Where are the catamaran innovations?

Discussion in 'Multihulls' started by simon, Feb 1, 2009.

  1. robherc
    Joined: Dec 2008
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    robherc Designer/Hobbyist


    Just got done looking over all of your sketches and I only have one question/problem with the design that I can see (at least without a good translation):
    Won't that bridgedeck be QUITE low & end up slamming a lot?
  2. catsketcher
    Joined: Mar 2006
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    catsketcher Senior Member

    Going flat

    Hello all

    In my moments of desperation I have often thought of a similar concept to the flat cat. I think the idea may do well. I like the idea of being able to produce the deckhouse - complete with all structural things like beam ends - on a flat floor. the interior would also have no curves. You could even get the local flat pack kitchen guys to make the interior for you - just give thjem the ply or Duflex to cut out.

    The bridgedeck clearance is an issue for offshore sailing but if this only for protected sailing and (and this is a really huge if ) if the designer is absolutley sure the boat will not sink more under load it may suffice. One point to remember about clearance. On boats with fine hulls - and this one looks relatively fine - a heavy cat will depress the leeward hull a reasonable amount leading to even less clearance in more wind and waves.

    My take on the flat pack cat was to make a forward bridge deck section - 2.4metres from front to back to take deck lockers and bunks. The next 2.4 metre section would be the cabin - this would have less bridgedck clearance than the other two sections as Robin Chamberlin does in his boats and the next 2.4 metre section would be the cockpit. The front and back wall of each section would be the box beams although as each section is a box these would be very light. This gives good proportions for about a 40 foot cat. Motors, storage and some private bunks would be in the hulls.

    This would allow anyone to build a 40ft cat anywhere. You make the sections on the floor and you ship them finished to a boatyard or river bank for a couple of months to glue the sections to the hulls. I think the boat would be much much faster to build than normal cats and also has the advantage that it can be done wherever you have space to build each section which then gets moved to a storage area when finished.

    Maybe in a few years when I have sold all my boats and need another. Until then the idea is just that an idea.


    Phil Thompson
  3. yipster
    Joined: Oct 2002
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    yipster designer

    going flat too

    drew ladybird, see my gallery, cant help doodling her flat to 12m

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  4. simon
    Joined: May 2002
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    simon Senior Member

    Why having side-decks on a higher level than the rest, if the space in the hulls is not used for cabins. The sidedecks could be lowered and a high
    bulwark left for safe moving around.

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  5. Othmar
    Joined: Dec 2006
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    Othmar Multihulls ...

    Hi friends,

    thanks for your comments to my "flatcat"-idea.

    @catsketcher/robherc - The bridge deck clearance is low, I know. But the boat is designed for coastal cruising, and lifeaboard. The payload can calculated in a way, that the minimum distance will not be lower. Further a lot of boats are sailing around the world with lower clearance, like Dean or Prout. You may add a nacelle against slamming.

    @catsketcher - The hulls are fine, yes. This will give a good performance, even with a lower and smaller rig, and also with small and lightweight engines, eg. outboarders. This boat will be not heavy! You save weight by the A-rig, which need no strong beam. You also do not carry four toilets and tons of water for 8-10 crew, like on charter catamarans. Also the principle of construction should be more like a monocoque.

    @simon - I thought also about this idea. But the proportions become ugly especially in the side view. May a compromise like Kelsalls "ma" designs with a higher bow section and lower aft section is possible.

    @fanie - How I said above, the boat is primarily for coastal cruising, and the reality is, that nobody cook there during bad weather on open sea. But you can add some jambs in the kitchen anywhere.

    My experiences in watching boat design is, that an "all-in-one device suitable for every purpose" isn't possible. I worked for a time in a marina, and saw how much older sailors/couples using their boat like a house boat. But with a really houseboat you cannot reasonable sail, and on a normal sailboat (also catamarans) you can at last not comfortable live.

    Hence "Flatcat" is a special boat for special people for a special use. And for these it should be perfect ;)
  6. Fanie
    Joined: Oct 2007
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    Fanie Fanie


    Some of your ideas on this thing. You know, I was just thinking. Since this is mostly for 'old' people I think you must reconsider some of the so called features.

    Take the low bridgedeck for instance. If you get waveslap there, what do you think it is going to do to those old folk ? Can you see the false teeth, ear pieces and other stuff hopping around there ? What is this going to do to pacemakers, not to speak of heart-lung equipment.

