Sail trim

[Henning 4148]

Recently when sailing close hauled in 6 gusting 7, another boat overtook us. They were faster and they pointed at least as high if not higher.

Both boats were exactly the same type / model / everything (Sun Fast 32), the other apparently a little newer. Also the sails may have been different, I would guess none of the boats had her original suit any more.

We had four people on the side deck, two reefs in the main and approx. 10 rolls in the genoa, mast bent back a bit, fighting hard to maintain the right angle to the wind, sometimes the sails flapping a bit, sometimes heeling a bit too much, but doing between 6 and 7 knots.

The boat overtaking us had also one or two reefs in the main, five people on the side deck, no roll in the Genua, was heeling less if anything and passing at say 1/4 to 1/2 knot exessive speed, pointing at least as high as we were. Also, one of the guys on my boat said that apparently their backstay had very little tension if any. They seemed to have less trouble with their sails flapping or with excessive heeling. Was their helmsman just so much better than me to keep her right on the wind edge, is it more twist in the sails, or what was happening there? If we had unrolled our Genoa in this wind, we would have made one sun shot after the other.

Suggestions please.

Also, is there a good book that describes how to trim these light boats properly? All in all I found I am not that good with light boats, I must be doing something wrong.

[Noah]

It could be a couple of things. The first, like you said is probably sails. All boat speed comes from sails. Their main may have been a much flatter cut sail, which would help in that kind of wind. Also, how about sail trim? What kind of traveler system does this boat have? Some of these cruising boats have such a short traveler that you can't let the trav down, and get the main in nice and hard, which is the key to less heel and more speed. They also could have been using the vang more to control sail shape.

The next thing is rig tension. A loose rig is good for light winds, but you want to come in on shrouds a bit in heavy air.

I think that you were doing the right thing with lots of back stay on, as that will usually get you good headstay tension.

The next question would be how aggressively you were driving the boat? In heavy winds often you will have headers and lifters in the gusts. Actively sailing to these changes in wind direction will get the boat upwind faster. You also need to drive to the waves. Each wave needs to be looked at and driven over in a way that won't kill boat speed. Generally a wet boat (taking lots of water and spray) means that you aren't driving into the waves quite the right way. On classic full-keeled boats they don't respond quickly enough to really drive the waves, but more modern boats with fin keels generally do.
It could be a couple of things. The first, like you said is probably sails. All boat speed comes from sails. Their main may have been a much flatter cut sail, which would help in that kind of wind. Also, how about sail trim? What kind of traveler system does this boat have? Some of these cruising boats have such a short traveler that you can't let the trav down, and get the main in nice and hard, which is the key to less heel and more speed. They also could have been using the vang more to control sail shape.

The next thing is rig tension. A loose rig is good for light winds, but you want to come in on shrouds a bit in heavy air.

I think that you were doing the right thing with lots of back stay on, as that will usually get you good headstay tension.

The next question would be how aggressively you were driving the boat? In heavy winds often you will have headers and lifters in the gusts. Actively sailing to these changes in wind direction will get the boat upwind faster. You also need to drive to the waves. Each wave needs to be looked at and driven over in a way that won't kill boat speed. Generally a wet boat (taking lots of water and spray) means that you aren't driving into the waves quite the right way. On classic full-keeled boats they don't respond quickly enough to really drive the waves, but more modern boats with fin keels generally do.

[Ian McColgin]

I'm betting on the roll in the genny.

Roller furling is not really roller reefing. Firstly, one of the great virtues of a driving sort of jib is the clean leading edge. Putting a roll up there just makes turbulence. Secondly, unlike window shades jibs are three dimensional. You can't make a clean roll as the luff and food will alway be too short in comparison to the increasingly sloppy belly at mid-luff.

Even with the fancy roller-reefing systems that claim to solve the belly problem - the compound foil winding or foam on the luff - there's only one place the sail will reef to and that's not a great shape anyway.

I'll bet the other boat benefited more from the really efficient jib shape even if they were wrestling with more sail area. You don't say, but they may even have had a jib that started smaller than yours, though doubtless they were showing more sail that day.

One of the boats I race with down here has both a 110 and a 150. The 110 has foam luff strips to help reefing but we don't often use it as the boat sails better keeping the jib out and reefing the main. Only time the reefing becomes useful - and for this any roller system would work anyway - is to shorten the jib enough to heave-to.

Test this yourself if you can find a good measured course to time a couple of runs.

I very much recommend having a smaller jib for those breezier days. Early spring and fall are way to nice to waste fighting with too much sail.

