'87 272LE- Loose foot or attached main?

M

Mickstr

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Jun 1, 2007
272
O'Day 322 Mt.Sinai
I looked in the archives and didn't see anything to help me...I need to replace my very tired main and headsail, and have gotten quotes from North Sails, Sail Warehouse, and Doyle. I've just asked for one from D&R. North and Doyle both quoted me loose foot mains. I've heard from at least one 272 owner that the loose foot main will yield higher performance, but can be harder on a boom, especially when gybing. In fact, his boom was snapped.

I don't race, I bounce around Great South Bay on Long Island, and cruise a few times a year for one-two weeks.

Anyone have an opinion? I'm a little leery of the loose foot from what I've heard and read so far....
 
T

TLW

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Jan 15, 2013
271
Oday 31 Whitehall, MI
I've been out of the sailmaking loop for quite awhile, but also needing a main so must get back into it soon. BUT, in the early 1980s we built mains with a "shelf-foot." I would be glad to hear what sailmakers are saying about that today. (I did move from a shelf-foot to loose-footed in mid 80s.) The shelf foot was, arguably, the best of both worlds. There was a bolt rope inserted in the boom, but the lower sail panel would set at 90 degrees to the rest of the sail - that is: horizontal to the boom. (creating a shelf)

Increasing outhaul tension would lessen the amount of "shelf." additionally, there was a "flattening reef." - another clew at the bottom of the 2nd panel. Pulling this flattening reef gave you a loose-footed main as the lower panel went slack much like the excess sail when you reef your sail normally. This flattening reef, of course, was only one panel so much smaller and just left "hanging."

This is all pretty much OLD SCHOOL I imagine, but would like to see some discussion of it.
 
Jackdaw

Jackdaw

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Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
TLW said:
I've been out of the sailmaking loop for quite awhile, but also needing a main so must get back into it soon. BUT, in the early 1980s we built mains with a "shelf-foot." I would be glad to hear what sailmakers are saying about that today. (I did move from a shelf-foot to loose-footed in mid 80s.) The shelf foot was, arguably, the best of both worlds. There was a bolt rope inserted in the boom, but the lower sail panel would set at 90 degrees to the rest of the sail - that is: horizontal to the boom. (creating a shelf)

Increasing outhaul tension would lessen the amount of "shelf." additionally, there was a "flattening reef." - another clew at the bottom of the 2nd panel. Pulling this flattening reef gave you a loose-footed main as the lower panel went slack much like the excess sail when you reef your sail normally. This flattening reef, of course, was only one panel so much smaller and just left "hanging."

This is all pretty much OLD SCHOOL I imagine, but would like to see some discussion of it.
Click to expand
The shelf foot mains have become less popular because there is no real advantage to them. You said best of both worlds.... I'm interested in what you thought the advantage of the shelf was. Some people think it helps hold the sail on the boom when lowering, but it really is no better than a loose footed sail with the foot pulled snug with the outhaul. And no worse than a bolt rope sail.

The shape of a loose footed main is much better, and easier to control and adjust.


Flattening reefs can be added to and design of mainsail.

TO THE OP:

Loose footed mains are really no harder on your boom. Almost all the loads of any mainsail are on the corners anyway. The clew strap and outhaul support the clew of the sail no matter what the foot type.
 
jmseas

jmseas

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Apr 18, 2011
14
Oday 34 Long Beach, California
I got a new Quantum main for my Oday 34 two years ago with a loose foot. It's a great sail - no complaints! Great shape control. I too was concerned about the loads, but my local rigger (that I trust) assured me the boom could handle the loads.
 
jibes138

jibes138

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Jan 27, 2008
3,086
ODay 35 Beaufort, NC
One of the issues with a loose footed sail is that low pressure air on the leeward side of the sail will mix with high pressure air on the windward side resulting in severe turbulence along the foot and a lot of drag. This is why airplanes have those big tiplets on the ends of the wings, to break up the vortex from the mixing along the edge of the end of the wing. Thoughts?
 
T

TLW

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Jan 15, 2013
271
Oday 31 Whitehall, MI
Jackdaw, my "best of both worlds" comment was from the original poster's point of view: the shelf foot offers all the shape control of a loose footed main, but is still attached all along the boom in the event of an accidental jibe (as was his concern)

Jibes, I can't imagine a loose footed main would induce any more turbulence than, or even as much as, the presence of a boom. What do you think?
 
Richard19068

Richard19068

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Jun 11, 2004
1,767
Oday 31 Redondo Beach
jibes138 said:
One of the issues with a loose footed sail is that low pressure air on the leeward side of the sail will mix with high pressure air on the windward side resulting in severe turbulence along the foot and a lot of drag. This is why airplanes have those big tiplets on the ends of the wings, to break up the vortex from the mixing along the edge of the end of the wing. Thoughts?
Click to expand

I know nothing about this but would this not be the same with an attached main? Does the boom break up or dissipate the vortex?
 
Jackdaw

Jackdaw

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Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
TLW said:
Jackdaw, my "best of both worlds" comment was from the original poster's point of view: the shelf foot offers all the shape control of a loose footed main, but is still attached all along the boom in the event of an accidental jibe (as was his concern)

Jibes, I can't imagine a loose footed main would induce any more turbulence than, or even as much as, the presence of a boom. What do you think?
Click to expand
Gotcha. I forgot that in his original question. But I'm not sure it helps.... As the shelf is loose, all shock would end up at the clew before the foot grew tight to absorb any. In any case I'm not sure it makes any difference with any foot style.

Regarding the turbulence, it's well understood that deck sweeping jibs and genoas benefit from the 'plate effect' from the deck proximity to reduce swirl turbulence (and drag), but the amount is minor. Much more benefit could be had at the top of the sail, it's one of reasons square top sails at growing in popularity.

As for the mainsail foot type, it has no effect on plate effect, and the boom is too far off the deck for it to help. All high performance boats sail with loose footed mains. The effects on sail shaping are amazing.

 
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