why has high buoyancy become so important?

Discussion in 'Multihulls' started by peterchech, May 6, 2011.

  1. Gary Baigent
    Joined: Jul 2005
    Posts: 2,959
    Likes: 102, Points: 63, Legacy Rep: 509
    Location: auckland nz

    Gary Baigent Senior Member

    We always knew that Hydroptere maxi was going to be catamaran-like because that is what the team has published over the last couple of years - and this latest interpretation looks more like a larger, wider, version of a foiled Decision 35 - which is a catamaran with a sharp central pod that looks like a hull - this to handle rig loads and set sails from. But to me, maxi Hydroptere is, as expected, an extrapolation of Hydropter ch with its very wide beam and large foils and sharp central pod. They've just made the central pod a bit deeper - but most of the time, except in large waves, it will be flying clear of the surface.
    Makes perfect sense since all the research and construction is based around Lake Geneva ... and follows D35 lake racer design philosophy and development - however this boat is designed to handle round the world, hard sailing conditions.
    Cats and tris are morphing together - guess we'll soon be calling them all catamarans .... except for the lightweight foilers, that is.
     
  2. cavalier mk2
    Joined: Mar 2010
    Posts: 2,103
    Likes: 46, Points: 48, Legacy Rep: 214
    Location: Pacific NW North America

    cavalier mk2 Senior Member

    I'd say they are concerned about crash recovery in big waves...sailing beyond reserve buoyancy is a calculated risk.
     
  3. jamez
    Joined: Feb 2007
    Posts: 492
    Likes: 25, Points: 28, Legacy Rep: 231
    Location: Auckland, New Zealand

    jamez Senior Member

    Just to clarify (now that I'm over my fit of 'I hate building fiddly stuff' :rolleyes:) i meant in the context of banana foils on a modernish 'sports' type cruiser/racer tri with modern 150% + floats. Older types with smaller floats have certainly benefited from having angled straight foils added to them as (among others) Gary did with Miranda, and Bernard Rhodes did way back on Kliss II.

    One of the neat things about farrier marine now stocking curved carbon foils and cases is they will inevitably find their way on to other boats, enabling some real world comparisons to take place.
     
  4. Samnz
    Joined: Nov 2008
    Posts: 235
    Likes: 3, Points: 0, Legacy Rep: 47
    Location: Auckland

    Samnz Senior Member

    Its clearly a high buoyancy Tri Gary. Amazing that your last remaining low buoyancy tri example has been replaced by a high buoyancy version.

    The thing you need to remember its not all about light weight, you need righting moment and sail area and seaworthiness to go fast too!

    The low buoyancy tris are just like proas, fast in theory but just not fast in real life
     
  5. Gary Baigent
    Joined: Jul 2005
    Posts: 2,959
    Likes: 102, Points: 63, Legacy Rep: 509
    Location: auckland nz

    Gary Baigent Senior Member

    Then these too are all high buoyancy trimarans??? See what I mean by morphing. Actually they are all catamarans.
     

    Attached Files:

  6. Samnz
    Joined: Nov 2008
    Posts: 235
    Likes: 3, Points: 0, Legacy Rep: 47
    Location: Auckland

    Samnz Senior Member

    Quoted from the Hydroptere team page I linked...

    "This maxi trimaran will measure approximately 30 meters in length and 32 meters in span."

    So a summary is:

    I claimed the reason "high bouyancy has become important" is because its faster, and I listed examples.

    you claimed low buoyancy foiling tris are faster than high buoyancy tris and used something from decades ago (that I have disregarded completely), and Hydroptere as examples.

    I provided evidence the Hydroptere team has decided to change their design philosophy to the "high buoyancy" which proves the low buoyancy is not as good as the low buoyancy.

    Now the only way you can win the argument is by bringing out one of your beautiful low buoyancy foiling tris and kicking my arse (same challenge I laid to Rob Denney) ;)
     

  7. Gary Baigent
    Joined: Jul 2005
    Posts: 2,959
    Likes: 102, Points: 63, Legacy Rep: 509
    Location: auckland nz

    Gary Baigent Senior Member

    These are trimarans?? Guess it all comes down to the viewer. My definition of a trimaran is that it has a dominant central hull that has its full, or near full length floating while at rest. Maybe, Samuel, you can discount that as you also easily discount history. If you disagree, then we should also call those historical cats like VSD, Royale 11, maxi Fleury Michon, Charente Maritime, British Oxygen and many others; all had central pods ... as do these images of the two Hydropteres, ch and maxi, then instead, according to your vision, they're all high buoyancy float trimarans!
     

    Attached Files:

Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.