    The other thing is you say it is going to be fast. Now between the fast and the slapping I think that boat is going to go out of control very easily and pretty soon we are going to have lost old people drifting all over the show, that is if they don't end up on some secluded beach somewhere. You saw Jurasic Park III, so you should know what secluded beaches can produce, right. Unless that is your idea of course.

    Also, a runaway boat may be looking like a getaway attempt, the military live for moments like these where they can play with their toys, bombs and stuff.

    Also, if the coast guard or military is going to confront them adrift somewhere they are also going to be traumatized. Some mornings I cannot even remember my own name, the wife has to tell me and then I am shocked... I am WHO ? ... Damn !

    And I am under a hundred still.

    An what is the jamb you refer to ? Is it something like the 'guides' in shopping centre's where people queue in ? In case you haven't noticed, those things are free standing. Anyone old leaning against those are going to bring the whole queue down. Old folk can also get strangled in those especially from within a walking ring...
  7. Fanie
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    Fanie Fanie

    Just giving you a hard time :D Go for it :D
  8. Othmar
    Joined: Dec 2006
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    Location: Turkey - near Marmaris

    Othmar Multihulls ...

    Hi Fanie,

    may you are sailing in rough areas, where steep sea are regular
    and dinosaurs climb the beaches in lonesome bays :confused:

    I am living currently in South Turkey at the Aegean Sea and
    the circumstances here seem quite normal ;)

    To have a "fast" cat means to reach the next bay restaurant within
    3 hours on flat sea with max. 10 knots wind. Otherwise you stay
    in the marina or mooring place :)

    And the old folks are clever enough to do it in this way, because
    they have time enough. So their "false teeth" remain in the cup :p .
  9. masalai
    Joined: Oct 2007
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    Location: cruising, Australia

    masalai masalai

    simon, there are many things to consider in selecting your boat design... Resale-ability - the ability to sell the boat and build the next one better to meet ones needs, budget, cruising ground, lifestyle, comfort, amount of "baggage" (weight is a disadvantage in a cat), and the list goes on and on and on.....

    First boat, go conservative, for ability to be sold easily for a good resale value... - cutting edge stuff sells very heavily discounted ("Oh so it didn't perform well", or "Are you developing a new faster design?" or "what is wrong with this one?" comes to mind as immediate impressions of a prospective buyer...)

    I do not see the point in making long passages across boring oceans where danger lurks and support is just a memory.... I would rather island hop and explore as I head in a general direction, bearing in mind seasonal influences such as doldrums, severe tropical rotating storms, need for occasional resupply and interesting things/places to see and do... So to this end I have opted to build a light vessel (Bob Oram 39'C) as it has a reasonable turn of sailing speed, is easily motored with a smaller engine, has shallow draft to sneak up creeks etc., to hide from stormy weather and is quite robust and capable of handling a bit of rough if caught out....

    If you have heaps of money to spend in "flights of fancy" then follow your dream with vigour, and if it is a real ****, insure it and let it get stolen by pirates and collect the insurance.... Otherwise, buy a second hand, cruise for a while, then work out what better suits your needs,,, - (to meet "aspirational" ideals you need lots of money) and follow a fairly conservative and well trodden (sailed) course....
  10. sigurd
    Joined: Jun 2004
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    sigurd Pompuous Pangolin

    I really like the looks of that tri with the short amas. But I would have though it is more natural to have them more forward, but what do I know.
    How many foils are there? 1 in each ama, one centerboard in vaka, and? rudder? A lifting foil in the vaka bow?
    Can you take more pics please?
  11. johnelliott24
    Joined: Dec 2006
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    johnelliott24 Junior Member

    Foiling tri

    Thanks. With "Precarious!" version 1, I just copied Hydroptere; otherwise I would have put the amas and foils further forward too. There is a daggerboard in the center hull and foils on each ama. I built a completely new boat "Precariuos!2", and still have to try her out. She is lighter, has more volume in the main hull and the beams are closer together to reduce weight and windage. I'll take some pictures when she goes out.

    From reading these forums I see that one person takes a lot of heat for advocating foils, but I have to somewhat agree with him. They are the way of the future. My long-term objective is to build some bulky, classic looking boats, with lots of room, but that are light weight. They will carry lots of sail like the old "sandbaggers" did and be very fast in light air, but then "fly" before they hit their low hull speeds. Their rigs will cant so they can carry lots of SA in heavy wind if you want. These "Precarious!" boats are lots of fun, but are really prototypes to do these classic boats. This forum is very interesting. Thanks.
  12. sigurd
    Joined: Jun 2004
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    sigurd Pompuous Pangolin

    sounds like fun. but I would not bother canting the mast. with the surface sensing foils the righting moment can be set independent of the heel angle.
  13. Chris Ostlind

    Chris Ostlind Previous Member

    John... perhaps a little bit of putting things in perspective is in order.

