated concept. But, it still does propel a boat.
    While I would expect a propeller driven boat to cost less to operate on a commercial boat, it wouldn't surprise me at all if the paddle system was cheaper to run for a small time boat builder that doesn't run it constantly.
     
  4. parkland
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    parkland Senior Member


    There is a guy that has a video on youtube, he built a 70 foot chinese junk, and he was running a variable pitch prop, allison 545, and some truck engine I think.

    11 minutes in.

    http://www.youtube.com/channel/UCj_XaV1ss-qdD-lPUtTEcXw
     
  5. gonzo
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    gonzo Senior Member

    A guy putting together a boat would have an easier time connecting a shaft to a transmission and a propeller. Paddle wheels and all the accompanying hamper have to be custom fabricated. Also, propeller calculators are available online for free. A paddlewheel needs to be calculated by a knowledgeable person = more money. I do not hate paddlewheels. They are fine within their limitations and lack of efficiency. The only call for one is nostalgia though.
     
  6. whitepointer23

    whitepointer23 Previous Member

    I think the o p will do better taking gonzo's advice here. Much easier to install a conventional marine shaft drive.
     
  7. AndySGray
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    AndySGray Senior Member

    While there were a few prototypes in the last part of the 18th century, the paddle wheel had it's heyday up until shortly after the middle of the 19th century - As mentioned Brunel ushered in the propeller age in 1843, and while the Waverley was built a hundred years after that, she was a replica of an 1890's ship that was already part of a bygone era.

    Many of the earlier paddlesteamers were effectively hybrids between sail and steam in order to get the range required for transatlantic crossings, and it was the increased efficiency of the propeller that made this much more cost effective.

    Of course once props become the norm for new ships, the paddlewheelers don't cease to exist but are relegated to coastal duties where the inefficiencies are less of a problem (if you can refuel at each of the ports, range is not a problem), and the skills to repair and rebuild them were still in existance right through to the end of the victorian era and beyond.

    Paddlewheels were therefore around for maybe a century but props have been the modern option for over 170 years. It's only sails and oars that can truly lay claim to 'centuries' (and actually also millenia...)

    Gramophones still work but when was the last time you saw a record store...

    :D
     
  8. parkland
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    parkland Senior Member

    Well it's not my boat haha, have to see what the OP is thinking as of lately.
     
  9. parkland
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    parkland Senior Member

  10. Dave T
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    Dave T Senior Member

    Paddle wheel driven boats will work but the cost and efficiency make them impractical except for someone that wants them for nostalgia or has a lot of parts and the ability to figure out some complicated design problems and can do most of the design and assembly themselves. The ops first problem is that he has stated a 100' boat with 16' diameter paddle wheels turning 60 RPM. This won't work 16' wheels turning at 60 RPM is way too fast. I would first do some simple math to see what would be more practical. Lets say since a boat this size driven by paddle wheels would be a displacement boat, a target top speed of 10 MPH would probably be reasonable. 10 MPH would be 52,800 ft per hour or 880 ft per minute. A 16' diameter paddle wheel would have a circumference of 50.24 ft at 60 RPM this is 3,014.4 ft per minute at 100% efficiency no slip. If the paddles have an efficiency of 50% or 50% slip this is still 1,507 ft per minute about twice as fast as the target speed so the gearing needs to be much lower or the paddle wheels need to be smaller. The next problem would be the size and number of paddle blades as this must be worked out to determine the required HP and torque needed. Paddle wheels are much more practical with steam power than a modern gas or diesel engine unless you are using them with electric or hydraulic. It can be done but just isn't practical when compared to a propeller drive that is so much simpler and cheaper.
     
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  11. AndySGray
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    AndySGray Senior Member

    Well said Dave, a good summary.

    I also believe the OP said it would be an ocean going scuba vessel. As soon as you start into the commercial side the option to go 'junkyard tech' disappears - you need to get stuff signed off by a NA who is trusted by the insurance company.
    The margins are small in this industry, so losing space to drivegear that could have had 2 more cabins and 4 more passengers is not going to work well.
    Fuel efficiency is revenue. A drive system which burns an extra couple of hundred a week is losing you 10,000 a year.
     
  12. Horn Island Boy
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    Horn Island Boy New Member

    I Will advise without any afterthoughts to use Diesel Power coupled to a chain drive, bathed in oil. Your shaft H.P.(RPM) will determine the gear reduction mass required. This coupled to the recommended paddle length + Blade Width+ depth of engagement, etc. must all be computed towards final analysis for speed, which will also be affected by boat length/width. draft, etc.
    We have, and use a paddle-wheel design concept on a vessel being used for 'Mother-ship' to process crabs on-board while passing through the islands of the Philippine Archipelago between Visayas and Bohol. It is a good conceptional design due to size of vessel and shallow draft due to shallow water in coral reef areas. This vessel was built using a Cat style with triple hulls built on an 84ft. length by 36ft. width (rather wide concept but also a factory type vessel.) It uses two Perkins 8-354 Diesels and powers triple staged paddle wheels between the Port pontoon and center and also between the Starboard pontoon and center. All at rear of vessel. The Paddle wheels are all five feet diameter and aligned in a row of three on each side of vessel, with each wheel staged to dip progressively deeper than the previous stage affront of it. In short, the forward wheel reaches down 4.in deep in water below stream flow of hull. The second wheel reaches a depth of 8 in. and the final third wheel reaches a depth of 12 inches, keeping the overall running depth below the hull at one foot plus the draft (which is overall about 16 to 18 inches making it a relatively shallow running vessel for the size (length). The wheel and paddles are constructed of 5086 marine Grade Aluminum Alloy and coated well. the drive shaft of each wheel is 17.4 PH Stainless and keyed to a dual toothed sprocket allowing for dual chain drives using No.50 oil submerged chain drive. The sprocket on the paddles are 20 inches in diameter while the sprockets on the engine gear reduction drive is 4in. dia. with a gear reduction of 2.75:1 off gear box. This vessel will clip along at approximately 16 knots at full throttle (which we never truly run due to risk of grounding on corral in unknown waters not constant charted). Essentially, a GPS course is maintained to be as safe as possible since we carry a crew of 24 Filipino process workers. This vessel incorporates some unique designs that allow it to full-fill the needs of its design quite well.
    I want now to build a river lake houseboat of similar style and design only laid out and finished for the comforts of using it as an actual live aboard that will allow me to enjoy multi region travels in U.S. using the Tombigbee/Tennessee River system and the Mississippi River tributaries, etc. Ambitious Thoughts but Mine so I understand when I see something of similar kind. I have designed and built larger commercial fishing vessels but this will be my first of this type and You may see a lot ofmy questions being asked herein. "THANKS FELLAS!"
     
  13. Horn Island Boy
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    Horn Island Boy New Member

    Nice response and while all very true, having paddle wheels as opposed to prop drives has advantages in shallow coastal waters and many river tributaries, particularly true along the Gulf Coast of the U.S.
     
  14. Rurudyne
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    Rurudyne Senior Member

    A few strays into the wrong patches of sea grass and having paddlewheel boat could just about pay for your fuel that trip.
     

  15. JSL
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    JSL Senior Member

    If believe the tourist paddle wheels here ( Fraser River, BC) are hydraulic powered. Simple, safe, effective.
     
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