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Thread: Rudders

  1. #1
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    Default Rudders

    Let us split gthis thread off from the matter of the legality or otherwise of Japanese Footys!

    The most complex and restrictive part of the Footy rule is that dealing with rudders. There are a number of reasons for this. Firsstt, when the 'box' rule was introduced it had to accomodate boty Brett's original New Zealand Boats (12" long, that's your lot) and existing British boats with transom hung rudders. If a boat with a transom hung rudder was not to be 'unfairly' treated, there had to be some means for the rudder to stick out of the box.

    However, it was feared that, if this were allowed, a rudder could effectively become a part of the hull, adding to the sailing length and possibly as a second keel. Hence the size of overhanging rudders was controlled in terms of fore-and-aft length, thickness and (to some extent) depth. The rules on a V in the box for the steering gear were an attempt to give a wide choice of steering gears without any risk of the steering gear itself becoming part of the sailing length of the hull.

    Nobody on the committe that designed the rule has any serious belief that they are faster on a Footy in the theitr commonest form - the type that appears on the tail end of an Open 60. The real target was twin rudders/keels arranged fore-and-aft in the general style of the 12 m USA and KZ23. These are REALLY complex and expensive - as well as being very effective if you can make them work. You can forget any idea of 'simlicity' or 'cheap' right awy. Moveable appendages were ruled out for the same reason.

    Assuming that we do not want KZ 23 type tandam keels or USA style bow and stern rudders, there seems to be little harm in alowing to produce character boats that look like Open 60s than there is to allowing them to produce siemi-scale Chinese junks or Arab dhows within the Footy rule. The stability characteristics and geometry of a Footy are so different from those of an Open 60 that they are unlikely to sail particularly well. Any complexity involved is therefore purely a matter for the owner/builder of the boat.

    What about a rule that goes somthing like this.?
    On boats registerd after dd/mm/yy, transom hung rudders and all fittings rigidly attached to them may have a maximum total volume of xxx ml. Such rudders must be removeable for measurement. Rudder operating gear may not be of a shape or size that is not appropriate to its primary purpose.
    I can see some ways you might get round this in the sense of not producing what the rule maker had in mind, but it is hard to see how you could get any speed advantage. What the does do (I hope) is to eliminate various artificialities and free the rule up - while retaining the quite worthy aspirantions of the original rule makers.

    Now you awkward squad! It's play time. Come and try to pull it to pieces.

    NB This is written as a private musing and does not represent any official view.
    A.

    He who dares sometimes wins.
    He who doesn't always looses

    Footys GBR 26 Little Gull
    GBR 28 Dingo
    GBR 61 Merlin
    GBR 71 Akela
    GBR 77 Sun Dog
    GBR 171 Mandeln i gröten

  2. #2
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    Default

    I not fond of your suggested change. Mostly because I have no interest in calculating volume of rudders at regattas. I'm also not sure how it fits into the existing rules.

    I am a bit tired of this whole rudder issue too. Let's put it to rest. How about this as a suggestion? Choose a proposed change to the Rules.

    Proposal #1
    E.1b Only a single rudder is permitted.

    Proposal #2
    E.1b There is no limit on the number of rudders. If more than one rudder exists, the rudders must be contained within the box. Use of the slot for rudder measurement in multi-rudder boats is not permitted.

    Let's kick the language and proposals around for a while, about 2-3 weeks. If it looks like we have something to vote on, I'd like a registered skipper to email their registrar with the proposal. Maybe everyone will prefer Angus' idea. We'll forward it to the Tech Team. After a short period, 1 month or less, we'll post their comments. Things like "well, now you've permitted canting keels and other movable foils" or "the proposed changes appear to only affect the number and measurement of rudders". And then you'll all get a ballot from your national registrar.

    Comments? Discussion?
    tallastro

    Victoria 1013
    Footys USA33 & 141
    RG65 USA17
    EC12 402

  3. #3
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    Default

    Keep going - you are still long way from an OD - but are making progress with each new sub-rule.


  4. #4
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    Gentlemen - I am bitterrly disappointed in both of you. I am also rather disappointed in myself and my ability to put across clearly what is happening.

    1) There is no longer any slot. One of the main effects of the change is to eliminate it. Transom hung rudders (i.e. ones that can extand sailing length) must be removed for measurement. We have no limits on steering gear heights, where tiller arms a located or any other such tomfoolery. What we are doing is opening the rule up, not narrowing it down.

    2) Measurement of he rudder and everything rigidly attached to it is easy, so long as it is demountable. You simply take a rerasonably accurately calibrated kitchen measuring jug and immerse the thing in water. The effect of the volume measurement is overall the same as that of the slot - lengtyh * breadth * height - except that the designer has more liberty in what he does with them and all sorts of complications about multiple rudders are eliminated(they normally have toe-in, for example. What is the overhang beYond the transom). Equally to the point,, we azre allowed foils on rudders to slow us down - almost anything we like except enough volume to make any significant difference to speed.

    Next bull please!
    A.

    He who dares sometimes wins.
    He who doesn't always looses

    Footys GBR 26 Little Gull
    GBR 28 Dingo
    GBR 61 Merlin
    GBR 71 Akela
    GBR 77 Sun Dog
    GBR 171 Mandeln i gröten

  5. #5
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    I don't think the current rule is so bad.
    So what.. you are only allowed one rudder.Pretty much like every other class.
    If only being able to have one rudder is going to put you off being involved with the class then the class probably wasn't for you anyway.

    Why is it than when someone doesn't like something in this class we have to justify the rules and then try to accomadate them??
    I don't see this happening with other classes.

    The class is growing well,So obviously the rule as it is working.

