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Re: Tunnel - Stern - Designs

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  • ronschwiesow
    ... so early as 1922 !!!! I´m hoping for a bit of help. Regards, Manfred This is helpful reference to additional support for the efficiency of Atkin s hull
    Message 1 of 4 , Dec 3, 2004
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      --- In AtkinBoats@yahoogroups.com, "liokai2002" <manfred.pech@w...>
      wrote:
      > What struck me most was the reverse-V tunnel stern.
      > From tank tests at Duisburg University and a tank in Berlin I know
      > that underwater shapes similiar to Sand Piper are hydrodynamically
      > the most effective - not only in shallow waters. Boats with these
      > shapes are faster, need less fuel an have more course stability in
      > waves (safer, RO-ROs with Bulb Bows need rudder corrections by
      > computer every 20 seconds). This is the result of tests and
      > development work from a friend over a span of 25 years. He started
      > with Sail- and Motor Boats and now develops RO - RO Carriers of 450
      > ft. The shapes are of course not the same, but they are similiar.
      > From this I´m very interested in any literature about the Tunnel-
      > Stern Designs (esp. Sand Piper). I´ve read already all the early
      > postings about Tunnel-Stern Designs an will continue my research
      > about the work of William Atkin who found out this effective shape
      so early as 1922 !!!! I´m hoping for a bit of help. Regards,
      Manfred

      This is helpful reference to additional support for the efficiency of
      Atkin's hull design. If you haven't yet seen it you might enjoy
      looking at information on the Atkin Rescue Minor that Robb White
      built and tested. See
      http://www.messingaboutinboats.com/archives/mbissueaugust02.html.
      Also Dave Gerr has at least one design with a similar hull; see
      http://www.gerrmarine.com/images/boat_images/power/gerr42tunnel/gerr42
      tunnelD.GIF
      The Higgins boats also used the reverse vee stern, although it is a
      little hard to determine that from available pictures. See
      http://www.higginsmemorial.com/design.asp and
      http://www.higginsboat.org/html/photo/phot012.html

      I am particularly interested in a cruiser for 2, intermediate in size
      between Atkin's Rescue Minor and his River Belle. Intended speed is
      slower than the designed maximum for either of these designs. I'm not
      sure how the tunnel-stern, V-bottom Seabright Skiff hull form
      performs at low speed, but Robb White's observations are encouraging.
      Ron
    • liokai2002
      Hello Ron and Rob thank you both very much for your kind help and support to understand more of Atkins SAND PIPER hull design. I would like to put some fotos
      Message 2 of 4 , Dec 7, 2004
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        Hello Ron and Rob thank you both very much for your kind help and
        support to understand more of Atkins SAND PIPER hull design. I would
        like to put some fotos of "Maderform" hulls (RO-ROs) and University
        papers into the files, but have difficulies with my Windows messenger
        since I've changed my Internet provider to DSL and am not able to
        extinguish the old server adress. But I hope to overcome my
        difficulties soon.
        As I understand the Links from you Ron, the genius William Atkin
        designed SAND PIPER and Mr. Higgins from Higgins Industries adepted
        it and modified it to EUREKA and then to a landing craft that helped
        to free us from Nazi Terrorism in Europe. Or are EUREKA and the
        LANDING boat Higgins own designs without the influence of the Atkins ?

        The "Maderform" hulls in Germany started in the seventies from the
        idea that the underside of an aircraft wing (too) gives aerodynamic
        lift. From this the underside (in water) of a boat has to have a
        similiar shape. But this was only a first step. Hundreds of tests
        have been made and boats and ships have been built with increasing
        successful results. As one can see from the University tests and the
        Mathematics with NAVIER - STOKES formula there is a certain amount of
        lift from the special underwater shape to counteract the sucction
        (Bernoulli) of other (convex) boat shapes and a very smooth waterflow
        and a very low wake behind the boats and ships. I do not know whether
        the designer of the "Maderform" hulls has ever seen the SAND PIPER
        drawings or Mr. Higgins Landing boats. But I would like to ask him
        next time I meet him.

        I don`t know whether the SAND PIPER has ever been tested in a Tank
        test. But it is my strong opinion that this design will show a lot of
        advantages over current boats. It is a pity that there is not known
        enough to get proved results and to give this designs the recognition
        and honor it deserves. Thank you for your help. Regards, Manfred
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