Fabricate your own Propeller.

Discussion in 'Props' started by tom kane, Sep 24, 2011.

  1. tom kane
    Joined: Nov 2003
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    tom kane Senior Member

    Fabricate your own propeller from flat steel to reach out of the way places.
    If you suffer a lot of prop damage make your own props from flat plate steel .
     

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  2. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Nice prop, but if you round the leading edge it will be even more efficient:

    [​IMG]

    (Hey, just kidding you :p ;) )
     
  3. baeckmo
    Joined: Jun 2009
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    baeckmo Hydrodynamics

    ......and more fun as well.....
     
  4. jehardiman
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    jehardiman Senior Member

  5. CatBuilder

    CatBuilder Previous Member

    :D:D:D:D:D:D:D

    Best post ever!
     
  6. DMacPherson
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    DMacPherson Senior Member

    John, that's not a fair fight. Prop diameters were large back then, and loading was a fraction of what we deal with today. Any lightly loaded two blade propeller of proper section form and radial load distribution should be pushing 75%-80%, so 60% was good, but not great.
     
  7. jehardiman
    Joined: Aug 2004
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    jehardiman Senior Member

    :D

    I know, I've put together some large low power HPV CR sets getting upwards of 85%, but it always irks me when I see a "modern" vessel that has twice (or more) HP but barely makes the speed of older similiar platforms. Compare the Blohm & Voss "A" to a late war MARAD C2. The C2 is only 60 feet (450 and even less if we consider LWL to 390 ) longer but displaces twice as much, has only half the HP (6,000 shp ST to 2x6035 hp MAN MSDs), but makes about the same speed (19 to 23). The client who built "A" most likely could have bought the NS Savannah cheaper if he wanted a big white boat...faster, cheaper to run (her breakeven point was ~$80/ton for fuel), and better looking also. Big slow turning wheels rule.
     
  8. DMacPherson
    Joined: Mar 2005
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    DMacPherson Senior Member

    Amen to that.
     

  9. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

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