PHRF ratings for Working Sails San Juan 21

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No Excuse
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Joined:Sat Apr 02, 2011 2:15 pm
PHRF ratings for Working Sails San Juan 21

Post by No Excuse » Sun May 08, 2011 3:24 pm

I am curious if anyone has any history or documentation on how the PHRF ratings were established and whether these are correct.
I believe (for no other reason than local discussion) that the All Sails boats have been assigned a PHRF rating of 252 . We, Fleet 1, have used a 267 for Working Sails boats. Again I can not cite any documentation other than local discussion. I doubt that there is actually a PHRF rating for a subclass of boats, (ie Working Sails), but If anyone can verify, or provide documentation as to the actual values that would be great information.

I can not question the validity of the 252 (All Sails) in relation to other types of boats, their ratings or adjusted performance. I do question the difference we (Fleet 1) have been using between All Sails and Working Sails (252 vs 267). I believe that the Working Sails rating needs to be increased to provide parity with the All Sails boats where PHRF ratings are or may be used. How much of an increase I can not speak to, but after the results of recent races, it appears to require a significant increase.

Your input and experience would be greatly appreciated.


EXTRACT TAKEN FROM WIKIPEDIA:
Performance Handicap Racing Fleet (PHRF) is a handicapping system used in yacht racing. It allows dissimilar classes of sailboats to be raced against each other. The aim is to cancel out the inherent advantages and disadvantages of each class of boats, so that results reflect crew skill rather than equipment superiority.
PHRF is used mainly for larger sailboats (i.e., 7 meters and above). For dinghy racing, the Portsmouth yardstick handicapping system is more likely to be used.
The handicap number assigned to a class of yachts is based on the yacht's speed relative to a theoretical yacht with a rating of 0. A yacht's handicap, or rating, is the number of seconds per mile traveled that the theoretical yacht should be in front of or behind that yacht. Most boats have a positive PHRF rating, but some very fast boats have a negative PHRF rating. If Boat A has a PHRF rating of 15 and Boat B has a rating of 30 and they compete on a 1 mile course, Boat A should finish approximately 15 seconds in front of Boat B. Results are adjusted for handicap by the race committee after all competitors have finished.

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cklamp
Posts:177
Joined:Fri Mar 25, 2011 3:34 pm

Re: PHRF ratings for Working Sails San Juan 21

Post by cklamp » Mon May 16, 2011 7:09 pm

No one has any thoughts?

Fleet 1 has been having some discussion of the issue so I ran some of the numbers.

From sailritesails.com

Jib
Area - 82.05*ft2 (7623mm2)
Mainsail
Area (no Roach) - 104.41*ft2 (9700mm2)
Spinnaker
Area - 251*ft2 (23319mm2)

We're talking 355.41sqft vs 186.46sqft with the two sail plans. Or more accurately, a 90% increase in Sail Area. But I have no idea how much faster that should increase boat times on the water.

Any thoughts?

Later
C
Fleet 1 Webmaster
http://www.sj21fleet1.org
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SJ21 1974 MKI #897, Mizu

Mark Sailmaker
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Joined:Thu Mar 31, 2011 10:42 pm

Re: PHRF ratings for Working Sails San Juan 21

Post by Mark Sailmaker » Thu May 26, 2011 1:45 pm

Here in Eastern NC we have also experimented with a 15 sec/mile differential between WS and AS. We've found that we have to have a fairly long downwind leg to make up the difference with a spinnaker. Bear in mind that unless you're using a genoa as well as a spinnaker, both classes have the same upwind sailplan and the WS boat carries his rating advantage all around the course. So while the upwind sailplan is identical, the AS boat is losing by 15 sec/mile for the whole upwind leg. We have some really talented people in WS and they are almost impossible to beat with the 15 sec differential unless it's blowing 12 or so and we have a long course. With more breeze it's even harder, because the jib boat will be at full power and the spin boat has a hard time breaking out on a regular basis. It sometimes takes a mile to pass a WS boat with a spinnaker boat, because the boats are so easily driven that they reach hull speed quickly. I certainly wouldn't look to a more generous rating split - perhaps more training/practice at downwind technique with the poled out jib? Simply sailing wing and wing pointing directly downwind is not always the fastest way to the mark.

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cklamp
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Re: PHRF ratings for Working Sails San Juan 21

Post by cklamp » Thu Jun 02, 2011 7:01 pm

Mark,

thanks for the input... nice to see a difference of opinion from an entirely different coast:)

later
C
Fleet 1 Webmaster
http://www.sj21fleet1.org
http://www.sj21fleet1forums.org
SJ21 1974 MKI #897, Mizu

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