Flattening reef

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B

Bob

If you have a flattening reef cringle on your mainsail, how often and under what conditions do you use it? What is the "threshold moment" when you say to yourself, "OK, it's time to put in a flattening reef?
 
May 12, 2004
165
- - Wasagaming, Manitoba
always in

Not sure what you mean by a flattening reef, but I assume it is the opposite of a rolling reef, ie. the sails are flaked onto the boom rather than rolled on to it. I have a jiffy reefing system, so when the mains comes down (AT THE END OF THE DAY), the first reef is engaged to make a 'pocket' to store the rest of the flaked sail into. I then store the sail with a mainsail cover over the whole works. The reef is therefore engaged while while moored. When I go out therefore, and leave the marina under power, one of my first tasks is to remove the sailcover. I put the boat head to wind, and raise the main. The first reef is already in, and stays that way for a purpose: If the wind conditions are strong, I don't have to worry about putting in a reef. (I think of this procedure as having the boat in first gear!) I don't even have to think about it, because this is the way the sail was stored. If the wind conditions permit shaking out the reef, then I can do so. If I have difficulty shaking it out, because the winds are too strong and there is too much tension on the system, I take that as a warning signal that perhaps the reef should stay in. Otherwise, I'm sailing under full set. If later in the day, the wind picks up and I have to reef, I use the adage that if you are thinking about it, do it now. Another few minutes is likely too late. Another telltale sign for me is that I'm always fighting the boat because it wants to round up from excessive heeling, or taking on water over the aft quarters. I turn the boat head to wind, or hove to, loose the main halyard, engage the first reef, rehoist the main, and resume sailing.
 
G

George

Reefing

Roger, This subject comes up regularly on this forum; however, this is the best approach I've seen. Very Slick!!
 
M

Mark

flattener

Hey Bob, Good question. I crew on a Santa Cruz 27 and there is constant debate on when to use the flattener. The flattener on the SC27 is used to depower the bottom of the main but there seems to be little consciences on our boat when to use it. I think it’s got to be blowing pretty hard for the flattener to add any advantage but I’d like to hear from someone that really knows! Mark
 

flyhop

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Aug 8, 2005
150
Oday 28 Guntersville AL
Please describe what a "flatterner" is...

Maybe include a picture? I've got a main that will double reef, but I'm not sure what a "flattening reef" is. Please describe. Or, are you describing the process of taking in a reef or two so as to "flatten" the boat's ride? Thanks.
 
Dec 2, 2003
1,637
Hunter 376 Warsash, England --
Flattener

In the days before loose footed mains on big boats, sailmakers used to build a 'shelf' into the foot of the sail to provide draught in the bottom third. They used a deliberately stretchy bolt rope and the shelf was of lighter cloth used on the bias. The idea was to stretch the foot rope when the sail needed flattening. This didn't work very well so a cringle was inserted about a foot up the leech and just above the shelf. When the boat was on its ear and the mainsail trimmer was having trouble keeping the boat on its feet, we used to put the flattener in. This pulled the cringle aft and to the boom and flattened the lower third. Then the trimmer could get back on the rail. Nowadays we have loose footed sails and nobody seems to worry about the loss of end plate effect.
 
Jun 2, 2004
649
Hunter 23.5 Calgary, Canada
Roger

Roger - I was in the Riverton - Hnausa area around the 7th of August and took a drive up to Gull Harbour on Hecla Island. I spoke to a sailor there that as I recall was from somewhere west of Winnipeg. Was that you? ;-) ...RickM...
 
W

Warren Milberg

Cunningham

I don't there is a rule or formula for when it's time to use the cunningham or "flattening" cringle in the luff of your main. Each type of boat will have different needs for flattening its main as the wind rises. On my H28.5 for example, I would use the cunningham to depower the main and reduce heeling somewhat when whitecaps begin to form (on the Chesapeake, that is the 12-15 kt range). As a mostly solo sailer, I use the cunningham because its easy to do. Yet this is the first step toward reefing the main or rolling up some genoa as the wind begins to rise. I suggest experimenting with your boat and you'll find the right wind/wave/weather range for using the flattening cringle.
 
May 12, 2004
165
- - Wasagaming, Manitoba
Rick MacDonald

no that wasn't me Rick. I sailed out of Pelican Lake at Ninette this year, and in the previous three was at Clear Lake in Riding Mountain National Park. I don't think I have ever been to Riverton.
 
B

Bob

Clarification

I can see my original question wasn't specific enough, but am glad for that mistake since I enjoyed reading Roger's technique of reefing and furling. Unfortunately it won't work for me at the moment, since I have a loose-footed main and roll it up rather than flaking it. However, I have made a mental note of his thoughts for future reference. The "flattening reef" I referred to originally is as Donalex describes: a cringle on the leech about a foot up so that a line from the end of the boom can pull it back and down - much the same as the leech cringle for a regular reef, but the purpose of this one is to be somewhat of a 'foot cunningham' to flatten the bottom of the sail without pulling the clew past the black band (if racing) and generally to flatten the sail more than the outhaul can. I suspect that it might allow a slightly larger mainsail (along the foot), but mostly it is "an extension of the outhaul, which takes over the outhaul function when the outhaul is at its limit," according to 'North U. TRIM' Normally on my boat I think of three clew positions: outhaul eased, outhaul tight, and flattening reef tight. But I don't have an objective idea of when to use the latter, other than when the wind is "really up." Does anyone have a more specific scale?
 

flyhop

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Aug 8, 2005
150
Oday 28 Guntersville AL
Pic of flattening cringle? And....

how would this perform better than say a boom vang? Thanks.
 
Oct 25, 2005
735
Catalina 30 Banderas Bay, Mexico
Old school

Flateners are old school. The main reason for them was due to the sailcloth of the day. If the sail had the right camber (flat) with the outhaul on, too much area was given up when the sail was powered up and the outhaul eased. The cloth stretched too much. The answer was to increase the range of outhaul adjustment by adding a flatening reef so the sail could have full area and never get stretched past the measurement band. Modern cloth and cuts do not stretch as much and flateners are not needed. One benefit of a flatener has been lost. The flatening reef also picks the end of the boom up. This keeps the end of the boom out of the water on a power reach. The answer to when to use it is to think of it as a continuation of the outhaul. When the sail is at the band and you still need to make the sail flatter, use the reef.
 
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Stephen, San Juan 21

I have one on my San Juan 21

I have a Flattening reef on my Kerr Sails. It makes a dramatic difference in the shape of the sail on the lower 1/3rd. It's used when the outhaul is full on, the cunningham is full on, and the backstay is threating to snap you mast in half, and you still need to flatten your sail a little more. It also helps when pinching up in heavy winds as it flattens the sail so it doesn't flap as much.
 
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