Mainsail - Two Reefs or Three ?

[frant]

Originally Posted by Erik de Jong

It's not... (in my experience) the problem is that it seldomly happens that there is a balanced tension on the reefline at the clew end and the one at the tack end.
Usually this results in damage to the sail with ripped off sliders or even torn cringles.

The maximum trysail size that ISAF allows for racing is 17.5% of lufflength of mainsail multiplied with foot length of mainsail (17.5% of triangle, not of real main surface) and I find it big for cruising. I usually advise not to go over 70-75% of the ISAF regulations, especially if the boat has a realtively large mainsail to start with.

As for the storm jib, the ISAF regulations are 5% of the forestay height squared as maximum size. Again, 70-75% percent is plenty for cruising, you only need it to keep some speed in the boat to be able to manouver.

Our boat is 22 ton (50') and the ISAF rules maxim-ze our storm jib to 24.2 sqm. I made a jib of 17 sqm and we usually run upwind at 5-6 knots in a 55 knot breeze, faster than that is also not desired when cruising. The risk of not enough sail is that the boat does not accelerate fast enough when stopped by a wave, if not accelerating quickly, you might loose steering control and risk a knok-down.

Thanks Eric, My sailmaker at Fareast and 2 against on this thread make it 3 strikes against single line reefing, and I had my own doubts about the balanced tensions on slab reefing also. I have reduced storm sail sizes to 12.6m2 c/f 14m2 from ISAF and trysail to 13 m2 c/f 18m2 from ISAF.
#1 at 20% of luff and #3 at 45%.These are to be confirmed on further consideration. What is the effective reefing range of a 135% roller furling genoa.

[Erik de Jong]

Originally Posted by frant

What is the effective reefing range of a 135% roller furling genoa.

That would be around 10% of foot length which is pretty much equal to 80% of the original surface. It would be a little less for boats that are wider than a B44.7. If you furl further than that, it will become hard to sail upwind, you will increase the heel angle instead of reducing it and NEVER go past the reef marks that the sail maker placed on the sail, if you do that you might damage your sail beyond repair.

[frant]

my post above should read that I have concerns about the balance of tensions on single line reefing, not slab reefing. obviously with slab reefing the lines are independently controlled and tensioned in order by crew.

[cwyckham]

Originally Posted by Erik de Jong

That would be around 10% of foot length which is pretty much equal to 80% of the original surface. It would be a little less for boats that are wider than a B44.7. If you furl further than that, it will become hard to sail upwind, you will increase the heel angle instead of reducing it and NEVER go past the reef marks that the sail maker placed on the sail, if you do that you might damage your sail beyond repair.

Could you expand on this? I have two roller furling genoas, neither of which has a reefing mark that I've noticed. I would guess that it is very common for cruisers to furl further than is best because they usually only have one headsail.

[Erik de Jong]

There are two types of furling headsails, first there is the furling headsail and second there is the furler reefing headsail. The first one is meant for sailing unfurled and furl it completely when you don't need the sail anymore. The furler reefing headsail has a large reinfcement on the top and a smaller one along the foot of the sail (not to be mixed up with the UV protection layer) those patches must remain visable at all times when reefing. Those are the reinforcements that are required to keep your sail alive when the original head and clew patch are furled away.

Generally you will have acceptable upwind performance when you furl the sail up to 10% of foot length, you can go further (given that your furler patches extent far enough) but do not expect much performance out of a sail.

[Cavalier]

Originally Posted by Erik de Jong

There are two types of furling headsails, first there is the furling headsail and second there is the furler reefing headsail. The first one is meant for sailing unfurled and furl it completely when you don't need the sail anymore. The furler reefing headsail has a large reinfcement on the top and a smaller one along the foot of the sail (not to be mixed up with the UV protection layer) those patches must remain visable at all times when reefing. Those are the reinforcements that are required to keep your sail alive when the original head and clew patch are furled away.

Generally you will have acceptable upwind performance when you furl the sail up to 10% of foot length, you can go further (given that your furler patches extent far enough) but do not expect much performance out of a sail.

Erik,

Thanks for posting all of this information: a veritable treasure trove of data and thought-exercises!

Phil

[Erik de Jong]

No problem, I learnt a lot from other topics and that is what a forum is for, isn't it?

[cwyckham]

Originally Posted by Erik de Jong

There are two types of furling headsails, first there is the furling headsail and second there is the furler reefing headsail. The first one is meant for sailing unfurled and furl it completely when you don't need the sail anymore. The furler reefing headsail has a large reinfcement on the top and a smaller one along the foot of the sail (not to be mixed up with the UV protection layer) those patches must remain visable at all times when reefing. Those are the reinforcements that are required to keep your sail alive when the original head and clew patch are furled away.

Generally you will have acceptable upwind performance when you furl the sail up to 10% of foot length, you can go further (given that your furler patches extent far enough) but do not expect much performance out of a sail.

I can hardly wait to get back home and check for patches. Thanks!

[Cavalier]

Originally Posted by Erik de Jong

No problem, I learnt a lot from other topics and that is what a forum is for, isn't it?

True - but a simple thank you costs nothing but is worth everything! The forum would be a wasteland of unanswered questions and opinionated jibes if it wasn't for the quality contributions!

[Erik de Jong]

Those are the patches I was referring to:
http://i31.photobucket.com/albums/c3...ngHeadsail.jpg(a completely random picture I found on the internet)
Look at the darker shaded patches on leach and luff, they are very often hidden under a UV protective layer, but you will be able to see the stitches on the other side.

