mainsail rule question

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cam
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mainsail rule question

Post by cam » Thu Nov 12, 2009 6:54 am

I need some clarification on the following rules .
Sail measurement .

Rule A1
C1
C4

Out of these rules I can see no reason why the sail can't be made above mast height , so long as the bolt rope is below the black bands . Also the black band rule applies to the mast only and says nothing about there being a projected line from it to stop the head of the sail ( or top battern) from being made above the black band .

Any Ideas?

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george
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Post by george » Thu Nov 12, 2009 11:54 am

This has been in discussion since well before the germany worlds, but sadly lots of dragging of feet and still no solution agreed. (? Rollo proposed a solution that is being voted on at present).
Yes, it is absolutely fine for the sail to project above the black band, so long as no part of the sail plan exceeds 7626mm above the sheer. The issue is that there is absolutely no way to measure this while sailing, and it is impossible to infer the height while sailing from a measurement taken ashore. Mast rake, and flex of both mast and sail contribute to this. Also the black band does not have to be at that height, though it is restricted by it.

Until the rule is resolved there is always going to be a risk of protest or mad measurers applying their own interpretation and insisting that people recut their sails before they can race.

cam
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Post by cam » Thu Nov 12, 2009 12:07 pm

The way I read the rules it's protest proof or due to the headboard rule everybody's current mains don't measure .

What do you think?

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george
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Post by george » Thu Nov 12, 2009 12:18 pm

All the mains measure. Not an issue. They have measurement certificates and have been fairly and accurately measured as specified in the class rules.

Sailplan height is more akin to hoisting your headboard above the black band, except that is simple to police.

Noone ever complains about people's sails extending below the lower black band, which is far more obvious and expressely forbidden in the rules!

cam
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Post by cam » Thu Nov 12, 2009 12:42 pm

The rule reads no part of the sail plan can exceed 7626 above the top edge of the hull in way of the mast . In way of the mast meaning this only applies to the sail at the mast .
So does this mean the first battern can be 300mm above the black band on the leech?

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george
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Post by george » Thu Nov 12, 2009 12:57 pm

never thought about "in way of the mast", i'm too linguistically inept to know exactly what that means, but if your interpretation is correct it nicley ends the argument. If pushed, i'm sure it would find a natural optimum anyway.

Perhaps it should be resolved in the new york court.

cam
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Post by cam » Thu Nov 12, 2009 1:00 pm

Bloody swiss .

cam
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Post by cam » Thu Nov 12, 2009 1:01 pm

Although it could be the best cup yet .

Ed Clay
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Post by Ed Clay » Thu Nov 12, 2009 1:57 pm

Not exactly sure what "in the way of the mast" means (unless it is to explain how I get bruises on my forehead when we run aground)

However rule 15.c.i says "The dimension A is to be measured between the upper edge of a lower band painted on the mast and the lower edge of an upper band painted on the mast. The upper edge of the lower band is to mark the lowest position where the line of the top of the boom when at right angles to the mast cuts the mast. No part of the headboard of the sail shall exceed in height the lower edge of the upper band."

As George says this has been a discussion point for some point as it is very difficult to determine if the current square top sails comply with this rule. The current rule proposal (which countries are voting on at the moment) looks to resolve this by changing the measurement technique for mainsails. The new method would measure the area of a trapezium at the top of the sail; rather than the current triangle, which leaves an unmeasured triangle at the leech on square top sails. The total maximum sail area would be increased to take account of the new area being measured.

If you have got strong views on this make sure you have voted.....

Ed

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Shu
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Post by Shu » Thu Nov 12, 2009 9:12 pm

cam wrote:The rule reads no part of the sail plan can exceed 7626 above the top edge of the hull in way of the mast . In way of the mast meaning this only applies to the sail at the mast .
So does this mean the first battern can be 300mm above the black band on the leech?
I believe the phrase "in way of the mast" refers to the top edge of the hull. So the sailplan may not exceed 7626 mm above the top edge of the hull. Do you really think the writer(s) were only refering to the bolt rope? If so, they wouldn't have included the headboard limitation.
Steve Shumaker
USA 1183

cam
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Post by cam » Thu Nov 12, 2009 11:40 pm

Read the headboard rule again steve . As per that rule eveyones mains are illegal .

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Post by cam » Thu Nov 12, 2009 11:52 pm

No part of the headboard of the sail shall exceed in height the lower edge of the upper band.


"The way I read it they are talking about the headboard only .


I believe the phrase "in way of the mast" refers to the top edge of the hull.

They are talking about the black bands only . And black bands refer to the mast only , not a projected horizontal line from it .

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rand
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Post by rand » Fri Nov 13, 2009 12:41 am

I've always thought that the new mains were illegal, but nobody listens to me.

But my main is legal, as it has a 90 degree headboard... Maybe I can collect some silver just by showing up and heading to court! :)
Rand Arnold
International 14 USA 1143
"A Bumblebee Called Kate"
(former US President, former US Measurer)

cam
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Post by cam » Fri Nov 13, 2009 1:15 am

I don't want to start a war of words over this . I'm starting to build a new main for the worlds and need to know if we'll strike trouble if I make it higher on the leech at the top battern .

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Post by Guest » Fri Nov 13, 2009 3:48 am

I asked this ? of Rollo at the POW aniversary regatta in Cowes 2-3 yrs. ago when saw the RMW main from up on the hill with a VERY positive head. No clear response at that time, however I know it started some discussions. I had heard this was being discussed and addressed at the Germany Worlds, which I unfortunetly was unable to attend. Thought there was some max angle from the band that they were going with, but haven't heard specifics. I know there was some discussion during the development of newer sails, but don't know if complete final answer.

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