Rule Drawing simpli...
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Rule Drawing simplified, a starting point for discussions!  


Eminent Member National Representative
Joined: 3 years ago
Posts: 34
22/03/2018 12:16 am  

The thing that originally had a lot of people questioning the rule and how it was applied was the drawing in the appendix.

Here is a starting point illustration based on a few changes that I hope would make the rule clearer, thoughts please!

-Max loa, 661cm ,included in which is a bow bumper minimum 4mm long. (do we actually need a max length of bumper, consider it a part of the hull, who will build a longer heavier bumper than needed.

-max rig height above deck near the mast, or better definition, not nessecariy at the sheer as many old boat have raised foredecks and were measured from there, we do not want to obsolete older boats.

-max sail area written in the measurement box, don't need all the descriptions of what the intent is, this should be covered in text of rule.

-keel depth, yes, contentious, but worth having a reasonable depth settled on if we can as has many advantages.

-do we still need transverse hollows rules , is this drawing trying to write out mutli hulls in a way that text cannot state that it is a monohull rule. if people want wings on the hull, why not?

Have a look at the drawing and lets see if it can help clean up the rule as a starting point.



Eminent Member National Representative
Joined: 3 years ago
Posts: 34
28/03/2018 12:18 am  

My proposal / talking point of the box drawing and consideration of the rule follows this thinking below and I think it’s what you are wanting to articulate with the rule.

I’m just seeking to clarify it more and make it simpler.

-Ok so with the box I have drawn a max length overall.

We use a measurement box (Marblehead rig box with internal width of 661mm) we can use to confirm class elegiblity, works well,
However min length?

On the box rule drawing I have only specified that the bumper should be a minimum 4mm long and on the bow.

I have not specified a minimum hull length this may be added, however is problematic.

Is a min loa to exclude smaller boats?

If so it does not work.

A micromagic with a permanent bowsprit/“deck extension” (made as part of the deck) would be class legal if the bowsprit had a bumper on the end.

This boat is clearly going to be faster in the light weather than traditional max length rgs, we know this.

Tried it.

A boat like this can be built as the only rule that comes close to stopping it is the concaves In the hull drawing.

However the rule on concaves is below the waterline and a bow extension is from the deck.

Min length could be stated though and would allow designs that currently have oversized and illegal bow bumpers to rate as rgs, this includes dragon forces and some other production build boats.

So minimum hull length not minimum bumper length.

-Then the concaves drawing and rule, ment to exclude multihulls I’m guessing?

This rule obviously came from world sailing class rules, the world sailing rules however determine how a waterline datum is established and from there under this waterline is a controlled area.

the Rg rule does not define waterline datum.

So is this concaves drawing useful to keep?

Indeed a monohull with outriggers, sponsons even buoyant wings is legal, a boat like hydroptre is class legal and would be fast if fully developed.

Especially open to designers as we have no equipment definitions to refer to.

Intent of the rule is a nice fluffy statement however what is written can be interpreted many ways!

So maybe as was recently suggested we have a maximum beam limit?

That would work wouldn’t it?

To discuss!

-rig height, we have a fixed height, was measured from highest point of deck at one stage and now from the sheer line.

So many of the newer boats as they are built from molds have highly radiused gunwhales at the sheer line, try measuring from a point in space that is a projection of where you think it should be!

A deck limit mark could work , but maybe the highest point of the deck near the mast would be a good measurement point?

Under the current rule designers could develop localised chainplates on the gun whales to lift the sheer line at measurement point, probably good to discourage, but we are an open rule so just make there no point in doing it is easier.

-keel depth.

Ok so this ones always contentious, here’s why I have included it.

If we do it properly (and not the way I have drawn it)
Our boat measurement box that measures width could measure overall height of boat, rig and fins!

Worth a thought , with rig height fixed length still it would allow for ease of measurement.

- sail area , well that hasn’t changed in terms of the drawing, it’s still same sail area.
(On a seperate note we need to look at definitions or a way to limit size of boom fittings so that people do not create monster size boom bangs that add a lot of area to Sails, that’s another discussion seperate from the illustration.)

-so that’s the motivation behind drawing the new illustration and putting it out there for comment.

Please have a think as I believe it articulates what the rules group have been moving to explain with each rule update and would make it a lot clearer for all!

Then there’s the text of the rules and clearing up items that are remaining and not explained in the drawing, makes it easier in any language!

Read , digest and help update the rule.

It’s not changing the rule, just defining it more concisely if we can and that’s what the rules team have sought to do with each update!

Eminent Member National Representative
Joined: 3 years ago
Posts: 34
12/04/2018 11:06 pm  

So inline with a simplified drawing I will also put forward the idea for the text of the rule to potentially incorporate something along the lines of

"no fittings shall project outside the plan view of the hull/deck line"

this is instead of limiting hull width which as an open class we do not wish to restrict.

instead it would limit fitting such as cross beams with foils fitted on the ends and help keep truly monohull designs being built.

boats like hydroptre have outboard foils with bulbus head fittings that are not hulls, best described as sponson fittings and we can limit boats like this.

a deck profile limit would also eliminate someone using a short waterline boat for low wind venues that has a deck extension, similar to a bow sprit to make up to minimum loa.

the profile rule would also help reduce any tendancy by designers to have a single keel unit that attaches to the hull centrally however is trident shapes with the 2 outer foils horizontally going out and past the hull plan view point for foiling, as in latest keel boats and dinghy j foils etc.

the other option is to leave the rule to allow for innovation of foilers.

that could be similar to when the g65 with its vane was outdated by the rg65 with radio controls, it is that kind of leap we have seen in the moth class!




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