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40435Re: [bolger] Re: design ideas

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  • Zack Tiger
    Nov 7 6:15 PM
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      Hi Jeff, Howard.
      Even more serious for the ocean going paddlewheeler,
      when steaming at ninety to 180 degrees off the wind,
      is the tendency for waves on the windward side to
      provide a lifting effect or pressure on the inside of
      the paddlebox,causing the ship to capsize. This is how
      Portland met her death.
      Feathering paddlewheels accomodate diferent paddle
      pressures and depths, but are complex. I am planning
      for very calm, interior waters,so straight,radial
      paddles should be okay. Besides, that little 9.9hp
      concealed in a well aft will help with docking and
      assist in getting inshore quick in the faceof
      worsening weather.

      --- Howard Stephenson <stephensonhw@...> wrote:

      > Thanks for that, Jeff. I'll have a look at that
      > site. Maybe it will
      > lead me to an answer to questions as to: 1) how
      > deeply do the blades
      > need to be immersed and 2) whether they should be
      > mounted radially,
      > or tilted slightly. Radial mounting seems to be
      > almost universal.
      > Recently I saw an interesting TV program about early
      > ocean-going
      > paddlesteamers. I was aware of the problem of
      > varying blade immersion
      > as waves move along along the hull or as
      > displacement varies, but
      > hadn't considered that there is a steering problem
      > when there are
      > transverse waves, which cause alternate paddles to
      > push harder. I.K.
      > Brunel solution was to use fore-and-aft sails to
      > limit the boat's
      > roll and thus make paddle immersion more constant.
      > No wonder the screw propellor quickly became almost
      > universal, except
      > for a few cases like the one you describe, Jeff, or
      > for passenger
      > boats on calm lakes.
      > Howard
      > --- In bolger@yahoogroups.com, "Jeff"
      > <boatbuilding@g...> wrote:
      > >
      > > Here's a good site to start with
      > http://gemort.wirefire.com/contents.htm

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