[Bruce Hooke]

My experience with roller reefing foresails is that they can be fine for cruising where you just want an easy way to cut down on the foresail area and don't mind if the reefed sail is not super-efficient because you are probably already moving along pretty well anyway if there is enough wind to reef. For racing on the other hand, they just don't cut it. In terms of efficiency, the last thing you want at the leading edge of a sail is something that messes up the air flow across the sail.

[Ian McColgin]

I'm more radical on Bruce's point.

Unless the sail has reinforced reef peak and tack areas that you roll to, it will tend to damage the sail.

I can think of quite a few local cruising sails that have been abused in this way and have interesting ripples on the foot and leech as a result.

And without something to take up the belly, they don't roll to shape worth a dang anyway.

If you find you want to reef down the jib, spend a little and have a smaller jib.

I've spent too many times wedged in a pulpit ahead of the jib with waves washing over me while I tried to tame a recalcitrant monster trying to blow all over as we did a headsail change. Frankly, it's so dangerous that I stay with hanked on headsails.

If you really must do this and you're not racing, it's far better to get off on a nice safe broad reach and bring strike the big and set the little under the lee of the main. For cruising couples, this means that you really need a fibre hallyard so that it can be either let forward to the pulpit or aft to the helm.

Even off the wind but especially if you value life and limb and might change sails on the wind, have a bunch of those guide gizmos. There's almost always one permanently tied to the bottom of a foil just above the drum. If you have enough, say one for every 6' or so of luff, then you can get them all on at the start of a drop, and push all but one further up the luff as you bring it down and out of the foil. The strings will keep the luff from escaping your clutches in the wind. Then bag the sail from the clew forward before sliding the guides off the sail.

A nice wrinkle for hard weather types. I find it best to secure the sail at the middle and flod the clew back up to near the luff. Then the sail will be nicely in the bag with all needed parts available to hoist right out of the bag, almost like a spinaker. I've even made some sail bags with a fist size hole in the bottom and a line on the outside where there's usually a handle loop anyway. So I can have the bag flattened back and the line leading through the hole to my left hand. My right hand is through the hole. I embrace the sail in the middle, grab the line with my right hand and pull it back through. I put my right hand through as I am often wearing a watch on the other hand. Once the line's secure, then I start deploying the bag and folding the sail and stuffing all in one motion.

'Course this is antithetical to the kevlar krowd. In that case, you reall need at least three people: One on the helm, one in the pulpit, and one dragging the nasty wet jib down the companion (don't use the forehatch for this!) into your previously dry saloon for careful rolling.

For day sailing, just do the change on the mooring and regret it not if the breeze drops and you could have flown the 175.

[Noah]

While I don't love roller furlers, I don't think they are as nasty as you boys are talking about. I don't have a ton of experience with them, but while sailing the J-105 with a reefed jib, it worked very well, and we were much faster with the reef than with-out. Granted this is just a jib that we rolled up, not some huge genoa, but the point is still there.

The more I sail on modern boats with big mains and small jibs, the more I like them. Sure you gets lots of power from the big 155% or what ever, but they are a pain. The main is much easier to shape and control than a big genoa...

Here is a picture of the reefed jib: (This was in 30-35 knots true. Boat speed was around 8.5."

http://www.morebutter.com/hinckley/images/heel.jpg

[ 09-22-2004, 11:02 AM: Message edited by: Noah ]

[Dan McCosh]

There are a couple of issues here. The main thing is that the lift/drag ratio of the rig becomes more critical as you get closer to the wind. Increasing drag will show up as excessive heel. The rolled-up jib is a classic case of bad aerodynamics, and heading upwind the increased drag could be significant , causing excessive heel, and actually offsetting the reduced sail area.
Also, the double reefed main in all likelihood is completely behind the jib- adding little drive or heel, but doing something to balance the helm. We carry a full-luff number two jib up to 25 knots of so of true wind, about 32 knots apparent, and it handles it comfortably with a double reefed main, or a depowered single-reef. Rolling up the jib loses wind angle, the boat falls off and can't point. With the full jib, it also is relatively easy to feather it in gusts.
I've witnessed a similar situation when a small jib loses out to a full-luff jib in heavy air, when the former has a full main; while the latter has a deep reef. The aero efficiency of the long luff jib wins out over total sail area upwind.

[ 09-23-2004, 10:32 AM: Message edited by: Dan McCosh ]

[John B]

10 rolls is a lot. I'd say all of the above too.