Cavalier, thanks!

[Billy Higgins]

I have to agree with Erik de Jong that the ISAF maximum sizes for storm sails are too large. On a Ranger 30, the storm jib would be 86.1 ft^2, and the strom trysail would be 64 ft^2. Together these are 32% of the total measured SA. I feel that 25% is more the target area for offshore work.

[wingssail]

Part of your decision will depend on the relative sail area of your boat.

If you have a conservative cruising boat with relatively less sail area than a racer, a SA/Displ less than 15 for example, then you may have more need for the first reef so that you can reef when you need to but still have enough sail area to drive the boat.

If you have a boat with a bigger rig (SA/Displ >16) then the first reef is less important, unless you are racing, because even at a reduction of 35% (standard 2nd reef) you still have some usefull sail area.

Stiffness is also a factor, a stiffer boat can also carry more sail.

Our boat has a big sail plan so we could get by without the 1st reef if we wanted to, however we do have three reef points in our main but the boom only has gear for two reefing lines. For inshore sailing we rig the 1st and 2nd. When going off shore we change the first reefing line to the third reef point, so we are rigged for 2nd and 3rd reefs.

When offshore and the wind comes up to where we feel like reefing (usually about 20kts true wind, upwind, 25 off the wind) we go straight to the 2nd reef. We find the boat still has enough power to maintain speed but the ride is a lot better with the reef. This is with a jib which is about 65% of the foretriangle.

Our third reef is deep, about 45% reduction of luff length, or less than 40% of the area of the full sail. With this size reefed mainsail we feel that we do without a tri-sail and we do not carry one.

We do have a storm jib, but other than to try it out, we've never used it. Out boat sails very well with just the main, and we have sailed a few times with the third reef in the main and no jib.

On the other hand we have sailed on some very well designed and rigged cruising boats where the full main and the jib rolled out is fine in over 22kts of true wind. On these boats going directly to a 2nd reef might be too dramatic.

So, to be safe, I'd recommend three reef points, which gives you lots of flexibility, and if you are going offshore, rig them as your expereince and SA/Displ indicates. Make sure your deepest reef is sufficient to carry you to 40kts true and you will probably never need a tri-sail., When the day comes that you do, drop the main and sail with the storm jib, or if your boat can sail on just the main, roll up the jib completely and sail with just the 3rd reefed main.

[mikefossl]

Originally Posted by wingssail

Our boat has a big sail plan so we could get by without the 1st reef if we wanted to, however we do have three reef points in our main but the boom only has gear for two reefing lines. For inshore sailing we rig the 1st and 2nd. When going off shore we change the first reefing line to the third reef point, so we are rigged for 2nd and 3rd reefs.

When offshore and the wind comes up to where we feel like reefing (usually about 20kts true wind, upwind, 25 off the wind) we go straight to the 2nd reef. We find the boat still has enough power to maintain speed but the ride is a lot better with the reef. This is with a jib which is about 65% of the foretriangle.

Our third reef is deep, about 45% reduction of luff length, or less than 40% of the area of the full sail. With this size reefed mainsail we feel that we do without a tri-sail and we do not carry one.

We do have a storm jib, but other than to try it out, we've never used it. Out boat sails very well with just the main, and we have sailed a few times with the third reef in the main and no jib.

On the other hand we have sailed on some very well designed and rigged cruising boats where the full main and the jib rolled out is fine in over 22kts of true wind. On these boats going directly to a 2nd reef might be too dramatic.

Second on all of the above. I could sail down wind with the third reef at 45 kts true (Bashi Strait, 6 days ago). Any more wind and I would be sailing with bare poles. I have a gale sail but not sure when I would want to use it. I can't imagine trying to hank it on during conditions it would be called for.

I have single line reefing and yes, we carry all that line aloft when off shore, but we're sure glad it was there when we needed it. In our experience the single line reefing works pretty well. Once the luff is tensioned, the foot follows suit.

[sck5]

We were very glad to have 3 reefs on ocean passages and also in the Caribbean during January and February. At higher wind speeds we are more into comfort than speed. If the boat is sailing as comfortably as we can make it then the speed takes care of itself in conditions where you would use the third reef.

But on Chesapeake Bay I never even rig the third reef. Sure, winds might get that high sometimes but there is always a place to wait it out relatively close by. In places like the Bay nobody is forcing you to sail in conditions like that so why do it?

[ice]

Originally Posted by wingssail

generally agree, but two comments

Make sure your deepest reef is sufficient to carry you to 40kts true and you will probably never need a tri-sail

In our experience, the reason for a trysail is not for further sail reduction, but rather twofold: (1) primarily saving the mainsail from wear and tear when hove-to or forereaching, and (2) secondarily having an alternative/back up if the mainsail blows up (Which usually happens in strong enough winds to make the try useful). We have twice had (Harken) batten cars blow up, and raised the trysail while we were sorting out the mainsail.

if your boat can sail on just the main, roll up the jib completely and sail with just the 3rd reefed main.

Fine for short term, like running thru a squall line. But it (running with just the main) is the most common mistake we have seen people make in the early storm experience. That rig exposed you to accidental jibes and is (on most boats) produces a squirrelly helm and increases the likelihood you will get sideways on a wave. Better if you are going to be running in strong stuff for any length of time to do it with the #4 or storm jib. The steering will (probably) be better and there is no jibe risk.

.,.,.