New low-cost "hardware store" racing class; input on proposed rules

Discussion in 'Sailboats' started by Petros, Mar 19, 2012.

  1. Segler
    Joined: Apr 2015
    Posts: 43
    Likes: 3, Points: 8, Legacy Rep: 18
    Location: Issaquah/WA

    Segler Junior Member

    What is a "hollow" and what is the point of this rule?
     
  2. Petros
    Joined: Oct 2007
    Posts: 2,936
    Likes: 148, Points: 63, Legacy Rep: 1593
    Location: Arlington, WA-USA

    Petros Senior Member

    it prevents "cheaters" that make tunnel hulls or catamaran hulls but fit within the dimensions of the mono-hull. This is so all "mono-hulls" compete with other monohulls, and not a rule beater "catamaran" hull.

    The 1" is just a number, but if you had a cat hull the gap could be over a foot. It is just a threahold number that allows some concavity on the shape, but small enough so it can never be construed to act like a multi hull.

    This btw, is a common way in most "open" class rules to keep a class ment for monohulls to keep it that way. Without such a rule, as soon as someone builds a multi hull that fits within the rules otherwise, there is such an advanage that the whole class becomes nothign but multi-hulls.

    This happened a number of years back with the America's cup compatition, it was always considered a mono-hull class for almost a century. As soon as someone entered a multi hull, there was big protests and complaints, but the team that built it pointed out there was nothing that explicitly prohibited it and it met the letter of all the rules. Ever since, all American's cup racers have been multi hulls.
     
  3. Richard Woods
    Joined: Jun 2006
    Posts: 2,209
    Likes: 172, Points: 63, Legacy Rep: 1244
    Location: Back full time in the UK

    Richard Woods Woods Designs

    Of course the ACup comment isn't quite true, but it did end the 12m involvement

    The "no hollow" rule is found in the Int Moth rule. The scow Moths could have 2 "bows' but they had to merge into one hull, IIRC about 750mm aft of the stem

    RW
     
  4. Petros
    Joined: Oct 2007
    Posts: 2,936
    Likes: 148, Points: 63, Legacy Rep: 1593
    Location: Arlington, WA-USA

    Petros Senior Member

    Richard, I may be wrong about that, it was what I recalled. I thought I remember there was a lawsuit over the interpretation of the Acup rules over this issue. though I do not know the details, there was a point in time when all Acup entries were monohull, and after the lawsuit (or perhaps threatened lawsuit) now all entries are mutli hull.

    If you know the details please tell! I will be happy to be corrected.

    the rule I borrowed from the moth class, but I have seen similar rules in other developmental classes and thought it was a good idea to separate mono and multi hull competition. It seems multi hulls are superior in speed (I used to race in a hobie cat class many years ago, and have built a number of multi hull day sailors), but mono-hulls far outsell multi hulls in North America, perhaps because of the utility and simplicity, or even just tradition.
     
  5. Segler
    Joined: Apr 2015
    Posts: 43
    Likes: 3, Points: 8, Legacy Rep: 18
    Location: Issaquah/WA

    Segler Junior Member

    Do you know of any catamarans within our mono-hull box rule that would out-sail a mono hull built to the same rules?
     
  6. CT249
    Joined: May 2003
    Posts: 1,380
    Likes: 156, Points: 63, Legacy Rep: 215
    Location: Sydney Australia

    CT249 Senior Member

    The history of sailboat racing proves that even if we can't think of one now, someone may build one later. For example, years ago some top sailors (including the Herreshoffs and an Olympic gold medallist whose family had been into cats for years) said you couldn't build a small cat that wouldn't nosedive. New Zealand's Jim Young then created a 12 foot long cat (the Kitty Cat) that didn't nosedive, and it beat all the monos in the NZ v Australia 12 Foot Skiff championship.

    The 14' Paper Tiger, 15' Quickcat, 15' Solo and 14' Arrow cats are pretty simple designs. The Arrow, for example, has simple flat-bottomed sharpie-type hulls and just one centreboard, swinging down the crossbeams. The Quickcat was similar. It's hard to see how you couldn't build an Arrow type cat, perhaps even a standard one, that would fit into the rules as I recall them.

    The Arrow is rated midway between a 505 and a 49er for speed. The monos closest to the box-rule boat are rated about as fast as a Laser, even with spinnakers and (in one case) a trapeze. With that sort of enormous speed difference, even carrying a ballast box isn't going to let the monos be competitive.

    Monos far outsell multis just about everywhere, and it can't really be just tradition because the multis have been heavily marketed for 45 years. In some places their popularity (as a proportion of all sailboats) has dropped since the '60s and '70s, so it's not as if their time is coming slowly. Top multihull designers like Ian Farrier, Nigel Irens and our own R Woods prefer monos for some purposes, so it can't be just idiots who like monos for some uses. So do innovative sailors like the foiler Moth guys, so it can't be conservatism. Cats are fantastic (I'm waiting to hear about the new one I'm buying to replace our current fast cat) but surely the evidence indicates that for most sailors in most situations the mono is a more suitable choice. If you make them uncompetitive the class won't succeed.
     
  7. macbeath
    Joined: Jul 2015
    Posts: 51
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: Seattle

    macbeath Junior Member

    Without the rule about hollows, it wouldn't be at all hard to design a catamaran that's faster than a monohull in the 14' x 5' box. Resistance is less, stability is more.
     