Did you re set the jib sheet cars for the new sail trim?

[bainbridgeisland]

How much have you practiced sailing in strong winds compared to your competitor? I was at a one-design North American Championships where one competitor finished an entire leg ahead of the next boat in windy conditions. He did this every time it was windy. Turns out he was from windy San Francisco and practiced twice a week year around. No one could touch him on windy days.

Sails are really important. In international competition, a new jib is only at its peak for 10-20 races. This is 2-3 major regattas. After this they can be noticeably slower. My point is, if the other guy had new sails and knew how to use them, you may have a hard time catching him no matter how skilled you were.

Sails cut for windier conditions perform better in a breeze. Obviously the other boat wasn't heeling too much. This suggests his sails were flatter. Flatter sails are much faster in a breeze.

[Ian Wright]

Sail trim is a mystery, some folk get it, some don't. I don't, which is why I'll never win a race.
Tillman is supposed to have said that there are three positions for a mainsail, in, out and halfway, "anything else is the effete fiddling of the dinghy racer" or something close to that.
On Patience sail trim follows Tillman's rule.
Headsails are let out 'til they flap a bit then sheeted in 'til they don't.
Well, it works for me,,,,,,,,,,,,

IanW

[Bruce Hooke]

Originally posted by Ian Wright:
Sail trim is a mystery, some folk get it, some don't. I don't, which is why I'll never win a race.
Tillman is supposed to have said that there are three positions for a mainsail, in, out and halfway, "anything else is the effete fiddling of the dinghy racer" or something close to that.
On Patience sail trim follows Tillman's rule.
Headsails are let out 'til they flap a bit then sheeted in 'til they don't.
Well, it works for me,,,,,,,,,,,,

IanWThat sounds about like my philosophy! :D :D

[Henning 4148]

Thank you so far. Yes, it is well possible that the jib on the other boat was smaller and / or flatter than ours. They certainly had a lot of twist in it to spill wind. Also, yes, the whole thing happened in a race of a series of 4 races and while we were finishing most races around rank 25 of 36 boats, the other boat was right on top in all the races, so they must be very good. Still - it seems there is room for improvement for me.

Next time I will remember about the inefficiency of the luff of the sail, we had a storm jib on board and would perhaps have done better using that and taking only one reef in the main.

[Hwyl]

I agree with the jib thing, but let's focus on the main. 80% of reefed mains that I see don't have the reefing pendant tight enough. The reefing clew has to be right down on the boom and the (reefed) foot should be very tight. Some people will back up the reefing pendant with a sail tie arond the boom.

I'm guessing that you don't have reef points (I think some people call them nettles).By way of illustration you often see them taking strain, which should never happen, it's all in the halyard tension and reefing pendant tension.

[brian.cunningham]

This certainly explains the use of multiple roller furled jibs.
http://www.bruceschwab.com/img/gallery/gal_031004-2.jpg

[Chris Coose]

Take an extended cruise - avoid racing.

[ahp]

On the contrary, race a lot. It sharpens you skills.

Go buy some telltails, the ribbon kind that you stick onto the sail. Stick a row of about four them, on both sides of the sail, starting about two feet above the boom and about about two feet aft the mast, tapering to a foot aft the mast about four feet from the headboard.

Do the about same thing on the jib. You won't need as many here. Perhaps another forum person can add their opinion here.

When all of them are laying flat back against the sail you have the trim about right. You can see the ones on the tother side through the sail. Some people have little windows in the sails, but I never found in necessary.

The telltails will tell you if you are sailing with the sail "stalled". Unlike an airplane, if the sail is stalled you don't fall out of the water. You instead notice that your competition is sailing past you.

[Ian McColgin]

On a jib, the outer telltale lets you know if you're off the wind too far. The inner telltale will go funky just a tad before the jib is luffing. They don't often admit it, but many of the best sailors around here try to fly in the zone with the inner tell funky but not a luff. Then you have a maximum venturi as the inside air is about dead.

On mainsails, leach tells can be useful but take some interpretation. A starting place is to have a tell at each batten pocket. If they all stream aft, then you've no edge vorticies and that's usually good. If the lowers stream nicely and the upper funks off, maybe vang the sail a bit unless you're deliberatly depowering at the head.

All that said, it takes longer to learn without tell tales and good sailmakers will enjoy tells all over the place, especially to test a sail and get to know it, but the race winners feel the boat as a totality. It's good to sail without the tells if you have a way to objectivly check isolated trim components against actual speed.

It's endless fun. G'luck.