    If it isn't broken don't fix it.

    removing rudders and mearsuring volumes will not help us..I can see the bun fight now...I see very thin rudders raked well aft with wings on the bottom.


    edit..with multiple rudders allowed my logical course of design action in the first instance would look into having a bow and stern rudder and no keel.
    2nd action..bow and stern rudder with very tiny hi tech keel strut to hold bulb..rudders are the lifting surface,keel strut does nothing except hold bulb.
    3rd action..with rudder thickness restrictions removed I would look into wings on the bottom of the rudders to help with handling and lift.
    Last edited by Brett; 07-15-2007 at 04:50 AM.
    http://homepages.ihug.co.nz/~bsmack
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    Design perfection is achieved, not when there is nothing else to add but when there is nothing else which can be taken away.

  6. #6
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    3 I am certain is a big no-no as far as performance is concerned.
    A.

    He who dares sometimes wins.
    He who doesn't always looses

    Footys GBR 26 Little Gull
    GBR 28 Dingo
    GBR 61 Merlin
    GBR 71 Akela
    GBR 77 Sun Dog
    GBR 171 Mandeln i gröten

  7. #7
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    I have not made a footy yet but plan on it this winter.

    I does not matter to me about the rudders as I will not be racing. But I had an idea from dingy racing, and that is could you elliminate the rudder slot and make a measuring tool like a rectangle peice of wood the a size to be determined by the class, and then have a slot in the middle, so the full rectangle would be max area of rudder and the slot would measure the thickness. This tool would put the rudder into its own box rule. Just an Idea

  8. #8
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    Why are we having this discussion? There is nothing wrong with the existing rule. I can not understand why JPN-001 has 2 tandem rudders. There is no apparent advantage to it (or am I missing something?)

  9. #9
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    OK Angus - a less sarcastic response.


    1. This issue was addressed to accomodate the UK (and other) boats built with transom hung rudders before the existing rule was adopted. They are simply "grandfathered" in if it is such a big deal to accomodate their "older" designs. Obviously new boats built since the rule was adopted don't qualify.

    2. If the older designs are truly that much superior than the new boats, simply issue a maximum length that will allow them to extend beyond the hull transom - again limiting any new boats to rules as written. I'm not certain why anyone would suggest that a 12 inch boat and a 14 inch rudder extending aft from the transom would even be considered as "legal". If you are going to subscribe to being an international class - a few "hard" decisions will come along. Proof of a class that wants to remain as developmental means having to say "no" sometimes - but as few times as possible is my suggestion.

    3. How many "old" boats are we talking about? If less than a dozen, it would seem you are messing with rules and trying to accomodate a very small portion of your members. You ( and others) keep saying how easy and quick it is to build these boats - so let the rules stand and let the owner build a new hull to comply.

    4. I have a one meter in an emerging class that requires a factory deck. Prior to the rule (and class formation) I had modified the hull to allow the deck to curve to the transom, and I have wood veneer that was to be the deck. With the rules adopted (and after my lobbying effort) my boat isn't legal - so end of story. Why would I think the class would deviate just to accomodate me? Something wrong with those folks who expect this treatment.

    5. Is it hard to say no to a boat built out of compliance? It seems to be - so why not let the class decide on proven performance. If the Japanese boat with two rudders is fast, others will modify to be equal, if it doesn't perform, the class will allow it to sail, but then who cares if single rudder boats win? I honestly think there is a bit too much concern over rule modifications - let the class decide. Each competitor has a rule book and can protest at any race. If the boat doesn't fit the rules, it's illegal. People can read so try to step back and let them become educated at the race site. If they want to take a chance and stretch the rules, let the protest committee decide as a group.

    6. Again, Brett (and others) brought forward a very simple idea - and too many fingers have added rules for personal agendas, or for some unknown reasons. Your posts (Angus) on another site of a very lightweight boat seems nullified by the silly battery requirement of AA size. Since the batteries are inside the boat and not in the keel (my original design thought) the hull weight loss has little bearing. Put the batteries at the bottom of the keel as part of the ballast and ....... ahhh, but I would NEVER think to argue that one for a personal boat, thus I elect not to play.
    Should the rules ever settle down so I know what I can develop I might proceed with one - but let me be free to design and provide performance proof. My guess is if it's faster, others will copy - if it isn't, at least I had a chance to compare performance and "then" set it on the shelf as a failed idea. Every time you poke the rules with the sharp stick, you remove yet another idea that someone might like to try.

    For these reasons I cast a suspicious eye on the so called development theory of the class.

    A second thought/suggestion - if you really must, make your rudder dimensions effective January 2008. Then those who are pushing limits at least have a deadline to build a boat that complies with the "class" rules.

  10. #10
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    Quote Originally Posted by Brett View Post
    I don't think the current rule is so bad.
    So what.. you are only allowed one rudder.Pretty much like every other class.
    If only being able to have one rudder is going to put you off being involved with the class then the class probably wasn't for you anyway.

    Why is it than when someone doesn't like something in this class we have to justify the rules and then try to accomadate them??
    I don't see this happening with other classes.

    The class is growing well,So obviously the rule as it is working.

    If it isn't broken don't fix it.

    removing rudders and mearsuring volumes will not help us..I can see the bun fight now...I see very thin rudders raked well aft with wings on the bottom.
    I agree completely Brett...

    As an OOD who hopes to run many more footy events I also agree with John that removing and measuring the volume of parts is not something I would want to do. May I dare to suggest that such a suggestion would not come from one who has to do it!

    Anyone may build a 12" boat with twin rudders... it simply isn't a 'Footy'. How hard is that to grasp?

    Graham

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