    While I would guess that virtually everyone who sails and/or has a serious appreciation of sailing, will quickly agree that foilers are captivating and also very speedy... the reality of it all is quite different from your, "they are the way of the future" comment.

    Don't get me wrong, as I love that the guys who are experimenting with the genre are out there, tweaking, fiddling and making personal discoveries while following their dreams... especially guys like you who are actually doing it and not driving a chair in front of your computer.

    But, like anything that is as specialized for a particular activity as is the foiling segment of the sailing world, there are loads of problems that have to be considered. These problems must then be dealt with successfully in order to produce a vessel that is, as you suggest, the way of the future.

    I see repeated postings, some to the level of nausea, where none of the problems are ever addressed, never accepted, never functionally dealt with to the point of a suitable solution. There is only a repetitive set of expressions bordering on rapturous giddy excitement, while the rest of the sailing industry, as well as the sailing public, simply go about their business, paying minimal attention.

    The problem looks like this. The issues that foilers must confront in order to come to a place where the segment is able to achieve large-scale market success are going to be tough to solve. Right now, it is not here, it's not getting here by any simple stretch of the imagination and the foiling genre is ultimately flopping in the bottom of the boat because of it.

    Work on the problems, find the solutions and come up with a product that can meet the needs of the sailing public as we know it and you MAY just be able to make something of a claim akin to the potential that is currently expressed... MAY

    Foiling aficionados and especially, Mr. Takes A Lot Of Heat, have a very big mountain of hard work to climb before anything resembling a comprehensive solution is reached with regard to the problems associated with foiling. A very few people are actually doing something about it and sadly, some others are only blabbing incessantly as if they work for an ad agency and are drawn to the business of hype more than effective solutions.

    The technology has been around for a very long time now. It has not compelled the boating public to demonstrate an overwhelming desire to rush off to the boat store and demand a foiling anything. Both the now defunct, Hobie Trifoiler and the Windrider Rave, are prime examples of the problems, costs and overall lack of sailing community interest. Well-financed, established boat companies put both forward with fairly good-sized budgets behind their corporate presence. Yet, both of them failed to generate the kind of interest that it would take to be remotely considered as the way of the future. There are some very big lessons to be learned there and I see nobody addressing those issues. Rather, I see more of a love affair with the wow factor of the technology, as if the issues will just evaporate, yielding a clear path.

    I'm really sorry to say this, but right now and until something wholly dramatic takes place in the genre, the foiling phenomenon is not much more than a tasty little flavor of the month in the vast world of boating history.
  14. Gary Baigent
    Joined: Jul 2005
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    Gary Baigent Senior Member

    ahead of the pack

    hey Chris
    Although you relish any chance to castigate foiler exponents, as is your wont, most foiler experimenters don't give a rat's fart about being accepted by the mainstream of yachting. They know they are a fringe group (albeit one that is rapidly gaining popularity amongst, say, forward thinking, yacht people) and they'll continue to do their experimentation and foil design improvements anyway. I mean, yachting history is loaded with conservative, to arch conservative attacks on avant garde ideas and developments - we all know that - but who cares? On average it takes four decades before acceptance is allowed to filter into the "backward" mainstream. Let's say, free thinkers enjoy breathing the fresh air out front of the madding crowd. And you don't belong to the latter, do you mate?

  15. Doug Lord

    Doug Lord Guest

    While "foiling" has been around for a long time bi-foiling technology only arrived about 10 years ago and has revolutionized the application of hydrofoils to monohull dinghies and with it monohull speed. For the first time in history an 11' monohull is the fastest sailboat in the world(under 20') beating even windsurfers in a lot of conditions. The fact that this boat has beaten every production catamaran under 20' is nothing short of incredible.
    There are numerous applications of bi-foiling technology to almost every type of sailboat including to multihulls and many people exploring these possibilities.
    But there are other possibilities using combinations of foiling and planing hulls,"power foils" to add power to carry sail to bi-foilers, small tri's with just two foils on the main hull ,Dynamic Stability Systems that has devised and is marketing a system that adds stability to monohulls and could to multihulls as well. "Foil Assist" proven on ORMA tris and now used on some beachcats as well as on the I-14 and Catri Tri is an application of foils to not just
    improve speed but seakeeping as well.
    All this is a testament that the statement "foils are the way of the future" is not too far off the mark!
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