Oval Foredeck holes

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Ray Flanigan
Posts: 28
Joined: 29 Aug 2004, 22:37
Location: GBR 85

Jib mounting point

Post by Ray Flanigan » 27 Oct 2005, 08:49

:?
Why not just state that "the jib mounting points to be in a position no lower than a line taken horizontally between port and starboard gunwale and to be positioned on the centerline of the hull", that should then restrict the options of where the jib take off point is and make it is easier to read and interpret for future home builders and "officials for the use of measuring" as I am sure they will get some stick because of the rule "interpretations".
At the end of the day you go out and buy a new car, you expect it to be road legal upon receipt, the manufacturers interpret the requirements (rules) as best and build accordingly but occasionly things do go pear shaped amongst the best of them.
Do not blame the builders/ designers they read the rules and build them accordingly, they have read the rules the same as us and have had the balls to do something about it.
If it is not in the rules it is prohibited, bit difficult because then all prohibited things will have to be listed so as to avoid confusion in the future. The designers/ builders have my sympathy and admiration cos I cannot do what they do I just plod along and lust after some of the new equipment out there.
:D

Lester
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Joined: 14 Oct 2004, 22:29
Location: GBR 105
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Post by Lester » 27 Oct 2005, 09:47

Hi Charles

Working with your idea for a moment, something like "the swivel attachment point to the hull shall be above the sheer at the lateral station where such attachment is made", it may be worth noting that a number of designs would fall foul of such a rule. In these designs, the swivel attachment point is recessed in a well or channel in the deck. And, in the case of a curved or peaked foredeck, as is very common, it would be difficult for a measurer to decide whether a recessed attachment point was indeed above or below the sheer.
Lester Gilbert
http://www.onemetre.net/

David Turton
IOMICA Treasurer
Posts: 126
Joined: 24 Nov 2003, 02:20
Sail number: 09
Club: Lake Kawana
Design: Destroyer
Location: AUS599, AUS709, AUS 1309,AUS 727

Post by David Turton » 27 Oct 2005, 09:53

From memory there were a couple of boats at the last worlds that had concave decks. the proposed rule makes them illegal post change?

Does someone want to write a summary of the views for changing the current rule?
David Turton
IOMICA Treasurer

Lester
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Location: GBR 105
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Post by Lester » 27 Oct 2005, 14:58

DT wrote:the proposed rule makes them illegal post change?
Hi David

I think we must trust the sanity of our rule-makers, and imagine existing designs would be grandfathered. But I think the real issue is, what about future builds of an existing design? We saw that Brad was very unhappy about a proposal to ban coloured glass, even though he has ceased production of his Disco, on the grounds that there was planned future production...
Lester Gilbert
http://www.onemetre.net/

Steve Landeau
Posts: 256
Joined: 26 Nov 2003, 07:25
Location: USA 12

Post by Steve Landeau » 27 Oct 2005, 19:18

DT wrote:Semingly there seems to be general consensus that the oval holes don't break the rule as it is currently written?

Has anybody worked out what the effects are of having such a system?
The intent is to allow the tack to fall closer to the centerline of the boat, thus allowing the boat to point higher. This theory is true, however I think the downfall of losing consistent settings outweighs the gain.
Steve Landeau
AMYA 10859
IOM USA 112
Finn USA 112
Cal 25 #548

Steve Landeau
Posts: 256
Joined: 26 Nov 2003, 07:25
Location: USA 12

Post by Steve Landeau » 27 Oct 2005, 19:28

I think the oval holes are legal based on the current rule, but does not meet the intent of the rule. Simply adding "and shall exit the hull within 2mm of the centerplane" to the existing rule will likely do the trick.
Steve Landeau
AMYA 10859
IOM USA 112
Finn USA 112
Cal 25 #548

Brad Gibson
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Post by Brad Gibson » 27 Oct 2005, 23:52

We saw that Brad was very unhappy about a proposal to ban coloured glass, even though he has ceased production of his Disco, on the grounds that there was planned future production...
.

Disco is in the final stages of pre-production in both the USA & Germany......
I will be meeting with the US builder next week in San Diego.
Thank you Lester for your interest.

With regards to the current topic, my thoughts are that the intent of the rules is to keep the forestay attatchment on the centreplane of the Deck(hull). This oval method does seem to bend itself around the rules with regards to the deck having no definition, or being defined as hull.

As Steve has posted below, an easy way to ammend our rules if desired by the members would be to define the amount of lateral movement allowed at where the cord/swivel exits the hull/deck.

Jury is out as to whether this system works for many minds. Paul Jones has had this system in use here in AUS the longest & swears by it.
Paul had the lowest total score in Mooloolaba so read into this what you may.

Myself, i am not a firm believer in the system with the way i would like my rigs to set up at present.

