I’m going to insert a comment here on keeping perspective with PHRF ratings.  I 
recently had a conversation with an individual affiliated with our local 
ratings and he commented that 3 secs equates to approximately 1 boat length for 
every mile raced.  So as nice as it is to get 3 or 6 secs, IMHO it’s really not 
a big deal.  I can blow a tack and lose a boat length, multiply that by how 
many tacks are made in a mile and, well, it points out I should spend time on 
boat handling and less worrying about ratings.  

 

Obviously know the rules and use what’s made available to you, but keep in mind 
where real gains are made.    

 

Hope that helps.

 

From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Dennis C. 
via CnC-List
Sent: Wednesday, May 07, 2014 4:48 PM
To: Gary Nylander; CnClist
Subject: Re: Stus-List Technical sail discussion

 

Gary,

You are right about the above deck furler.  I'm in the Gulf Yachting 
Association (gya.org) Here's the rule:

"The PHRF committee may allow +6 seconds per mile in rating for a roller 
furling headsail and +12 seconds for an optional IN-MAST roller furling 
mainsail. Boats must have a SA/DSPL less than 20.01 and an inboard or saildrive 
(non-retractable) engine to be eligible for credit(s). The attached form must 
be submitted to receive this credit.

1. Uses a working roller furling headsail attached to an above deck mounted 
roller furling system. Roller furling headsails must be tacked above the drum 
and may be interchangeable with other working roller furling headsails while 
racing. Possible +6 seconds!

2. Uses an optional working Roller Furling in-mast mainsail, which may have no 
more than 5 vertical battens and that the roach of the sail does not extend 
past the backstay (or a line from the top of the mast to the deck edge of the 
transom if a back stay is not standard on the boat) and is furled vertically by 
rolling rather than flaking. Possible +12 seconds!

3. For the Roller Furling Headsail credit the boat must have a sail 
area/displacement of less than 20.01. This value (SA/DSPL) is based on the 
following formula: SA/DSPL = SA / (DSPL/64)^2/3.

Sail area and displacement values will be based on the standard dimensions 
published for the boat class by US Sailing (http://offshore.ussailing.org/phrf) 
“Critical dimensions” using 100% of the foretriangle and 100% mainsail and 
mizzen sail area.

4. Each boat has to apply for this credit individually, and the committee 
reserves the right to refuse the credit(s) to boats that they deem to be more 
racing than cruising. (Refer to GYA-PHRF.com for a copy of the form)

5. Will notify the PHRF Committee of any changes made to the above items."

Touche's SA/DSPL is 20.0

 

Dennis C.

Touche' 35-1 #83

Mandeville, LA

 

On Wed, May 7, 2014 at 2:30 PM, Gary Nylander via CnC-List 
<cnc-list@cnc-list.com> wrote:

I don't know about your PHRF area, but Chesapeake requires that the furler drum 
is above deck AND you have the UV patch (heavy cloth) on both the foot and 
leach of the sail. Then you get the six seconds.

Gary
----- Original Message ----- From: "Martin DeYoung via CnC-List" 
<cnc-list@cnc-list.com>
To: "Dennis C." <capt...@gmail.com>; <cnc-list@cnc-list.com>
Sent: Wednesday, May 07, 2014 1:32 PM


Subject: Re: Stus-List Technical sail discussion



Calypso's headsails were also cut for a furler with the higher foot, now about 
18" off the deck.

We still get a significant "speed bubble" in the main at the mid to upper wind 
range for the light and heavy #1s.  The bubble shows up 6' to 25' (off the 
deck) on the mainsail.

>From my miss-spent youth crewing with serious race programs I expect there to 
>be an advantage to the deck sweeper type headsails, more so for the early IOR 
>type sail plans with big fore triangles and smaller mainsails. The engineers 
>may reference something about an end plate effect.

Over the last 10 years of club racing Calypso with roller furling headsails we 
see a significant decrease in performance at the low end of the wind range, 
especially in acceleration.  Side by side with another C&C 43 that had newer, 
non-furling headsails Calypso was left in the dust as the wind built from calm 
to 5 knots.  Once the TWS was above 7 knots the speed difference was much less 
but the newer sails still pointed higher.

After reading about your +6 per mile for the roller furler I need to take a 
close look at the PHRF-NW book and re-file Calypso's data.  We are still using 
the old IMS/IOR type measurements.

Martin
Calypso
1971 C&C 43
Seattle

-----Original Message-----
From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Dennis C. 
via CnC-List
Sent: Wednesday, May 07, 2014 5:51 AM
To: cnc-list@cnc-list.com
Subject: Stus-List Technical sail discussion

I recently re-filed my PHRF certificate to get +6 seconds for a roller furler.  
Subsequently, I just had the luff my Mylar/Kevlar 155 cut down to fit on the 
furler.  My sail maker cut a bunch off the foot.

I was chatting about losing the sail area with one of the really good sailors 
in the club. He said it may actually be a good thing that the foot is higher 
off the deck. He said with the older narrow IOR designs, deck sweeper genoas 
may cause the slot to be less efficient. Might increase the bubble in the main.

In my simplistic mind I kinda see where he's coming from. The slot gets 
restricted at the deck by the cabin. The lower part of the air flow would get 
pushed upward into the bottom of the main. A higher foot allows some flow to 
escape and keep the air flow lines smooth in the lower slot.

Does this make sense?

Dennis C.
Touché 35-1 #83
MandevilleLA

Sent from my iPhone
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