Swath ???

Discussion in 'Boat Design' started by Matt.D, Nov 28, 2010.

  1. Matt.D
    Joined: Oct 2007
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    Matt.D Junior Member

    Awesome!!! I want one! That will stop some of the Riv owners thinking they own the broadwater!!!
     
  2. Squidly-Diddly
    Joined: Sep 2007
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    Location: SF bay

    Squidly-Diddly Senior Member

    Check my gallery for weird possibly swath SAILBOAT

    this thing has been sitting in a lot off hwy 101 in Redwood City, CA forever.

    one of those "more questions than answers" jobs.
     
  3. apex1

    apex1 Guest

    Thanks Matthew,

    but that is neither a SWATH nor a Icebreaker.

    By the builders definition, it is a catamaran with some SWATH features when ballasted. Hence a "hybrid" craft.
    It may be icegoing to some extend, but not icebreaking. By the very nature, a Icebreaker needs to deploy his weight above the ice surface to break it. A SWATH has its weight BELOW the surface.

    Regards
    Richard
     
  4. BMcF
    Joined: Mar 2007
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    BMcF Senior Member

    That is quite incorrect. the SLICE variant of SWATH design has the submerged hulls broken in to two sections, fore/aft. So they have two starboard hulls and two port hulls. Of course that is also why they have multiple struts...but there have been conventional SWATH with multiple struts too,
     
  5. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    Exactly.

    Icebreakers ride up and over the ice, and use their weight to crush the ice. A SWATH (true SWATH) can't do this, as the buoyancy (hulls) is below the lwl not above!
     
  6. MatthewDS
    Joined: Mar 2010
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    Location: Juneau, Alaska

    MatthewDS Senior Member

    Regarding the icebreaking capabilities and SWATH nature of the ship I posted, this is what the builder has to say: (http://www.akship.net/pages/news.html)

    "The vessel will have three distinct modes of operation: a catamaran mode for high speeds; a small-water-area-twin-hull (SWATH) mode for stability in high sea states; and a shallow-draft landing-craft mode that provides substantial buoyancy for maneuvering in shallow water. In addition, the Susitna will be the world´s first ice-breaking twin-hulled vessel."

    Richard points out correctly that it is not purely a SWATH, however, it operates as a SWATH in one of it's three modes, and I felt that was enough to make it relevant to this thread.

    Additionally, while I agree that typically an icebreaker operates by riding up on the ice and breaking it from above, the reality is that the hulls on the Susitna are designed to break ice from below. If this means that it isn't really an icebreaker that's fine, but it is designed to break ice, and is not simply reinforced to withstand ice.
     
  7. apex1

    apex1 Guest

    Regardless of the manufacturers claims, that is NOT a icebreaker, and it will not break ice! Ice cream maybe........but lemon only.:)
    By the very nature of the hulls, that is just not possible, no matter how strong they are made. And that was said by one who operated icebreakers for many years, me.
    This hull shape gets immediately stuck in real ice conditions, and it will not break free again, the shape is too sharp.
    Retards have designed that craft, it is the worst of all worlds, a real goat.

    Regards
    Richard
     
  8. MatthewDS
    Joined: Mar 2010
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    Location: Juneau, Alaska

    MatthewDS Senior Member

    Richard, I see your point. Regardless of whether or not it was designed as an icebreaker, you contend that the hull form will not work as intended. Fair enough, time will tell.

    I have attached a picture of the waterbody that the ferry is designed for, which has ice pans, but no solid ice. I should also note, that I am not associated with the designer or the builder, in case anybody thought that.

    [​IMG]
     
  9. HReeve
    Joined: Dec 2009
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    HReeve Junior Member

    I stand corrected.
     

  10. sdowney717
    Joined: Nov 2010
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    sdowney717 Senior Member

    2 feet of loose pack ice pans or 2 feet of solid ice??
    Maybe that center hull can lower down and crush the ice under it, but unlikely.
    must just be loose ice.
     
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