Cruising Catamaran Righting System

Discussion in 'Multihulls' started by Iridian, Aug 3, 2021.

  1. Iridian
    Joined: Jan 2020
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    Location: MD

    Iridian Junior Member

    I've been reading about capsizes of cruising catamarans recently, and it had me thinking. Would it be possible to make a righting system for a cruising catamaran? Something that could be used to flip the boat back upright once the weather permits... It seems that in most capsize situations, the boat remains largely intact. I am unsure as to the state of the rigging though.

    For the Leopard and the Anna, both boats seemed to be fine in the inverted position, though both were rescued soon after capsize. The Rose Noelle, on the other hand, was capsized for 118 days.

    The first thing I thought of was intentionally flooding one of the hulls.. This by itself would be insufficient to accomplish much. The next thing I thought of was to inflate an air bladder of sufficient volume, then pull it down the main halyard, assuming the mast is still intact. Or perhaps drag the bladder down with an attached hose, then fill the bladder after it's at the tip of the mast, or more likely at the strongest point (where the shrouds connect). If the mast is strong enough to support the buoyancy of the air bladder without shattering, the boat could potentially raise up on one hull...

    The system would need to be functional with 1-2 people and not require any electrical power.

    I'm not sure how you'd then get the boat flipped the rest of the way, though potentially a combination of flooding one of the hulls along with the bladder would be sufficient.

    Not sure if something like this is even viable, but would appreciate any thoughts on the matter.
     
  2. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    Go research AYRS publications.
    Lots of discussion and ideas over the last 50 years.
    A couple of proved systems for re-righting.
    But only proven in calm water under controlled conditions.
    The Gougeons had a trimaran they did the same to.
     
  3. catsketcher
    Joined: Mar 2006
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    catsketcher Senior Member

    There was book published in the 80s called "The Capsize Bugaboo".

    Capsize Bugaboo - AbeBooks https://www.abebooks.com/book-search/title/capsize-bugaboo/

    The best system was the Ruiz system, further developed by Gunter Ullrich for his Kelsall cat that actually did a test before fitout.

    Catamaran equipped with re-righting device - ULLRICH; GUNTER https://www.freepatentsonline.com/4227474.html

    In the end, no one has worried much. With modern epirbs, you don't have to wait long and getting salvage is probably easier than re-righting on your own.
     
  4. alan craig
    Joined: Jul 2012
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    alan craig Senior Member

    I have a suggestion, but have not researched prior art.
    Step 1 is inflatable buoyancy at the top of the mast to prevent the boat from turning turtle. This would operate like modern life jackets or possibly car airbags.
    Step 2 is the system used on the Catapult catamaran dinghy - upper shroud is slackened and lower shroud is shortened until the upper hull can be pulled down or in this case of a larger boat, drops down to water surface.
    Disadvantages: weight and windage at top of mast and long lines at lower end of shrouds.
     

  5. redreuben
    Joined: Jan 2009
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    Location: South Lake Western Australia

    redreuben redreuben

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