I guess if the current systems used are to be deemed allowable, the only method for change would be by a Rule ammendment proposed by an NCA? If members feel strongly enough they should take this option.

Cheers
BG

cfwahl
Posts: 79
Joined: 23 Nov 2003, 23:01
Location: CAN 62

Post by cfwahl » 28 Oct 2005, 01:37

Lester wrote:. . . it may be worth noting that a number of designs would fall foul of such a rule. In these designs, the swivel attachment point is recessed in a well or channel in the deck. And, in the case of a curved or peaked foredeck, as is very common, it would be difficult for a measurer to decide whether a recessed attachment point was indeed above or below the sheer.
I am not aware of designs with a concave deck (any pointers to an image?). Sheer is a useful concept, mainly because it's defined in ERS, though I can see problems with it. I just chose it as an arbitrary, though I think reasonable, limit for the alignment shenanigans.

As I understand the definitions, the sheerline is what most folks think of as the gunwale; that sharp transition on a conventional boat between the deck and the sides of the hull; and the definitions appear to assume that this is the case, relying on "projection" where this is not a sharp cusp. I know that there are R/C boats that don't have this feature, where the transition is so gradual that it's like a monocoque structure; more aerodynamic. And now I'm told that there are concave decks. So the definition of sheer as the projection of the sheerline on the centreplane (I'll humour the spelling for now) would be difficult to establish for such a design. If pressed, I'd say that where the section goes vertical, that is, where a vertical straightedge placed against the hull at any station touches, that's the sheerline. String-in-hole fanatics could drop this point on their designs, but at a certain point the sublime turns ridiculous: you give up freeboard for jib attachment depth. I don't think that this would affect peaked or curved decks (such as the Cockatoo) at all.

So, having thought about it, I think that the actual addition at C.7.6 could be shortened to:
"Elements of the swivel and/or fittings, which are susceptible to changes in alignment due to rigging tension, shall not extend lower than the sheer."

And perhaps a special definition of sheer would be necessary to deal with unorthodox designs. People with concave decks could always make up a fixing point that meets the restriction. But I think that setting a "depth" limit for the fixed attachment is the only effective way to close the loophole.

In the end, I think that stuff like this jib attachment is heading the IOM in a "development" direction, and my own opinion is that this is not in the best interest of the class. In the class's short history, we've already been through the "skiff" phase (does anyone disagree that the "skiff" is all but dead?) so all those guys need to move on to a more moderate-beamed boat to be competitive in all but a gale. Next, we'll all need to invest in a design that has these weird holes in the deck; the latest screwy go-fast that tortures the "boat-ness" of the basic design. The class should be about racing well-matched boats together, not about constantly buying and building the next best thing. So I'm all for a rule change on this one, that nips it in the bud.
Charles Wahl

cfwahl
Posts: 79
Joined: 23 Nov 2003, 23:01
Location: CAN 62

Post by cfwahl » 02 Nov 2005, 03:08

Having thought about this some more, it might be simpler to limit the extent of the swivel by relating it to the rig, rather than the hull/deck. Certainly this would be easier to measure. So how about

Add, at the end of C.7.6: "Elements of the swivel and/or fittings, which are susceptible to changes in alignment due to rigging tension, shall not extend more than 50 mm from the closest point on the foot of the foresail."

I realize that this then becomes a second relationship between rig and hull (the other being the lower limit mark at 60 to 100 mm above the deck limit mark). However, it puts all foresail attachments on an even playing field, respecting the foresail, and how "extensive" the swivel can be. If someone thinks that 50 mm is not enough, then let's have concrete examples (other than boats that are "surfing" the current rule) demonstrating that it's insufficient to cover a reasonable design. Perhaps 60 mm is a more reasonable figure.
Charles Wahl

Steve Landeau
Posts: 256
Joined: 26 Nov 2003, 07:25
Location: USA 12

Post by Steve Landeau » 02 Nov 2005, 17:24

In my opinion it is a waste of time going down the road to eliminate the tube altogether. Bantock has been building his boats with it for over 5 years now, as well as at least a few other manufacturers since then, and that is simply too many boats to either change or grandfather. Restricting the tube is a possibility, but again, I really do not think that making these oval holes is going to win races. It is still the skippers thumbs that will complete that task. I say we spend our efforts on the real stuff like rubber bands under the jib boom, or little wires on main luffs... or Texalium... :twisted:
Steve Landeau
AMYA 10859
IOM USA 112
Finn USA 112
Cal 25 #548

David Turton
IOMICA Treasurer
Posts: 126
Joined: 24 Nov 2003, 02:20
Sail number: 09
Club: Lake Kawana
Design: Destroyer
Location: AUS599, AUS709, AUS 1309,AUS 727

Post by David Turton » 02 Nov 2005, 20:38

Here here,
Focus energies on promotion, and putting/keeping the fun in sailing
David Turton
IOMICA Treasurer

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