• Paddlewheel versus Propeller

    From burningcyprustree@gmail.com@21:1/5 to Dan Bollinger on Sun Oct 15 19:12:02 2017
    On Monday, March 4, 2002 at 5:43:46 PM UTC-5, Dan Bollinger wrote:
    The 455' long steamboat the 'Commonwealth' was fitted with compound engines and feathering wheels instead of a propeller powered by steam turbines. Operating costs were estimated to be identical. They noted that the reduced space and vibration of a paddlewheel made the deciding factor. Its top
    speed was 23 mph in the trial run. Dan


    "Glenn Ashmore" <gashmore@mindspring.com> wrote in message news:3C83CDF7.4070309@mindspring.com...
    Just thinking about the physics, aside from the wheels and drive
    mechanism being a lot heavier, I would suspect that paddle wheels will waste a lot of energy producing a lot more side eddies than a prop will
    and as the speed increases it will start throwing more water up than back.

    As for Junkyard wars, the only thing the paddle wheel has going for it
    is less draft. As it is highly unlikely that they will convence the
    owner of that antique tripple compound that siezed up for lack of oil
    last year to lend it out again, they will probably seed the yard with a couple of gas engines so I would go with a prop unless the contest is in water only a few inches deep. But then one of the teams will probably luck into a discarded Arneson surface drive. ;-)

    mecker@home.net wrote:

    I'd like to know if anyone has references to theoretical comparisions. I've alway thought a paddlewheel could be more efficient than a prop.
    I assumed they went out of style because they were large and bulky and fuel was cheap. I think there could also be problems with wave,
    suface interactions, and I can't see it working well for a high speed planing hull.
    -



    --
    Glenn Ashmore

    I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com



    Dan, Where did you find this information? Im curious on the subject.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John B.@21:1/5 to All on Mon Oct 16 13:32:26 2017
    On Sun, 15 Oct 2017 19:12:02 -0700 (PDT), burningcyprustree@gmail.com
    wrote:

    On Monday, March 4, 2002 at 5:43:46 PM UTC-5, Dan Bollinger wrote:
    The 455' long steamboat the 'Commonwealth' was fitted with compound engines >> and feathering wheels instead of a propeller powered by steam turbines.
    Operating costs were estimated to be identical. They noted that the reduced >> space and vibration of a paddlewheel made the deciding factor. Its top
    speed was 23 mph in the trial run. Dan


    "Glenn Ashmore" <gashmore@mindspring.com> wrote in message
    news:3C83CDF7.4070309@mindspring.com...
    Just thinking about the physics, aside from the wheels and drive
    mechanism being a lot heavier, I would suspect that paddle wheels will
    waste a lot of energy producing a lot more side eddies than a prop will
    and as the speed increases it will start throwing more water up than back. >> >
    As for Junkyard wars, the only thing the paddle wheel has going for it
    is less draft. As it is highly unlikely that they will convence the
    owner of that antique tripple compound that siezed up for lack of oil
    last year to lend it out again, they will probably seed the yard with a
    couple of gas engines so I would go with a prop unless the contest is in >> > water only a few inches deep. But then one of the teams will probably
    luck into a discarded Arneson surface drive. ;-)

    mecker@home.net wrote:

    I'd like to know if anyone has references to theoretical comparisions. >> > > I've alway thought a paddlewheel could be more efficient than a prop.
    I assumed they went out of style because they were large and bulky and >> > > fuel was cheap. I think there could also be problems with wave,
    suface interactions, and I can't see it working well for a high speed
    planing hull.
    -



    --
    Glenn Ashmore

    I'm building a 45' cutter in strip/composite. Watch my progress (or lack >> > there of) at: http://www.rutuonline.com



    Dan, Where did you find this information? Im curious on the subject.

    I assume that this was the sidewheeler STEAMER COMMONWEALTH, delivered
    to the owners in 1908.

    Try googleing on 'THE STEAMER COMMONWEALTH' (without the quotation
    marks of course) there is a very informative PDF copy about the boat,
    with the above title, of a paper Read at the sixteenth general meeting
    of the Society of Naval Architects and Marine Engineers, held
    New York, November 19 and 20, 1908.

    --
    Cheers,

    John B.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From lachlanfergusson@gmail.com@21:1/5 to All on Thu Jul 19 03:37:09 2018
    Does anyone think that perhaps a propellor is more efficient because it's blades are moving through the water in a way similar to the wings of an aircraft at an efficient angle of attack, whereas paddle wheels have no laminar flow, like a plane in a
    stall or a boat with the sails close hauled when on a reach?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From robmoreau67@gmail.com@21:1/5 to All on Fri Jun 5 13:27:23 2020
    I've read that ships at sea, because of wave action, tend to rock from side to side, causing the paddles to lose contact with the water, sometimes 50% of the time greatly affecting the efficiency. Screw props are always in full contact with the water.
    In my opinion, the main reason paddlewheels fell out of favor is that the mechanisms are more complex and most importantly, take up a lot of space.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John B.@21:1/5 to robmoreau67@gmail.com on Sat Jun 6 08:16:50 2020
    On Fri, 5 Jun 2020 13:27:23 -0700 (PDT), robmoreau67@gmail.com wrote:

    I've read that ships at sea, because of wave action, tend to rock from side to side, causing the paddles to lose contact with the water, sometimes 50% of the time greatly affecting the efficiency. Screw props are always in full contact with the water.
    In my opinion, the main reason paddlewheels fell out of favor is that the mechanisms are more complex and most importantly, take up a lot of space.

    I believe that there are still Paddle Wheel vessels operating. See https://en.wikipedia.org/wiki/Paddle_steamer
    --
    cheers,

    John B.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)