  8. Segler
    Joined: Apr 2015
    Posts: 43
    Likes: 3, Points: 8, Legacy Rep: 18
    Location: Issaquah/WA

    Segler Junior Member

    If that is so evident, why hasn't anybody done it? There are plenty of mono hulls in the neighborhood of 14x5, maybe 5+, but no cats. And if it were true, why don't we all do it?
     
  9. CT249
    Joined: May 2003
    Posts: 1,380
    Likes: 156, Points: 63, Legacy Rep: 215
    Location: Sydney Australia

    CT249 Senior Member

    But don't the cats that DO fit into the box, or could fit into the box, show how easily a cat would win? The Hobie Bravo, which is only a few cm wider but three foot shorter, is rated faster than a Laser (which is itself faster than most 15' cruiser/racer dinghies), and you could build a much faster cat than the Bravo within the same dimensions.

    As noted, the Arrow is only 1ft wider and even the home-made ply Arrow is almost as fast as a carbon fibre, semi-foiling International 14. Even with one foot off the beam and no trapeze an Arrow would beat a 505 or International Canoe most of the time. The Arafura Cadet, which is a baby Arrow for little kids, is rated faster than a Laser and it's much smaller than this box.

    Why doesn't everyone sail cats? Because some people don't like the slower turning, many people don't like the stability (as in cycling, rock climbing, surfing, dancing etc, humans LIKE leaning and being out of balance), the helm is slower to respond, rig loads are higher, etc.

    Obviously cats have many advantages; they are much faster, they feel fantastic when flying a hull, the feeling of power is superb, the efficiency is breathtaking. Neither is better than the other, just like windsurfing isn't better than yachting.
     
  10. Richard Woods
    Joined: Jun 2006
    Posts: 2,209
    Likes: 172, Points: 63, Legacy Rep: 1244
    Location: Back full time in the UK

    Richard Woods Woods Designs

    Check out the Laser Vortex. An attempt to combine the two types. It failed because of the extra hull surface area and the complicated hull/deck joint which was rarely watertight for long

    RW
     
  11. sharpii2
    Joined: May 2004
    Posts: 2,181
    Likes: 291, Points: 83, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    I believe that some time during the long history of ocean racing, someone built a boat that had a sort of a tunnel hull. I'm not sure the top arch of this tunnel even cleared the waterline. But what it did do was allow a much greater buoyancy shift to leeward when it heeled, which gave it greater sail carrying power. I believe this boat was named the Seawanka, or something like that. It created such a stir, with its superior performance, that a new rule was created against its type, and even given the offending boat's name.

    IIRC, the Hobie 12 started out as a scow, made out of a block of foam. As the designer worked it over, the hull got hollowed out more and more along its length. With each hollowing out, it sailed faster and faster. Eventually the arch of the hollowing out cleared the waterline, and the boat became a catamaran.

    I know this is tricky, when talking about high performance sailing dinghies, as in many of them, the crew weight makes up a significant portion of the entire boat weight. By hiking out, the CG of the boat is moved quite a bit to windward, which has much the same effect as the CB shifting to leeward.

    So, if we are going to compare types, we had better stipulate that both types have hiking out or not, or trapezes or not.

    I'd bet that in all cases the greater buoyancy shift to leeward would give even the tunnel hull an advantage over a more conventional shape, especially wit design rules where the Sail Area is not directly limited, such as with this class.
     
  12. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 346, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Dominion

    In 1898, Dominion became the first tunnel hulled scow and cleaned up. She defended the Sewanhaka Cup for the Royal St. Lawrence Yacht Club. It was designed and sailed by Herrick Duggan. After her victory the Dominion type tunnel hull was banned.....

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  13. Petros
    Joined: Oct 2007
    Posts: 2,936
    Likes: 148, Points: 63, Legacy Rep: 1593
    Location: Arlington, WA-USA

    Petros Senior Member

    I have spent several days, all day, on the trampoline of a Hobie 18, and I have spend many hours, and several days at a time, in mono-hulls of different sizes. The cat was fast and fun, but very tiring, even in fair weather. But on the cat there was not much room for gear, all gear had to be secured, and moving about, accessing gear, food, charts, etc. was all a lot more effort than on even a small mono. Many hours on a mono hull are relaxing (with fair weather of course), and it is more comfortable in all points of sail, and even tied up at the dock.

    Sailing a cat reminds me of off road motorcycling, vs. a road trip in a large comfortable family sedan, like being in mono hull. Or down hill skiing on steep double diamond (expert) runs, vs. cross country skiing on nice trails with the family dog tagging along.

    Both have their attractions, but both are very different experiences, skiing steep expert runs, or ripping up steep trails on bike, are exhilarating, but very tiring activities. Very few people that ski actually will attempt the steep narrow chutes below the cornice at the top of the ski area, comfortable road bikes out sell off road bikes by a very large margin.

    And mono hulls way out sell multi hulls for perhaps the same reason.
     
  14. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 346, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    I found sitting on a tramp really uncomfortable as was crawling across for every tack or gybe. But most of the cats I sailed had trapezes and that was comfortable-except tacking. Thats why I like trimarans with a center cockpit.
    But I still love a planing mono or even a keelboat heeled over-its mostly all good.....
     

  15. Richard Woods
    Joined: Jun 2006
    Posts: 2,209
    Likes: 172, Points: 63, Legacy Rep: 1244
    Location: Back full time in the UK

    Richard Woods Woods Designs

    I don't want to trawl through all the pages again. The original rules were posted on page 30, post 445.

    Where are the Challenge 600 rules? Page/post

    which rules are people building to?

    thanks

    RW
     
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.