Classic Rating Formula (CRF) "Rig Factor"

[griffinb]

I suspect the rig correction factors have been arrived at through experience and time.

At 0.91 its time to step a broom stick with a token 2 sq ft of rag on it down aft on your sloop and call it a yawl. What does the rule say about % division of SA?.

Better still lash your broom stick to the pulpit and call it a schooner.

Nah second thoughts that will probably determine your spinnaker size.

I can't find anything written about minimum main/mizen mast ratio to qualify as a yawl/ketch.

I'm sure if you pushed it too far the race organizers would just call you a sloop.

 

[griffinb]

One thought is that you are clearly seeing the event as a competition between the designer and the rule writers. The event organisers may not see it like that. If they consider that the rule is simply there to attempt to provide as fair as possible racing between a fleet of disparate boats, then they may see a deliberate attempt to design to the rule as being against the intention of the event and against the interests of the vast majority of competitors. In which case they may simply decide that the best interests of the majority are served by refusing your entry.

You're absolutely right. And the creators of this rating formula seem to be paying better attention than some. For instance, when IOR boats started getting ugly to try to beat that Rating rule.

I'm sure if anyone showed yo with foils or wingsails the wouldn't be allowed to race, even if the rules don't expressly forbid those designs.

The challenge is to beat the rule without looking like you're trying. Build a boat that blends in with the rest of the classic fleet, but finished at the front.

 

[Bruce Woods]

I can't find anything written about minimum main/mizen mast ratio to qualify as a yawl/ketch.

I'm sure if you pushed it too far the race organizers would just call you a sloop.

Griff its time to Lawyer up and find out. All along the path of development/measurement rules there has been many loopholes found, exploited and plugged.

Who can forget the IOR 1/4 tonner with Mainsail only rig, or the Moth class windsurfer, or the 12 foot class gate crashed by Jim Youngs Kitty Cat.
What may appear obvious to some , ain't to others.

Sure there been a few rejected before the start gun, the most notable was another IOR boat with forestay and back stay but no Shrouds. With a athwarts stay base length of "0" the vessel gained a large sail area advantage. I'm sure CT249 will know the goss.

 

[Earl Boebert]

The title of the classic book on the topic says it all: "Men Against The Rule."

Cheers,

Earl

 

[gggGuest]

Sure there been a few rejected before the start gun, the most notable was another IOR boat with forestay and back stay but no Shrouds.

Strictly speaking it wasn't rejected. The rule folks used a provision in the rule to allow them to make an adjustment. It was still allowed to compete, but with a rating that much better reflected the actual boat - meaning the owner had spent a large sum of money for at best no measurement benefit at all. At that point the boat was withdrawn from the event and never competed.

 

[griffinb]

Looking at the foretriangle area rating for LP% > 1, there seems to be an error in the formula. An LP of 1.01 with a J of 9 feet drops the rated area by 38% compared to a LP% of 1.00. This is in reference to the 4/25/17 formulas referenced above and on the website. These foretriangle formulas should blend smoothly.

edit - I suspect the second open parentheses should fall after the 1, not before, thus guaranteeing a number bigger than 1.

Good eye. It doesn't seem like rating should change much from a 99% to 100% to 101% jib.

On the topic of parentheses, the formulas for LBRC, DLF, and SaDF have odd numbers of them...

I'm going to email the rule committee and ask for clarification.